859 Sentences With "gonads" | Random Sentence Generator

No one is yet talking of printing gonads for people.

Pearlfish go inside the sea cucumbers' butt and eat their gonads.

But I ain't just gonna place my gonads in your hands.

The spiders' gonads are in their legs — and so are their guts.

With sea urchins, it's the gonads of both males and females that we're after.

" With the specimen, though, "we have RNA, a skeleton, gonads, tissues in cryogenic storage.

For many of these intersex males, their gonads were more like female ovaries than testes.

First things first is to check the gonads, which confirmed the bat is a boy.

A viral tweet shows that children aren't afraid to ask the big questions about the gonads.

Most of his body disintegrates, but his gonads remain and produce sperm for the female to use.

What an oyster does when it gets reproductive is it actually transforms [its] body tissue into gonads.

The fish at Elkano is so fresh that even the gonads are served alone as delicious starters.

But as seasons change, warming water may induce oysters to spawn, releasing the contents of their gonads.

This creates what the company calls an "electromagnetic shield" around your gonads, repelling harmful rays at every turn.

After these initial triggers, gene expression governing the wrasses' gonads significantly shifted relative to the brain's genetic expression.

And we can't all have the gonads/decency it takes to be honest when we're not feeling someone.

Red urchins, larger than purple urchins, are commercially viable because people eat them — or more specifically, their gonads.

If you can get over the fact that you're gnawing on another mammal's gonads, you might actually enjoy them.

Never mind the Hitler's gonads, what does this particular fantasy say about the world we're living in right now?

Who knew that my most heartening ideological conversation in ages would involve gonads, gender wars, and for heaven's sake Reddit?

"As a result, the gonads occupy a relatively large proportion of the total body volume," he wrote in an email.

Within the bell, the radial canals in red are connecting points for what looks like the gonads in bright yellow.

Though commonly referred to as roe, the edible part of the sea urchin is actually its reproductive organs, or gonads.

But credit to Shelton and Fallon, they were adventurous to try shitasu (fried bait) and a shot of sea urchin gonads.

" Boehner on the failure to repeal and replace Obamacare: "Their gonads shriveled up when they learned this vote was for real.

The birds might also feed selectively on certain parts of jellies, like their gonads, which are rich in fats and proteins.

"Their gonads shriveled up when they learned this vote was for real," he said in a wide-ranging interview with Politico.

Often, when a baby is born intersex — meaning that they were born with sex characteristics (including genitals, gonads, and chromosome patterns) that don't fall within strict definitions of male or female — doctors recommend "normalizing" surgeries to make their genitals look more like how society expects men and women to look, or to remove internal gonads like testes.

Avoid the embarrassment, and just at least take a glance at some shaving products that will change your life, and your gonads.

A child may be born with the external sex characteristics of a female baby, yet have undescended gonads (so-called male genitalia).

The day that we are no longer allowed to flash the world our gonads is the day that freedom of expression dies.

The most troubling part of all this wasn't my wife's lack of interest in the new and improved odor profile of my gonads.

The team obtained samples of the wrasses' gonads and brains throughout the transition process and examined them with RNA-sequencing and epigenetic analyses.

Seth McFarlane's go-to set o' gonads belong to one Tom Brady ... as we learned when Seth dropped some "Ted 2" trivia on us.

Early during an embryo's development, the germ cells — which are basically the cellular grandparents or great grandparents of sperm — travel to the nascent gonads.

Various hypotheses have been proposed, including the idea that dangling gonads are a way to signal virility and good health, but none are satisfactory.

We swayed in unison, dutifully did our figure eights with our ovaries and "gonads," a word I have never heard with such frequency before.

For me, surgery to remove my gonads as an infant was the first stop on the track to female — but the train didn't stop there.

Without the pampering they get at the farm, the urchins would contain hardly any "uni," as their yolk-colored gonads are called at sushi restaurants.

"You'd cross a line: it's not just restoring function — sexual and urinary function — you've granted a person the ability to reproduce, but with someone else's gonads."

Business meetings, family dinners, a job interview, a first date; your gonads can't be trusted to not spontaneously release noxious gases and send strangers screaming for cover.

Developmental disorders of the genitals and gonads, known as intersex conditions, affect about 1% of people, but very rarely lead to ambiguity about which sex a person is.

And for my puppy Summa there is the sac of gonads— male or female, I know not which— glistening memento of pursuit, colonizing whitherso tide or tidings sway.

"In these chimeras from two different sexes there is a gonadic combination resulting in ambiguous genitalia and they have a higher risk of cancer in the gonads," Pappas said.

For instance, when the photoperiod reaches 12.5 hours of sunlight per day – which in the U.S. happens in late March – the gonads of male and female hamsters instantly begin revving up.

One option is to literally cut open the turtle to examine its gonads, said McKnight, a procedure which may weaken the animal, make it vulnerable to infection, or even be fatal.

In Swyer syndrome, small mutations in a gene on the Y chromosomes cause an XY individual to develop a normal vulva, vagina, and uterus, but with poorly formed gonads containing testicular tissue.

As many as 1.7 percent of babies are born with genitals, gonads, reproductive organs, hormones or chromosomes that don't fit the usual expectations of male and female, according to the United Nations.

Eugene Porter — Alexandria's awkward, mullet-adorned bowl of country gravy — just earned a lot of respect on The Walking Dead ... and all he had to do was bite some dude in the gonads.

But there's a second aspect: Once an oyster develops a whole bunch of gonads after that period, when the oyster has expelled all that, then it becomes a thin, watery, barely marketable product.

As many as 1.7 percent of babies are born with genitals, gonads, reproductive organs, hormones or chromosomes that do not fit the usual expectations of male and female, according to the United Nations.

A synopsis in the CDC journal Emerging Infectious Diseases says more research is needed for studying immunologically protected body sites, like male gonads and parts of the eye, as potential new chains of transmission.

Complicating matters further: The temperature around us and our gonads is fluctuating all the time, meaning that the testicles are constantly being let out and reeled in to keep them in the Goldilocks Zone.

"There's a huge amount of growth and disappearance of bird gonads during the off-breeding season," Dr. McGowan said, referring to the way bird testes may expand or shrink, depending on the time of year.

After strutting round the room, feeling the way our bodies moved, we were instructed to focus on our "ovaries or gonads," circling our hips in a figure of eight with this part of our anatomy.

Two of the NBA's biggest stars had a rather awkward encounter Wednesday night when Clippers point guard Chris Paul freed himself for a jumper by — well, by hitting Thunder forward Kevin Durant right in the gonads.

Instead, this digonic hermaphrodite (born with both male and female gonads) has "selfing" capabilities: If no partner is found, it releases a cloud of egg and sperm into the water, and poof, external tadpole larvae develop.

Credit where credit is due: Evolution has invented a lot of clever adaptations, from fish that swim up sea cucumber's butts and eat their gonads to parasites that mind-control their hosts in wildly complex ways.

Rand Paul last weekend, causing six broken ribs, was aggressively anti-Trump and anti-GOP in his social media, calling for the impeachment of the president and urging Russia investigator Robert Mueller to 'fry Trump's gonads.

"It's something you're told to be quiet about," Ms. Odiele said of being intersex, a term that covers dozens of variations in genitals, gonads and chromosome patterns that don't fit into a binary conception of male or female.

According to Merriam Webster, intersexuality is the condition "of either having both male and female gonadal tissue in one individual or of having the gonads of one sex and external genitalia that is of the other sex or is ambiguous."

In 2009, when she breezed to a World Championship title, the International Association of Athletics Federations (IAAF), the sport's governing body, began examining whether she might be intersex—an umbrella term for people with developmental conditions affecting the genitalia and gonads.

In their first two games of the season, Antonio Conte's Chelsea have shown themselves capable of winning by any means possible, and have certainly shown that they're willing to give their opponents a vicious boot to the face/shin/ankle/gonads in the process.

" Yet, according to The Human Rights Watch and intersex youth advocacy network interACT, these surgical interventions aren't medically necessary — there's no evidence that atypical gonads, genitals, or chromosomes are dangerous to a person's health — and the organizations released a joint report in July calling normalizing surgeries a "surgical 'solution' to a social problem.

In 2009, when she breezed to a World Championship title as an 18-year-old, the International Association of Athletics Federations (IAAF), the sport's governing organisation, announced that it was investigating whether she might be intersex—an umbrella (and misleading) term for people with a wide range of developmental conditions affecting the genitalia and gonads.

First identified in the late 1980s, the so-called endocannabinoid system consists of CB1 receptors predominantly located in the nervous system, connective tissues, gonads, glands, and organs; and CB2 receptors, primarily found in the immune system and also present in the spleen, liver, heart, kidneys, bones, blood vessels, lymph cells, endocrine glands, and reproductive organs.

Gonads can only be determined and sexed under a microscope. There is no apparent sexual dimorphism among individuals, unless gonads are ripe. When gonads are ripe, males are a white color, while females gonads are orange. The brown sea cucumber has an elongated body and can be described as having a soft or gelatinous texture.

The gonads, in a "bipotential state", may develop into either testes (the male gonads) or ovaries (the female gonads), depending on the consequent events. Through the seventh week, genetically female and genetically male fetuses appear identical. At around eight weeks of gestation, the gonads of an XY embryo differentiate into functional testes, secreting testosterone. Ovarian differentiation, for XX embryos, does not occur until approximately week 12 of gestation.

The species name ' means "edible". Sea urchin roe is used as food around the world, but ' is not among the preferred sea urchin species, due to its white gonads. Sea urchin species with orange gonads are preferred. It is not actually the eggs that are eaten but the gonads, both male and female.

Unlike most other jellyfish, males and females of C. medeopolis have many gonads located on their dorsal endoderm. These gonads have been described as arranged like "skyscrapers in a downtown business district".

The gonads are located near the base of each mesentery.

In males, the sex cords fully invade the developing gonads.

When a neovagina is made from a segment of bowel, it tends to leak mucus; when made with a skin graft, lubrication is necessary. Less common complications include fistulas, uncomfortable scarring, and problems with urinary continence. Gonadectomy is removal of the gonads. If the gonads are dysgenetic testes or streak gonads and at least some of the cells have a Y chromosome, the gonads or streaks must be removed because they are nonfunctional but have a relatively high risk of developing gonadoblastoma.

Gonads are formed on the oral proboscis. Polyps carry filamentous tentacles.

In animals, these siRNAS and piRNAs are most active in the gonads.

At the base of each ray, there is a pair of gonads.

This structure has been interpreted as the impression of gonads, intestine and mouth.

There are five pairs of gonads, each associated with a fluid-filled sac.

Main article: Primordial germ cell migration Primordial germ cells, germ cells that still have to reach the gonads (also known as PGCs, precursor germ cells or gonocytes) divide repeatedly on their migratory route through the gut and into the developing gonads.

In the blastocyst of the mammalian embryo, primordial germ cells arise from proximal epiblasts under the influence of extra-embryonic signals. These germ cells then travel, via amoeboid movement, to the genital ridge and eventually into the undifferentiated gonads of the fetus. During the 4th or 5th week of development, the gonads begin to differentiate. In the absence of the Y chromosome, the gonads will differentiate into ovaries.

Sea urchins have five gonads. These gonads (roe) are a sought after as a delicacy. Echinoderms are marine animals, widespread in all oceans, but not found in fresh water. Just below their skin is an endoskeleton composed of calcareous plates or ossicles.

XY gonadal dysgenesis, also known as Swyer syndrome, is a type of hypogonadism in a person whose karyotype is 46,XY. They typically have normal female external genitalia, identify as female, and are raised as girls. The person is externally female but with functionless gonads, fibrous tissue termed "streak gonads," and if left untreated, will not experience puberty. Such gonads are typically surgically removed (as they have a significant risk of developing cancer).

The appearance of Gonionemus vertens is usually described as having a transparent bell lined with 60–80 (exceptionally up to 100–110) tentacles. The gonads are distinctly colored orange, red or violet if the specimen is female, or yellow-brown if it is male. The gonads are arranged hanging from four radial canals so that when viewed from above, the gonads are lined perpendicularly. The manubrium, colored tan, hangs down in the middle.

Criteria for the diagnosis of hermaphroditism in fishes. Copeia 1987(1): 136–156. Juveniles less than long are mottled with a yellowish head and have undifferentiated gonads (not male or female). Immatures that are long are mottled brownish and have immature female gonads (ovaries).

Nuttallochiton is a genus of chitons; the only one to have paired rather than fused gonads.

Gonadal torsion refers to torsion of the gonads. It may refer to testicular torsion or ovarian torsion.

The gonads are posterior to the ventral sucker and the genital pore opens on the ventral surface.

FANCE is stated to have been expressed in 151 organs with the highest level in female gonads.

500px In both males and females, LH works upon endocrine cells in the gonads to produce androgens.

Adult Chrysaora hysoscella are often parasitised by Hyperia medusarum. C. hysoscella found inshore and closer to the surface are more likely to have the parasite. The parasite can be found inside of the body cavity in the umbrella and gonads but tends to move from umbrella to gonads if there is space for them there. The gonads are more enriched in carbon and protein content then any other part of the body, making this region the ideal location to settle and feed.

The disc is torn into two portions and over time, new arms grow on each section. As a result, the new individuals are asymmetric and often have six or seven arms of varying lengths. The original arms grow more slowly than the new ones so that, by the time the arm length reaches 27 mm, all the arms are much the same length. After fission, the gonads regress and individuals that previously had mature female gonads become masculinized, developing male-type gonads.

The consequences to the girl with XX gonadal dysgenesis: # Her gonads cannot make estrogen, so her breasts will not develop and her uterus will not grow and menstruate until she is given estrogen. This is often given through the skin now. # Her gonads cannot make progesterone, so her menstrual periods will not be predictable until she is given a progestin, still usually as a pill. # Her gonads cannot produce eggs so she will not be able to conceive children naturally.

This ragworm is pale brown but changes to green as the gonads mature and the breeding season approaches.

The developing wings are present in later stage instars and the gonads start development in the egg stage.

In the male cat, the genitalia includes two gonads and the penis, which is covered with small spines.

Vertebrates share key elements of their reproductive systems. They all have gamete-producing organs known as gonads. In females, these gonads are then connected by oviducts to an opening to the outside of the body, typically the cloaca, but sometimes to a unique pore such as a vagina or intromittent organ.

This means that typically, the brain will form from one embryo, and the gonads from a different one. Hanley appears to be the originator of this theory, that half the time when human embryos merge the brain will be one sex, and gonads and body form will be the opposite sex.

Ovaries have a fine texture and a tan to orange color. Male gonads are coarse-grained and creamy white.

Acquired diseases include mumps orchitis, Coxsackievirus B infection, irradiation, chemotherapy, or trauma; all problems causing the gonads to fail.

Sea urchins are prized as a delicacy in many places worldwide (particularly in Japan, France, South Korea, Chile, New Zealand, the Philippines, Italy, Spain, the Mediterranean, and North America) for their briny-flavoured gonads. The gonads are often eaten raw, such as in sushi (typically called uni), and some people prefer to eat them immediately after they are cut open. Scissors are often used to avoid the protective spines whilst cutting the animal open. The gonads do not move, even when taken from the live animal.

Genetic sex in mammals is determined by the presence or absence of the Y chromosome at fertilization. Sexually dimorphic development of embryonic gonads into testes or ovaries is activated by the SRY gene product. Sexual differentiation is then directed by hormones produced by embryonic testes, the presence of ovaries, or complete absence of gonads. SF-1 transcripts initially localize to the urogenital ridge before SF-1 expressing cells resolve into distinct adrenocortical and gonadal precursors that ultimately give rise to adrenal cortex and gonads.

Gonads arise from the thickening of coelomic epithelium, which at first appears as multiple cell layers. They later commit to sex determination, becoming either female or male under normal circumstances. Regardless of sex, though, WNT4 is needed for cell proliferation. In mouse gonads, it has been detected only eleven days after fertilization.

Very little is known of the reproductive biology. Breeding is thought to occur between June and September with a clutch of two eggs incubated by the female. Two descriptions of female specimens indicate their gonads are well developed in February and April; but a single male specimen obtained in February had “small” gonads.

Dissections of Ipnops species’ gonads indicate that these fish are hermaphroditic and lay an average of 900 eggs per clutch.

The male pseudohermaphrodite has male gonads and karyotype, but varying degrees of virilisation of the internal and external genital tracts.

A recent genetic analysis has suggested that Microhydrula limopsicola, originally classified as a member of the order Limnomedusae, is in fact a developmental stage of Haliclystus antarcticus. In its mature form H. antarcticus has eight gonads which are organised into four pairs and run from the central mouth to the ends of the arms. The gonads are approximately 1.6–12.9 mm in length and are visible through the wall of the calyx. The gonads are mature in specimens which have a calyx height of about 11.72 mm and greater.

Streak gonads without a Y chromosome cell line need not be removed but will not function. Finally, the gonads in true hermaphroditism must be directly examined; atypical gonads with Y line or potential testicular function should be removed but in rare instances a surgeon may try to preserve the ovarian part of an ovotestis. Potential surgical problems: A lifetime of hormone replacement will be required, to avoid osteoporosis and enable sexual functioning. Cloacal exstrophy and bladder exstrophy repair is needed regardless of the sex of assignment or rearing.

Gonadal dysgenesis is classified as any congenital developmental disorder of the reproductive system in the male or female. It is the atypical development of the gonads in an embryo, with reproductive tissue replaced with functionless, fibrous tissue, termed streak gonads. Streak gonads are a form of aplasia, resulting in hormonal failure that manifests as sexual infantism and infertility, with no initiation of puberty and secondary sex characteristics. Gonadal development is a genetically controlled process by the chromosomal sex (XX or XY) which directs the formation of the gonad (ovary or testis).

The regulation and differentiation of germ cells into primary gametocytes ultimately depends on the sex of the embryo and the differentiation of the gonads. In female mice, the protein RSPO1 is responsible for the differentiation of female (XX) gonads into ovaries. RSPO1 activates the β-catenin signaling pathway by up-regulating Wnt4 which is an essential step in ovary differentiation. Research has shown that ovaries lacking Rspo1 or Wnt4 will exhibit sex reversal of the gonads, the formation of ovotestes and the differentiation of somatic sertoli cells, which aid in the development of sperm.

In the gonads, the germ cells undergo either spermatogenesis or oogenesis depending on whether the sex is male or female respectively.

When a free-living male B. apogon encounters a female he latches onto her belly with his mouth and their tissues gradually fuse, with the male becoming parasitic. Free-living males and unparasitised females never have fully developed gonads, but after fusion, the male's gonads enlarge and he continues to grow, the largest known parasitic male being about long.

Lifespans range from 3 to over 30 years. Adults of most species are of one sex throughout their lives. The gonads are masses of developing gametes (ova or sperm), and most species have four gonads, two in each valve. Those of articulates lie in the channels of the mantle lobes, while those of inarticulates lie near the gut.

E1S is produced via estrogen sulfotransferases from the peripheral metabolism of the estrogens estradiol and estrone. Estrogen sulfotransferases are expressed minimally or not at all in the gonads. In accordance, E1S is not secreted in meaningful amounts from the gonads in humans. However, measurable amounts of estrogen sulfates are said to be secreted by the ovaries in any case.

During the maturity, the follicles of the gonads are filled with multiple layers of mature sperm.The mature spermatozoa exhibit a rounded shape are slightly dorso-ventrally flattened. A thin layer of spermatocytes is present at the periphery. Spawning is when the individuals have mated, and therefore the follicles in the gonads are empty due to the sperm being released.

Their function may be to increase the population of the parasite to keep up with the growth of the host. Rhombogens contain hermaphroditic gonads developed within the axial cell. These gonads, more correctly termed infusorigens, self-fertilise to produce infusoriform larvae. These larvae possess a very distinctive morphology, swimming about with ciliated rings that resemble headlights.

P. noctiluca has eight marginal tentacles alternating with eight marginal sense organs. Four gonads arise as elongated endodermal proliferations, developing into ribbon-like folds in the interradial sectors of the stomach wall slightly distal to the rows of gastric filaments. Male and female gonads vary only slightly and the main difference is the thickness of the follicle.

The insertion and subsequent expression of hobo-like sequences results in the loss of germ cells in the gonads of developing flies.

The greatest reproductive activity, the highest rate of development of gonads, and the most energy spent in migration happens when rainfall occurs.

Aromatase is expressed in the gonads, placenta, brain, adipose tissue, bone, and other tissues. It is almost undetectable in adult human liver.

The gonads are epidermal and have lobes either side of the groove.Order Narcomedusae - Haeckel, 1879 The Hydrozoa Directory. Retrieved 2011-11-07.

Both sexes possess pairs of gonads, opening via a channel called a gonoduct into a common genital opening, the gonopore, which is located on the rear ventral side. Both the gonads and the gonoduct are derived from true coelom tissue. A dissected Euperipatoides kanangrensis. The two ovaries, full of stage II embryos, are floating to the bottom of the image.

The gonads are the precursors of the testes in males and ovaries in females. They initially develop from the mesothelial layer of the peritoneum.

The medusae of Linantha lunulata can be distinguished from other crown jellyfish medusae by having four inter-radial gonads shaped like horseshoes, and no subumbrella.

However, despite containing relatively few cell types and lacking elaborate organ structures, the medusa have much greater anatomical complexity than their polyp form. Adult medusa are on average 1 cm in diameter. They are almost entirely transparent, their gonads, radial canals, short stomach, and four-lipped mouth being their most clearly visible anatomical structures. Each medusa has four gonads positioned midway along each endodermal radial canal.

The species moves through these 5 stages on an annual cycle. In the undetermined stage, gametes or gonads observed in the individuals, and therefore they are sexually viable. Any gonads that can be observed cannot be accurately distinguished at this stage. Connective tissue in the lumen is present and the gonadal wall is thickened The following four stages are different among males and females.

Jellyfish , The Visual Dictionary. Retrieved 28 March 2015 The mouth opens into the gastrovascular cavity, where digestion takes place and nutrients are absorbed. This is subdivided by four thick septa into a central stomach and four gastric pockets. The four pairs of gonads are attached to the septa, and close to them four septal funnels open to the exterior, perhaps supplying good oxygenation to the gonads.

Gametogonium (plural gametogonia) are stem cells for gametes located within the gonads. They originate from primordial germ cells, which have migrated to the gonads. Male gametogonia which are located within the testes during development and adulthood are called spermatogonium (plural spermatogonia). Female gametogonia, known as oogonium (plural oogonia), are found within the ovaries of the developing foetus and were thought to be depleted at or after birth.

This is done in three circumstances. (1) If the gonads are dysgenetic testes or streak gonads and at least some of the boy's cells have a Y chromosome, the gonads or streaks must be removed because they are nonfunctional but have a relatively high risk of developing gonadoblastoma. (2) In rare instances when an XX child has completely virilizing congenital adrenal hyperplasia (Prader stage 5), the ovaries can be removed before puberty to stop breast development and/or menstruation. (3) Gonadectomy can be performed in the equally rare instance of a child with true hermaphrodite virilized enough to raise as male, in which ovaries or ovotestes can be removed.

The excretory system consists of segmented "kidneys" containing protonephridia instead of nephrons, and quite unlike those of vertebrates. Also unlike vertebrates, there are numerous, segmented gonads.

The female gonads are located in the second to fourth segments with beige-colored grape-like clusters of variously-sized ova (with a maximum diameter of ).

Problems that emerge in persons with lipoid CAH can be divided into: # mineralocorticoid deficiency, # glucocorticoid deficiency, # sex steroid deficiency, and # damage to gonads caused by lipid accumulation.

In the reproductive system, inhibins and follistatin counterregulate activins, to control follicle-stimulating hormone and so the release of gonads. Inhibins and activins also regulate bone mass.

Regular sea urchins have five gonads, lying underneath the interambulacral regions of the test, while the irregular forms have only four, with the hindmost gonad being absent.

Doliolids alternate through sexual and asexual generations. The sexual generation consists of individuals featuring eight muscle bands, each having male or female gonads. These individuals are called gonozooids. Fertilized eggs produce slightly different individuals, featuring nine muscle bands, no gonads, and two stalks growing from each individual's body: the shorter one at the ventral side, and the longer one growing from the dorsal edge of the posterior siphon.

In the presence of a functional SRY gene, the bipotential gonads develop into testes. Gonads are histologically distinguishable by 6–8 weeks of gestation. Subsequent development of one set and degeneration of the other depends on the presence or absence of two testicular hormones: testosterone and anti-müllerian hormone (AMH). Disruption of typical development may result in the development of both, or neither, duct system, which may produce morphologically intersex individuals.

The primary sex organs are the gonads, a pair of sex organs, specifically the testes in the male or the ovaries in the female. As primary sex organs, gonads generate reproductive gametes containing inheritable DNA. They also produce most of the primary hormones that affect sexual development, and regulate other sexual organs and sexually differentiated behaviors. Secondary sex organs refer the rest of the reproductive system, whether internal or external.

The stocky galaxias is confined to freshwater with no downstream migration to the sea or estuary during its lifecycle. The spawning period is unknown, but likely to be in winter. Fish collected in mid March showed some development of the gonads (filling around 50 percent of the body cavity) with one male and one female almost running ripe and the gonads filling 75 percent of the body cavity.

Migration begins with 50 gonocytes and about 5,000 PGCs arrive at the gonads. Proliferation occurs also during migration and lasts for 3–4 weeks in humans. PGCs come from the epiblast and migrate subsequently into the mesoderm, the endoderm and the posterior of the yolk sac. Migration then takes place from the hindgut along the gut and across the dorsal mesentery to reach the gonads (4.5 weeks in human beings).

The hypothalamic–pituitary–gonadal axis can also be affected at the level of the brain. The brain does not send its hormonal signals to the gonads (low gonadotropins) causing the gonads to never be activated in the first place resulting in hypogonadotropic hypogonadism. The HPG axis can be altered in two places, at the hypothalamic or at the pituitary level. CNS disorders such as childhood brain tumors (e.g.

Video of swimming bigfin reef squids Bigfin reef squids exhibit two most common social body patterning and posturing behaviours related to mating. The first is dubbed "accentuated gonads", in which they will sometimes increase the visibility of their gonads while reducing the rest of their body colouration. This makes their reproductive organs appear bright white through the transparent mantle. It may indicate the reproductive condition of the signalling squid.

The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testes in males and the ovaries in females. The gonads initially develop from the mesothelial layer of the peritoneum. The ovary is differentiated into a central part, the medulla, covered by a surface layer, the germinal epithelium. The immature ova originate from cells from the dorsal endoderm of the yolk sac.

Large amounts of connective tissue are present in the gonadal walls. Phagocytes are involved in reducing the number of gonads present, thus ending the reproductive cycle in females.

The main stalky body of the colony is composed of a coenosarc, which is covered by a protective perisarc. The next generation of the life cycle begins when the medusae are released from the gonozooids, producing free swimming only male medusae velum with gonads, a mouth, and tentacles. The physical appearance of the male and female medusae velum, including their gonads, are indistinguishable, and the sex can only be determined by observing the inside of the gonads, which will either contain sperm or eggs. The medusae reproduce sexually, releasing sperm and eggs that fertilize to form a zygote, which later morphs into a blastula, then a ciliated swimming larva called a planula.

In 1997, Arai summarized that seasonal reproduction leaves the gonads open to infection and degradation. Some metazoan parasites attack Aurelia aurita, as well as most other species of jellyfish.

After splitting into two populations, the germ cells continue migrating laterally and in parallel until they reach the gonads. Columbus proteins, chemoattractants, stimulate the migration in the gonadal mesoderm.

Left and right gonads (g) in Rhabdopleura compacta. In recent years, living graptolites have been used as a hemichordate model for Evo-Devo studies, as have their sister group, the acorn worms. For example, graptolites are used to study asymmetry in hemichordates, especially because their gonads tend to be located randomly on one side. In Rhabdopleura normani, the testicle is located asymmetrically, and possibly other structures such as the oral lamella and the gonopore.

Swyer syndrome represents one phenotypic result of a failure of the gonads to develop properly, and hence is part of a class of conditions termed gonadal dysgenesis. There are many forms of gonadal dysgenesis. Swyer syndrome is an example of a condition in which an externally unambiguous female body carries dysgenetic, atypical, or abnormal gonads. Other examples include complete androgen insensitivity syndrome, partial X chromosome deletions, lipoid congenital adrenal hyperplasia, and Turner syndrome.

Westralunio carteri generally has separate sexes (males and females), but hermaphrodites occur occasionally. Gametes (sperm in males or eggs in females) develop in the gonads and, with the onset of spawning, eggs migrate from the female gonads (ovaries) into specialised areas of the gills known as 'marsupia'. At this stage, females are 'gravid'. Fertilised eggs of Westralunio carteri (and other species of Hyriidae) are brooded to become embryos, which develop into larvae, known as 'glochidia'.

The sexes are usually separate in bivalves but some hermaphroditism is known. The gonads are located close to the intestines, and either open into the nephridia, or through a separate pore into the mantle cavity. The ripe gonads of male and females release sperm and eggs into the water column. Spawning may take place continually or be triggered by environmental factors such as day length, water temperature, or the presence of sperm in the water.

In mature individuals, the male gonads are cream coloured and the female gonads bright red. When ripe they are enlarged and visible in the live animal where they obscure the view of the animal's digestive tract. The eggs are fertilised externally and the initial trochophore larvae soon develop into veliger larvae which form part of the zooplankton and disperse with the currents. After some weeks, these settle and undergo metamorphosis before becoming juveniles.

Studies have found that it takes approximately 3 years for the little tunny's gonads to reach sexual maturity. The average size of a sexually mature individual is in fork length.

As the juvenile mollusc grows, its posterior end pushes its way into the sea cucumber's body cavity, and the gonads develop, the interior of the mollusc becoming a brood pouch.

Yet, the eggs from a small sample of females (about six) are more commonly stripped from the gonads using Pasteur pipettes and fertilized by sperm from a similar number of males.

Most amphibians exhibit external fertilization of eggs, typically within the water, though some amphibians such as caecilians have internal fertilization. All have paired, internal gonads, connected by ducts to the cloaca.

August Weismann's 1892 germ plasm theory. The hereditary material, the germ plasm, is confined to the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm.

Human embryos develop similarly for the first six weeks, regardless of genetic sex (46,XX or 46,XY karyotype); the only way to tell the difference between 46,XX or 46,XY embryos during this time period is to look for Barr bodies or a Y chromosome. The gonads begin as bulges of tissue called the genital ridges at the back of the abdominal cavity, near the midline. By the fifth week, the genital ridges differentiate into an outer cortex and an inner medulla, and are called indifferent gonads. By the sixth week, the indifferent gonads begin to differentiate according to genetic sex. If the karyotype is 46,XY, testes develop due to the influence of the Y chromosome’s SRY gene.

The sexes are separate in most species, though a few are hermaphroditic or protandric. The gonads are located in the disk, and open into pouches between the arms, called genital bursae. Fertilisation is external in most species, with the gametes being shed into the surrounding water through the bursal sacs. An exception is the Ophiocanopidae, in which the gonads do not open into bursae and are instead paired in a chain along the basal arm joints.

Since LH and FSH stimulate the gonads to produce estrogens and androgens in females and males respectively, histrelin can effectively be used to decrease the sex steroids in the blood of patients.

During mammalian development, the gonads are at first capable of becoming either ovaries or testes.Online textbook: "Developmental Biology" 6th ed. By Scott F. Gilbert (2000) published by Sinauer Associates, Inc. of Sunderland (MA).

Their roe (male and female gonads) is soft and melting, with a colour ranging from orange to pale yellow, and is sought after as a human delicacy in many parts of the world.

More recently, fibrillin-3 was described and is believed to be located mainly in the brain. Along with the brain, fibrillin-3 has been localized in the gonads and ovaries of field mice.

Sea urchins are spiky echinoderms with spherical bodies which usually contain five gonads. They move slowly, feed mostly on seaweed, and are important for the diet of sea otters. Sea urchins are dioecious, having separate male and female sexes, although there is generally no easy way to distinguish the two. The gonads are lined with muscles underneath the peritoneum, and these allow the animal to squeeze its gametes through the duct and into the surrounding sea water, where fertilization takes place.

Most polychaetes have separate sexes, rather than being hermaphroditic. The most primitive species have a pair of gonads in every segment, but most species exhibit some degree of specialisation. The gonads shed immature gametes directly into the body cavity, where they complete their development. Once mature, the gametes are shed into the surrounding water through ducts or openings that vary between species, or in some cases by the complete rupture of the body wall (and subsequent death of the adult).

Cryptasterina hystera is a hermaphrodite; the gonads can produce both sperm and eggs and are known as ovotestes. Fertilization of the eggs take place when sperm liberated by another starfish is drawn into the gonad through the gonoduct. The eggs are few in number and have large yolks and are retained inside the starfish which is viviparous. The brachiolaria larvae that develop inside the gonads "swim" in the fluid there and are eventually released into the sea through the gonopore as juvenile starfish.

DHEA is produced in the zona reticularis of the adrenal cortex under the control of adrenocorticotropic hormone (ACTH) and by the gonads under the control of gonadotropin-releasing hormone (GnRH). It is also produced in the brain. DHEA is synthesized from cholesterol via the enzymes cholesterol side-chain cleavage enzyme (CYP11A1; P450scc) and 17α-hydroxylase/17,20-lyase (CYP17A1), with pregnenolone and 17α-hydroxypregnenolone as intermediates. It is derived mostly from the adrenal cortex, with only about 10% being secreted from the gonads.

During mammalian development, the gonads are at first capable of becoming either ovaries or testes. In humans, starting at about week 4, the gonadal rudiments are present within the intermediate mesoderm adjacent to the developing kidneys. At about week 6, epithelial sex cords develop within the forming testes and incorporate the germ cells as they migrate into the gonads. In males, certain Y chromosome genes, particularly SRY, control development of the male phenotype, including conversion of the early bipotential gonad into testes.

In typical prenatal development, sex organs originate from a common primordium during early gestation and differentiate into male or female sexes. The SRY gene, usually located on the Y chromosome and encoding the testis determining factor, determines the direction of this differentiation. The absence of it allows the gonads to continue to develop into ovaries. Thereafter, the development of the internal, and external reproductive organs is determined by hormones produced by certain fetal gonads (ovaries or testes) and the cells' response to them.

Germ cell tumor is a rare cancer that can affect people at all ages. As of 2018, germ cell tumors account for 3% of all cancers in children and adolescents 0-19 years old. Germ cell tumors are generally located in the gonads but can also appear in the abdomen, pelvis, mediastinum, or brain. Germ cells migrating to the gonads may not reach that intended destination and a tumor can grow wherever they end up, but the exact cause is still unknown.

It usually takes place between the ages 10 – 16. It is initiated by hormonal signals from the brain to the gonads - either the ovaries or the testes. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sexual organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when the child has developed an adult body.

Bucephalus polymorphus is a parasite residing exclusively in host connective tissues. The gonads of its first intermediate host, Dreissena, is the primary target of infection and sporocyst proliferation. As infection intensifies, the sporocyst develops branches through connective tissue passages, emerges from the gonads, and can spread into other body regions. Such secondary sites of infection have been previously reported to occur in the digestive glands, the gills, the bundles of adductor muscle, and the mantle epithelium lining the interior of the shells.

45,X/46,XY mixed gonadal dysgenesis. Orfa.net; August 2015. Psychomotor development is normal. As the gonads may not be symmetrical, the development of the Müllerian duct and Wolffian duct may be asymmetrical, too.

Males and females are identical in appearance. The central disk is rounded with small bumps on its upper side. The disk can be up to across. It contains the mouth, digestive system, and gonads.

During their first year, young urchins increased their diameter by about a month. Growth slowed thereafter and halted completely after maturity was reached while the gonads were ripening. After liberation of the gametes, growth restarted.

The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus.

The Moontail bullseye, Priacanthus hamrur, is the host of Philometra priacanthi The type host of this parasite is the Moontail bullseye, Priacanthus hamrur, at its gonads. Its type locality is off Nouméa, in New Caledonia.

The polyps of the regal sea fan extend their tentacles to feed and gather plankton and small organisms from the surrounding water. Individual colonies are either male or female. Females start breeding at the age of two whereas the males do not do so until they are six years old. In a study in the Gulf of Mexico, where this species is a dominant member of the shallow reef community, it was found that the female gonads began developing in January and the male gonads in April.

Hypothalamic-pituitary- testicular axis and the hormones produced by each part of the axis. The + signs indicate that the organ is stimulated by the hormones released from the previous organ in the chain. Primary failure of the ovaries or testes (gonads) will cause delayed puberty due to the lack of hormonal response by the final receptors of the HPG axis. In this scenario, the brain sends a lot of hormonal signals (high gonadotropin), but the gonads are unable to respond to said signals causing hypergonadotropic hypogonadism.

Males have their gonads under the chin – along with a serrated saw and rod for grasping females. The name cuulong is from the Vietnamese name of the river system where they are found, Cửu Long River.

The arms lack dorsal and ventral shields; the madreporite is on edge of central disc. The digestive glands extend into proximal portions of arms. It has no bursae for gonads and gas exchange/excretion.R.C.Brusca, G.J.Brusca. Invertebrates.

Females transition into male fish, known as secondary males, at a length of between . Secondary males can be told from primary males by examination of their gonads. The male digs a burrow and guards the nest.

It has been shown, however, that SOX9, in the presence of PDG2, acts directly on Amh (encoding anti-Müllerian hormone) and is capable of inducing testis formation in XX mice gonads, indicating its vital to testes development.

EST profiling of NBPF19 shows it to be ubiquitously expressed in most human tissues at unremarkable amounts. It is expressed in relatively higher amounts in the skin, lymphoid organs (lymph nodes, spleen) and the gonads (ovary, testes).

Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed.

Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of gonadal ridges, and only later are differentiated to male or female sex organs. The presence of the SRY gene, located on the Y chromosome and encoding the testis determining factor, determines male sexual differentiation. In the absence of the SRY gene from the Y chromosome, the female sex (ovaries instead of testes) will develop. The development of the gonads is a part of the development of the urinary and reproductive organs.

Female (right) with egg sac, note the male at left (circled) Before a juvenile male leaves its mother's web, it builds a small sperm web on which it deposits its sperm from its gonads and then collects it back into each of its two palps (copulatory organs), because the gonads and palps are not internally connected. After it moults into its last instar, it sets off wandering to seek a female. The male spider does not eat during this period. How males find females is unclear, and it is possible they may balloon like juveniles.

A D. virilis male (top) and female (bottom), showing the bright red gonads of the male Drosophila virilis is a species of fruit fly with a worldwide distribution (probably due to human movements), and was one of 12 fruit fly genomes sequenced for a large comparative study. The males have bright red gonads that can be seen through the cuticle. The life cycle of D. virilis is longer than that of D. melanogaster, in part owing to its larger body size; adult D. virilis are approximately twice the size of D. melanogaster.

In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable sexually transmitted diseases.STD's Today National Prevention Network, Center for Disease Control, United States Government, retrieving 2007 Most other vertebrates have generally similar reproductive systems consisting of gonads, ducts, and openings. However, there is a great diversity of physical adaptations as well as reproductive strategies in every group of vertebrates.

In most mammals, specification occurs first, followed by migration, and then the proliferation process begins in the gonads. PGCs interact with a wide range of cell types as they move from the epiblast to the gonads. The PGCs move passively (without the need for energy) with underlying somatic cells, cross epithelial barriers, and respond to cues from their environment during active migration. An epithelium must be crossed in many species during germ cell migration, and changes in adhesion are observed in PGCs during their exit from the endoderm and during the initiation of active migration.

In both males and females, the sex organs consist of three structures: the gonads, the internal genitalia, and the external genitalia. In males, the gonads are the testes and in females they are the ovaries. These are the organs that produce gametes (egg and sperm), the reproductive cells that will eventually meet to form the fertilized egg (zygote). As the zygote divides, it first becomes the embryo (which means 'growing within'), typically between zero and eight weeks, then from the eighth week until birth, it is considered the fetus (which means 'unborn offspring').

Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed.

Puberty is the process of physical changes by which a child's body matures into an adult body capable of sexual reproduction to enable fertilization. It is initiated by hormonal signals from the brain to the gonads. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sexual organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when the child has developed an adult body.

Odiele was born on 8 October 1988 in Kortrijk, Belgium. She was born intersex as a result of androgen insensitivity syndrome, meaning that she was born with a vulva and vagina despite her DNA being XY and internal gonads being testes; Odiele's cells do not respond to the testosterone that her DNA causes her gonads to produce. As a child, Odiele underwent medical procedures relating to her condition, which she said took place without her or her parents' informed consent. Odiele was told about her intersex variation weeks before beginning her modelling career.

The gonads are on the lower pinnules and there are brood pouches between these pinnules and the arms. This crinoid is dark red in colour, a colour that is already becoming apparent in the late stage, stalked larvae.

The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer, also called the caudal genital ligament) are embryonic structures which begin as undifferentiated mesenchyme attaching to the caudal end of the gonads (testes in males and ovaries in females).

In males, the gonads mature over a few weeks after the final ecdysis and their weight also steadily increases. Female weight increases as a result of mating stimulating egg maturation. Mating occurs once females reach at least 30g.

Orchitophrya stellarum is a species of single-celled marine ciliates, a member of the class Oligohymenophorea. It is found living freely in the north Atlantic and Pacific Oceans but is also parasitic, being found inside the gonads of starfish.

Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estrogen (e.g., estradiol) as hypoestrogenism.

Gonadal GCTs include Testicular GCTs in males and Ovarian GCTs in females. Extracranial extragonadal GCTs are tumor cells that had been spread out through tissue, lymph system or blood to other areas of the body other than the gonads.

A gonadal tissue neoplasm should not be confused with a urogenital neoplasm, though the two topics are often studied together. The embryology of the gonads is only indirectly related to the embryology of the external genitals and urinary system.

These develop internally sending out root-like growths into the host's tissues, and later developing an external, stalked protuberance housing the parasite's reproductive organs; its presence effectively castrates the host by causing the host's gonads to diminish in size.

Marine Species Identification Portal. Retrieved 15 June 2019. C. tagi has gonads along the edge of its stomach in an X shape. It has the octant formation typical of Catostylus jellies, the height of the octants are also variable.

Germ cells migrate from near the allantois and colonize the primordial gonads. In the female, the germ cells colonise the cortex and become oogonia. In the male, the germ cells colonise the seminiferous cords of the medulla, becoming spermatogonia.

RSPO1 is required for the early development of gonads, regardless of sex. It has been found in mice only eleven days after fertilization. To induce cell proliferation, it acts synergistically with WNT4. They help stabilize β-catenin, which activates downstream targets.

Darwin's pangenesis theory. Every part of the body emits tiny gemmules which migrate to the gonads and contribute to the next generation via the fertilised egg. Changes to the body during an organism's life would be inherited, as in Lamarckism.

There are up to 200 slender, translucent, white or pale pink tentacles up to one and a half centimetres long arranged in five rings. When the orangeish-pink gonads are ripe, they may be visible through the wall of the column.

Internally the body wall has numerous drop-shaped gonads (called polycarps) and the pharynx wall is perforated with many bands of stigmata (slits).Picton, B.E. & Morrow, C.C. (2015). Polycarpa pomaria (Savigny, 1816). [In] Encyclopedia of Marine Life of Britain and Ireland.

Ablation of the gonads in these two nematodes causes vulval precursor cell death. This is opposite of what is seen in C.elegans and many other nematode species typically if there is ablation of the gonads the vulval precursor cells default to an epidermal fate and do not undergo programmed cell death. “Evidence of a mate-finding cue in the hermaphrodite nematode Caenorhabditis elegans”(2002) Simon and Sternberg performed several different assays and found that males specifically, respond to a sexually dimorphic cue that hermaphrodites gives off. They found that the cue is not discharged from vulva tissue.

The male and female gonads are thereby activated, which puts them into a state of rapid growth and development; the triggered gonads now commence mass production of hormones. The testes primarily release testosterone, and the ovaries predominantly dispense estrogen. The production of these hormones increases gradually until sexual maturation is met. Some boys may develop gynecomastia due to an imbalance of sex hormones, tissue responsiveness or obesity. Facial hair in males normally appears in a specific order during puberty: The first facial hair to appear tends to grow at the corners of the upper lip, typically between 14 and 17 years of age.

Brittle stars, crinoids and sea cucumbers in general do not have sensory organs but some burrowing sea cucumbers of the order Apodida have a single statocyst adjoining each radial nerve and some have an eyespot at the base of each tentacle.Ruppert, Fox & Barnes (2004) pp. 872–929 The gonads occupy much of the body cavities of sea urchins and sea cucumbers, while the less voluminous crinoids, brittle stars and starfish have two gonads in each arm. While the ancestral condition is considered to be the possession of one genital aperture, many organisms have multiple gonopores through which eggs or sperm may be released.

Due to the inability of the streak gonads to produce sex hormones (both estrogens and androgens), most of the secondary sex characteristics do not develop. This is especially true of estrogenic changes such as breast development, widening of the pelvis and hips, and menstrual periods. As the adrenal glands can make limited amounts of androgens and are not affected by this syndrome, most of these persons will develop pubic hair, though it often remains sparse. Evaluation of delayed puberty usually reveals elevation of gonadotropins, indicating that the pituitary is providing the signal for puberty but the gonads are failing to respond.

Prior to their arrival at the gonads, PGCs express pluripotency factors, generate pluripotent cell lines in cell culture (known as EG cells,) and can produce multi-lineage tumors, known as teratomas. Similar findings in other vertebrates indicate that PGCs are not yet irreversibly committed to produce gametes, and no other cell type. On arrival at the gonads, human and mouse PGCs activate widely conserved germ cell-specific factors, and subsequently down-regulate the expression of pluripotency factors. This transition results in the determination of germ cells, a form of cell commitment that is no longer reversible.

Charles Darwin's pangenesis theory postulated that every part of the body emits tiny particles called gemmules which migrate to the gonads and are transferred to offspring. Gemmules were thought to develop into their associated body parts as offspring matures. The theory implied that changes to the body during an organism's life would be inherited, as proposed in Lamarckism. Pangenesis was Charles Darwin's hypothetical mechanism for heredity, in which he proposed that each part of the body continually emitted its own type of small organic particles called gemmules that aggregated in the gonads, contributing heritable information to the gametes.

But, during sexual differentiation of the foetus, labioscrotal folds in the males normally fuse longitudinally in the middle, forming a sack for male gonads (testicles) to descend into it from the pelvis, while in the females these folds normally do not fuse, forming the two labia majora and the pudendal cleft between them. Female gonads (ovaries) do not descend from the pelvis, thus the structure of labia majora may seem simpler (just fatty tissue covered with skin) and of lesser significance for functioning of the female body as a whole than the scrotum with testicles for males. The ridge or groove remaining of the fusion can be traced on the scrotum. In some cases of intersex with disorders of sex development male/female genitalia may look ambiguous for either gender with phallus too small for a typical penis yet too big for a clitoris, with external urethral opening in an atypical location, and with labia/scrotum fully or partially fused but without descended gonads in them.

The gonads (testes and ovaries) respond to rising levels of LH and FSH by producing the steroid sex hormones, testosterone and estrogen. The adrenal glands are a second source for steroid hormones. Adrenal maturation, termed adrenarche, typically precedes gonadarche in mid-childhood.

Eventually, a pair would sink down to a sandy bottom, where eggs and sperm were released. The fish then diverged and swam away. Each individual appears to spawn more than once in each period, with only part of the gonads ripe in spawners.

The gastric peduncle dangles inside the bell, and the mouth at the tip of the small manubrium has four simple lips. Mature individuals have eight white, sausage-shaped gonads which are visible through the bell. This hydrozoan is usually some shade of pink.

Another characteristic of phlebobranchians is the gonads being surrounded by a loop of gut. The posterior part of the abdomen is absent, and many species also lack the epicardial cavity that surrounds the heart and other internal organs in many other sea squirts.

A few species are parasitic on other marine organisms. One of these is Peachia quinquecapitata, the larvae of which develop inside the medusae of jellyfish, feeding on their gonads and other tissues, before being liberated into the sea as free-living, juvenile anemones.

As the scrotum and labia majora form in males and females respectively, the gubernaculum aids in the descent of the gonads (both testes and ovaries). The testes descend to a greater degree than the ovaries and ultimately pass through the inguinal canal.

Reproduces throughout the year, early summer seems to be the peak period. Gonads in the abdominal region. The sperm have ellipsodal heads 5μm in diameter, tail about 55μm long. The eggs are 110μm in diameter, a mature female can obtain 75 eggs.

When Fell graduated in 1922 and found no open scientific positions in Edinburgh, she began work full-time as a research assistant to Strangeways. She earned a Ph.D. in 1924 entitled Historical studies on the gonads of the fowl and a D.Sc in 1932.

August Weismann's germ plasm theory. The hereditary material, the germ plasm, is confined to the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm. In 1883 August Weismann conducted experiments involving breeding mice whose tails had been surgically removed.

Pink sea stars are primarily gonochoric, which is to say that individuals are either male or female. Each arm contains two gonads. These stars lift their central discs off the bottom to spawn, releasing their microscopic gametes into the water. Their eggs are in diameter.

The crocodilian penis is permanently erect and relies on cloacal muscles for eversion and elastic ligaments and a tendon for recoil. The gonads are located near the kidneys.Huchzermeyer, p. 19. The eyes, ears and nostrils of crocodilians are at the top of the head.

Calza, C.; Anjosa, M.J.; Castroa, C.R.F.; Barrosob, R.C.; Araujoc, F.G.; and Lopesa, R.T. (2004). Evaluation of heavy metals levels in the Paraíba do Sul River by SRTXRF in muscle, gonads and gills of Geophagus brasiliensis. Radiation Physics and Chemistry 71: 787–788.ICMBio (2011).

Diagram of August Weismann's germ plasm theory. The hereditary material, the germ plasm, is confined to the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm. Whatever may happen to those cells does not affect the next generation.

Lion's paw scallops are known to be hermaphroditic, so they have both male and female gonads. In external fertilization, an organism will release both eggs and sperm. The lion's paw shell is valuable to collectors because of its size, vibrant colors, and extremely distinctive features.

Because of the inability of the streak gonads to produce sex hormones (both estrogens and androgens), most of the secondary sex characteristics do not develop. This is especially true of estrogenic changes such as breast development, widening of the pelvis and hips, and menstrual periods. Because the adrenal glands can make limited amounts of androgens and are not affected by this syndrome, most of these girls will develop pubic hair, though it often remains sparse. Evaluation of delayed puberty usually reveals the presence of pubic hair, but elevation of gonadotropins, indicating that the pituitary is providing the signal for puberty but the gonads are failing to respond.

Gonadotropin-releasing hormone (GnRH) neurons differ across sexual phenotypes in the hypothalamus of bluehead wrasses and also with androgen implants that induce sex change. Behavioral sex change is very rapid in T. bifasciatum under field conditions, with male-typical behaviors being observed within minutes to hours after dominant terminal phase males are removed. Behavioral sex change occurs even in females whose gonads (ovaries) have been surgically removed prior to becoming socially dominant. Behavioral sex change is associated with increases in expression of a neuropeptide hormone termed arginine vasotocin or AVT and these increases occur regardless of whether sex changing females have gonads or not.

Increasingly, jurisdictions also provide a procedure for changes of legal gender for transgender people. Gender assignment, when there are indications that genital sex might not be decisive in a particular case, is normally not defined by a single definition, but by a combination of conditions, including chromosomes and gonads. Thus, for example, in many jurisdictions a person with XY chromosomes but female gonads could be recognized as female at birth. The ability to change legal gender for transgender people in particular has given rise to the phenomena in some jurisdictions of the same person having different genders for the purposes of different areas of the law.

Members of this genus are characterised by having exactly six tentacles and six rhopalia, twelve marginal lappets and twelve pedalia. The bell ranges from in diameter. The bell is colourless and transparent and the four orange gonads can be seen inside. The mouth has four lips.

The reproductive system is observed to remain intact, and even the gonads of the Turritopsis dohrnii are existing. Some species exhibit "negative senescence", in which reproduction capability increases or is stable, and mortality falls with age, resulting from the advantages of increased body size during aging.

Knockout mice lacking the ligand binding domain of PPARδ are viable. However, these mice are smaller than the wild type both neo and postnatally. In addition, fat stores in the gonads of the mutants are smaller. The mutants also display increased epidermal hyperplasia upon induction with TPA.

Potential surgical problems: The most complicated aspect of closure involves moving the urethra to the phallus if it is not already there (i.e., repairing a perineal hypospadias). Fistulas, scarring, and loss of sensation are the main risks. Gonadectomy (also referred to as "orchiectomy") removal of the gonads.

The two worms fuse completely, with no trace of separating partitions. The fusion stimulates maturation. Gonads appear; the male genital duct of one terminates near the female genital duct of the other, permitting cross-fertilization. Two more pairs of clamps develop in the opisthaptor of each.

The mouth is located between the proboscis and the collar. The trunk is the longest part of the animal. It contains the pharynx, which is perforated with gill slits (or pharyngeal slits), the esophagus, a long intestine, and a terminal anus. It also contains the gonads.

Heterozygous mutations in the ZFPM2 gene are responsible for sporadic, very rare cases of a familial form of disorders of sex development, ambiguous genitalia. The disorder likely reflects haploinsufficiency of the ZFPM2 protein and consequential reduced regulation of GATA4 in promoting normal development of the gonads.

The six pairs of mesenteries are complete, in that their sheetlike membranes join the gastrodermis of the body wall with that of the pharynx, and are sterile, in that they do not bear gonads. The nematocysts consist of a mixture of spirocysts, basitrichs and microbasic p-mastigophors.

In this experiment, there was no relation in regard to the size of the gland and the fertility of the cockerel. There were some exceptions in the experiment that Dove writes could have been due to late development of the gonads in comparison to the opposite sex’s.

25 cm (10-in) is its total length. Ground-feeder but roosts and nests on bushes or vines; seen in pairs in a flock. Birds with enlarged gonads recorded in April and May and a recent fledgling obtained on May 3. Nest and eggs are undescribed.

The male reproductive system. Male internal reproductive structures are the testicles, the duct system, the prostate and seminal vesicles, and the Cowper's gland. The testicles (male gonads), are where sperm and male hormones are produced. Millions of sperm are produced daily in several hundred seminiferous tubules.

Sea urchins are dioecious, meaning they either contain male or female reproductive organs. They contain five gonads tucked under the test. These are located close to the anus and are protected by genital plates. One of these plates is perforated, and also acts as the madreporite.

Natural sex steroids are made by the gonads (ovaries or testes), by adrenal glands, or by conversion from other sex steroids in other tissue such as liver or fat. Image:Steroidogenesis.svg Image:Biosinthesis of steroid hormones (simplified version).jpg Image:Biosinthesis of steroid hormones (extended version).jpg Image:Стероидогенез прогестогенов.

Gonads form from endoderm. And, each organ typically forms from one cell apparently. So each organ will be expected to be nearly 100% from one embryo or the other, except in very rare cases. There is some infiltration of cells from the other embryo, but it's minor.

Ophiothrix suensoni is dioecious. Breeding takes place all year round but peaks in the late summer and autumn. The males have larger gonads than the females perhaps in order to increase the concentration of sperm in the vicinity of females as they do not synchronize their spawning.

Androgens are synthesized from cholesterol and are produced primarily in the gonads (testicles and ovaries) and also in the adrenal glands. The testicles produce a much higher quantity than the ovaries. Conversion of testosterone to the more potent DHT occurs in prostate gland, liver, brain and skin.

Little is known of the reproduction of this fish. Adults with ripe gonads have been found in May and early July and adults that have already spawned have been found in late July. Examination of the stomach contents of this fish showed algae, plant material and detritus.

The ciliate parasite Orchitophrya stellarum has been found in the gonads of up to 20% of male Asterias forbesi in Long Island Sound. They feed on the tissue of the gonad and effectively castrate their host. A small number of females were also found to contain the parasite.

August Weismann's 1892 germ plasm theory. The hereditary material, the germ plasm, is transmitted only by the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm. August Weismann proposed the germ plasm theory in the 19th century, before the foundation of modern genetics.

The starfish, Dermasterias imbricata, has been observed feeding on larger anemones in Puget Sound.Metridium giganteum Evergreen Natural History Database. Retrieved 2011-11-24. Reproduction takes place with the liberation of eggs and sperm from the gonads embedded in the body wall which are then ejected through the mouth.

The mouth is on the lower or oral surface. It serves also as an anus and leads to a blind gut. This large coelomic cavity can extend from the disc into the arms. The paired gonads are also located in the arms and release gametes via the gonoducts.

Psilaster andromeda is a carnivore, detritivore and omnivore. It mainly feeds on molluscs such as Abra. Nucula, Rissoa and Tellina, echinoderms, foraminifera, and sometimes crustaceans and annelids. The gonads of Psilaster andromeda are located at the base of the arms and each one opens through a single gonopore.

The axis controls development, reproduction, and aging in animals. Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus by GnRH-expressing neurons. The anterior portion of the pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the gonads produce estrogen and testosterone. In oviparous organisms (e.g.

Fish Reproduction A small portion of fish species are either viviparous or ovoviviparous, and are collectively known as livebearers.Science, Biology, and Terminology of Fish reproduction: Reproductive modes and strategies-part 1. 2002. MARTIN MOE. THE BREEDER'S NET Online Magazine Fish gonads are typically pairs of either ovaries or testes.

Others are members of gelatinous zooplankton such as Beroe ctenophores and various Scyphozoa (jellyfish). The comb jelly has the capacity for self- fertilization, as they are hermaphroditic. They have gonads that contain the ovary and spermatophore bunches in their gastrodermis. It carries 150 eggs along each meridional canal.

A 2006–2007 investigation on the biological habitat and characteristics of Sphyraena jello found that the species' feeding takes place after releasing its gonads to spawn. This release creates space for the stomach to magnify its capacity for appropriate feeding (Halpern, 2004). This takes place in October and November.

The deeplet sea anemones have their largest gonads (sex glands) in late winter. The females have pink, spherical eggs with a membrane, and are large compared to other anemones. When its nucleus is fertilized, it will make several daughter nuclei. Each nuclei will spread until they are evenly distributed.

Morchellium argus draws in water through its buccal siphon, filters out zooplankton and other food particles and then expels the water. Gas exchange takes place at the same time. Morchellium argus is a hermaphrodite. The gonads are in the body cavity and sperm passes out with the exhalent water.

Sex determination is variable in fish from environmental factors like temperature to genetic mechanisms. Some fish have XX/XY chromosomes and others have ZZ/ZW. So far one gene in specific, DMRT1bY, has been described as a sex determining gene. This gene is expressed before gonads develop and differentiate.

Black Katy chitons are primarily dioecious, diploid organisms. They reach sexual maturity at about 35mm in length. The decrease in temperature experienced around fall will trigger within a newly settled organism the growth of the gonads. Around springtime, the increase in temperatures will trigger the actual production of gametes.

Nausithoe aurea is a species of crown jellyfish found off the southeastern coast of Brazil. The central disc has been measured to be 10.5 mm. N. aurea is transparent with yellow and brown spots located around the gonads. N. aurea can reproduce either asexually by strobilation or sexually.

Some teleost species are hermaphroditic, which can come in two forms: simultaneous and sequential. In the former, both spermatozoa and eggs are present in the gonads. Simultaneous hermaphroditism typically occurs in species that live in the ocean depths, where potential mates are sparsely dispersed.Wootton and Smith p. 54.

In the largest species, the medusae can grow to . Centripetal canals may be present or absent and the radial canals are unbranched. The gonads are beside the radial canals, except in Limnocnida, where they are on the manubrium. The fertilised eggs develop into planula larvae which become polyps.

Members of this family have dome-shaped bells and numerous tentacles set above the undulating margin of the bell. They do not have gastric pouches as do other members of the order. The gonads are situated inside the wall of the stomach.Order Narcomedusae - Haeckel, 1879 The Hydrozoa Directory.

The amber pen shell is a hermaphrodite, the gonads producing both sperm and ova. The larvae are planktonic and drift with the currents. The shells of the planktonic larvae are transparent, pale golden or amber in color, and also triangular. Larvae likely settle anywhere they can attach byssal threads.

Persistent replication of HzNV-2 in insect hosts make asymptomatic (AS), fertile carriers. Unlike baculoviruses, the productive replication of this virus does not kill the hosts. Instead, it causes malformed gonads, sterilizing the hosts. When healthy females mate with infected males, the offspring are infected through the eggs (transovarially).

Max Beck has described how his sex was not determinable at birth. Through testing it was discovered that he had mosaic XY/X0 chromosomes. His gonads were removed, and he was raised female, with yearly visits to endocrinologists and urologists. Beck's genitals were described as not yet "finished".

Animal models such as rodents, Drosophila melanogaster, and Caenorhabditis elegans, have been used to observe the origins and/or extent of sex bias in the brain versus the hormone-producing gonads of an animal. With the rodents, studies on genetic manipulation of sex chromosomes resulted in an effect on one sex that was completely opposite of the effect in the other sex. For example, a knockout of a particular gene only resulted in anxiety-like effects in males. With studies on D. menlanogaster it was found that a large brain sex bias of expression occurred even after the gonads were removed, suggesting that sex bias could be independent of hormonal control in certain aspects.

This condition used to be called "true hermaphroditism". This is defined as having asymmetrical gonads with ovarian and testicular differentiation on either sides separately or combined as ovotestis. In most cases, the cause of this condition is unknown; however, some research has linked it to exposure to common agricultural pesticides.

Some burrowing sand dollars have an elongated papilla that enables the liberation of gametes above the surface of the sediment. The gonads are lined with muscles underneath the peritoneum, and these allow the animal to squeeze its gametes through the duct and into the surrounding sea water, where fertilization takes place.

The anatomy of catenulids is simple and lacks hard parts. The mouth is located anteriorly and connects to a simple pharynx and a simple intestine that forms a ciliated sac. They possess two pairs of nerve cords and often a statocyst, as well as a single protonephridium. The gonads are unpaired.

Garry Bushell (born 13 May 1955) is an English newspaper columnist, rock music journalist, television presenter, author, musician and political activist. Bushell also sings in the Cockney rock bands GBX and the Gonads. He managed the New York City Oi! band Maninblack until the death of the band frontman Andre Schlessinger.

Their sex can be determined by examining the gonads, and it can change from year to year, normally during the winter. In certain environmental conditions, one sex is favoured over the other. Protandry is favoured in areas of high food abundance and protogyny occurs in areas of low food abundance.

The spermatozoa of animals are produced through spermatogenesis inside the male gonads (testicles) via meiotic division. The initial spermatozoon process takes around 70 days to complete. The process starts with the production of spermatogonia from germ cell precursors. These divide and differentiate into spermatocytes, which undergo meiosis to form spermatids.

4-Androstenedione is naturally produced in the body by the adrenal glands and gonads. In addition to testosterone, it is also a precursor of estrone and estradiol. 5-Androstenedione is on the World Anti- Doping Agency's list of prohibited substances, and is therefore banned from use in most major sports.

There are no organized gonads, but gametes are produced. Adults producing sperm are very rarely observed, but eggs and embryos are known to occur in follicles. Eggs of Xenoturbella are wide, pale orange and opaque. Newly hatched embryos are free- swimming (tending to stay close to water surface) and ciliated.

On the western coast of Ireland, these sea cucumbers bury themselves in the sediment between October and February and go into a form of hibernation. They do not feed during this time and their body wall condition deteriorates, but the gonads continue developing, and spawning takes place in early spring.

2015 Sep;18(3):507–26. . In young individuals in which sex determination would not be feasible by visualisation of external morphologic features, this technique permits noninvasive visualisation of gonads, and therefore sex determination.Selleri P, Di Girolamo N, Melidone R. "Cystoscopic sex identification of posthatchling chelonians". J Am Vet Med Assoc.

The basic body plan of Aurelia consists of several parts. The animal lacks respiratory, excretory, and circulatory systems. The adult medusa of Aurelia, with a transparent look, has an umbrella margin membrane and tentacles that are attached to the bottom. It has four bright gonads that are under the stomach.

Umbrella up to 18 mm, with very thick, bluntly conical projection; 64-72 marginal tentacles in adults; 8-9 tentacles and 2 statocysts in each octant; base of tentacles surrounded by broad thickening of marginal cnidocyst tissue; gonads oval, well separated from manubrium in middle portion of 8 broad radial canals.

Thirteen pairs of symmetrically arranged gonads have been identified, as have possible gill slits. However, some authors think that Yunnanozoon is closely related to the chordate Haikouella and that Yunnanozoon is probably a chordate rather than a hemichordate. A close relationship between Yunnanozoon and the taxon Vetulicolia has also been proposed.

The intermediate mesoderm connects the paraxial mesoderm with the lateral plate and differentiates into urogenital structures. In upper thoracic and cervical regions this forms the nephrotomes, and in caudally regions this forms the nephrogenic cord. It also helps to develop the excretory units of the urinary system and the gonads.

Once it has penetrated, a paralyzing saliva subdues the prey and the snail feeds at leisure, often beginning with the softest parts such as the gonads and gut. Tritons ingest smaller prey animals whole without troubling to paralyse them, and will spit out any poisonous spines, shells, or other unwanted parts later.

The hatched stage 2 juvenile, while migrating through and feeding on cells in the cortex, then completes 3 successive molts, and after the final molt, immature adult females and males emerge with gonads not yet fully developed. The complete life cycle takes one month from the egg to develop into an adult.

Orthonectida are found in the body spaces of various marine invertebrates including tissue spaces, gonads, genitorespiratory bursae. This pathogen causes host castration of different species. The best known of Orthonectida is the parasite of brittle stars. The multinucleate syncytial stage lives within tissues and spaces of the gonad but can spread into arms.

There is a marginal row of distinctive larger scales forming a bevelled edge. Sometimes the disc and ray areas are swollen with sunken inter-radial areas between. This may happen when the starfish has recently fed or when its gonads are enlarged prior to spawning. The general colour is yellow, orange or pink.

During their "female phase" they actually have functioning male and female tissues in their gonads and produce both types of gamete. When paired, they take turns fertilizing each other's eggs. Lysmata occur in the tropics and in warmer temperate waters. They usually live on rock and coral reefs, in shallow and deeper areas.

Unbowed, pp. 109–11. In 1971, she became the first Eastern African woman to receive a PhD, her doctorate in veterinary anatomy, from the University College of Nairobi, which became the University of Nairobi the following year. She completed her dissertation on the development and differentiation of gonads in bovines.Unbowed, p. 112.

Acropora secale is a zooxanthellate species of coral. This means that it has symbiotic dinoflagellates living within its tissues. These, combined with pigments in the tissue, are responsible for the colour of the colony. Acropora secale is a hermaphrodite and both female gonads and testes are present and mature once a year.

Astrologically speaking, Mars is associated with aggression, confrontation, energy, strength, ambition and impulsiveness. Mars governs sports, competitions and physical activities in general. The 1st-century poet Manilius, described the planet as ardent and as the lesser malefic. In medicine, Mars presides over the genitals, the muscular system, the gonads and adrenal glands.

This leads to a four-chambered stomach which opens through four openings into a ring sinus which has sixteen branching pouches extending into the lappets. Eight gonads are present, arranged in four crescent-shaped pairs. This jellyfish has symbiotic zooxanthellae in its tissues which supply a major part of its energy requirements.

The fisher will then cut out its intestine and sometimes its respiratory system and gonads, as well, and release the still-living animal. The viscera are eaten raw and fresh, or bottled and sold in the community. Apparently, most cucumbers survive this treatment, at least in the short term.Eriksson, H., et al. (2007).

Umbrella 30–40 mm wide, thick, disk-like, with small apical projection; 8 clusters of gelatinous papillae above margin, mouth wide circular opening; 8 broad, band-like, radial canals; broad circular canal; gonads flattened, extending along almost entire length of radial canals; tentacles up to 640; 3-4 statocysts in each octant.

R. Tucker Abbott (1952) failed to find sperm in the gonads of male Tarebia granifera from Florida. Most Tarebia granifera are therefore clones of the female parent. Embryos develop in a brood pouch. This pouch is a compartmentalized structure lying immediately above the oesophagus and develops only after the snail has reached maturity.

The original male white lion from Timbavati in South Africa was also maneless. The hormone testosterone has been linked to mane growth; castrated lions often have little to no mane because the removal of the gonads inhibits testosterone production. Increased testosterone may be the cause of maned lionesses reported in northern Botswana.

They also contain the gonads. Other secondary polyps are siphonozooids, which can force water into and out of the colony to ventilate it. When the colony is disturbed, it can pump water out and retract into its bulbous base. At this time it emits bioluminescence, perhaps in order to startle a potential predator.

The gonads are located in the metacoel. There are two blood vessels running along the ventral and dorsal sides of the body with capillaries in the tentacles. These are made easily visible by the haemoglobin in the red blood cells. There is a single nerve fibre on the left side of the body.

The lineage of germ cells is called germ line. Germ cell specification begins during cleavage in many animals or in the epiblast during gastrulation in birds and mammals. After transport, involving passive movements and active migration, germ cells arrive at the developing gonads. In humans, sexual differentiation starts approximately 6 weeks after conception.

It was found that when female controls, gonadectomized (removal of gonads) females, hermaphrodites, and castrated males were injected prenatally with testosterone propionate, the mean number of mounts increased. This increase in male-typical reproductive behavior shows that prenatal androgens have a masculinizing effect. Moreover, the organizing effects of hormones can have permanent effects.

Male flower urchin (Toxopneustes roseus) releasing milt, November 1, 2011, Lalo Cove, Sea of Cortez Sea urchins are dioecious, having separate male and female sexes, although no distinguishing features are visible externally. In addition to their role in reproduction, the gonads are also nutrient storing organs, and are made up of two main type of cells: germ cells, and somatic cells called nutritive phagocytes. Regular sea urchins have five gonads, lying underneath the interambulacral regions of the test, while the irregular forms mostly have four, with the hindmost gonad being absent; heart urchins have three or two. Each gonad has a single duct rising from the upper pole to open at a gonopore lying in one of the genital plates surrounding the anus.

Marywadea is a genus of Ediacaran biota shaped like an oval with a central ridge. It is a bilaterian organism as evidenced by its symmetry, vaguely resembling a very primitive trilobite. The fossil has an asymmetrical first chamber of the quilt. It has transverse ridges away from the central axis that may be gonads.

In an embryo, the conversion of the gonads into testicles in males-to-be and into ovaries in females-to-be is the function of Leydig cells. In testicular agenesis, this process fails. Penile agenesis can be caused by testicular agenesis. Testes are the sole producer of 5-alpha dihydrotestosterone (5aDHT) in the male body.

Latex rubber elastrator rings and pliers In animal husbandry, rubber bands are used for docking and castration of livestock. The procedure involves banding the body part with a tight latex (rubber) band to restrict blood flow. As the blood flow diminishes, the cells within the gonads die and dehydrate. The part eventually drops off.

Both sexes showed more or less similar growth rate. The seasonal growth curve was chiefly influenced by feeding intensity in fishes of 1st year class, while in adults it was affected by feeding intensity as well as by maturation of the gonads. The body is elongate. Its dorsal profile is more convex than the ventral.

In males, the gametogenesis stage is called spermatogenesis, and refers to when there is a build up of sperm in the gonads. During spermatogenesis, folds in the gonadal wall are present that the lumen. Additionally, Spherical spermatocytes accumulate at the periphery. The accumulation of spermatocytes causes a decrease in the thickness of the connective tissue.

As there is a trade-off between reproductive investment and growth, the sneakers have much larger gonads related to body size than the territorial males. Their sperm quality is also shown to be better for the sneaker, as it is longer-lived. About 5 – 20% of the males in a population tend to be sneakers.

In humans, biological sex is determined by five factors present at birth: the presence or absence of a Y chromosome, the type of gonads, the sex hormones, the internal genitalia (such as the uterus in females), and the external genitalia.Knox, David; Schacht, Caroline. Choices in Relationships: An Introduction to Marriage and the Family. 11 ed.

Sea otters have been observed to rip off an arm of this sea star to eat the gonads inside. Gulls will attempt to consume a pink sea star exposed at low tide. They are also preyed upon by other sea stars, such as the morning sun star. Sheep crabs also eat these sea stars.

Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans.William F Ganong MD, 'Review of Medical Physiology', 22nd Ed, McGraw Hill, 2005, p. 362. DHEA is produced in the adrenal glands,The Merck Index, 13th Edition, 7798 the gonads, and the brain.

GnRH is found in organs outside of the hypothalamus and pituitary, and its role in other life processes is poorly understood. For instance, there is likely to be a role for GnRH1 in the placenta and in the gonads. GnRH and GnRH receptors are also found in cancers of the breast, ovary, prostate, and endometrium.

The polyps are hermaphrodite, possessing four sets of male and four sets of female gonads. Pocillopora can reproduce asexually via fragmentation.Green, E. and Shirley, F. (1999) The Global Trade in Corals. World Conservation Press, Cambridge, UK. They also reproduce sexually and the larvae develop inside the polyps rather than free floating in the water.

Intermediate mesoderm or intermediate mesenchyme is a narrow section of the mesoderm (one of the three primary germ layers) located between the paraxial mesoderm and the lateral plate of the developing embryo. The intermediate mesoderm develops into vital parts of the urogenital system (kidneys, gonads and respective tracts), as well as the reproductive system.

The primary tentacles are solid and usually held above the bell in the direction of locomotion when the animal is foraging. The tentacles bear cnidocytes on the aboral side. The gonads have not yet been observed, perhaps because they were not ripe at the time of the year when observations were made (June/July).

The tiger trout (Salmo trutta fario × Salvelinus fontinalis) is a genetic cross between a river trout and a brook trout. It gets its name from its characteristic golden yellow markings. Tiger trout are sterile, despite male and female may be distinguished by their external markings. The female tiger trout does not develop any gonads.

Intersex people are born with sex characteristics, such as genitals, gonads and chromosome patterns, "that do not fit typical binary notions of male or female bodies". This list consists of notable researchers on intersex issues, including human rights, legal recognition and medical issues. The individual listings note the subject's main occupation or source of notability.

HzNV-2 is able to change the molecular processes of their hosts. Though infected larvae appear to be very normal, when they emerge from their cocoons as adults, they may be without gonads. This condition is described as being "agonadal". The reproductive systems of both sexes are malformed as appear as a large "Y" shape.

Certain ceratioids rely on parabiotic reproduction. Free-living males and unparasitized females in these species never have fully developed gonads. Thus, males never mature without attaching to a female, and die if they cannot find one. At birth, male ceratioids are already equipped with extremely well-developed olfactory organs that detect scents in the water.

The gonads release eggs and sperm which rise to the surface where the eggs are fertilised. They have large yolks and the developing larvae rely on this and do not feed. They can swim and they drift with the currents as part of the zooplankton. They later sink to the seabed and undergo metamorphosis into juvenile starfish.

The ciliate protozoan Orchitophrya stellarum is sometimes a parasite of the common starfish. It normally lives on the outer surface of the starfish feeding on sloughed-off epidermal tissue. It appears to become parasitic when the host starfish has ripe gonads and is a male. It enters the starfish through the gonopores, the orifices where gametes are released.

In most species, the gonads are located in the pinnules but in a few, they are located in the arms. Not all the pinnules are reproductive, just those closest to the crown. The gametes are produced in genital canals enclosed in genital coeloms. The pinnules eventually rupture to release the sperm and eggs into the surrounding sea water.

In this family of snails, the male phase ends in December, followed by an egg maturation phase, and ends with oviposition, the act of laying eggs during May of the following year. Phylogenetic evidence for this is present based on the overall condition of the gonads especially in the degree of development of the genital ducts.

Most molluscs' circulatory systems are mainly open. Although molluscs are coelomates, their coeloms are reduced to fairly small spaces enclosing the heart and gonads. The main body cavity is a hemocoel through which blood and coelomic fluid circulate and which encloses most of the other internal organs. These hemocoelic spaces act as an efficient hydrostatic skeleton.

His conclusion was that these substances were produced by the adrenal cortex as well as by the gonads. This conclusion was supported by findings made jointly with A.C. Crooke, working at the London Hospital, that patients with Cushing's syndrome, caused by a tumour of the adrenals, had very high levels of androgenic substances in the urine.

Gonadotropin deficiency due to pituitary disease results in hypogonadism, which can lead to infertility. Treatment includes administered gonadotropins, which, therefore, work as fertility medication. Such can either be produced by extraction and purification from urine or be produced by recombinant DNA. Failure or loss of the gonads usually results in elevated levels of LH and FSH in the blood.

The gonadotropins act on the gonads, controlling gamete and sex hormone production. Gonadotropin is sometimes abbreviated Gn. The alternative spelling gonadotrophin which inaccurately implies a nourishing mechanism is still sporadically used. There are various preparations of gonadotropins for therapeutic use, mainly as fertility medication. There are also fad diet or quack preparations, which are illegal in various countries.

The five marine species of nematomorph are contained in Nectonematoida.Pechenik, 'Biology of the Invertebrates, 2010, pg 457. Adults are planktonic and the larvae parasitise decapod crustaceans, especially crabs. They are characterized by a double row of natotory setae along each side of the body, dorsal and ventral longitudinal epidermal cords, a spacious and fluid-filled blastocoelom and singular gonads.

Two species are sold as fish bait. In most species the sexes are separate, but all the freshwater species are hermaphroditic. Nemerteans often have numerous temporary gonads (ovaries or testes), and build temporary gonoducts (ducts from which the ova or sperm are emitted), one per gonad, when the ova and sperm are ready. The eggs are generally fertilised externally.

Foetal gonads enlarge during the second half of pregnancy. African bush elephants mate during the rainy season. Bulls in musth cover long distances in search for females and associate with large family units. They listen for the females loud, very low frequency calls and attract females by calling and by leaving trails of strong-smelling urine.

Like other tunicates, Ciona savignyi is a hermaphrodite. The male and female gonads do not ripen simultaneously so it does not normally self-fertilise. Gametes are released into the sea and after fertilisation, the eggs hatch into tadpole- like larvae. After a few days of development these attach themselves to a firm surface and undergo metamorphosis into juvenile tunicates.

Mesenteries are usually in pairs. The free edge of incomplete mesenteries are thickened to form glandular, ciliated bands called mesenterial filaments. The lower ends of the mesenterial filaments are elongated into acontia which are armed with cnidocytes (stinging cells) and can protrude through the body wall or mouth. The gonads are situated on the mesenteries alongside the mesenterial filaments.

A gonadal tissue neoplasm is a tumor having any histology characteristic of cells or tissues giving rise to the gonads. These tissues arise from the sex cord and stromal cells. The tumor may be derived from these tissues, or produce them. Although the tumor is composed of gonadal tissue, it is not necessarily located in an ovary or testicle.

Ostracod swimming motions (in real time) The body consists of a head and thorax, separated by a slight constriction. Unlike many other crustaceans, the body is not clearly divided into segments. The abdomen is regressed or absent, whereas the adult gonads are relatively large. The head is the largest part of the body, and bears most of the appendages.

The main feature of CAH in newborn female is the abnormal development of the external genitalia, which has varying degrees of virilization. According to clinical practice guidelines, for newborns found to have bilateral inaccessible gonads, CAH evaluation should be considered. If virilizing CAH cannot be identified and treated, both boys and girls may undergo rapid postnatal growth and virilization.

The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation. If none develops, then the animal becomes sterile.

Members of the order Rhizocephala such as S. carcini alter male hosts' hormonal balance, to encourage nurturing behavior similar to that seen in females. The parasite usually spends its entire life within the host; however, if it is removed from the host in a laboratory setting, male hosts will subsequently grow partial or complete female gonads.

All species are hermaphrodites and reproduce sexually, having both female and male gonads. Although no detailed figures are available, it is assumed that self- fertilization is the exception among nudans. The fertilized eggs hatch into miniature versions of the adult animal, rather than distinct larval forms. They lack tentacles and are otherwise similar to the Cydippea larvae.

CCL27 is expressed in numerous tissues, including gonads, thymus, placenta and skin. It elicits its chemotactic effects by binding to the chemokine receptor CCR10. The gene for CCL27 is located on human chromosome 9. Studies of a similar murine protein indicate that these protein-receptor interactions have a pivotal role in T cell-mediated skin inflammation.

Organs formed inside a coelom can freely move, grow, and develop independently of the body wall while fluid cushions protects them from shocks. The mesoderm has several components which develop into tissues: intermediate mesoderm, paraxial mesoderm, lateral plate mesoderm, and chorda-mesoderm. The chorda-mesoderm develops into the notochord. The intermediate mesoderm develops into kidneys and gonads.

Vallentinia gabriellae can grow to about 12 millimetres (0.5 in) in diameter but is more usually 6 to 8 millimetres across. The dome-shaped bell of the medusa is two thirds as high as it is wide. It is transparent and gelatinous and has 4 radial canals. Alongside their lower ends lie 4 folded, sac-like gonads.

The sporocysts rapidly multiply by asexual reproduction, each forming numerous daughter sporocysts. The daughter sporocysts move to the liver and gonads of the snail, where they undergo further growth. Within 2–4 weeks, they undergo metamorphosis and give rise to fork-tailed cercariae. Stimulated by light, hundreds of cercariae penetrate out of the snail into water.

Diapause allows O. bicornis to survive harsh winter conditions. Typically in adult insects, reproductive diapause is characterized by a late development of gonads and a buildup of energy reserves. However, diapause in O. bicornis is somewhat different. The ovaries of females are not completely inactive during overwintering, as the development of oocytes continues in the vitellarium region.

Genitalia and gonads vanish, and a second two-chambered heart forms in the groin at the fusion of the femoral veins. The arms lengthen. Fingernails turn into retractable claws. Teeth fall out and the lips and gums fuse, the mouth forming a horny beak (flat in protectors transformed from humans, non-flat in protectors transformed from Pak).

Testosterone, an androgen secreted by the gonads, causes irreversible changes in the cartilages and musculature of the larynx when present in high enough concentrations, such as during a cisgender boy's puberty: The thyroid prominence appears, the vocal folds lengthen and become rounded, and the epithelium thickens with the formation of three distinct layers in the lamina propria.

Its gonads also stretch into the arms, also common to asteroids. Both of these are hardly present in other orders of the class. The skeleton is similar to other ophiuroids, except the paired right and left vertebrae are not fused, albeit set in orderly fashion. Also absent are ventral arm plates and radial and oral shields.

Any particles too large to be ingested get incorporated into the tube structure. Reproduction takes place in the spring, and fertilization is external. The gonads are on the dorsal side of the abdomen and the gametes mature in the coelomic spaces. They are then passed forward by cilia along the faecal groove and are released into the water column.

They capture prey by drawing it into their large mouth by creating a powerful suction as the mouth opensand then swallowing it whole. The belted sandfish is a synchronous hermaphrodite, i.e. the fish have both male and female functional gonads and self fertilisation is, at least, theoretically possible. This fish demonstrates three different types of mating strategy.

Haematoxylin & Eosin staining of sections of human gonads at E16.5. GO/G1 quiescent oogonia are indicated by arrowheads. Normal oogonia in human ovaries are spherical or ovoid in shape and are found amongst neighboring somatic cells and oocytes at different phases of development. Oogonia can be distinguished from neighboring somatic cells, under an electron microscope, by observing their nuclei.

Diagram of Charles Darwin's pangenesis theory. Every part of the body emits tiny particles, gemmules, which migrate to the gonads and contribute to the fertilised egg and so to the next generation. The theory implied that changes to the body during an organism's life would be inherited, as proposed in Lamarckism, and that inheritance would be blending.

Seisonidae is a family of rotifers, found on the gills of Nebalia, a marine crustacean. Peculiar among rotifers, males and females are both present and equal in size. Males and females are similar with paired gonads. It is considered to have diverged from the other rotifers early on, and in one treatment is placed in a separate class Seisonoidea.

In animals, egg cells are also known as ova (singular ovum, from the Latin word meaning 'egg'). The term ovule in animals is used for the young ovum of an animal. In vertebrates, ova are produced by female gonads (sex glands) called ovaries. A number of ova are present at birth in mammals and mature via oogenesis.

The copulatory organ is absent in this species. The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation.

Monterey: Brooks Cole In humans, typical male or female sexual differentiation includes the presence or absence of a Y chromosome, the type of gonads (ovary or testes), the balance of sex hormones (testosterone and estrogen), the internal reproductive anatomy (e.g. uterus or prostate gland), and the external genitalia (e.g. penis or vulva).Knox, David; Schacht, Caroline.

Like almost all other bivalves, this species is a filter feeder. Water is drawn into the shell from above and passed over the ctenidium before being expelled into the open water at the exposed part of the shell. It is a hermaphrodite, the gonads producing both sperm and ova. The larvae are planktonic and drift with the currents.

The gonads of the C. annaskala have been described as folded into a ribbon in a genital band. The stretched out gonadial ribbon reached 300 mm. Epithelial cavities will make chambers which fuse to become a genital sinus. Spermatozoa are formed in follicles which stay connected to the genital sinus, providing a conduit for the spermatozoa to travel.

Male and female broods are distinguished by examining the gonads and based on the external morphological features: the upper lip of the male is more pronounced and the dorsal ventral fins are more pointed at the posterior end than those of the female. Like other Anabantoids, this species is a bubble nest builder and the fertilization is external.

Aporometra wilsoni is found living in close association with brown algae such as Cystophora and Sargassum. Crinoids are dioecious, with separate male and female individuals. They do not have true gonads, instead producing gametes from genital canals found inside some of the pinnules. In most species, the sperm and eggs are released into the water column when the pinnules rupture.

The major endocrine glands of the body. Pituitary hormones control the function of the adrenal gland, thyroid gland and the gonads (testes and ovaries). Deficiency of all anterior pituitary hormones is more common than individual hormone deficiency. Deficiency of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), together referred to as the gonadotropins, leads to different symptoms in men and women.

The Cotton-Spinner Adult black sea cucumbers are normally either male or female. The gonads take a long time to mature and gametes are released synchronously into the water column in early spring, probably as a result of a rise in water temperatures. The larvae become part of the zooplankton. After several moults they grow tentacles and settle out onto the sea floor.

The adults have gonads in the gastroderm, and these release ova and sperm into the water in the breeding season. This phenomenon of succession of differently organized generations (one asexually reproducing, sessile polyp, followed by a free-swimming medusa or a sessile polyp that reproduces sexually)Vernon A. Harris (1990). "Hydroids". Sessile animals of the sea shore. Springer. p. 223, .

A micrograph view of dysgerminoma, showing actively dividing lobulated nuclei.Dysgerminomas are comparable to testicular seminomas and account for approximately 32- 37% of all OGCTs. They are particularly prominent in individuals with dysgenic gonads of 46, XY pure gonadal dysgenesis patients. Based on gross examinations, dysgerminomas are characterized by having a ‘solid, lobulated, tan, flesh-like gross appearance with a smooth surface'.

Ptychostomella sp., Macrodasyida Gastrotrich reproduction and reproductive behaviour has been little studied. That of macrodasiyds probably most represents that of the ancestral lineage and these more primitive gastrotrichs are simultaneous hermaphrodites, possessing both male and female sex organs. There is generally a single pair of gonads, the anterior portion of which contains sperm-producing cells and the posterior portion producing ova.

There are no difficulties assigning appropriate sex for most infants with CAH. Genetic males have normal male genitalia and gonads and simply need hormone replacement. Most virilized females are assigned and raised as girls even if their genitalia are ambiguous or look more male than female. They have normal ovaries and uterus and potential fertility with hormone replacement and surgery.

Arachnids may have one or two gonads, which are located in the abdomen. The genital opening is usually located on the underside of the second abdominal segment. In most species, the male transfers sperm to the female in a package, or spermatophore. Complex courtship rituals have evolved in many arachnids to ensure the safe delivery of the sperm to the female.

Sex change is also not well described that the transitional gonads has different definitions. Their growth rate can differ due to food supply, water temperature and habitat as other fish do. Sex can also influence the growth rate. Male grow faster and larger than female. P. colias have the potential to grow up to 50 cm in length and weight 4 kg.

Weismann's germ plasm theory. The hereditary material, the germ plasm, is transmitted only by the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm. Weismann's work on the demarcation between germ-line and soma can scarcely be appreciated without considering the work of (mostly) German biologists during the second half of the 19th century.

They have a tendency to lay a large number of eggs. A likely explanation for such actions are to produce as many surviving offspring as possible, as many most likely die early in life. In females, the gonads enlarge when it is time to shed her eggs. However, after they are shed, these eggs will not hatch if the water is below .

BPS has shown to both disrupt signalling and damage DNA. Androgenic and antiandrogenic activity have also been confirmed by BPS disrupting function of the androgen receptors. Studies on zebrafish have shown decreased egg quality, reduced sperm count, an increased frequency of embryo abnormalities, as well as changes in the mass of gonads; suggesting that BPS is a reproductive toxin for both sexes.

Arachnids may have one or two gonads, which are located in the abdomen. The genital opening is usually located on the underside of the second abdominal segment. In most species, the male transfers sperm to the female in a package, or spermatophore. Complex courtship rituals have evolved in many arachnids to ensure the safe delivery of the sperm to the female.

These fish have both ovaries and testes and can produce both eggs and sperm at the same time. Others are sequential hermaphrodites. These fishes start life as one sex and undergo a genetically programmed sex change at some point during development. Their gonads have both ovarian and testicular tissues, with one type of tissue predominant while the fish belongs to the corresponding gender.

Turbo cornutus spawns from August to September, although the gonads begin to mature from May. Larvae have a very short period as free-floating plankton at approximately five days, after which they settle and begin to develop a shell. The planktonic and early shell- growing stages are highly dangerous times for young horned turban shells, and they are eaten in large numbers.

It is a small, pelagic species that lives in tropical and subtropical waters of the western and eastern Atlantic Ocean, the Pacific Ocean, the Mediterranean, and occasionally, the Black Sea. The gonads start to develop in April and are fully mature one month later. Plankton in spawning regions are full of eggs and larvae from the end of June into September.

The jellyfish is almost entirely translucent, usually about in diameter, and can be recognized by its four horseshoe-shaped gonads, easily seen through the top of the bell. It feeds by collecting medusae, plankton, and mollusks with its tentacles, and bringing them into its body for digestion. It is capable of only limited motion, and drifts with the current, even when swimming.

Members of the genus Olindias have a dome-shaped bell, four radial canals and many centripetal canals. The gonads are beside the radial canals and have characteristic papilliform processes. There are a few primary tentacles growing part way down the bell with adhesive suckers and cnidocytes in bands. There are a pair of statocysts adjoining the base of each primary tentacle.

Clinical manifestation include primary amenorrhea, hypergonadotropic hypogonadism, streak gonads, infertility and failure to develop secondary sex characteristics. Turner Syndrome is not diagnosed until a delayed onset of puberty with Müllerian structures found to be in infantile stage. Physical phenotypic characteristics include short stature, dysmorphic features and lymphedema at birth. Comorbidities include heart defects, vision and hearing problems, diabetes and low thyroid hormone production.

Pufferfish are slow moving fish. They defend themselves by swallowing and filling the stomach with water, thus inflating themselves to intimidating proportions. When the fish is inflated, the spines project; the fish also produces and builds up toxic substances in its skin, gonads and liver, including tetrodotoxin and saxitoxin. During the day, this fish is sometimes found lying on the muddy seabed.

The next steps of the evaluation usually include checking a karyotype and imaging of the pelvis. The karyotype reveals XX chromosomes and the imaging demonstrates the presence of a uterus but no ovaries (the streak gonads are not usually seen by most imaging). At this point it is usually possible for a physician to make a diagnosis of XX gonadal dysgenesis.

The developmental stages of alt=Illustration of two life stages of seven jelly species Most species appear to be gonochorists, with separate male and female individuals. The gonads are located in the stomach lining, and the mature gametes are expelled through the mouth. After fertilization, some species brood their young in pouches on the oral arms, but they are more commonly planktonic.

The sensory organs include a statocyst – which presumably helps them orient to gravity –, and, in some cases, ancestral pigment-spot ocelli capable of detecting light. Acoelomorphs are simultaneous hermaphrodites, but have no gonads and no ducts associated with the female reproductive system. Instead, gametes are produced from the mesenchymal cells that fill the body between the epidermis and the digestive vacuole.

There are two sexes that look alike. A pair of gonads are located in the mid-region of the trunk, and open to pores in the final segment. In most species, the sperm duct includes two or three spiny structures that presumably aid in copulation, although the details are unknown. Individual spermatozoa can reach a quarter of the total body length.

After the gonads and their ducts have finished maturing, the female reproductive organs begin to mature. The oviduct develops a vagina and enlarges into the uterus, where fertilization and embryonic development occur. Egg formation is a result of copulation. A proglottid can copulate with itself, with other proglottids in the same worm, or with proglottids in other worms, and hypodermic fertilization sometimes occurs.

Umbrella 15–17 mm wide, 9–10 mm high, almost hemispherical, with very thick, hemispherical apex; about 96 marginal tentacles in adults; about 12 marginal tentacles and 3 statocysts in each octant; thickening of marginal cnidocyst tissue less pronounced than in H. conica; gonads broadly oval, about 2/5 as long as radial canals, located slightly nearer manubrium than bell margin.

Here they are sorted by a pair of labial palps (mouth appendages), before being ingested. Rejected particles are formed into mucous- wrapped blobs. These are ejected from the mantle cavity at intervals along with the faeces by a rapid clapping of the valves. When the gonads are ripening, a raised level of microalgae in the diet has been found to increase gonadal development.

They have paired serial gonads arranged segmentally along the arm. The hyponeural groove is covered by soft integument, which forms a spacious epineural canal that is not closed over by ventral arm plates. The disk is covered by naked or granulated skin, or by imbricating scales. The Oegophiurida are extinct except for a recent species, Ophiocanops fugiens, which has several remarkable features.

Its reproductive cycle is divided into three distinct stages, the prereproductive, reproductive, and postreproductive. The prereproductive stages occurs from January to April and the postreproductive stage occurs from September to December. During these periods, the gonads are much smaller than the reproductive stage. Mating occurs in the summer from May to August, during which testes and ovaries grow significantly in size.

Steroidogenesis with enzymes and intermediates. The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids. They can pass through the cell membrane as they are fat-soluble, and then bind to steroid hormone receptors (which may be nuclear or cytosolic depending on the steroid hormone) to bring about changes within the cell.

The stomach is subdivided into four gastric pouches, with the four gonads situated on the oral walls of the pouches. Some semaeostomids are suspension feeders, but others supplement this with prey such as small fish, crustaceans, worms and other jellyfish. The pulsating action of the bell is linked by a nerve ring to the sensory inputs received by the rhopalia.

Cuninidae is a family of hydrozoans in the order Narcomedusae. They have dome- shaped bells and tentacles set above the undulating margin of the bell. Their gastric pouches contain the gonads situated in line with the tentacles, the number of pouches being the same as the number of tentacles. The pouches do not extend below the points of origin of the primary tentacles.

17α-Hydroxypregnenolone is a pregnane (C21) steroid that is obtained by hydroxylation of pregnenolone at the C17α position. This step is performed by the mitochondrial cytochrome P450 enzyme 17α-hydroxylase (CYP17A1) that is present in the adrenal and gonads. Peak levels are reached in humans at the end of puberty and then decline. High levels are also achieved during pregnancy.

As with other Dipterans, T. dalmanni flies undergo a larval phase before transitioning into adults. There is little information available on the systematics and behavior of the larval stage in T. dalmanni. As holometabolous insects, the flies have dividing cells restricted to the gut and gonads. Due to this, the adult size is fixed by the nutrition received in the larval phase.

Most anillins can be sequestered to the nucleus during interphase, but there are exceptions – Drosophila anilins in the early embryo, C. elegans ANI-1 in early embryos, C. elegans ANI-2 in oogenic gonads, and Mid2p in fission yeast. These anillins that are not sequestered during interphase suggest that anillins may also regulate cytoskeletal dynamics outside the contractile ring during cytokinesis.

Oxyurichthys petersii lives on soft bottoms and is a carnivorous species which has been found to have sand and mud in their intestinal tract which suggest they feed on the bottom. Animals found in samples include formaniferans, harpactoid copepods, tanaidaceans, amphipods, isopods, ostracods, molluscs and echinoderms. The gonads of fish sampled in August and November off Israel were well developed.

Halfway up the inside of the bell is the velarium, a horizontal ring of tissue partially blocking the aperture. The manubrium is a central column hanging down inside the bell with the mouth at its tip. The rounded stomach has four pouches connecting to radial sinuses along the edges of the bell. The gonads are on either side of the radial canals.

Aplousobranchia is a suborder of sea squirts in the class Ascidiacea. They are colonial animals, and are distinguished from other sea squirts by the presence of relatively simple pharyngeal baskets. This provides the etymology of their name: in ancient greek, () means "simple". The posterior part of the abdomen contains the heart and gonads, and is typically larger than in other sea squirts.

Sexual reproduction can be seen as a strategy to survive during times of low nutrients and other unfavorable conditions. H. viridissima has three sexes: female, male, and hermaphrodite. Simultaneous hermaphrodites are dominant during the growing season. It is thought that female gonads need a longer period of inductive conditions for production, that means that there is a scarcity of females in most populations.

Bill also has a small penis and oddly shaped gonads which his maker gave him in order to encourage humility but which instead produced only more humiliation for Bill, perhaps explaining his gruesome hobby of collecting the testicles of men who have somehow been mysteriously deprived of them. Bill was at some point castrated himself, and is now a eunuch.

Pearlfishes are unusual in that the adults of most species live inside various types of invertebrates. They typically live inside clams, starfish, or sea squirts, and are simply commensal, not harming their hosts. However, some species are known to be parasitic on sea cucumbers, eating their gonads and living in their anal pores. Pearlfish usually live alone, or in pairs.

Smooth toadfish grow steadily larger as they grow older, with one long individual calculated to be 13 years old from examination of its otoliths. Their gonads develop when they reach a total length of about . The smooth toadfish can be distinguished from the otherwise similar common toadfish by its lack of spines and its larger- and bolder-patterned markings on its upperparts.

Mesothelium lines coeloms. Mesoderm forms the muscles in a process known as myogenesis, septa (cross-wise partitions) and mesenteries (length-wise partitions); and forms part of the gonads (the rest being the gametes). Myogenesis is specifically a function of mesenchyme. The mesoderm differentiates from the rest of the embryo through intercellular signaling, after which the mesoderm is polarized by an organizing center.

However, music critic Dave Thompson has said, regarding Splodgenessabounds' 1981 album: Other punk pathetique bands included Television Personalities, Half Man Half Biscuit, the Shapes, the Gonads, the Adicts, Notsensibles, the Postmen, Desert Island Joe, the Hoopers, Pierre the Poet (Garry Butterfield), Paul Devine, Lord Waistrel & the Cosh Boys, Stephen Louis Knoche Jr & His Raging Cronies, the Alaska Cowboys, Percy Throwers Man Eating Plans, SexyCows, and the Orgasm Guerrillas. Later, the mantle was inherited by the Bus Station Loonies, Monkish and Macc Lads, who performed comic punk singalongs in very much the same style. Toy Dolls, Peter and the Test Tube Babies, the Gonads, and Splodgenessabounds continue to tour and record. In Germany, the similar Fun-Punk genre emerged in the mid-1980s as a response to hardcore punk, which at that time was marked by political correctness and negative imagery.

Paragonimus is a genus of flukes (trematodes). Some tens of species have been described, but they are difficult to distinguish, so it is not clear how many of the named species may be synonyms. The name Paragonimus is derived from the combination of two Greek words, “para” (on the side of) and “gonimos” (gonads or genitalia). Several of the species are known as lung flukes.

Like all hexavalent uranium compounds, UO3 is hazardous by inhalation, ingestion, and through skin contact. It is a poisonous, slightly radioactive substance, which may cause shortness of breath, coughing, acute arterial lesions, and changes in the chromosomes of white blood cells and gonads leading to congenital malformations if inhaled. abstract However, once ingested, uranium is mainly toxic for the kidneys and may severely affect their function.

Within Holothuroidea, C. robustus belongs to a clade called Neoholothuriida, a highly diverse group identified by having two gonads. Neoholothuriida contains the orders Dendrochirotida, Synallactictida, Molpadida, and Persiculida. Therefore, C. robustus, as a member of the Dendrochirotida order, is most closely related to sea cucumbers within Synallactitida, Molpadida, and Persiculida. C. robustus is more distantly related to the Holothuriida, Elasipodida, and Apodida orders of sea cucumbers.

The genetic makeup of sex is a theme that is brought up numerous times within this film. Alex's situation is very unique, in that she was born as an intersex individual. Intersex means that a person was born with some sort of sexual variation that is evident in either their chromosomes, gonads, hormones, genitals, etc. In this case, Alex has both the female and male sexual organs.

Members of this family have five arms which subdivide near the base giving them ten arms in total. The arms can reach in length, and there are thirty to sixty or more cirri. The gonads are located on the arms, and the embryos are brooded in cavities in the arms. The aboral surface (underside) of the disc has five deep radial pits arranged in a star- shape.

The simplest molluscan reproductive system relies on external fertilization, but with more complex variations. All produce eggs, from which may emerge trochophore larvae, more complex veliger larvae, or miniature adults. Two gonads sit next to the coelom, a small cavity that surrounds the heart, into which they shed ova or sperm. The nephridia extract the gametes from the coelom and emit them into the mantle cavity.

The release of gonadotropins, LH and FSH, act on the gonads for the development and maintenance of proper adult reproductive physiology. LH acts on Leydig cells in the male testes and theca cells in the female. FSH acts on Sertoli cells in the male and follicular cells in the female. Combined this causes the secretion of gonadal sex steroids and the initiation of folliculogenesis and spermatogenesis.

It causes the destruction of starfish ovary and eggs to cause castration (the male gonads are usually unaffected). The stages of the plasmodium develop into more plasmodia by simple fragmentation; at some point, they decide to go sexual. The syncytia are dioecious (either male or female), but young syncytia can fuse to produce both male and female. The males are ciliated and smaller than the females.

Adults have cylindrical gonads, opening into the cloaca. The larvae have rings of cuticular hooks and terminal stylets that are believed to be used to enter the hosts. Once inside the host, the larvae live inside the haemocoel and absorb nutrients directly through their skin. Development into the adult form takes weeks or months, and the larva moults several times as it grows in size.

A 7.4 x 5.5-cm seminoma in a radical orchiectomy specimen from a 27-year-old man Seminoma is the second-most common testicular cancer; the most common is mixed, which may contain seminoma. Abnormal gonads (due to gonadal dysgenesis and androgen insensitivity syndrome) have a high risk of developing a dysgerminoma.Sadler, T.W. 2006. Langman's Medical Embryology, 10th Edition, Chapter 15, pp. 251-252.

Males go through numerous morphological changes at maturation including, an increase in body depth, hump height, and snout length. Snout size also increases in females, but hump height and adipose fin length do not increase. This could mean that longer snout sizes are sexually selected, but hump height and adipose fin length are not. Females develop large gonads that are about 25% of the body mass.

Where the gonads fail to metamorphose into testes, there is no 5aDHT. Therefore, the masculising process that builds the genital tubercle, the precursor to the penis, is stillborn. When this happens, the child is born with both penile and testicular agenesis and is known by the slang term "nullo". This combination of both conditions is estimated to occur in between 20-30 million male births.

Nepanthia belcheri is a hermaphrodite and can reproduce both sexually and asexually. The gonads generally produce oocytes, but in some, no spermatogenic material is present, so they function as ovaries, while others produce sperm and function as testes. Sexual reproduction takes place in October and November. The eggs have large yolk sacs so the larvae are probably lechithotrophic, living on the nutrients already present in the eggs.

The lining of the tube and its secretions sustain the egg and the sperm, encouraging fertilization and nourishing the ovum until it reaches the uterus. If the ovum divides after fertilization, identical twins are produced. If separate eggs are fertilized by different sperm, the mother gives birth to non-identical or fraternal twins. The ovaries (female gonads), develop from the same embryonic tissue as the testicles.

In reproductively mature males, the head becomes elongated and prominent external teeth develop on the upper and lower jaws. Males with teeth tend to have larger gonads than those without. The coloration is a uniform pale white with a pinkish hue caused by subdermal capillaries, especially over anal fin pterygiophores (fin support bones). The operculum is pink due to the presence of the gills underneath.

Giant sea stars have small eggs, and their sperm contain spherical heads. Once their larvae are born, they are bilaterally symmetrical. By the time they mature and reach adulthood they are centered on a set point with radial symmetry to their bodies. The gonads of the giant sea star grow in a winters time just in time for spawning season between the months of March and April.

Diodora aspera, underside When the tide comes in, this keyhole limpet crawls around, scraping bryozoans and algae off the rock surface with its radula. Certain species of sponges are also consumed. The sexes are separate and individuals with ripe gonads occur throughout the year. The eggs and sperm are shed into the sea where fertilisation takes place, and the larvae settle on the sea bed.

Csiromedusa medeopolis is a species of hydrozoan described in 2010. It was discovered in the estuarine waters of the River Derwent near to the Commonwealth Scientific and Industrial Research Organisation's Marine and Atmospheric Research branch in Hobart, Tasmania, Australia. C. medeopolis has been described as presenting a new family and genus as well as species. Its binomial name is derived from "CSIRO jellyfish" and "city of gonads".

It is often used to indicate sites occupied by octopuses as it waits at the entrance scavenging the octopus's discarded parts of shellfish. The spawning season runs from late spring to early summer with the eggs being laid under stones near the shore. It is a synchronous hermaphrodite, i.e. each individual has both male and female gonads and may be capable of self-fertilisation.

The internal genitalia are all the accessory glands and ducts that connect the gonads to the outside environment. The external genitalia consist of all the external reproductive structures. The sex of an early embryo cannot be determined because the reproductive structures do not differentiate until the seventh week. Prior to this, the child is considered bipotential because it cannot be identified as male or female.

Virilization can occur in childhood in both males and females due to excessive amounts of androgens. Typical effects of virilization in children are pubic hair, accelerated growth and bone maturation, increased muscle strength, acne, and adult body odor. In males, virilization may signal precocious puberty, while congenital adrenal hyperplasia and androgen producing tumors (usually) of the gonads or adrenals are occasional causes in both sexes.

M. marginata has a small medusa with a bell diameter of up to . It is hemispherical in shape and the gonads hang from the four distinctive radial canals. The marginal ring canal has 50 short centripetal canals branching from it with a dense marginal fringe of about 600 short trailing tentacles. This hydrozoan is opaque white with a slightly reddish tinge near the bell margin.

Stages of the trematode life-cycle Adult worms are characterized by a flesh-colored body containing an egg-filled uterus that appears black by reflected light. The worms contain a cuticula with a subterminal oral sucker. They also contain a muscular pharynx, ventral sucker, and ceca. The gonads of the worm are arranged in a triangle, containing an ovary with an anterior and posterior testis.

The puffer fish is known for carrying lethal amounts of tetrodotoxin. Tetrodotoxin (TTX) is a poison produced by organisms belonging to the Tetraodontiformes order, which includes the puffer fish, ocean sunfish, and porcupine fish. Within the puffer fish, TTX is found in the liver, gonads, intestines, and skin.Ahasan 2004 TTX can be fatal if consumed, and has become a common form of poisoning in many countries.

At the base of these tentacles there are single ocelli. The stomach and marginal bulbs are pink or yellowish-brown while the ocelli are black or dark red. As the medusa grows, the oral tentacles branch but the general form of the medusa remains much the same. The gonads develop on the margins and may extend onto the underside of the umbrella beside the radial canals.

Blending would therefore directly oppose natural selection. In addition, Darwin and others considered Lamarckian inheritance of acquired characteristics entirely possible, and Darwin's 1868 theory of pangenesis, with contributions to the next generation (gemmules) flowing from all parts of the body, actually implied Lamarckism as well as blending. August Weismann's germ plasm theory. The hereditary material, the germ plasm, is confined to the gonads and the gametes.

Adult garden tiger moths exhibit clear warning signals, which they share with other tiger moths to advertise very real toxicity upon consumption. Adults can also spray an irritating compound when threatened. The chemical, produced in glands that are exposed when threatened, is a choline ester. A similar compound is found in the tissues of the adults, with the eggs, gonads, and abdomens having the highest concentrations.

In the latter case, raccoons apparently exploit low water levels in winter to access the muckets for food. Trematodes have sometimes been found to infest the gonads in adults, and such infestation has been significantly linked with mortality. Introduced species found in the Neosho mucket's range such as zebra mussels and Asian clams also threaten to outcompete this mussel for food and habitat space.

Cells in zona reticularis of the adrenal glands produce male sex hormones, or androgens, the most important of which is DHEA. In general, these hormones do not have an overall effect in the male body, and are converted to more potent androgens such as testosterone and DHT or to estrogens (female sex hormones) in the gonads, acting in this way as a metabolic intermediate.

The pituitary is sometimes referred to as the “master gland” because it has a crucial role in maintaining homeostasis and guiding the activity of other glands. The anterior lobe secretes growth hormone, prolactin and tropic hormones for the thyroid, gonads and adrenal glands. The posterior lobe stores and releases oxytocin and vasopressin, also known as antidiuretic hormone (ADH), which are produced in the hypothalamus.

While some oysters have two sexes (European oyster and Olympia oyster), their reproductive organs contain both eggs and sperm. Because of this, it is technically possible for an oyster to fertilize its own eggs. The gonads surround the digestive organs, and are made up of sex cells, branching tubules, and connective tissue. Once the female is fertilized, she discharges millions of eggs into the water.

The most serious parasitic crustaceans among fish in general are sea lice. However, L. branchialis is probably the most serious parasitic crustacean among cod. Infestation reduces the efficiency with which food can be utilised, delaying the development of the gonads. Up to 30% loss in weight can occur, with increases in mortality because of open lesions with loss of blood, and possibly occlusion of vessels or aorta.

Hydrozoans with dome-shaped bells and tentacles set above the undulating margin of the bell. There are gastric pouches containing the gonads situated between the tentacles, the number of pouches being greater than the number of tentacles. The pouches extend below the points of origin of the primary tentacles. Some genera have a peripheral canal system and others do not, and some have secondary tentacles.

Sex specification of the germ cells requires the repression of pluripotency and relies on the communication between the somatic cells of the gonads and germ cells Reitzel et al., 2015. The mechanisms for male and female differentiation are markedly different, since a population of sperm producing spermatogonia are retained throughout development and into adult life Reitzel et al., 2015, unlike oogonia which only produce oocyte in utero.

Sulfatases are found in lower and higher organisms. In higher organisms they are found in intracellular and extracellular spaces. Steroid sulfatase is distributed in a wide range of tissues throughout the body, enabling sulfated steroids synthesized in the adrenals and gonads to be desulfated following distribution through the circulation system. Many sulfatases are localized in the lysosome, an acidic digestive organelle found within the cell.

In Drosophila, anillin is necessary to organize myosin into rings in the cellularization front. Depletion of anillin in Drosophila and humans leads to changes in the spatial and temporal stability of myosin during cytokinesis. In C. elegans, ANI-1 organizes myosin into foci during cytokinesis and establishment of polarity, whereas, ANI-2 is a requirement for the maintenance of myosin-rich contractile lining of oogenic gonads.

These sea stars mainly follow an annual schedule for their reproductive cycle. Looking at Acrocnida brachiata, gonads begin forming in late Summer and Autumn, with the spawning taking place within a range of March to May. This places Acrocnida brachiata and other members of the genus in the category of "discreet annual breeder." Eggs created by Acrocnida brachiata lie in a range of 180 to 350 micrometers.

Female hosts infected through vertical transmission often do not develop several reproductive structures, including their ovaries, bursa copulatrix, accessory glands, and spermatheca. In addition, their common and lateral oviducts are malformed and enlarged. Viral replication in female gonads result in hypertrophy of the oviducts and proliferation of the cells making up these tissues. These enlargements appear to begin as early as their last instar as larvae.

In August Weismann's germ plasm theory, the hereditary material, the germ plasm, is confined to the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm. Whatever may happen to those cells does not affect the next generation. The Weismann barrier, proposed by August Weismann in 1892, distinguishes between the "immortal" germ cell lineages (the germ plasm) which produce gametes and the "disposable" somatic cells.

Germ plasm () is a biological concept developed in the 19th century by the German biologist August Weismann. It states that heritable information is transmitted only by germ cells in the gonads (ovaries and testes), not by somatic cells. The related idea that information cannot pass from somatic cells to the germ line, contrary to Lamarckism, is called the Weismann barrier. The theory to some extent anticipated the development of modern genetics.

Larger planktonic prey can be caught in a trap composed of the endopods of the thoracic appendages. Some benthic species, especially members of the subfamily Erythropinae, have been observed feeding on small particles which they collected by grooming the surfaces of their bodies and legs. Neomysis integer Individual mysids are either male or female, and fertilisation is external. The gonads are in the thorax and are tubular in shape.

By the end of puberty, there is little day-night difference in the amplitude and frequency of gonadotropin pulses. Some investigators have attributed the onset of puberty to a resonance of oscillators in the brain. By this mechanism, the gonadotropin pulses that occur primarily at night just before puberty represent beats. An array of "autoamplification processes" increases the production of all of the pubertal hormones of the hypothalamus, pituitary, and gonads.

Echiurans are dioecious, with separate male and female individuals. The gonads are associated with the peritoneal membrane lining the body cavity, into which they release the gametes. The sperm and eggs complete their maturation in the body cavity, before being stored in genital sacs, which are specialised metanephridia. At spawning time, the genital sacs contract and the gametes are squeezed into the water column through pores on the worm's ventral surface.

Larger species often break up when stimulated, and the fragments often grow into full individuals. Some species fragment routinely and even parts near the tail can grow full bodies. All reproduce sexually, and most species are gonochoric (the sexes are separate), but all the freshwater forms are hermaphroditic. Nemerteans often have numerous temporary gonads (ovaries or testes), forming a row down each side of the body in the mesenchyme.

These two hormones play an important role in communicating to the gonads. In females FSH and LH act primarily to activate the ovaries to produce estrogen and inhibin and to regulate the menstrual cycle and ovarian cycle. Estrogen forms a negative feedback loop by inhibiting the production of GnRH in the hypothalamus. Inhibin acts to inhibit activin, which is a peripherally produced hormone that positively stimulates GnRH-producing cells.

He worked for Shell as a messenger, and then the London Fire Brigade before attending North East London Polytechnic and the London College of Printing simultaneously. Pink Tent evolved into 1977 punk band the Gonads, who have also described themselves Oi!, punk pathetique and "Oi-Tone" because they play ska and street punk. Many of their songs are comical party tunes, but they have occasionally written more serious material.

However, if the testes are lost after 14 weeks, the baby will have partial male genitalia with the notable absence of gonads. Tests include observable lack of testes, low testosterone levels (typical female levels), elevated follicle stimulating hormone and luteinizing hormone levels, XY karyotype, ultrasound or magnetic resonance imaging showing absent gonadal tissue, low bone density, low anti-Müllerian hormone levels, and surgical exploration for evidence of male gonadal tissue.

The first specimens of Aporometra paedophora to be described were found clinging by their cirri to the pinnules and cirri of the crinoid, Ptilometra macronema. Crinoids are dioecious, with separate male and female individuals. They do not have true gonads, instead they produce gametes from genital canals found inside some of the pinnules. In most species, the sperm and eggs are released into the water column when the pinnules rupture.

The term "germinoma" most often refers to a tumor in the brain that has a histology identical to two other tumors, dysgerminoma in the ovary and seminoma in the testis. Since 1994, MeSH has defined germinoma as "a malignant neoplasm of the germinal tissue of the gonads, mediastinum, or pineal region" and within its scope included both dysgerminoma and seminoma. Collectively, these are the seminomatous or germinomatous tumors.

Madracis auretenra is a zooxanthellate coral, housing symbiotic single-celled protists within its tissues. These provide the products of photosynthesis to the coral and use some of the coral's waste products. To supplement this food supply, the coral polyps spread their tentacles to catch zooplankton, feeding mostly on the larvae of crustaceans, polychaete worms and arrow worms. M. auretenra is a hermaphrodite; individual colonies contain both male and female gonads.

There are five different locations where the horns can develop: at the back, middle or front of the head, and on the front or side of the thorax. Some males do not have horns, and therefore do not come into the fight, but have larger gonads. A similar dimorphism in males have been found in some other species (Ageopsis nigicollis, Podischnus agenor). This adaption reduces direct competition with horned males.

Penile agenesis is a birth anomaly in humans, occurring about once in 5–6 million male births, in which a male child is born without a penis. A partner condition is testicular agenesis or gonadal agenesis. This is when a male child is born without gonads and consequently develops no testes. Penile agenesis occurs often as a consequence of testicular agenesis, but the reverse is never the case.

However, the ultimate source of STX is often still uncertain. The dinoflagellate Pyrodinium bahamense is the source of STX found in Florida. Recent research shows the detection of STX in the skin, muscle, viscera, and gonads of “Indian River Lagoon” southern puffer fish, with the highest concentration (22,104 μg STX eq/100 g tissue) measured in the ovaries. Even after a year of captivity, the skin mucus remained highly toxic.

Hypergonadism is a condition where there is a hyperfunction of the gonads. It can manifest as precocious puberty, and is caused by abnormally high levels of testosterone or estrogen, crucial hormones for sexual development. In some cases, it may be caused by a tumor, which can be malignant, but is more commonly benign. Anabolic steroids may also be a major cause of high androgen and estrogen functional activity.

Connective tissue is reabsorbed in the gonadal wall of the follicle, the gonads are engulfed by phagocytes, therefore ending a single reproductive cycle in males. In females, the gametogenesis stage is called oogenesis, and is when the oocytes are young and in the process of developing.Oogonia are attached to the germinal epithelium in the lumen. The oocytes are arranged in a single layer, and have a defined nucleus and peripheral nucleoli.

Kisspeptin, neurokinin B, and dynorphin (KNDy) neurons are neurons in the hypothalamus of the brain that are central to the hormonal control of reproduction. KNDy neurons in the hypothalamus coexpress kisspeptin, neurokinin B (NKB) and dynorphin. They are involved in the negative feedback of gonadotropin-releasing hormone (GnRH) release in the hypothalamic–pituitary–gonadal (HPG) axis. Sex steroids released from the gonads act on KNDy neurons as inhibitors of kisspeptin release.

Fertilised eggs move from the gonads to the gills (marsupia) where they further ripen and metamorph into glochidia, the first larval stage. Mature glochidia are released by the female and then attach to the gills, fins or skin of a host fish. Typically, the freshwater mussel larvae (glochidia) have hooks, which enable the individual to attach itself to fish. Some freshwater mussels release their glochidia in mucilaginous packets called conglutinates.

Like other sea anemones, S. troglodytes is a carnivore and feeds on small invertebrates which it traps with its tentacles and channels into its mouth. Any undigested pieces are expelled from the mouth over the period of a few hours or days. S. troglodytes is a hermaphrodite with gonads inside the body cavity. The eggs are discharged from the mouth, being wafted out individually by cilia on the tentacles.

Especially in mosaic cases of Turner syndrome that contains Y-chromosome (e.g. 45,X/46,XY) due to the risk of development of ovarian malignancy (most common is gonadoblastoma) gonadectomy is recommended. Turner syndrome is characterized by primary amenorrhoea, premature ovarian failure (hypergonadotropic hypogonadism), streak gonads and infertility (however, technology (especially oocyte donation) provides the opportunity of pregnancy in these patients). Failure to develop secondary sex characteristics (sexual infantilism) is typical.

Cengage Learning; 10 October 2011 [cited 17 June 2013]. . p. 64–66. Chromosomal sex is determined at the time of fertilization; a chromosome from the sperm cell, either X or Y, fuses with the X chromosome in the egg cell. Gonadal sex refers to the gonads, that is the testis or ovaries, depending on which genes are expressed. Phenotypic sex refers to the structures of the external and internal genitalia.

The Siberian sturgeon feeds on a variety of benthic organisms, such as crustaceans and chironomid larvae. The species had been in steep decline in its natural range due to habitat loss, degradation, and poaching. Up to 40% of the Siberian sturgeon spawning habitat has been made inaccessible by damming. High levels of pollution in certain places have led to significant negative impacts on the reproductive development of gonads.

Nectonematids also possess a blindly-ending intestine and double rows of dorsal and ventral cuticular natatory bristles. In males, sperm sacs attached to the dorsal epidermis are the gonads, while females possess a vesicle-rich tissue called a gono-parenchyne during early developmental stages. Additionally, spines are formed on nectonematid eggs after they make contact with seawater. Like all horsehair worms, there is a lack of excretory organs or blood.

The septa walls contain the gonads, which are thick, linear and Y-shaped, joining at the base of the bell and then extending outwards to the arms. It has eight arms which are arranged in a circle. On the end of each arm is a cluster of up to thirty five tentacles, each of which has a rounded head. Unlike Haliclystus salpinx, C. cruxmelitensis does not have tentacle anchors.

Hunts in a typical flycatcher manner, sallying from a perch to catch insects in flight. It is suspected to breed in January to February and March to June in Ethiopia with enlarged gonads recorded from specimens taken in June, December and March to May. The nest is cup shaped and is placed at a narrow fork of a horizontal tree branch, the clutch consists of 3 blue-grey, blotched eggs.

The secondary pathway involves conversion of 17α-hydroxyprogesterone, most often a precursor to cortisol, to androstenedione directly by way of 17,20-lyase. Thus, 17,20-lyase is required for the synthesis of androstenedione, whether immediately or one step removed. Androstenedione is produced in the adrenal glands and the gonads. The production of adrenal androstenedione is governed by adrenocorticotrophic hormone (ACTH), whereas production of gonadal androstenedione is under control by the gonadotropins.

The complementary result for the X-chromosome follows, either a double or a single X. Therefore, direct sex differences are usually binary in expression (although the deviations in complex biological processes produce a menagerie of exceptions). These include, most conspicuously, male (vs female) gonads. Indirect sex differences are general differences as quantified by empirical data and statistical analysis. Most differing characteristics will conform to a bell-curve (i.e.

Differentiation of the gonads requires a tightly regulated cascade of genetic, molecular and morphogenic events. At the formation of the developed gonad, steroid production influences local and distant receptors for continued morphological and biochemical changes. This results in the appropriate phenotype corresponding to the karyotype (46,XX for females and 46,XY for males). Gonadal dysgenesis arises from the failure of signalling in this tightly regulated process during early foetal development.

Amphiura chiajei becomes sexually mature at about four years of age and may live for ten years. The gonads grow in size over the winter and spring and broadcast spawning takes place in late summer and early autumn. The larvae drift with the current and settle on the seabed and undergo metamorphosis at around eight days. This short larval period means that their potential to disperse is limited.

Endocrinology is a branch of internal medicine. A number of glands that signal each other in sequence are usually referred to as an axis, such as the hypothalamic-pituitary-adrenal axis. In addition to the specialized endocrine organs mentioned above, many other organs that are part of other body systems have secondary endocrine functions, including bone, kidneys, liver, heart and gonads. For example, the kidney secretes the endocrine hormone erythropoietin.

Feminization is likely caused by estrogen-like compounds present in municipal wastewater effluent, agriculture, and cattle operations near the Oldman River, however this mechanism is not well understood. It is not known if increased vitellogenin expression and intersex gonads significantly decrease reproductive success and will impact the long term viability of longnose dace in these systems. There is not evidence of skewed sex ratios in the Bow River.

Air is taken in through spiracles along the sides of the abdomen and thorax supplying the trachea with oxygen as it goes through the lepidopteran's respiratory system. Three different tracheaes supply and diffuse oxygen throughout the species' bodies. The dorsal tracheae supply oxygen to the dorsal musculature and vessels, while the ventral tracheae supply the ventral musculature and nerve cord, and the visceral tracheae supply the guts, fat bodies, and gonads.

Viral gametocytic hypertrophy is a pathological condition observed in the Pacific oyster. The condition was first discovered in Maine in 1973, and was later observed in Germany Ireland, Spain and South Korea. It involves the presence of basophilic inclusions in the gonads and the presence of virus particles that have been classified as papovaviruses/ papillomaviruses- polyomaviruses. They may be propagated during spawning or by vertical transmission and have an icosahedral shape.

The ovaries are considered the female gonads. Each ovary is whitish in color and located alongside the lateral wall of the uterus in a region called the ovarian fossa. The ovarian fossa is the region that is bounded by the external iliac artery and in front of the ureter and the internal iliac artery. This area is about 4 cm x 3 cm x 2 cm in size.

They resemble primitive bone marrow in hagfish. Cartilaginous fish (sharks and rays) have a more advanced immune system. They have three specialized organs that are unique to chondrichthyes; the epigonal organs (lymphoid tissues similar to mammalian bone) that surround the gonads, the Leydig's organ within the walls of their esophagus, and a spiral valve in their intestine. These organs house typical immune cells (granulocytes, lymphocytes and plasma cells).

They discovered that fish treated with aromatase inhibitors showed decreased gonodal weight, plasma estrogen level and spermatogonial proliferation in the testis as well as increased androgen levels. Their results suggest that estrogens are important in the regulation of spermatogenesis in this protogynous hermaphrodite. Previous studies have also investigated sex reversal mechanisms in teleost fish. During sex reversal, their whole gonads including the germinal epithelium undergoes significant changes, remodeling, and reformation.

FGF9 has also been shown to play a vital role in male sex development. FGF9’s role in sex determination begins with its expression in the bi-potent gonads for both females and males. Once activated by SOX9, it is responsible for forming a feedforward loop with Sox9, increasing the levels of both genes. It forms a positive feedback loop upregulating SOX9, while simultaneously inactivating the female Wnt4 signaling pathway.

It is analogous to andropause in men and menopause in women, the abrupt or gradual decline in production of sex hormones from the gonads with age. DHEA can be supplemented or taken as a medication in the form of prasterone to replace adrenal androgens later in life if it is desired. Some clinical studies have found benefits of DHEA supplementation in the elderly and people with adrenal insufficiency.

The manubrium of the medusae is short. They lack a gastric peduncle, ocelli (making them effectively blind) and excretory pores, and have 4 simple radial canals and in adults at least 16 statocysts. The tentacles at their margin are hollow and at the side carry cirri; cirri are lacking from around the margin however. The gonads are located at the radial canals; they do not reach the manubrium.

A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Unlike animals, plants do not have germ cells designated in early development.

The germ cells split into two populations and move to the paired gonadal ridges. Migration starts with 3-4 cells that undergo three rounds of cell division so that about 30 PGCs arrive at the gonads. On the migratory path of the PGCs, the orientation of underlying cells and their secreted molecules such as fibronectin play an important role. Mammals have a migratory path comparable to that in Xenopus.

At hatching, the larvae are barely discernible and are about 10 mm long. The larvae soon become pelagic, remaining far from the surface and bed, and negatively phototactic, or attracted to darkness, while searching for rocky places to hide. About two weeks after hatching, they disperse downstream with the current for several miles until settling back down upon the river bottom. As juveniles, all definitive adult structures, except for gonads, form.

It is followed by an esophageal region with a distinctive reddish-coloured oesophagus. Posterior to this is a dark-coloured hepatic region and a long greyish intestinal region. This is transparent and the gut is visible meandering to its termination at the anus, which is controlled by a strong sphincter. In mature individuals, the gonads are long dark masses and extend dorsally most of the way down the trunk.

Its most notable characteristic are the 4 ribbon-shaped gonads which extend down the bell along the radial canals at times all the way down to the base. They also have two short, distinct, club- like tentacles extending from each of their 4 marginal bulbs. These marginal bulbs also contain ocelli or light sensing organs. On each of the marginal bulbs they have 14-18 longer thin tentacles that extend downward.

The development of the gonads starts during the winter and the shrimps reach sexual maturity in their second summer. Sexually mature males have an extended reproductive capacity and are able to mate throughout the year, however the females mature seasonally. In the Strait of Sicily the females maturate and spawn from spring until autumn, with a peak in summer- autumn. This species gathers in shoals when mating and spawning.

Most insects have a high reproductive rate. With a short generation time, they evolve faster and can adjust to environmental changes more rapidly than other slower breeding animals. Although there are many forms of reproductive organs in insects, there remains a basic design and function for each reproductive part. These individual parts may vary in shape (gonads), position (accessory gland attachment), and number (testicular and ovarian glands), with different insect groups.

Kev Moore (born 20 May 1958) is an English bass player and lead vocalist. Formerly with Tubeless Hearts, he played with English pop band Christie from 1990 to 2003, and was featured in Graham Oliver's Saxon on two European tours, before other commitments resulted in John Ward taking over vocal duties for the resulting Oliver/Dawson Saxon CD releases. Nevertheless, he appeared on Graham Oliver's solo album End of an Era returning the favour after Oliver appeared on Tubeless Hearts' Three CD. Since 1998 he has been an occasional member of The Gonads, the punk band founded in the mid-1970s by journalist Garry Bushell, touring America and appearing on the albums Back and Barking and Schiz-oi-phrenia in addition to two videos of songs from the yet-to-be- released third Gonads album featured on the Bushell on the Box DVD. As of 2005, Moore has been lead vocalist and bassist with BC Sweet, the band founded by Sweet vocalist, the late Brian Connolly.

Members of this family have five arms which subdivide near the base giving them ten arms in total. The arms can reach in length and at the base of the calyx there are up to 25 cirri, often longer than the arms. Unique among Comatulida, the cirri are flattened on the underside. The gonads are located on the pinnules and not on the arms, and the embryos are brooded in cavities in the arms.

This is a small species of crinoid with arms up to long. The five arms each divide close to the base giving ten arms in total, with feather-like pinnules fanning out on either side. There are also up to 25 unusual cirri with flattened undersides which may be longer than the arms. Both the gonads, and the chambers in which the larvae are brooded, are located on the pinnules in this species.

Orchitophrya stellarum is often associated with sea stars and other invertebrates, living on their outer surface and feeding on sloughed-off epidermal tissue. It only appears to become parasitic when the male host starfish has ripe gonads. It probably enters the starfish through the gonopores, the orifices where gametes are released. There may be a pheromone that alerts it to the fact that the testes are ripe and causes it to change its behaviour.

In both sexes the gonads go on to form the testes and ovaries; because they are derived from the same undeveloped structure, they are considered homologous organs. There are a number of other homologous structures shared between male and female reproductive systems. However, despite the similarity in function of the female Fallopian tubes and the male epididymis and vas deferens, they are not homologous but rather analogous structures as they arise from different fetal structures.

Gametes are produced within the gonads through a process known as gametogenesis. This occurs when certain types of germ cells undergo meiosis to split the normal diploid number of chromosomes (n=46) into haploid cells containing only 23 chromosomes.Development of sex cells in Reproductive system, Body Guide. Adam. Anatomy of the testis In males, this process is known as spermatogenesis, and takes place only after puberty in the seminiferous tubules of the testes.

Intersex, in humans and other animals, describes variations in sex characteristics including chromosomes, gonads, sex hormones, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". Intersex people were historically termed hermaphrodites, "congenital eunuchs",Nguyễn Khắc Thuần (1998), Việt sử giai thoại (History of Vietnam's tales), vol. 8, Vietnam Education Publishing House, p. 55 or even congenitally "frigid".

Prebreeding enlargement of ovaries and testes begins in winter in the complete darkness of the burrow. Following emergence from the burrow, the lengthening photoperiod of spring apparently triggers final enlargement and development of gonads for breeding. Access to succulent green vegetation in spring may enhance reproductive success of females. Captive female Great Basin pocket mice from eastern Washington fed lettuce and seeds had significantly larger ovaries than control females fed only seeds.

Living specimen attached to rock (scale bar: 1.2 cm) The original type specimens for this species have been lost. however the species was re-described in 2009. Individuals vary in colour from red-orange with light red gonads (individuals found at King George Island, Antarctica) to red and/or green (individuals found in Valdivia, Chile). Haliclystus antarcticus has a 'stalk' (peduncle) which is a half to two thirds the length of its calyx.

Large specimen next to a shrimp mound, Grahams Harbor, San Salvador Island, Bahamas The West Indian sea egg feeds on algae but tends to avoid the crustose, highly calcified coralline algae. Ripe gonads were found in urchins at any time of year but breeding probably takes place mostly in the summer. Male and female urchins liberate gametes into the sea where fertilisation takes place. The eggs soon hatch into larvae which are planktonic.

Buster Gonad is a cartoon character in the British comic Viz. The strip involves the surreal adventures of "the boy with unfeasibly large testicles". During a storm, Buster's gonads were zapped by cosmic rays which enlarged them to an enormous size, so that he needs a wheelbarrow to carry them around. As a result, they are impossible to conceal and are therefore out on open display for everyone to see and marvel at.

After the second molt the tail disappears and there is rapid growth in the intestine region. Female gonad development begins in the third stage juvenile with the esophagus measuring 28% body length and the stylet measuring 18µ. After the fourth molt female gonads are completely developed but the vulva and vagina are not visible until molting is complete. An adult female has an esophagus measuring 22% body length and a stylet of 22.5µ.

Marine gastropods mating. The reproductive system of marine gastropods such as those from class Opisthobranchia and order Archaeogastropoda from the class Prosobranchia, is a continuous cycle of alternating male and female reproductive role prevalence. Immediately after spawning in late summer, the predominance of the female reproductive functions are terminated and gametogenesis initiates immediately, with the start of the predominance of the male reproductive role. Gametes remain in the gonads throughout the winter and early spring.

The endocrine reproductive system consists of the hypothalamus, the pituitary, the gonads, and the adrenal glands, with input and regulation from many other body systems. True puberty is often termed "central puberty" because it begins as a process of the central nervous system. A simple description of hormonal puberty is as follows: #The brain's hypothalamus begins to release pulses of GnRH. #Cells in the anterior pituitary respond by secreting LH and FSH into the circulation.

Members of this family have bell-shaped medusae with a four-part manubrium or sub-umbrella, a mouth with four plain or pleated lips and four, often broad, radial canals. The gonads are smooth or folded and positioned on the walls of the manubrium and sometimes extend onto the radial canals. There are fine, hollow tentacles along the margin of the bell, mostly growing from small carrot-shaped bulbs. The hydroids have threadlike tentacles.

They are the ones that extend from the protective crevice and are the primary food collecting structures. Shorter arms opposite the long ones often have better developed gonads and may even lack food-collecting ambulacral grooves. Although a few species occur at depths exceeding 600 m, most comasterids are found in less than 100 m and constitute the great majority of reef-dwelling species in both the tropical Western Atlantic and Indo-Western Pacific regions.

Intersex people are born with sex characteristics, such as chromosomes, gonads, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". Intersex people were historically termed hermaphrodites, "congenital eunuchs",Mason, H.J., Favorinus’ Disorder: Reifenstein’s Syndrome in Antiquity?, in Janus 66 (1978) 1–13.Nguyễn Khắc Thuần (1998), Việt sử giai thoại (History of Vietnam's tales), vol.

In addition, teleost fish possess a thymus, spleen and scattered immune areas within mucosal tissues (e.g. in the skin, gills, gut and gonads). Much like the mammalian immune system, teleost erythrocytes, neutrophils and granulocytes are believed to reside in the spleen whereas lymphocytes are the major cell type found in the thymus. In 2006, a lymphatic system similar to that in mammals was described in one species of teleost fish, the zebrafish.

The mother sporocysts reproduce asexually to generate many mother rediae. The mother rediae migrates to the digestive glands of the snail where it produces many daughter rediae. For the duration of the snail's life the daughter rediae generate cercariae after feeding on the snail's gonads. In the water, the cercariae seek out and penetrate the body surface or orifice of a second intermediate host, which is usually a fish, leech, tadpole, or another snail.

If stressed, they adopt a pattern with broad horizontal white stripes. At larger sizes, the adult colours appear and the male or female gonads are mature. The adult females are red with a yellow-edged greyish saddle shape on the back and a yellow spot at the base of the tail. The males are overall greyish with paler underparts and no distinctive markings, although typically with blackish bars on the throat and opercular.

The mouth is on the underside of the body and is surrounded by a tuft of 20 or 30 cirri or slender sensory appendages. The gut runs just below the notochord from the mouth to the anus, in front of the tail. There is a flap-like, vertical fin surrounding the pointed tail. Gas exchange takes place as water passes through gill slits in the mid region, and segmented gonads lie just behind these.

Some specimens bear a dark stain representing decay fluids injected into the surrounding wet sediment. (See Dark stain.) Muscle can in very rare cases survive by silicification, or by authigenic mineralization by any of a range of other minerals. However, predominately soft tissues, such as muscles and gonads, are never preserved by the carbonaceous-compression preservational pathway. Phosphatisation and the presence of other enzymes means that guts and mid-gut glands are often preserved.

CPA blocks the effects of androgens like testosterone in the body, which it does by preventing them from interacting with their biological target, the androgen receptor (AR), and by reducing their production by the gonads and hence their concentrations in the body. In addition, it has progesterone-like effects by activating the progesterone receptor (PR). It can also produce weak cortisol- like effects at very high doses. CPA was discovered in 1961.

Sex is genetically determined in amphibians. Temperature-induced sex reversal has been documented in some species of anuran and caudate amphibians. Temperature only can have an effect on sex differentiation during a window period called thermosensitive period (TSP) which varies among species. Tadpoles or larvae exposed to specific higher or lower temperatures, depending on the temperature thresholds of the species, can differentiate gonads that do not align with their primary sexual fate.

The cortisol- mediated pathway and epigenetic regulatory pathway are thought to be the potential mechanisms involved in TSD. The eggs are affected by the temperature at which they are incubated during the middle one-third of embryonic development. This critical period of incubation is known as the thermosensitive period (TSP). The specific time of sex-commitment is known due to several authors resolving histological chronology of sex differentiation in the gonads of turtles with TSD.

Sex differences in humans have been studied in a variety of fields. In humans, biological sex consists of five factors present at birth: the presence or absence of the SRY gene (an intronless sex-determining gene on the Y chromosome), the type of gonads, the sex hormones, the internal reproductive anatomy (such as the uterus), and the external genitalia.Knox, David; Schacht, Caroline. Choices in Relationships: An Introduction to Marriage and the Family.

Most sponges are hermaphrodites (function as both sexes simultaneously), although sponges have no gonads (reproductive organs). Sperm are produced by choanocytes or entire choanocyte chambers that sink into the mesohyl and form spermatic cysts while eggs are formed by transformation of archeocytes, or of choanocytes in some species. Each egg generally acquires a yolk by consuming "nurse cells". During spawning, sperm burst out of their cysts and are expelled via the osculum.

He pointed to the earlier ruling of Corbett v Corbett (Otherwise Ashley) (1971), which ruled that sex is determined at birth by chromosomes, gonads and genitals. The judge in that ruling, Omrod J, decided that a transgender male could not fulfill the role of a wife. The Attorney General attempted to use this ruling in the case of Re Kevin. Kevin and the Human Rights and Equal Opportunity Commission brought forth evidence to counter this.

Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized from cholesterol and secreted mainly from the gonads, though they can also be formed from adrenal androgens in adipose tissue. Relative to estradiol, both estrone and estriol have far weaker activity as estrogens.

Diagram of Charles Darwin's pangenesis theory. Every part of the body emits tiny particles, gemmules, which migrate to the gonads and contribute to the fertilised egg and so to the next generation. The theory implied that changes to the body during an organism's life would be inherited, as proposed in Lamarckism. Mendel's work was published in a relatively obscure scientific journal, and it was not given any attention in the scientific community.

Leydig's organ (named after the German histologist Franz Leydig who first described it in 1857) is a unique structure found only in some, but not all, elasmobranchs (sharks and rays). Nestled along the top and bottom of the esophagus, it produces red blood cells, as do the spleen and special tissue around the gonads. Heterophilic and eosinophilic granulocytes are produced, closely resembling structures of mammalian plasma cells. Leydig's organ is part of the immune system.

The number of births where the baby is intersex - where they do not fit into typical definitions of male and female - has been reported to be as low as 0.018% up to roughly 1.7%, depending on which conditions are counted as intersex. The number of births with ambiguous genitals is in the range of 0.02% to 0.05%. These conditions may complicate sex assignment. Other intersex conditions involve atypical chromosomes, gonads or hormones.

The sex of the moth is determined during the larval stage. The karyotype of codling moths has shown a diploid system (2n=56), which means the offspring receives two sets of chromosome, one from each parent. Females have a WZ sex chromosome system, while males have ZZ. Males have two brown spots near the end of the dorsal side, which become the gonads. The eggs can hatch at night or day, depending on humidity.

There are reports of the sea anemone itself being eaten by the sea slug Aeolidia papillosa ("shag rug nudibranch"), the sea spider, Pycnogonum littorale, wentletrap sea snails Epitonium spp., the flounder, Pseudopleuronectes americanus and the black bream, Spondyliosoma cantharus. M. senile is a protandric hermaphrodite – it starts life as one sex and changes to the other when it is older. Eggs or sperm develop in the gonads embedded in the mesentery that lines the coelom.

The gonads are located beside the anal vesicles and liberate gametes into the coelum or body cavity. Here they mature and are then stored in the nephridia before being liberated into the sea in the late winter or spring. After fertilisation, the eggs hatch into planktonic trochophore larvae. After several developmental stages over a period of about six months, the larvae settle on the seabed and undergo metamorphosis into juvenile spoon worms.

In addition, teleost fish possess a thymus, spleen and scattered immune areas within mucosal tissues (e.g. in the skin, gills, gut and gonads). Much like the mammalian immune system, teleost erythrocytes, neutrophils and granulocytes are believed to reside in the spleen whereas lymphocytes are the major cell type found in the thymus. In 2006, a lymphatic system similar to that in mammals was described in one species of teleost fish, the zebrafish.

Jellyfish deteriorate rapidly at room temperature so processing starts soon after they are caught. The bell is separated from the dangling oral arms and both are washed in seawater before being scraped to remove the gonads and mucus. Dehydration is traditionally undertaken by sprinkling the jellyfish with table salt and alum, draining off the brine and repeating the process. Finally the jellyfish are heaped to drain, turned several times and left to dry.

Apparently, it is the mature Irukandji that are highly venomous (in all species). Apparent Malo maxima juveniles have been identified without the halo-rings, and without gonads, and have demonstrated far weaker toxicity in stinging researchers. The stingers (nematocysts) are in clumps, appearing as rings of small red dots around the bell and along the tentacles. The Irukandji's small size and transparent body make it very difficult to see in the water.

They also have two anal fins which can be used for identification between species. The lateral line on this species is prominent, with a hump above the pectoral fin and extends the length of the fish toward the caudal fin. Illustration of white marlin Internally, white marlin do not have a swim bladder, but instead have small, bubble-shaped chambers that act as a swim bladder. Similarly to most vertebrates, they have symmetrical gonads.

10x magnification photo of Adult hermaphroditic female Parasitic nematode (Phasmarhabditis hermaphrodita). 1 Eye Piece Unit = 9.5μm P. hermaphrodita is unsegmented, vermiform, bilateral symmetrical pseudocoelomate. The body dimensions and structure of P. hermaphrodita is comparable to C. elegans' with a body length 1.3 - 1.7 mm long and an estimated circumference of 0.180mm. The primary structures are the Rhabditida-specific mouth, the pharynx, the intestine, the reproductive system (uterus, spermatheca, gonads) and the cuticle.

In any population there will be just one morphological type of male. Workers have, so far, been unable to find any individuals with gonads in transition from female to male but particular environmental or social conditions may still be involved in inducing sex change in at least a some of the fishes in a population. Abstract Unlike other wrasses which are protogynous hermaphrodites populations of Notolabrus fucicola can have large individuals of both sexes.

Disappearing or diminishing populations of whelks have been observed since the early 1970s, especially in the North Sea and the Wadden Sea. Additionally, vast beds of empty shells have been discovered where no living whelks are present. Imposex, the occurrence of male gonads on female whelks, has been detected since the early 1990s, and is thought to be a product of the shipping industry. Specifically, TBT has been shown to reduce viability of whelk populations.

They have incomplete digestive tracts where the food enters, is digested, and expelled through the same opening. During the polyp stage, the mouth is situated at the top of the body, surrounded by tentacles, whereas during the medusa stage, the mouth is situated at the distal end of the main body structure. Four gonads lie in this main body structure, or manubrium. When food is taken in through the mouth, it enters the manubrium.

Thalassoma bifasciatum and its congener, the saddle wrasse (T. duperrey) have become important models for understanding the physiological and neurobiological bases of sex change. Sex change can be induced socially in both species by making large females the largest members of social groups. Sex change in experimental pens by saddle wrasses involves complete gonadal transformation with associated decreases in a key steroid hormones (estradiol and 11-ketotestosterone) and steroid hormone synthesizing enzymes in the gonads.

Platyceratidae is an extinct family of Paleozoic sea snails, marine gastropod mollusks. This family may belong in the Patellogastropoda or the Neritimorpha. Platyceratids are known for the complex symbiotic relationships they had with crinoids. Platyceratids are thought to have been parasitic on crinoids, either drilling into the stomach to steal the crinoid's food in a form of kleptoparasitism or drilling into the anal sac to feed on the gonads or the hindgut.

Anillins are required for the faithfulness of cytokinesis and its F-actin-, myosin-, and septin-binding domains implicate anillin in actomyosin cytoskeletal organization. In agreement with this belief, anillin-mutant cells have disrupted contractile rings. Additionally, it is hypothesized that anillin couples the actomyosin cytoskeleton to microtubules by binding MgcRacGAP/CYK-4/RacGAP50C. Anillins have also been shown to organize the actomyosin cytoskeleton into syncytial structures observed in Drosophila embryos or C. elegans gonads.

The natural host of HzNV-2 is the corn earworm moth (Helicoverpa zea). The virus is spread to offspring through their mothers' eggs (Vertical transmission) and through mating attempts between adult moths (Horizontal transmission). Infected moths are referred to as either asymptomatic (AS) or agonadal (AG), due to the virus causing larvae to never form functional gonads. HzNV-2 is very common among wild moths, and it is very able to survive in host populations.

Pituitary necrosis following postpartum haemorrhage (Sheehan's syndrome) leads to failure and atrophy of the gonads, adrenal and thyroid. Chronic psychoses can supervene many years later, based on myxoedema, hypoglycaemia or Addisonian crisis. But these patients can also develop acute and recurrent psychoses, even as early as the puerperium. Shoib S, Dar M M, Arif T, Bashir H, Bhat M H, Ahmed J (2013) Sheehan’s syndrome presenting as psychosis: a rare clinical presentation.

Asexual reproduction produces many daughter (secondary) sporocysts which are called cecariacysts, that eventually release cercariae. Unlike most digenetic trematodes, Bucephalus Polymorphus lacks a redial stage and thus emerges as a cecaria directly from the sporocyst stage. Rapid proliferation of sporocysts results in a knotted white mass of tubules, which is found primarily in the gonads of the mussel. Released from the infected mussels, cercariae attach to fish (second intermediate host), encyst, and transforms into metacercariae.

Initial development of external genital is independent of androgens before indifferent gonads differentiate into testes. It occurs by week eight of gestation, as directed by a number of genes. External genitalia develop from mesenchymal cells underlying coelomic epithelium lining urogenital ridges on posterior wall of abdomen. Primordial germ cells (PGCs), precursors of gametes, migrate from egg sac into urogenital ridges, the site of gonad development in early embryonic development, by week six.

Mature males with ripe gonads have their nostrils extended into a dark coloured tube. There is a row of 24 to 28 large scales along the lateral line. The dorsal fin has 10 to 12 soft rays, the ventral fin has 1 spine and 8 soft rays and the pectoral fin has 1 spine and 11 to 13 soft rays. The head is steely blue, darker below, with a dark line edging the gill covers.

In male mammals, AMH prevents the development of the Müllerian ducts into the uterus and other Müllerian structures. The effect is ipsilateral, that is each testis suppresses Müllerian development only on its own side. In humans, this action takes place during the first 8 weeks of gestation. If no hormone is produced from the gonads, the Müllerian ducts automatically develop, while the Wolffian ducts, which are responsible for male reproductive parts, automatically die.

Hereditary haemochromatosis (or hemochromatosis) is a genetic disorder characterized by excessive intestinal absorption of dietary iron, resulting in a pathological increase in total body iron stores. Humans, like most animals, have no means to excrete excess iron. Excess iron accumulates in tissues and organs, disrupting their normal function. The most susceptible organs include the liver, adrenal glands, heart, skin, gonads, joints, and the pancreas; patients can present with cirrhosis, polyarthropathy, adrenal insufficiency, heart failure, or diabetes.

The development of the reproductive system and the development of the urinary system are closely tied in with the development of the human fetus. Despite the differences between the adult female and male are derived from the intermediate mesoderm. The three main fetal precursors of the reproductive organs are the Wolffian duct, the Müllerian ducts, and the gonads. Endocrine hormones are a well-known and critical controlling factor in the normal differentiation of the reproductive system.

The gelatinous substance of the disk is translucent milky-blue in color, while the gastro- vascular space, gonads, radial and circular muscles of the subumbrella and the entodermal cores of the tentacles are purplish-pink. The outer parts of the veil-like folds of the palps are amber-brown, while the parts adjacent to the mouth are pink. The concretions of the 8 sense-organs are reddish-brown. The planulae are yellow, but the ephyra is pink.

Dead birds retained large amounts of DDT in their fatty tissues and gonads which may have caused the birds to become infertile. Moreover, small animals ate plants that were sprayed with other pesticides which were then eaten by the birds of prey. More than 100,000 bald eagles were killed in Alaska from 1917 to 1953. Public awareness arose during this time, and many groups and individuals dedicated to make the conservation of eagles a national issue.

S. aeruginosa is a herbivorous deposit feeder. It consumes mainly epiphytic algae, but its diet also includes detritus, bacteria, aquatic plants, sand grains, diatoms, green algae, and cyanobacteria such as Microcystis. Its consumption of cyanobacteria during algal blooms may result in bioaccumulation of toxic microcystins (microcystin-LR, microcystin- RR) from Microcystis in the gonads, the hepatopancreas and the digestive tract. Adult snails feeding ad libitum under ideal laboratory conditions eat 16.0 mg of fish food daily.

Hypergonadotropic hypogonadism (HH), also known as primary or peripheral/gonadal hypogonadism, is a condition which is characterized by hypogonadism due to an impaired response of the gonads to the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and in turn a lack of sex steroid production and elevated gonadotropin levels (as an attempt of compensation by the body). HH may present as either congenital or acquired, but the majority of cases are of the former nature.

Cephalopods that are sexually mature and of adult size begin spawning and reproducing. After the transfer of genetic material to the following generation, the adult cephalopods then die. Sexual maturation in male and female cephalopods can be observed internally by the enlargement of gonads and accessory glands. Mating would be a poor indicator of sexual maturation in females; they can receive sperm when not fully reproductively mature and store them until they are ready to fertilize the eggs.

These and other species are colloquially known as bêche de mer or trepang in China and Indonesia. The sea cucumbers are boiled for twenty minutes and then dried both naturally and later over a fire which gives them a smoky tang. In China they are used as a basis for gelatinous soups and stews.Wikisource:1911 Encyclopædia Britannica/Bêche-de-Mer Both male and female gonads of sea urchins are also consumed particularly in Japan, Peru, Spain and France.

The body cavity is known as a "pseudocoel", or haemocoel. Unlike a true coelom, a pseudocoel is not fully enclosed by a cell layer derived from the embryonic mesoderm. A coelom is, however, formed around the gonads and the waste-eliminating nephridia.As the name haemocoel suggests, the body cavity is filled with a blood-like liquid in which all the organs are embedded; in this way, they can be easily supplied with nutrients circulating in the blood.

The gametes (sperms and ova) are produced in the swollen gonads, around the stomach. The gametes swim through the metacoelom to the metanephridia. Sperm exit by the nephridiopores and some are captured by the lophophores of individuals of the same species. Species that lay small fertilized eggs release them into the water as plankton, while species with larger eggs brood them either in the body's tube or stuck in the center of the lophophore by adhesive.

They are often known as "lamp shells", since the curved shells of the class Terebratulida resemble pottery oil-lamps. Lifespans range from three to over thirty years. Ripe gametes (ova or sperm) float from the gonads into the main coelom and then exit into the mantle cavity. The larvae of inarticulate brachiopods are miniature adults, with lophophores that enable the larvae to feed and swim for months until the animals become heavy enough to settle to the seabed.

Flounder that were 45 cm in length released up to 1.25 million eggs, while smaller females that were only 30 cm, released around 250,000 eggs. The winter before spawning season, the gonads of both sexes increase in size and weight. The ovaries in females also begin to develop and mature certain eggs to get them ready for fertilization. Adult flounders migrate offshore during the winter to breed in deeper, coastal areas over the winter and spring months.

P. parvivipara has a very unusual lifecycle for a starfish. The adults are self-fertilising hermaphrodites and the eggs are brooded within the gonads. No planktonic larval stage is seen, and the directly developing juveniles are cannibalistic, feeding on other embryos and juveniles while in the brood pouch. When mature enough, they are released into the water in batches of up to 20, where they continue their lives, quite probably in the same rock pool as their parents.

The black sea nettle can be quite massive, with a bell diameter potentially up to 1 meter and oral arms extending to 5 or 6 meters. The bell color is a distinctive opaque dark purple to nearly black, with the margin having a lighter brown reticulated pattern. No other West Coast jelly that visits near shore waters has this dark pigmentation. Four gonads are attached to finger-like projections that extend through subumbrellar openings (the ostia).

Determining the sex of the obscure snakehead can only be done through the dissection of the gonads. Reproduction happens throughout the year, especially during and right after flooding. Males and females during spawning make a color change. The males change from brown to bright blue and the females' brown spots turn a deeper dark brown and the bright spots on their fins turn blue, and both male and female pectoral fins turn white at the tips.

Estrone is biosynthesized from cholesterol. The principal pathway involves androstenedione as an intermediate, with androstenedione being transformed into estrone by the enzyme aromatase. This reaction occurs in both the gonads and in certain other tissues, particularly adipose tissue, and estrone is subsequently secreted from these tissues. In addition to aromatization of androstenedione, estrone is also formed reversibly from estradiol by the enzyme 17β-hydroxysteroid dehydrogenase (17β-HSD) in various tissues, including the liver, uterus, and mammary gland.

Most mature clitellates (the group that includes earthworms and leeches) are full hermaphrodites, although in a few leech species younger adults function as males and become female at maturity. All have well-developed gonads, and all copulate. Earthworms store their partners' sperm in spermathecae ("sperm stores") and then the clitellum produces a cocoon that collects ova from the ovaries and then sperm from the spermathecae. Fertilization and development of earthworm eggs takes place in the cocoon.

In the middle part, the trunk or third body region, is full of vascularized solid tissue, and includes body wall, gonads, and the coelomic cavity. Here is located also the trophosome, spongy tissue where a billion symbiotic, thioautotrophic bacteria and sulfur granules are found. Since the mouth, digestive system, and anus are missing, the survival of R. pachyptila is dependent on this mutualistic symbiosis. This process, known as chemosynthesis, was recognized within the trophosome by Colleen Cavanaugh.

Thus, the function and quality of a differentiated sperm cell is dependent upon the capacity of its originating spermatogonial stem cell (SSC). Gonocytes represent the germ cells undergoing the successive, short-term and migratory stages of development. This occurs between the time they inhabit the forming gonads on the genital ridge to the time they migrate to the basement membrane of the seminiferous cords. Gonocyte development consists of several phases of cell proliferation, differentiation, migration and apoptosis.

The eight gonads are located in pairs on either side of the four septa. The margins of the septa bear bundles of small gastric filaments which house nematocysts and digestive glands and help to subdue prey. Each septum is extended into a septal funnel that opens onto the oral surface and facilitates the flow of fluid into and out of the animal. The box jellyfish's nervous system is more developed than that of many other jellyfish.

Like other sea urchins, Heterocentrotus mammillatus periodically develops gametes to be released into the water for fertilization and undergoes a rest period in order to resume the cycle again. However, the timing and duration of these cycles varies from urchin to urchin. H. mammillatus from a reef near where the Gulf of Aqaba meets the Red Sea displayed an annual reproductive cycle. Its resting period is from October to January, accumulating nutrients in its gonads in preparation for gametogenesis.

It functions as a metabolic intermediate in the biosynthesis of the androgen and estrogen sex steroids both in the gonads and in various other tissues. However, DHEA also has a variety of potential biological effects in its own right, binding to an array of nuclear and cell surface receptors, and acting as a neurosteroid and modulator of neurotrophic factor receptors. In the United States, DHEA is sold as an over-the-counter supplement, and medication called prasterone.

This suggests that WT1 is unconditionally required for a proper kidney formation and development. Apart from that, the WT1 knock-out mice lacked several types of glands, such as gonads or adrenal glands. The effect of the knock-out was as well visible on heart and blood circulation - several abnormalities concerning heart and diaphragm, as well as troubles with swelling and lymph circulation were described. Due to those defects, the mouse died before it was even born.

Air is taken in through spiracles along the sides of the abdomen and thorax supplying the trachea with oxygen as it goes through the lepidopteran's respiratory system. There are three different tracheae supplying oxygen diffusing oxygen throughout the species body: The dorsal, ventral, and visceral. The dorsal tracheae supply oxygen to the dorsal musculature and vessels, while the ventral tracheae supply the ventral musculature and nerve cord, and the visceral tracheae supply the guts, fat bodies, and gonads.

Most species are simultaneous hermaphrodites, but some switch from male to female as they mature, while individuals of some species remain of the same sex all their lives. Individuals have one or two pairs of gonads, placed between the atrium and stomach, and opening into a single gonopore in the atrium. The eggs are thought to be fertilized in the ovaries. Most species release eggs that hatch into planktonic larvae, but a few brood their eggs in the gonopore.

The expected tenure of breeding females is roughly 12 years and is relatively long for a fish of its size, but is characteristic of other reef fish. Why the nonbreeders continue to associate with these groups has been unclear. Unlike nonreproductives in some animal groups, they cannot obtain occasional breeding opportunities, because their gonads are not functional. They cannot be regarded as helpers at the nest, since their presence does not increase the reproductive success of the breeders.

Anemonia sulcata has a symbiotic relationship with zooxanthellae, which inhabit the tissues and provide energy for the sea anemone. It is dioecious, with individuals becoming sexually mature when they weigh about and the basal disc measures about across. There are no gonads, and the germ cells develop inside the mesenteries and break through the epithelium to enter the body cavity and thence move into the water column. At this stage, the oocytes already contain symbiotic zooxanthellae.

A progonadotropin, or hypergonadotropin, also known as a gonad stimulant, is a type of drug which increases the secretion of one or both of the major gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This, in turn, results in increased function and maintenance of the gonads and increased gonadal steroidogenesis of sex hormones such as androgens, estrogens, and progestogens. Progonadotropins are the functional opposites of antigonadotropins. They have clinical applications in the treatment of hypogonadism and infertility.

A variety of conditions can lead to hypoestrogenism: menopause is the most common. Primary ovarian insufficiency (premature menopause) due to varying causes, such as radiation therapy, chemotherapy, or a spontaneous manifestation, can also lead to low estrogen and infertility. Hypogonadism (a condition where the gonads – testes for men and ovaries for women – have diminished activity) can decrease estrogen. In primary hypogonadism, elevated serum gonadotropins are detected on at least two occasions several weeks apart, indicating gonadal failure.

Distinctive pigment bands along the calyx and the relatively short stalk (or peduncle) distinguish it from related Manania species. Manania handi is also described typically as green with cream coloured gonads and vivid white nematocyst vesicles. However the colour patterns of M. handi can vary from brownish-yellow to vivid green. The name "handi" refers to Cadet Hand, major professor of G.F. Gwilliam and co-author with Gwilliam on a number of studies describing Stauromedusae species.

Likewise, monogamous pine voles have a high-density of OTRs; non-monogamous meadow voles do not. The way in which hormones alter these receptors is an important behavioral regulator. Consider the ways in which gonads affect OTRs in different rodents. In female rats, gonadal estrogen increases the level of OTR binding and, when the ovarian cycle maximizes the amount of estrogen in the bloodstream, causes OTRs to appear in ventrolateral regions of the structure called the ventromedial nucleus.

The stomach is expanded, thin-walled, and clear and is used in breathing air. A thin, clear tube exits the main body of the stomach anterodorsally, terminating at the pylorus just anterior to the posterior extent of the stomach. The intestine tends to have less coils than other members of Ancistrini. The expanded stomach is slightly larger in males; this is due to the males having more space due to a difference in the relative size of the gonads.

7=testicles or ovaries Fish reproductive organs include testes and ovaries. In most species, gonads are paired organs of similar size, which can be partially or totally fused. There may also be a range of secondary organs that increase reproductive fitness. The genital papilla is a small, fleshy tube behind the anus in some fishes from which the sperm or eggs are released; the sex of a fish often can be determined by the shape of its papilla.

Two female specimens taken from in August 1967, both with small gonads and unused oviducts, had heavy contour molt and light fat. Murphy described the species as difficult to distinguish in life from the black petrel, with the chief difference being a much shorter tarsus. Adult males have a wingspan of compared to a wingspan of in adult females, and the tarsus is in adult males and in females. Tails are in adult males and in adult females.

Bucephalus mytili is a parasitic flatworm of the class Trematoda. It is a parasite of fish and a parasitic castrator of the mussel Mytilus edulis, where it destroys the mussel's gonads and causes the mussel to grow much larger than normal. The cercaria of B. mytili were described in 1935 occurring in Mytilus edulis in Wales. They are the sporocysts, which are long and tangled within the mollusk host's digestive gland, and cause parasitic castration of the host.

Teeth (often used to identify lamprey to species) develop on the oral disk, and the eyes develop from the eye spots at metamorphosis. Least brook lamprey do not have a juvenile period (see life cycle), and maturation continues directly into the adult stage, at which point the body swells as the gonads are developed. Populations are likely physically distinct depending on the locality where they are captured. Therefore, the physical description provided herein is only a general description.

A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence cortico-) and sex steroids (typically made in the gonads or placenta). Within those two classes are five types according to the receptors to which they bind: glucocorticoids and mineralocorticoids (both corticosteroids) and androgens, estrogens, and progestogens (sex steroids). Vitamin D derivatives are a sixth closely related hormone system with homologous receptors.

Oldendorf, 42(2), 181-194. After splitting, the brittle star may still be able to reproduce sexually but some fragments of the disc may have no gonads and thus be unable to spawn until regeneration is complete. In Taiwan, mature gametes occur at any time from March to December, but most of the population of O. savignyi spawn during May and June. Fission takes place at any time of year but mostly occurs between July and December.

When testosterone is produced in the brain and gonads in both genders, the androgen receptors in neural and peripheral tissues are being possessed and trigger behavioural and physiological responses to testosterone. The role of androgenic steroids is to activate or facilitate aggressive behaviour. High levels of oestrogen are shown to have an effect on women's derogation on potential competitors (e.g. rating other female faces as less attractive) but there is no effect on ratings of male attractiveness.

In the sense that different from other with known species in all. This species is characterized as comparatively large size, about 20 mm width as well as height, and large amounts of folded hanging gonads from the wall around the circumference to the proximal area of the radial canals. Also, The edge tentacles have extinct species, and the oral tentacles have anti-inflammatory properties. Nogueira, M., Rodriguez, C. S., Mianzan, H., Haddad, M. A., & Genzano, G. (2013).

The condition develops in males that consist of normal functioning reproductive organs and gonads, but also female reproductive organs such as the uterus and fallopian tubes. The female reproductive organs origin from a structure from when both genders are still foetuses, called the “Mullerian Duct”. In males, the secretion of ‘Anti- Mullerian Hormone (AMH)’ causes the regression of the Müllerian Duct. Normally, both the Mullerian and Wolffian ducts are present during the 7th week of gestation.

A brief version of the female default paradigm can be stated as follows: #A set of specific genetic instructions must be present and a series of differentiating events mediated by hormones must occur in order for a mammalian zygote to become a fully reproductively functional male. ##The Y chromosome, SRY, SOX9, and SF1 genes must be present and functional. ##Functional Leydig cells must form in the gonads. ##The Leydig cells must be able to produce testosterone.

For example, Hemioniscus balani, a parasitic castrator of hermaphroditic barnacles, feeds on ovarian fluid, so that its host loses female reproductive ability but still can function as a male. This is a case of direct parasitic castration (feeding on host gonads). Indirect strategies are also seen such as diverting host energy from gonad development or secreting castrating hormones. The parasitic castration strategy is used by some larval trematode parasites of snails and some isopod and barnacle parasites of crustaceans.

Premature adrenarche is the most common cause of the early appearance of pubic hair ("premature pubarche") in childhood. In a large proportion of children it seems to be a variation of normal development requiring no treatment. However, there are three clinical issues related to premature adrenarche. First, when pubic hair appears at an unusually early age in a child, premature adrenarche should be distinguished from true central precocious puberty, from congenital adrenal hyperplasia, and from androgen- producing tumors of the adrenals or gonads.

Although its breeding habits are unknown, the gonads are large as compared with the body size, suggesting that it may have a promiscuous mating system. Breeding takes place between January and May, and newly settled juveniles are found on inner reef areas between April and June. This butterflyfish is sometimes collected from the wild for the aquarium trade. Its feeding habits make it more suitable for keeping in a reef aquarium than more specialist butterflyfish species that feed on scleractinian corals.

The mature female wasp seeks out adult female ladybirds, although they will sometimes oviposit into a male adult or larval instar. One egg is planted in the host's soft underbelly. The wasp larva hatches after 5–7 days into a first instar larva with large mandibles and proceeds to remove any other eggs or larvae before beginning to feed on the ladybird's fat bodies and gonads. The wasp larva inside the ladybird goes through four larval instars in 18–27 days.

Most of the body is transparent or translucent, with a whitish or greenish tinge. The (usually) four large flat sex organs (gonads) are attached to the four radial canals, and are usually opaque white. The many tentacles each contain thousands of cells called cnidocytes, which contain nematocysts (also known as cnidocysts), and are used to capture prey and pass it to the mouth. Food is taken in the mouth opening, and waste is finally expelled out of the same opening.

Gynandromorphs occasionally afford a powerful tool in genetic, developmental, and behavioral analyses. In Drosophila melanogaster, for instance, they provided evidence that male courtship behavior originates in the brain, that males can distinguish conspecific females from males by the scent or some other characteristic of the posterior, dorsal, integument of females, that the germ cells originate in the posterior-most region of the blastoderm, and that somatic components of the gonads originate in the mesodermal region of the fourth and fifth abdominal segment.

The tunicate produces a secondary metabolite called trabectedin which has been shown to have anti- tumour properties. As it feeds, the flatworm gradually builds up the concentration of this chemical in its body. For this reason, it may be of interest to the pharmaceutical industry as a source of this compound which has been approved for medical use in the European Union. Maritigrella crozierae is a simultaneous hermaphrodite, which means that an individual has both male and female gonads at the same time.

Death is normally due to ventricular arrhythmias, progressive hypotension unresponsive to treatment, and aspiration pneumonitis. Symptoms in domestic animals vary: dogs tend to show nervous system signs such as convulsions, vocalization, and uncontrollable running, whilst large herbivores such as cattle and sheep more predominantly show cardiac signs. Sub-lethal doses of sodium fluoroacetate may cause damage to tissues with high energy needs — in particular, the brain, gonads, heart, lungs, and fetus. Sub- lethal doses are typically completely metabolised and excreted within four days.

The Japanese sea cucumber sifts through the sediment on the seabed with its tentacles and feeds on detritus and other organic matter including plant and animal remains, bacteria, protozoa, diatoms and faeces. The sexes are separate in the Japanese sea cucumber. Males and females release a mass of gametes into the sea where fertilization takes place. In the laboratory, spawning from ripe gonads can be induced by varying the temperature at which the adults are kept or by use of the neuropeptide cubifrin.

The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In some deepwater sharks, the column is reduced.Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date As they do not have bone marrow, red blood cells are produced in the spleen and the epigonal organ (special tissue around the gonads, which is also thought to play a role in the immune system).

"In the 1950s, John Money and his colleagues took up the study of intersex individuals, who, Money realized, 'would provide invaluable material for the comparative study for bodily form and physiology, rearing, and psychosexual orientation'." "Money and his colleagues used their own studies to state in the extreme what these days seems extraordinary for its complete denial of the notion of natural inclination." They concluded that gonads, hormones, and chromosomes did not automatically determine a child's gender role.Fausto-Sterling, Anne (2000).

The front part of the tapeworm is milky-white but further back it is grey. Each segment has several sets of ovaries and testes and produces very large numbers of eggs (probably more than the 700,000 a day produced by the beef tapeworm, Taenia saginata). In one study by the Russian zoologist A. Skryabin, who described T. calyptocephalus in 1961, the largest proglottids were wide and contained fourteen gonads. Mating takes place between two proglottids from either the same or different tapeworms.

Coelomic epithelium refers to the epithelium that lines the surface of the body wall and abdominal organs. It constitutes the outermost layer of the male and female gonads, thus forming the germinal epithelium of the female or of the male. It is also called the germinal epithelium of Waldeyer or sometimes the superficial epithelial cells in embryology. It is often encountered in the medical setting as an important source of various types of ovarian cancer, primary peritoneal serous cancer and endometriosis (coelomic metaplasia).

Intracranial germinoma occurs in 0.7 per million children. As with other germ-cell tumors (GCTs) occurring outside the gonads, the most common location of intracranial germinoma is on or near the midline, often in the pineal or suprasellar areas; in 5-10% of patients with germinoma in either area, the tumor is in both areas. Like other GCTs, germinomas can occur in other parts of the brain. Within the brain, this tumor is most common in the hypothalamic or hypophyseal regions.

In severe cases, there was congestion of hemal sinuses, two principal empty areas along the digestive tube and vessels. Mass amounts of yeast-like cells compressed nerve fibers and the gill lamellae were destroyed. Mollusks clinical signs vary from scattered spots of brownish discoloration on the mantle tissues to general deterioration of mussel condition. In severe cases, there were black-bodied mussels with a distinct odor and black yeast-cells infected the connective tissues around the gonads and the digestive tract.

Accessory spleens may undergo hypertrophy after splenectomy Very rarely, it may cause bleeding (pictured).Note: The case is possibly splenosis rather than an accessory spleen: If splenectomy is performed for conditions in which blood cells are sequestered in the spleen, failure to remove accessory spleens may result in the failure of the condition to resolve. During medical imaging, accessory spleens may be confused for enlarged lymph nodes or neoplastic growth in the tail of the pancreas, gastrointestinal tract, adrenal glands or gonads.

Spawning occurs in Isostichopus fuscus from July to September, with post-spawning gonads occurring in October. Gametogenesis was documented between January and July, with oogenesis occurring approximately one month before spermatogenesis. Peaks in reproduction followed by drastic declines have characterized I. fuscus as an episodic spawner, in which water temperature is thought to play a large role as a reproductive indicator. The reproductive cycle of the brown sea cucumber consists of five gonadal stages: under-determined, gametogenesis, maturity, spawning and post-spawning.

Twentieth century advocates of some schools of yoga, such as B. K. S. Iyengar, made claims for the effects of yoga on specific organs, without adducing any evidence. Iyengar claimed that this pose benefits the abdominal organs "quickly", and like Yoganidrasana "tones the kidneys, liver, spleen, intestines, gall bladder, prostates [sic] and the urine bladder", freeing them from disease with "continued practice". He claimed it "exercises the gonads" and rests "the nerves", storing "energy .. for better thinking and better work".

Human karyotype Sexual identity is determined at fertilization when the genetic sex of the zygote has been initialized by a sperm cell containing either an X or Y chromosome. If this sperm cell contains an X chromosome it will coincide with the X chromosome of the ovum and a female child will develop. A sperm cell carrying a Y chromosome results in an XY combination, and a male child will develop. Genetic sex determines whether the gonads will be testes or ovaries.

Derrier and other intersex persons of the period, such as Katharina/Karl Hohmann, became traveling medical specimens, exchanging permission to examine their bodies for food and lodging, or money. Out of these examinations, sexing standards, based on the presence of gonads, were established. Traveling intersex specimens also contributed to scientific exchanges between researchers, as they carried their "portfolio" of diagnostic statements with them. Reconstructing Dürrge's travels from the medical reports made, he left Berlin in 1801 and traveled to Jena.

Aurelia with an anomalous number of gonads — most have four. Aurelia does not have respiratory parts such as gills, lungs or trachea, it respires by diffusing oxygen from water through the thin membrane covering its body. Within the gastrovascular cavity, low oxygenated water can be expelled and high oxygenated water can come in by ciliated action, thus increasing the diffusion of oxygen through cell. The large surface area membrane to volume ratio helps Aurelia to diffuse more oxygen and nutrients into the cells.

While both sperm and eggs are present in gonads, spawning has never been observed. Planktonic disposition and transmission of their early larva indicate that the eggs are fertilized and dispersed in the plankton. While specific life histories differ among species and genera, postlarval barracudina size classes are found more frequently within proximity to continental shelf escarpments at certain times of the year. However, this could also be a sampling artifact, since barracudina are only rarely caught by fisheries-independent sampling.

The onset of puberty is marked by an increase in gonadotropin secretion, which leads to sexual maturity and the ability to reproduce. Puberty can also be affected by a range of environmental factors, and is known to be affected by a person's metabolic capacity. Gonadotropin secretion is brought about and regulated by gonadotropin releasing hormone (GnRH). GnRH leads to the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH), which primarily target the gonads to trigger puberty and reproduction.

Researchers found no evidence of differences in the measurements of the gonads, or the levels of the sex hormones of exclusively homosexual western gulls and ring-billed gulls. Additional studies pertaining to hormone involvement in homosexual behavior indicate that when administering treatments of testosterone and estradiol to female heterosexual animals, the elevated hormone levels increase the likelihood of homosexual behavior. Additionally, boosting the levels of sex hormones during an animal's pregnancy appears to increase the likelihood of it birthing a homosexual offspring.

The adrenal cortex produces three main types of steroid hormones: mineralocorticoids, glucocorticoids, and androgens. Mineralocorticoids (such as aldosterone) produced in the zona glomerulosa help in the regulation of blood pressure and electrolyte balance. The glucocorticoids cortisol and cortisone are synthesized in the zona fasciculata; their functions include the regulation of metabolism and immune system suppression. The innermost layer of the cortex, the zona reticularis, produces androgens that are converted to fully functional sex hormones in the gonads and other target organs.

Mutations in Sox9 or any associated genes can cause reversal of sex and hermaphroditism (or intersexuality in humans). If Fgf9, which is activated by Sox9, is not present, a fetus with both X and Y chromosomes can develop female gonads; the same is true if Dax1 is not present. The related phenomena of hermaphroditism can be caused by unusual activity of the SRY, usually when it's translocated onto the X-chromosome and its activity is only activated in some cells.

It plays a role in the activation of the S and G2/M checkpoints. In the male sexual development pathway, GADD45G is essential for activating SRY, leading to proper formation of the gonads and sex-determination. This could occur through GADD45G interaction with the p38 MAPK signaling pathway. Deletion of an enhancer close to the GADD45G gene is correlated to increased proliferation of neuronal cells, which could account for part of the difference in neural development between humans and other species.

Parasitic Sacculina destroys a crab's gonads, rendering the crab permanently infertile. When a female Sacculina is implanted in a male crab, it interferes with the crab's hormonal balance. This sterilizes it and changes the bodily layout of the crab to resemble that of a female crab by widening and flattening its abdomen, among other things. The female Sacculina then forces the crab's body to release hormones, causing it to act like a female crab, even to the point of performing female mating dances.

About a quarter way up the bell are four rhopalia, cylindrical structures containing light-sensitive cells. About half way up the bell, the four flattened gonads can be seen on the inside of the bell. The underside of the bell is partially constricted by a velarium, a horizontal ring of tissue, and in the centre is a manubrium, a tube-like structure which hangs down with the mouth at its tip. This box jellyfish is a translucent yellowish-brown colour.

L. janetae has 8 gonads which are shaped like lances and arranged in pairs extending from the centre of the calyx to the base of the arms. They give the organism an orange/pink colour when reproductively active. The scientists who originally identified L. janetae have speculated that this species may also be capable of asexual reproduction. This had not been shown for any Stauromedusan at the time the paper was written, although it has subsequently been suggested for Haliclystus antarcticus.

Whether daggertooth have a significant impact on northern Pacific Salmon stock remained inconclusive. It has been noted that as daggertooths age their teeth begin to diminish and their stomachs and intestines atrophy while their gonads increase greatly in size. This observed, ontogenetic shift hints to a potentially semelparous reproductive modality, while this aspect of life history has not yet been fully substantiated. Like their relatives, it is thought that daggertooths are simultaneous hermaphrodites while their spawning and actual reproductive behavior remains a mystery.

The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the NR5A1 gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles in endocrine function have since been discovered.

Oral estradiol often has difficulty adequately suppressing testosterone levels, due to the relatively low estradiol levels achieved with it. Prior to orchiectomy (surgical removal of the gonads) or sex reassignment surgery, the doses of estrogens used in transgender women are often higher than replacement doses used in cisgender women. This is to help suppress testosterone levels. The Endocrine Society (2017) recommends maintaining estradiol levels roughly within the normal average range for premenopausal women of about 100 to 200 pg/mL.

Bdelloids are of interest in the study of the evolution of sex because a male has never been observed, and females reproduce exclusively by parthenogenesis, a form of asexual reproduction where embryos grow and develop without the need for fertilization; this is akin to the apomixis seen in some plants. Each individual has paired gonads. Despite having been asexual for millions of years, they have diversified into more than 450 species and are fairly similar to other sexually reproducing rotifer species.

489 The median amount of radiation needed to kill a marsh rice rat is 5.25 Gy and the lethal dose of potassium cyanide is 7.20 mg/kg; both values are relatively low for cricetid rodents.O'Farrell and Dilley, 1975, table 1 In one study, wild rice rats in radioactively contaminated areas did not show signs of disease.Childs and Cosgrove, 1966, p. 309 Exposure to more daylight and higher food availability cause increased development of the gonads in both adult and juvenile rice rats.

D. nigrospiracula exhibit sexual dimorphism through differing ratios of phosphorus concentration in adult males and females. Females have about 3 times as much phosphorus in their gonads as males. This inequality is due to the importance of phosphorus in the synthesis of nucleic acids during oogenesis. The cacti on which D. nigrospiracula breed and feed have low concentrations of phosphorus, but research has shown that the higher concentration in females comes from the phosphorus transferred from the male to the female during copulation.

Retrieved on March 14, 2009. Adult D. longipes exhibit paedomorphic characteristics found in the juveniles of other opisthoproctids, such as poorly developed muscles (for example the lack of ventral muscles, meaning the gut is enclosed only by the peritoneum and the skin), rudimentary scales and coloration, and the placement of the pectoral and pelvic fins on peduncles that are not connected to the body by muscles. Developed gonads have been observed in a male and a female. Their lifespan is 5 years.

This is relatively large compared to other bivalves and contains the visceral mass and the gonads. J. Lützen, B. Berland & G.A.Bristow, Morphology of an endosymbiotic bivalve, Entovalva nhatrangensis (Bristow, Berland, Schander & Vo, 2010) (Galeommatoidea); Molluscan Research 31(2): 114–124 ; ISSN 1323-5818 Entovalva nhatrangensis can be distinguished from the other three previously described species in the genus Entovalva by the different shape of its body and foot, and by the fact that its outer body epithelium is distinctively folded.

The number of births where the baby is intersex has been reported to be as low as 0.018% up to roughly 1.7%, depending on which conditions are counted as intersex. The number of births with ambiguous genitals is in the range of 0.02% to 0.05%. Other intersex conditions involve atypical chromosomes, gonads, or hormones. Some intersex persons may be assigned and raised as a girl or boy but then identify with another gender later in life, while most continue to identify with their assigned sex.

The common pathway of sexual differentiation, where a productive human female has an XX chromosome pair, and a productive male has an XY pair, is relevant to the development of intersex conditions. During fertilization, the sperm adds either an X (female) or a Y (male) chromosome to the X in the ovum. This determines the genetic sex of the embryo. During the first weeks of development, genetic male and female fetuses are "anatomically indistinguishable", with primitive gonads beginning to develop during approximately the sixth week of gestation.

The scale worm Arctonoe fragilis is often found living on the surface or in an ambulacral groove of the mottled star as a commensal. The parasitic ciliate Orchitophrya stellarum has several hosts, one of which is the mottled star. It lives among the spines on the body and arms until the starfish is ready to breed when it moves inside its host, probably entering through a gonopore. It makes its way to the gonads of the male starfish and feeds on the sperm, effectively castrating its host.

Sacculina, a parasitic castrator (highlighted), inspired Philip Fracassi's novella of that name. Parasitic castration is found in nature in greatly reduced parasites that feed on the gonads of their crab hosts, making use of the energy that would have gone into reproduction. It is seen in fiction in Philip Fracassi's 2017 horror novella Sacculina, named for a genus of barnacle-like crustaceans with this lifestyle. It tells the tale of a chartered fishing boat, far from home, that is overrun by parasites from the deep.

These are responsible for the observed signs and symptoms. Hypogonadism can decrease other hormones secreted by the gonads including progesterone, DHEA, anti-Müllerian hormone, activin, and inhibin. Sperm development (spermatogenesis) and release of the egg from the ovaries (ovulation) may be impaired by hypogonadism, which, depending on the degree of severity, may result in partial or complete difficulty or inability to have children. In January 2020, the American College of Physicians issued clinical guidelines for testosterone treatment in adult men with age-related low levels of testosterone.

The mantle cavity, a fold in the mantle, encloses a significant amount of space. It is lined with epidermis, and is exposed, according to habitat, to sea, fresh water or air. The cavity was at the rear in the earliest molluscs, but its position now varies from group to group. The anus, a pair of osphradia (chemical sensors) in the incoming "lane", the hindmost pair of gills and the exit openings of the nephridia ("kidneys") and gonads (reproductive organs) are in the mantle cavity.

Dolioletta gegenbauri is a small, transparent, gelatinous marine invertebrate up to one centimetre long. It has a complex life cycle and exists in several forms of which the gonozooid, or mature zooid with gonads, is the most often seen. It is roughly cylindrical with a siphon at both of the flat ends, and has 8 bands of muscle arranged like hoops round a barrel. The U-shaped gut and other organs can be seen through the test which is pierced by 10 to 40 gill slits.

The preservation of the animal is unusual in several respects. Firstly, in Orsten-type microfossils muscle preservation is very rare and it is much more common that other tissue is preserved in phosphate in this way. Secondly, when onchyophorans are rotted in seawater or saline solution, body wall muscles are the first parts to decay, well before organs such as gonads or the gut and before harder parts such as the hollow claws present in this species, of which only the inner bases remain.

When removed from the water, the animal often violently expels water from these siphons, hence the common name of "sea squirt". The body itself can be divided into up to three regions, although these are not clearly distinct in most species. The pharyngeal region contains the pharynx, while the abdomen contains most of the other bodily organs, and the postabdomen contains the heart and gonads. In many sea squirts, the postabdomen, or even the entire abdomen, are absent, with their respective organs being located more anteriorly.

A tunicate group from East Timor Almost all ascidians are hermaphrodites and conspicuous mature ascidians are sessile. The gonads are located in the abdomen or postabdomen, and include one testis and one ovary, each of which opens via a duct into the cloaca. Broadly speaking, the ascidians can be divided into species which exist as independent animals (the solitary ascidians) and those which are interdependent (the colonial ascidians). Different species of ascidians can have markedly different reproductive strategies, with colonial forms having mixed modes of reproduction.

The two spawning seasons for Siganus sutor are January/February and May/June.The presence of these seasons is determined by three factors: (1) temporal changes in the condition factor and relative weight of the gonads, (2) the progression of peaks of maturity stages with seasonal presence of spent fish in the samples, and (3) the seasonal appearance of juveniles.[Ntiba, M. J.; Jaccarini, V. (1990). "Gonad maturation and spawning times of Siganus sutor off the Kenya coast: evidence for definite spawning seasons in a tropical fish".

The stomach occupies most of the interior of the bell and there are a ring of small cream or white gonads round its edge. The colouration of this jellyfish varies, but in general, the bell is translucent and colourless or a pale shade of buff, sometimes with irregular streaks of light brown. The dangling lappets round the edge of the bell are darker brown and the lower parts of the oral tentacles may be brown as well, the upper parts being colourless.Lychnorhiza lucerna Marine Species Identification Portal.

Brachiopods also have colorless blood, circulated by a muscular heart lying in the dorsal part of the body above the stomach. The blood passes through vessels that extend to the front and back of the body, and branch to organs including the lophophore at the front and the gut, muscles, gonads and nephridia at the rear. The blood circulation seems not to be completely closed, and the coelomic fluid and blood must mix to a degree. The main function of the blood may be to deliver nutrients.

Each pedalium bears a small non-retractible tentacle, and the margin of the bell bears either four or eight rhopalia (sensory organs) in the niches between flaps known as lappets. The coronal groove and the creases provide flexibility in the otherwise rather stiff bell. The short manubrium is four- sided and has a large mouth at its tip. The mouth opens into a central stomach which is divided into four pockets by septa, on which are located the gastric filaments and the eight gonads.

August Weismann's germ plasm theory stated that the hereditary material is confined to the gonads. Somatic cells (of the body) develop afresh in each generation from the germ plasm, so changes to the body acquired during a lifetime cannot affect the next generation, as neo-Lamarckism required. Critics of neo- Lamarckism pointed out that no one had ever produced solid evidence for the inheritance of acquired characteristics. The experimental work of the German biologist August Weismann resulted in the germ plasm theory of inheritance.

The first known step of sexual differentiation of a normal XY fetus is the development of testes. The early stages of testicular formation in the second month of gestation requires the action of several genes, one of the earliest and most important of which is SRY: the sex-determining region of the Y chromosome. Mutations of SRY account for many cases of Swyer syndrome. When such a gene is defective, the indifferent gonads fail to differentiate into testes in an XY (genetically male) fetus.

The chunky body shape makes them easy to handle and wounds heal well; individuals recover easily from surgery and can be used repeatedly for further experiments. The oocytes are large and transparent and remain viable when removed from the gonads. They have been used for studies of oocyte maturation, fertilization, and larval development. It has been shown that if the embryo of this starfish is dissociated into its constituent cells, a collection of these cells is capable of re-aggregation into a viable bipinnaria larva.

Taiaroa tauhou is a solitary coral that reproduces solely by means of sexual reproduction. It may be a hermaphrodite, as one individual examined contained both eggs and spermaries (sperm producing organs), but other individuals only contained eggs or were exclusively male. It is unclear whether the gonads in the bisexual individual were attached to the body wall. It may be that the males liberate spermaries which are ingested by the females, resulting in internal fertilisation, and this would mean that the animals are not hermaphroditic.

Elagolix acts as a potent and selective competitive antagonist of the gonadotropin-releasing hormone receptor (GnRHR), the biological target of the hypothalamic peptide hormone gonadotropin-releasing hormone (GnRH). As such, it is a GnRH antagonist. The affinity (KD) of elagolix for the GnRHR is 54 pM. By blocking the GnRHR in the pituitary gland, elagolix suppresses the GnRH-induced secretion of the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary, and thereby decreases the production of sex hormones by the gonads.

A male cyprid larva settles on the externa and fertilises the eggs by antennule penetration, the larvae developing inside the brood chamber. Here they develop directly into cyprid larvae, missing out the nauplius stage of more typical crustaceans. The cyprid larvae are at first unisex, becoming male or female according to what role they play in the reproductive cycle. The presence of this parasite effectively sterilises the host hermit crab, the gonads do not degenerate, but they fail to produce mature eggs and sperm.

Today, neuroendocrinology embraces a wide range of topics that arose directly or indirectly from the core concept of neuroendocrine neurons. Neuroendocrine neurons control the gonads, whose steroids, in turn, influence the brain, as do corticosteroids secreted from the adrenal gland under the influence of adrenocorticotrophic hormone. The study of these feedbacks became the province of neuroendocrinologists. The peptides secreted by hypothalamic neuroendocrine neurons into the blood proved to be released also into the brain, and the central actions often appeared to complement the peripheral actions.

Alatina alata is a transparent box jellyfish with an pyramidal with rounded tip umbrella, smooth exumbrella and thin and transparent mesoglea. The manubrium is short, square, with four simple lips, and without mesenteries joining manubrium walls to subumbrellar stomach walls. Four crescentric gastric phacellae at interradial corners of stomach, disposed horizontally. Three simple to palmate branching velarial canals per octant, each with a velarial lappet bearing a row of 3 to 4 nematocyst warts; Gonads are conspicuous, extending from the base of stomach to nervous ring.

Continuous capillaries are continuous in the sense that the endothelial cells provide an uninterrupted lining, and they only allow smaller molecules, such as water and ions, to pass through their intercellular clefts. Lipid-soluble molecules can passively diffuse through the endothelial cell membranes along concentration gradients. Continuous capillaries can be further divided into two subtypes: :# Those with numerous transport vesicles, which are found primarily in skeletal muscles, fingers, gonads, and skin. :# Those with few vesicles, which are primarily found in the central nervous system.

The colonies of dead man's fingers are nearly always either male or female, although a small number of hermaphrodite colonies are found. Colony growth occurs mainly in the first half of the year with the polyps becoming inactive in late summer, and the base tissue turning reddish or brownish due to the growth of algae and hydroids on the surface. At this time the gonads are developing and spawning occurs in December and January. Populations have been found to synchronize their gametogenesis and spawning activities.

46,XY gonadal dysgenesis is characteristic of male hypogonadism with karyotype 46,XY. In embryogenesis, the development of the male gonads is controlled by the testis determining factor located on the sex-determining region of the Y chromosome (SRY). The male gonad is dependent on SRY and the signalling pathways initiated to several other genes to facilitate testis development. The aetiology of 46,XY gonadal dysgenesis can be caused by mutations in the genes involved in testis development such as SRY, SOX9, WT1, SF1, and DHH.

Sperm from multiple males may compete through this mechanism. Most female birds have a single ovary and a single oviduct, both on the left side, but there are exceptions: species in at least 16 different orders of birds have two ovaries. Even these species, however, tend to have a single oviduct. It has been speculated that this might be an adaptation to flight, but males have two testes, and it is also observed that the gonads in both sexes decrease dramatically in size outside the breeding season.

Nautiluses reproduce by laying eggs. Gravid females attach the fertilized eggs, either singly or in small batches, to rocks in warmer waters (21-25 Celsius), whereupon the eggs take eight to twelve months to develop until the juveniles hatch. Females spawn once per year and regenerate their gonads, making nautiluses the only cephalopods to present iteroparity or polycyclic spawning. Nautiluses are sexually dimorphic, in that males have four tentacles modified into an organ, called the "spadix", which transfers sperm into the female's mantle during mating.

Broodstock conditioning is the process of bringing adults into spawning condition by promoting the development of gonads. Broodstock conditioning can also extend spawning beyond natural spawning periods, or for production of species reared outside their natural geographic range with different environmental conditions. Some hatcheries collect wild adults and then bring them in for conditioning whilst others maintain a permanent breeding stock.Kungvankij P., Tiro L.B. Jr, Pudadera B.J. Jr., Potesta I.O. (1985) Training Manual: Biology and Culture of Sea Bass (Lates calcarifer) FAO, Rome, 75pp.

Unlike 17α-hydroxyprogesterone, 21-deoxycortisol is not produced in the gonads and is uniquely adrenal-derived. Hence, 21-deoxycortisol is a more specific biomarker of 21-hydroxylase deficiency than is 17α-hydroxyprogesterone. The corticosteroid activity of 21-deoxycortisol is lower to that of cortisol. As 21-deoxycortisol can be at high levels in congenital adrenal hyperplasia, and it has structural similarity to cortisol, it can cross-react in immunoassays, resulting in a falsely normal or high cortisol result, when the true cortisol is actually low.

Ovary of a marine fish and its parasite, the nematode Philometra fasciati Birds have only one functional ovary (the left), while the other remains vestigial. Ovaries in females are analogous to testes in males, in that they are both gonads and endocrine glands. Ovaries of some kind are found in the female reproductive system of many animals that employ sexual reproduction, including invertebrates. However, they develop in a very different way in most invertebrates than they do in vertebrates, and are not truly homologous.

The branch initially focused on thyroid physiology and diseases, but later expanded to encompass diabetes as well as disorders of growth hormone and the gonads. Under Rall, the CEB hosted many visiting international scientists and had a longstanding association with the laboratory run by Nino Salvatore in Italy. In 1962, Rall was appointed Director of Intramural Research of the National Institute of Diabetes and Digestive and Kidney Diseases. He served as Deputy Director for Intramural Research for NIH in 1983 until his retirement in 1990.

After female (XX) germ cells collect in the undifferentiated gonads, the up-regulation of Stra8 is required for germ cell differentiation into an oogonium and eventually enter meiosis. One major factor that contributes to the up-regulation of Stra8, is the initiation of the β-Catenin signaling pathway via RSPO1, which is also responsible for ovary differentiation. Since RSPO1 is produced in somatic cells, this protein acts on germ cells in a paracrine mode. Rspo1, however, is not the only factor in Stra8 regulation.

They also lack parapodia and appendages on the prostomium, the body and the periproct (terminal segment on which the anus is located). The gonads are located in a few segments near the clitellum, with the testes being anterior to the ovaries. There are four bundles of one to twenty-five chaetae on each segment; these have muscles attached to their bases and can be extended or retracted. Leeches and their relatives, in the subclass Hirudinea, mostly have flattened bodies, usually tapered at both ends.

The SRY (Sex-determining Region of the Y chromosome) directs male development in mammals by inducing the somatic cells of the gonadal ridge to develop into a testis, rather than an ovary. Sry is expressed in a small group of somatic cells of the gonads and influences these cells to become Sertoli cells (supporting cells in testis). Sertoli cells are responsible for sexual development along a male pathway in many ways. One of these ways involves stimulation of the arriving primordial cells to differentiate into sperm.

Brooding anemone (Epiactis prolifera) with developing young Unlike other cnidarians, anemones (and other anthozoans) entirely lack the free-swimming medusal stage of their lifecycle; the polyp produces eggs and sperm, and the fertilized egg develops into a planula larva which develops directly into another polyp. Both sexual and asexual reproduction can occur. The sexes in sea anemones are separate in some species, while other species are sequential hermaphrodites, changing sex at some stage in their life. The gonads are strips of tissue within the mesenteries.

Beroe ovata is a hermaphrodite, and the gonads are located under the rows of cilia. Gametes are liberated into the water and fertilisation is external. The eggs are large and transparent and the planktonic larvae pass through a number of developmental stages before adopting the adult form. When the comb jelly Mnemiopsis leidyi was accidentally introduced into the Black Sea in the 1980s, it flourished and by 1989 there were as many as 400 individuals per cubic metre of water (more than 10 per cubic foot).

The stages of Mullerian duct development in the human embryo and its associated outcomes during normal and impaired development. The human female reproductive system consists of the gonads, external genitalia and the Mullerian duct system. Initially in the embryo, both the Wolffian (mesonephric) and Mullerian (paramesonephric) ducts are present, where development of the Wolffian ducts give rise to the male reproductive tract and development of the Mullerian ducts give rise to the female reproductive tract. These ducts are identical until approximately week 6 of embryonic development.

Nomeus gronovii, the man-of-war fish, or bluebottle fish, is a species of fish in the family Nomeidae, the driftfish. It is native to the Atlantic, Pacific and Indian Oceans, where adults are generally found at depths from . It is notable for its ability to live within the deadly tentacles of a siphonophore, the Portuguese man o' war, upon whose tentacles and gonads it feeds. The fish is striped with blackish-blue blemishes covering its body, and the caudal fin is extremely forked.

Little is known of the biology of this crayfish. It is probably an opportunistic omnivorous scavenger and may feed on the Georgia blind salamander (Haideotriton wallacei) which shares the same range. It has a low metabolic rate, perhaps associated with the limited availability of food, and consequently it is possible that it may live for twenty years or more. Males with ripe gonads have been found between July and October but females bearing eggs have not been found and nor have juveniles or sub-adults.

The purpose of these structures is debated—they are light-sensitive and may serve to detect bioluminescent prey; it has also been proposed that the organs themselves may be luminescent and act as lures. Ipnops have a well-developed lateral line, which has been suggested to have a primary sensory function given the degenerate state of their other senses. Like other bathypteroid fishes, Ipnops is hermaphroditic, with male and female gonads combined into a single organ. External fertilization is likely, possibly with ripe eggs held by the pelvic fins to facilitate fertilization.

The nervous system has small ganglia around the oesophagus from which two pairs of main nerve cords run through the body; one pair supplying the foot, and the other the visceral organs. As in the chitons, these main nerve cords are connected by a series of lateral nerves, giving the layout of the nervous system an appearance somewhat like a ladder. There are two pairs of gonads, which release gametes into the water through one of the pairs of nephridia. The sexes are separate, and fertilisation is external.

When pubarche occurs prematurely (in early or mid-childhood), it is referred to as premature pubarche or precocious puberty and may warrant an evaluation. Premature adrenarche is the most common cause of premature pubarche. Early occurrences can arise due to congenital adrenal hyperplasia, androgen-producing tumors of the adrenals or gonads. When adrenarche, central puberty, and all pathologic conditions have been excluded, the term isolated premature pubarche is used to describe the unexplained development of pubic hair at an early age without other hormonal or physical changes of puberty.

It is also a simultaneous hermaphrodite but its reproductive method varies across its range. Each polyp usually contains twelve gonads, the six nearest the mouth being ovaries and the other six spermaries. In South Africa the gametes are released simultaneously from both of these and spawning takes place at new moon in January (mid-summer) with the gametes being liberated into the water column. However, at Enewetak Atoll in the Marshall Islands, this species has been shown to fertilise the eggs internally and brood the developing planula larvae.

Some potential risk factors include smoking, alcohol consumption, specific genetic syndromes, congenital abnormalities, and more. Among these risk factors, specifically, the Klinefelter syndrome (KS) and cryptorchidism increase the possibility for males having testicular tumors and the Turner syndrome (TS) affects the risk of having ovarian cysts in females. Swyer syndrome and other syndromes may increase the risk of having EGCTs in the gonads. The diagnosis is made by a combination of picture-taking testaments, physical examinations, and the investigation of samples from blood, urine, and tissue by using microscope.

The gonads of the West Indian sea egg are traditionally consumed in the West Indies and there is an important fishery in Barbados. Urchins are collected by skin diving and it used to be possible to collect a thousand in a few hours. In order to conserve stocks, a closed period was introduced during the breeding season (May to August) during which no sea urchins were allowed to be taken. Despite this, sea urchin numbers have declined during the late twentieth century and they are now uncommon and the fishery non-viable.

The biology and ecology of the mesobathypelagic jellyfishes is poorly known. Their gelatinous bodies tend to have a low proportion of protein; P. rufescens has a protein content of 0.1% of the body dry weight as compared to an average of 4% for all gelatinous taxa. Some parts of the body have a higher nitrogenous content than others, and in the Pacific, leatherback sea turtles, whose diet consists largely of jellyfish, have been observed feeding on their gonads and tentacles, the parts which have the highest nutritional values.

They can grow up to an average length of 22 cm with the largest reaching up to 40 cm, and reach maturity around 16 cm or 200 grams with some growing as much as 300 grams in one year. It is unknown how long they live undisturbed, but they can live to at least 10 years. Their gonads are found through a single genital orifice on their dorsal anterior end. Their digestive system is made up of a mouth, an esophagus, a stomach, an intestine, a cloaca, and an anus.

The arcuate nucleus of the hypothalamus is the driver of the reproductive system. It has neurons which generate and release pulses of GnRH into the portal venous system of the pituitary gland. The arcuate nucleus is affected and controlled by neuronal input from other areas of the brain and hormonal input from the gonads, adipose tissue and a variety of other systems. The pituitary gland responds to the pulsed GnRH signals by releasing LH and FSH into the blood of the general circulation, also in a pulsatile pattern.

Intersex people are born with variations in physical and sex characteristics including those of the chromosomes, gonads, sex hormones, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit the typical definitions for male or female bodies". Such variations may involve genital ambiguity, and combinations of chromosomal genotype and sexual phenotype other than XY-male and XX-female. Preimplantation genetic diagnosis allows the elimination of embryos and fetuses with intersex traits and thus has an impact on discrimination against intersex people.

While in its male swimming form, it resembles a typical isopod with antennae, jointed limbs, and a segmented exoskeleton. When fully mature, the adult female form of H. balani is reduced to a bloated, star-shaped egg sac, up to 8 mm in length inhabiting the mantle cavity of its barnacle host. The barnacle host species are simultaneous hermaphrodites, with both male and female gonads in each adult. H. balani feeds on its host's ovarian fluid, so the barnacle loses female reproductive ability, but can still produce sperm.

Despite his interest in health, Cummings was also a methamphetamine addict from the mid-1950s until the end of his life. In 1954, while in New York to star in the Westinghouse Studio One production of Twelve Angry Men, Cummings began receiving injections from Max Jacobson, the notorious "Dr. Feelgood". His friends Rosemary Clooney and José Ferrer recommended the doctor to Cummings, who was complaining of a lack of energy. While Jacobson insisted that his injections contained only "vitamins, sheep sperm, and monkey gonads", they actually contained a substantial dose of methamphetamine.

At first they fed on food particles in the gastrovascular cavity of the jellyfish but after 11 days they developed parasitic habits and began to feed on their hosts' gonads, moving on later to other tissues. One anemone larva was able to consume a gonad completely in two days. Thirty-one days after becoming parasitic they had developed into juvenile sea anemones with an adult body plan. At this stage they detached themselves from their hosts and dropped to the sea floor where they started to live independently.

Pea crabs are small crustaceans about the size of a pea or dime, with a "smooth dorsal surface of the carapace, or upper exoskeleton". The exoskeleton of males is hard and circular and has eyes and antennae extending from their fronts, and the chelipeds are more robust in males than in females, which have more elongated chelipeds. The bodies of the female pea crabs are often translucent and show the inner organs and gonads as yellow and red, with the males being a "more yellowish-grey with patches of brown".

Osr1 is the earliest marker of the intermediate mesoderm, which will form the gonads and kidneys. This expression is not essential for the formation of intermediate mesoderm but for the differentiation towards renal and gonadal structures. Osr1 acts upstream of and causes expression of the transcription factors Lhx1, Pax2 and Wt1 which are involved in early urogenital development. In normal kidney development, activation of the Pax2-Eya1-Hox11 complex and subsequent activation of Six2 and Gdnf expression allows for branching of the ureteric bud and maintenance of the nephron-forming cap mesenchyme.

All three stages of kidney formation are affected in mice lacking Osr1 expression and are similar to mice with reduced Wt1 and Pax2 expression – the Wollfian duct is abnormal, there are fewer mesonephric tubules and the kidney-forming metanephros and gonads are missing. In embryonic day 10.5, embryos lacking Osr1 expression fail to grow a ureteric bud that migrates into the uncompacted metanephric mesenchyme. The lack of inductive signals from the ureteric bud combined with a downstream reduction in Pax2 expression results in apoptosis and agenesis of the kidney.

For example, erythrocytes, macrophages and plasma cells are produced in the anterior kidney (or pronephros) and some areas of the gut (where granulocytes mature.) They resemble primitive bone marrow in hagfish. Cartilaginous fish (sharks and rays) have a more advanced immune system. They have three specialized organs that are unique to chondrichthyes; the epigonal organs (lymphoid tissue similar to mammalian bone) that surround the gonads, the Leydig's organ within the walls of their esophagus, and a spiral valve in their intestine. These organs house typical immune cells (granulocytes, lymphocytes and plasma cells).

Genital reconstructive surgery was pioneered between 1930 and 1960 by urologist Hugh Hampton Young and other surgeons at Johns Hopkins Hospital in Baltimore and other major university centers. Understanding of intersex conditions was relatively primitive, based on identifying the type of gonad(s) by palpation or by surgery. Since ability to determine even the type of gonads in infancy was limited, sex of assignment and rearing were determined mainly by the appearance of the external genitalia. Most of Young's intersex patients were adults willingly seeking his help with physical problems of genital function.

Hypoandrogenism is caused primarily by either dysfunction, failure, or absence of the gonads (hypergonadotropic) or impairment of the hypothalamus or pituitary gland (hypogonadotropic), which in turn can be caused by a multitude of different stimuli, including genetic conditions (e.g., GnRH/gonadotropin insensitivity and enzymatic defects of steroidogenesis), tumors, trauma, surgery, autoimmunity, radiation, infections, toxins, drugs, and many others. Alternatively, it may be the result of conditions such as androgen insensitivity syndrome or hyperestrogenism. More simply, old age may also be a factor in the development of hypoandrogenism, as androgen levels decline with age.

A post-anal tail is present in juvenile member of the acorn worm family Harrimaniidae. The prosome of pterobranchs is specialized into a muscular and ciliated cephalic shield used in locomotion and in secreting the coenecium. The mesosome extends into one pair (in the genus Rhabdopleura) or several pairs (in the genus Cephalodiscus) of tentaculated arms used in filter feeding. The metasome, or trunk, contains a looped digestive tract, gonads, and extends into a contractile stalk that connects individuals to the other members of the colony, produced by asexual budding.

Spawning in the Pacific oyster occurs at 20 °C. This species is very fecund, with females releasing about 50-200 million eggs in regular intervals (with a rate at 5-10 times a minute) in a single spawning. Once released from the gonads, the eggs move through the suprabranchial chambers (gills), are then pushed through the gill ostia into the mantle chamber, and finally are released in the water, forming a small cloud. In males, the sperm is released at the opposite end of the oyster, along with the normal exhalent stream of water.

Clinical indications of infection in salmons include lethargy, loss of body mass, darkening of the skin, ascites, exopthalmia and kidney pustules, These symptoms vary from one salmonid species to another, and also depend on life stage of the host. Internally, infection with C. shasta affects entire digestive tract, liver, gall bladder, spleen, gonads, kidney, heart, gills, and muscle tissues. Infection with C. shasta in adult chinook salmon causes mortality through intestinal perforations and co-occurring bacterial infections. Cold temperatures and salinity may reduce progress of disease, but do not eliminate infection.

Mutations in Pten, CyclinD1, Dmrt1 and Dnd1 oncogenes in mice resulted in testicular teratomas, and variants are related with the same tumours in humans. Tumour formation (neoplasm) from foetal gonocytes suggests that they are incapable of maintaining proliferative arrest and resistance to further differentiation. Even so, the origin of these teratomas could be distinct from the PGCs failing in migration. Extragonadal germ cell tumours (GCTs) evolve due to a lesion along the midline of the body, prior to the migratory PGCs movement through the hindgut and the medial mesentery to the gonads.

The two parts so formed are about equal in size and each can regenerate the lost organs. The gut is the most important organ for survival and both front and rear portions are able to feed again within two months. The gonads take longer to regenerate. In the Bermudan population studied, no juvenile specimens of Holothuria parvula were found during the course of the study, and the researchers thought it likely that little or no recruitment involving planktonic larvae takes place and that fission is an annual event and the main means of reproduction.

The signaled by retinoic acid 8 (Stra8) gene is activated only upon stimulation by retinoic acid and expresses a cytoplasmic protein in the gonads of male and female vertebrates. This protein functions to initiate the transition between mitosis and meiosis, aiding in spermatogenesis and oogenesis. In females, its signaling begins 12.5 days after conception, is localized in the primordial germ cells of female ovaries, and ushers in the first stage of meiosis. Male expression begins postnatally and continues throughout life, matching the need of spermatogenesis compared to the limited window of oogenesis in females.

The eyeballs were likely thicker, stronger, and more convex than in other cephalopods. The mantle cavity of cephalopods serves to contain the gills, gonads, and other organs; also, water is siphoned into and expelled out of the mantle cavity via a tube opening near the arms of the animal, the hyponome, for jet propulsion. Though the hyponome was well-developed in belemnites, the phragmocone was large, implying a small mantle cavity and thus less jet propulsion efficiency. Like some modern squid, belemnites may have mainly used large fins to coast along currents.

Fromia indica Nectria ocellata Neoferdina insolita Goniasteridae are usually middle-sized sea stars with a characteristic double range of marginal plates bordering the disk and arms. Most of them have five arms, often short and triangular, around a broad central disc; many species are pentagonal or subpentagonal, covered densely with granular, seed-like protuberances, hence the name of the family "seed-star" (gonium+aster). The aboral face is often covered with tiny spines looking like paxillae. Pedicellariae are often valvate, and the gonads are located at the interradius.

The reproductive cycle of this chiton happens annually. They reproduces between summer and mid-winter demonstrated with an increase in gonads size. Some earlier observations showed that their reproductive period might be effected by the changes of external environment, such as water temperature or the abundance of food supply. The major cause of triggering T. Insignis’s reproductive period was believed to be the water temperature, which is between 7 to 8 °C in spring.. However, the data from 1971 showed that T. Insignis started their reproductive cycle when the temperature was still 6.3 °C.

The next steps of the evaluation usually include checking a karyotype and imaging of the pelvis. The karyotype reveals XY chromosomes and the imaging demonstrates the presence of a uterus but no ovaries (the streak gonads are not usually seen by most imaging). Although an XY karyotype can also indicate a person with complete androgen insensitivity syndrome, the absence of breasts, and the presence of a uterus and pubic hair exclude the possibility. At this point it is usually possible for a physician to make a diagnosis of Swyer syndrome.

Before the work of Beard, the use of enzymes to treat cancer had almost never been proposed; an exception is the advocation for using papaya enzymes by indigenous populations, an argument not scientifically developed. Beard, on the other hand, ultimately recommended the use of pancreatic enzymes to treat cancer from his extensive knowledge base of embryology. In 1902, Beard determined that cancer developed because of germ cells that lost direction to the gonads during the process of embryogenesis. These problematic germ cells ultimately developed into an "irresponsible trophoblast", as coined by Beard.

Adults spend most of the year in bays and estuaries, migrating into deeper offshore waters to spawn during fall and winter (peaking between late October-mid-December). Specimens with ripe gonads have been collected at depths of 20–40 m in the eastern Gulf of Mexico. Larvae migrate inshore during January–February. The age at maturity for females is 1 year (FWRI 2010) with all mature by 2 years and size at 50% maturity is 35–38 cm TL. Males reach maturity between 30–35 cm TL. Females grow faster and larger than males.

After opposition MP John Cannis heckled him as a racist in the House of Commons, he replied "Do you have the fortitude or the gonads to stand up and come across here and say that to me, you son of a bitch?" Eventually the Speaker chided both men for unparliamentary language. Later that same year, after Progressive Conservative leader Jean Charest called him a bigot in a heated exchange, Stinson replied that Charest was a "fat little, chubby, little sucker." In 1999, he was accused of challenging Liberal MP Steve Mahoney to fight.

The mouth is at the centre of the oral disc and leads into a tubular pharynx which descends for some distance into the body before opening into the gastrovascular cavity that fills the interior of the body and tentacles. Unlike other cnidarians however, the cavity is subdivided by a number of radiating partitions, thin sheets of living tissue, known as mesenteries. The gonads are also located within the cavity walls. The polyp is retractable into the corallite, the stony cup in which it sits, being pulled back by sheet-like retractor muscles.

50px Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Stony corals have a great range of reproductive strategies and can reproduce both sexually and asexually. Many species have separate sexes, the whole colony being either male or female, but others are hermaphroditic, with individual polyps having both male and female gonads. Some species brood their eggs but in most species, sexual reproduction results in the production of a free-swimming planula larva that eventually settles on the seabed to undergo metamorphosis into a polyp.

Some polychaetes breed only once in their lives, while others breed almost continuously or through several breeding seasons. While most polychaetes remain of one sex all their lives, a significant percentage of species are full hermaphrodites or change sex during their lives. Most polychaetes whose reproduction has been studied lack permanent gonads, and it is uncertain how they produce ova and sperm. In a few species the rear of the body splits off and becomes a separate individual that lives just long enough to swim to a suitable environment, usually near the surface, and spawn.

At nine weeks, male differentiation of the gonads and the testes is well underway. Internal changes include the formation of the tubular seminar Chris tubules in the Rete testis from the primary sex cord. Developing on the outside surface of each testis is a Phibro muscular cord called the gubernaculum. This structure attaches to the inferior portion of the testis and extends to the labial sacral fold of the same side at the same time, a portion of the embryonic mesonephric duct adjacent to the testis becomes attached and convoluted informs the epididymis.

Budding sites vary by species; from the tentacle bulbs, the manubrium (above the mouth), or the gonads of hydromedusae. In a process known as strobilation, the polyp's tentacles are reabsorbed and the body starts to narrow, forming transverse constrictions, in several places near the upper extremity of the polyp. These deepen as the constriction sites migrate down the body, and separate segments known as ephyra detach. These are free-swimming precursors of the adult medusa stage, which is the life stage that is typically identified as a jellyfish.

Levinseniella deblocki is a parasitic fluke that occurs in salt marshes along the eastern coast of the Gulf of Mexico. Its life cycle includes a metacercarial stage in the gonads of fiddler crabs (Uca) and one intermediate host is a gastropod from the genus Heleobops (family Hydrobiidae). Adults are found in the digestive tracts of marsh rice rats (Oryzomys palustris), raccoons (Procyon lotor), and clapper rails (Rallus crepitans). Within the subgenus Austromicrophallus, L. deblocki is most similar to the European L. polydactyla and the Californian L. ophidea, but differs in size, ecology, and morphology.

Aromatase, also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily (), which are monooxygenases that catalyze many reactions involved in steroidogenesis. In particular, aromatase is responsible for the aromatization of androgens into estrogens. The enzyme aromatase can be found in many tissues including gonads (granulosa cells), brain, adipose tissue, placenta, blood vessels, skin, and bone, as well as in tissue of endometriosis, uterine fibroids, breast cancer, and endometrial cancer.

The AGM region is derived from the mesoderm layer of the embryo. During organogenesis (around the fourth week in human embryos), the visceral region of the mesoderm, the splanchnopleura, transforms into distinct structures consisting of the dorsal aorta, genital ridges and mesonephros. For a period during embryonic development, the dorsal aorta produces hematopoietic stem cells, which will eventually colonise the liver and give rise to all mature blood lineages in the adult. By birth, the dorsal aorta becomes the descending aorta, while the genital ridges form the gonads.

Assigned female at birth (AFAB): a person of any age and irrespective of current gender whose sex assignment at birth resulted in a declaration of "female". For example, when an attending midwife or physician announces, "It's a girl!" Synonyms: female assigned at birth (FAAB) and designated female at birth (DFAB). Intersex, in humans and other animals, describes variations in sex characteristics including chromosomes, gonads, sex hormones, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies".

Nomeidae, the driftfishes, are a family of percomorph fishes found in tropical and subtropical waters throughout the world. The family includes about 16 species. The largest species, such as the Cape fathead, Cubiceps capensis, reach 1 m in length. Several species are found in association with siphonophores (which are colonies of tiny individual animals that have specialised functions which resemble jellyfish) such as the Portuguese man o' war; the man-of-war fish, Nomeus gronovii, is known to eat its tentacles and gonads, as well as feeding on other jellyfishes.

Congrogadus are secretive fish which hide among rocks and coral rubble and they occur from the surface down to . They feed mainly on crustaceans but larger specimens will take fish, and their large mouth enable them to swallow quite large prey. Most species of the subfamily are protogynous hermaphrodites but Congrogadus subducens appears to be different because the females greater than long have been observed to have small gonads, a feature which almost certainly means that they are not protogynous hermaphrodites. All of this subfamily lay eggs in a small clump.

The uptake to the liver depends on the individual and increases with age. In the bones, americium is first deposited over cortical and trabecular surfaces and slowly redistributes over the bone with time. The biological half-life of 241Am is 50 years in the bones and 20 years in the liver, whereas in the gonads (testicles and ovaries) it remains permanently; in all these organs, americium promotes formation of cancer cells as a result of its radioactivity.Frisch, Franz Crystal Clear, 100 x energy, Bibliographisches Institut AG, Mannheim 1977, , p.

The chelipeds in P. zealandicus are much hairer at their tips than those of P. planifrons. The four pairs of well-developed walking legs are used for most movement, but the pleopods are small and no use for swimming; when alarmed, koura can flick their tails forward violently to propel themselves backwards at speed. They can be sexed by looking at their underside; males have a pair of gonads that protrude from the base of the fourth pair of legs, while females have holes at the base of the second pair of legs.

Trachymedusae are identifiable by their umbrella edge which lacks any lobes. The tentacles at the edge of the umbrellas are solid or solid and hollow, there is a thickened tissue ring that has a large number of nematocysts, the radial canals number from 4 to 6 to 8 and more than 8, though 8 is the most common amount found. The sensory clubs can be open or closed with the endodermal axis. The gonads are generally located at the radial canal or where the radial canal and the manubrium connect.

In the roach, river pollution has caused the intersex condition, in which an individual's gonads contain both cells that can make male gametes (such as spermatogonia) and cells that can make female gametes (such as oogonia). Since endocrine disruption also affects humans, teleosts are used to indicate the presence of such chemicals in water. Water pollution caused local extinction of teleost populations in many northern European lakes in the second half of the twentieth century. The effects of climate change on teleosts could be powerful but are complex.

For example, erythrocytes, macrophages and plasma cells are produced in the anterior kidney (or pronephros) and some areas of the gut (where granulocytes mature.) They resemble primitive bone marrow in hagfish. Cartilaginous fish (sharks and rays) have a more advanced immune system. They have three specialized organs that are unique to Chondrichthyes; the epigonal organs (lymphoid tissue similar to mammalian bone) that surround the gonads, the Leydig's organ within the walls of their esophagus, and a spiral valve in their intestine. These organs house typical immune cells (granulocytes, lymphocytes and plasma cells).

Intersex people are born with sex characteristics, such as genitals, gonads and chromosome patterns that, according to the UN Office of the High Commissioner for Human Rights, "do not fit the typical definitions for male or female bodies". Intersex people have many different sex assignments and gender identities, and so there is no presumption that people on this list have any particular sex assigned at birth, nor any particular gender identity. This list consists of well-known intersex people. The individual listings note the subject's main occupation or source of notability.

Depending on the mutation, a person with a 46,XY karyotype and AIS can have either a male (MAIS) or female (CAIS) phenotype, or may have genitalia that are only partially masculinized (PAIS). The gonads are testes regardless of phenotype due to the influence of the Y chromosome. A 46,XY female, thus, does not have ovaries or a uterus, and can neither contribute an egg towards conception nor gestate a child. Several case studies of fertile 46,XY males with AIS have been published, although this group is thought to be a minority.

The sound has been made more noisy and dirty, especially the drums in the verse, and the intro has been shortened. When performed live, elements of the "Grungy Gonads" mix are used in an extended intro and throughout the song. The B-side is "My Joy", the only exclusive B-side from the Songs of Faith and Devotion album, and is a rock track in the vein of "I Feel You". The song was cited by then-member Alan Wilder to be his favourite song from the album together with "In Your Room".

It is a fairly rare chromosomal disorder, with an estimated incidence rate of about 1 in 15,000 live births. The clinical manifestations are highly variable, ranging from partial virilisation and ambiguous genitalia at birth, to patients with completely male or female gonads. Most individuals with this karyotype have apparently normal male genitalia, and a minority have female genitalia, with a significant number of individuals showing genital abnormalities or intersex characteristics. A significantly higher than normal number of other developmental abnormalities are also found in individuals with X0/XY mosaicism.

The part remaining inside, the interna, develops tendrils which spread throughout the crab. They take over the stomach, intestines, and nervous system to absorb nourishment and enable the parasite to control the behavior of its host. The presence of the parasite inhibits the development of the crab's gonads, which eventually atrophy; it also prevents the crab from molting, consequently preventing it from regenerating lost limbs. The parasite causes a male crab to develop certain feminine characteristics including the broadening of its abdomen, while in females, the abdomen becomes narrower and the pleopods degenerate.

Several studies have shown that the interaction of Slit with its receptors is crucial in regulating the processes involved with the formation of organs. As previously discussed, these interactions play a key role in cell migration. Not surprisingly then, this gene has been found expressed during the development of tightly regulated tissues, such as the heart, lungs, gonads, and ovaries. For example, in early development of the heart tube in Drosophila, Slit and two of its Robo receptors guide migrating cardioblasts and pericardial cells in the dorsal midline.

The colonies of red dead man's fingers are nearly always either male or female, although a small number of hermaphrodite colonies are found. Colony growth occurs mainly in the first half of the year with the polyps becoming inactive in late summer, and the base tissue turning reddish or brownish due to the growth of algae and hydroids on the surface. At this time the gonads are developing and spawning occurs in December and January. The polyps feed at various times of the day with their tentacles extended.

Confined to freshwater for its entire lifecycle, Galaxias mungadhan is the only native fish recorded within its current range. Spawning time is unknown and is possibly different from year to year depending on conditions, however gonads of adults collected during mid April 2008 were at an advanced stage of development consistent with a winter/spring spawning season. Collection of juvenile fish, presumed young of the year, of various lengths at different times suggest an extended spawning season from late winter to spring. Able to withstand very cold water less than .

The number of radial canals and whether they are branched or not is variable in this family. Their marginal is branched, with nematocyst clusters on the upper and adhesive organs on the lower branches. The manubrium is cylindrical and in some has perradial pouches and/or above it a dorsal brood pouch; the gonads either surround the manubrium entirely or are carried on manubrial extrusions or (if present) the brood pouch. The mouth is bordered either with clusters of nematocysts, or with short lips of tissue, or fringed with branching tentacles.

Deepsea lizardfish are hermaphrodites, bearing both male and female sex organs, thought to be an adaptation to low population densities. Mature gonads found in samples from November to January off the coast of Virginia show that their reproduction is synchronous, a means of maximizing breeding population densities without increasing the size of the feeding population. Mean fecundity rates of around 32,000 ova per fish were observed for eight specimens. Not much is known about their mating habits; however, larval deepsea lizardfish have been recorded at the surface of the ocean.

S. prolifera is a "stolonate" worm and has an unusual life cycle. When the worm has reached a length of about forty segments, the posterior portion of the worm develops into a stolon inside which the gonads mature. The stolon is either female (pale orange) or male (whitish) and becomes a storage receptacle for the eggs or sperm. Breeding is regulated by the phases of the moon, and when the breeding period arrives, the stolon becomes detached and joins others to swarm in the water column, in a process known as "epitoky".

Androgens act by binding to and activating the androgen receptor, their biological target in the body. Antiandrogens work by blocking androgens from binding to the androgen receptor and/or by inhibiting or suppressing the production of androgens. Antiandrogens that directly block the androgen receptor are known as androgen receptor antagonists or blockers, while antiandrogens that inhibit the enzymatic biosynthesis of androgens are known as androgen synthesis inhibitors and antiandrogens that suppress androgen production in the gonads are known as antigonadotropins. Estrogens and progestogens are antigonadotropins and hence are functional antiandrogens.

The germ cell nuclear factor (GCNF), also known as RTR (retinoid receptor- related testis-associated receptor) or NR6A1 (nuclear receptor subfamily 6, group A, member 1), is a protein that in humans is encoded by the NR6A1 gene. GCNF is a member of the nuclear receptor family of intracellular transcription factors . In adults, GCNH is expressed mainly in the germ cells of gonads and is involved in the regulation of embryogenesis and germ cell differentiation. Its expression pattern suggests that it may be involved in neurogenesis and germ cell development.

The gonads of FANCF mutant mice function abnormally, having compromised follicle development and spermatogenesis as has been observed in other Fanconi anemia mouse models and in Fanconi anemia patients. Histological examination of the testes from FANCF-deficient mice showed that the seminiferous tubules were devoid of germ cells. At 14 weeks of age, FANCF- deficient female mice were almost or completely devoid of primordial follicles. It was concluded that FANCF-deficient mice display a rapid depletion of primordial follicles at a young age resulting in advanced ovarian aging.

Embryonated Microphallus eggs are ingested from sediment and hatch in the snail's gut, penetrate the intestine, and migrate to the gonads and digestive gland. Following successful establishment, the parasite then undergoes asexual reproduction, replacing much of the host's reproductive tissue and digestive gland, which results in complete sterilization of the snail. The first visible parasite developmental stages (blastocercariae) are detectable after approximately 75 days post- exposure and metacercariae are common by 90 days post-exposure at 16 °C in the lab. The life cycle is completed when snails containing metacercariae are consumed by waterfowl.

Male juvenile Esmeraldas woodstars were previously misidentified by researchers as adult females because of their similar appearance and extremely small gonads. Male juveniles have white underparts, a yellowish-brown throat with a few purple feathers, and a distinctive rounded, green tail with a rufous-cinnamon base and pale cinnamon to whitish tips. Young Esmeraldas woodstars that are still nest-bound have yellowish-brown underparts with green and cinnamon wings. Male Esmeraldas woodstars that have recently left their nest are similar to male juveniles but without the purple feathers on their throat.

Their main conclusion was that pineal gland hormones affected the size of rats' gonads, although the hormones had not yet been identified. Melatonin was originally discovered by Aaron Lerner, a Yale dermatologist, and colleagues, who had hoped it could be used to treat vitiligo. Although melatonin did not prove to be relevant to dermatology treatments, it was quickly confirmed to be secreted by the pineal gland to affect the brain. Further research found that circadian melatonin rhythms persisted under constant darkness, which suggested that light alone is not responsible for the cycle of melatonin secretion.

"True hermaphroditism," which is clinically known as ovotesticular disorder of sex development, is a medical term for an intersex state in which a human is born with both testicular and ovarian tissue. Often one or both gonads is an ovotestis which contains both types of tissue. It is similar in some ways to mixed gonadal dysgenesis but the conditions can be distinguished histologically. The condition has several effects on the body, one of which is imbalanced hormonal output, which is why it is currently considered a disqualifying condition for military service in the United States.

In each species, they are expressed by a subset of neurons as well as at sites of pattern formation and morphogenesis. In Drosophila, a teneurin known as ten-m or Odz is a pair-rule gene, and its expression is required for normal development. The knockdown of teneurin (ten-1) expression in C. elegans with RNAi leads to abnormal neuronal pathfinding and abnormal development of the gonads. The intracellular domain of some, if not all, teneurins can be cleaved and transported to the cell nucleus, where it proposed to act as a transcription factor.

Females in some of these species contain large, developed ovaries and free-living males have large testes, suggesting these sexually mature individuals may spawn during a temporary sexual attachment that does not involve fusion of tissue. Males in these species also have well-toothed jaws that are far more effective in hunting than those seen in symbiotic species. Sexual symbiosis may be an optional strategy in some species of anglerfishes. In the Oneirodidae, females carrying symbiotic males have been reported in Leptacanthichthys and Bertella—and others that were not still developed fully functional gonads.

The embryological link between the urinary tract, the genital system, and the gastrointestinal tract is the basis of the radiation of pain to the gonads, as well as the nausea and vomiting that are also common in urolithiasis. Postrenal azotemia and hydronephrosis can be observed following the obstruction of urine flow through one or both ureters. Pain in the lower- left quadrant can sometimes be confused with diverticulitis because the sigmoid colon overlaps the ureter, and the exact location of the pain may be difficult to isolate due to the proximity of these two structures.

In typical female differentiation, the Müllerian duct system develops into the uterus, Fallopian tubes, and inner third of the vagina. In males, the Müllerian duct-inhibiting hormone MIH causes this duct system to regress. Next, androgens cause the development of the Wolffian duct system, which develops into the vas deferens, seminal vesicles, and ejaculatory ducts. By birth, the typical fetus has been completely "sexed" male or female, meaning that the genetic sex (XY-male or XX-female) corresponds with the phenotypical sex; that is to say, genetic sex corresponds with internal and external gonads, and external appearance of the genitals.

An Extracranial Germ-Cell Tumor (EGCT) occurs in the abnormal growth of germ cells in the gonads (testes or ovaries) and the areas other than the brain via tissue, lymphatic system, or circulatory system. The tumor can be benign or malignant (cancerous) by its growth rate. According to the National Cancer Institute and St. Jude Children's Research Hospital, the chance of children who are under 15 years old having EGCTs is 3%, in comparison to adolescents, a possibility of 14% with aged 15 to 19 can have EGCTs. There is no obvious cut point in between children and adolescents.

At least three species are known to have evolved separate sexes (dioecy); Ocyropsis crystallina and Ocyropsis maculata in the genus Ocyropsis and Bathocyroe fosteri in the genus Bathocyroe. The gonads are located in the parts of the internal canal network under the comb rows, and eggs and sperm are released via pores in the epidermis. Fertilization is generally external, but platyctenids use internal fertilization and keep the eggs in brood chambers until they hatch. Self- fertilization has occasionally been seen in species of the genus Mnemiopsis, and it is thought that most of the hermaphroditic species are self-fertile.

If women have organs that resemble those of men, and since men obviously experience an orgasm, the woman must too. Women needed to orgasm to produce fluids during intercourse that would stir with the male ejaculate to conceive a child. Laqueur notes that "the fact that women had gonads like men, that they had sexual desires, that they generally produced fluid during intercourse and presumably showed signs of 'delight and concussion', all confirmed the orgasm/conception link."Laqueur (1999), 100 Albrechet von Haller, an eighteenth-century biologist, felt that male and female sexual experiences were the same.

Evidence indicates past solar particle event (SPE) radiation levels that would have been lethal for unprotected astronauts. However, due to the currently used risk models for endometrial, ovarian and breast cancer, women at NASA can currently only spend half as much time on missions as men, which limits their career options compared to men. German standards for pregnant woman set a limit of 50 mSv/year for the gonads (ovaries) and uterus, and 150 mSv/year for the breasts. Astronauts on Apollo and Skylab missions received on average 1.2 mSv/day and 1.4 mSv/day respectively.

Gonadotropin-releasing hormone (GnRH) insensitivity is a rare autosomal recessive genetic and endocrine syndrome which is characterized by inactivating mutations of the gonadotropin-releasing hormone receptor (GnRHR) and thus an insensitivity of the receptor to gonadotropin-releasing hormone (GnRH), resulting in a partial or complete loss of the ability of the gonads to synthesize the sex hormones. The condition manifests itself as isolated hypogonadotropic hypogonadism (IHH), presenting with symptoms such as delayed, reduced, or absent puberty, low or complete lack of libido, and infertility, and is the predominant cause of IHH when it does not present alongside anosmia.

The mouse Polycomb group (PcG) protein M33 maintains repressed states of developmentally important genes, including homeotic genes and forms nuclear complexes with other PcG members. e.g.BMI1. It also direct and/or indirect controls the vicinity of Hox genes regulatory regions, which are the accessibility of retinoic acid response elements . The deletion of Cbx2/M33 in mice results in male-to-female sex reversal, homeotic transformations of the axial skeleton, and growth retardation. The expression of Sry and Sox9 genes in gonads of XY Cbx2-knockout mice is reduced, suggesting that Cbx2 is required for the expression of Sry in gonadal development.

Laird began her career in 1975 at the University of Stirling Aquatic Pathobiology Unit, on a Shell Fellowship. She also published key papers on basic techniques now considered routine: freeze branding of juvenile salmon, and benzocaine as a fish anaesthetic. The following year she obtained Nuffield Foundation funding for a project at Aberdeen University on methods of inducing auto-immune rejection of fish gonads. She applied her fundamental knowledge of life cycles of salmon to the developing aquaculture industry in Scotland and Norway which at that time was struggling with problems of control of sexual maturation in salmon.

In some extreme cases, the vagina has been reported to be aplastic (resembling a "dimple"), though the exact incidence of this is unknown. The gonads in these women are not ovaries, but instead, are testes; during the embryonic stage of development, testes form in an androgen-independent process that occurs due to the influence of the SRY gene on the Y chromosome. They may be located intra-abdominally, at the internal inguinal ring, or may herniate into the labia majora, often leading to the discovery of the condition. Testes in affected women have been found to be atrophic upon gonadectomy.

They are hermaphroditic and have distinct tongue-shaped gonads which are red or orange in colour for the female gonad and white for the male. It is estimated that a three-year old scallop releases 15 - 21 million oocytes per emission. There appear to be two spawnings in many parts of the range, normally there is a partial one in the Spring and a full one in late August, however younger scallops have a single spawning event in the late summer. In some areas this pattern is reversed and the major spawning is in the Spring.

Hardheads from the Feather River which had grown to were aged at 9–10 years old, and it is considered that older and larger fish may occur in the Sacramento River. Hardhead found in smaller streams rarely reach longer than while old records suggest that this species attained total lengths of up to . Hardhead reach sexual maturity after their second year and spawn in April and May when the adults migrate upstream into the smaller tributary streams. Females have been found with mature eggs in March and specimens of both sexes examined in July and August had spent gonads.

The gonads themselves are transparent, allowing for visualization of the oocytes within. Each medusa typically has around 32 tentacles, each of which are covered in stinging nematocyte cells. These nematocytes are considered specialized nerve cells despite the fact that they are composed of a pressurized capsule (nematocyst), a rapid-firing, harpoon- like dart and lethal toxins made for killing prey. Clytia’s nervous system is well-organized and highly specialized. Two parallel condensed nerve rings run around the periphery of the medusa’s bell; the outer rings is responsible for integrating sensory inputs, while the inner ring coordinates motor responses.

Anorchia (also called anorchidism or anorchism) is a disorder of sex development in which a person with XY karyotype, which usually corresponds to male sex, is born without testes. Within a few weeks of fertilization, the embryo develops rudimentary gonads (testes), which produce hormones responsible for the development of the reproductive system. If the testes fail to develop within eight weeks, the baby will develop female genitalia (see Swyer syndrome). If the testes begin to develop but are lost or cease to function between eight and 10 weeks, the baby will have ambiguous genitalia when it is born.

The pharmacology of cyproterone acetate (CPA), concerns the pharmacology (pharmacodynamics, pharmacokinetics, and routes of administration) of the steroidal antiandrogen and progestin medication cyproterone acetate. CPA blocks the effects of androgens like testosterone in the body, which it does by preventing them from interacting with their biological target, the androgen receptor (AR), and by reducing their production by the gonads and hence their concentrations in the body. In addition, it has progesterone-like effects by activating the progesterone receptor (PR). By activating the PR, CPA has antigonadotropic effects and can inhibit fertility and suppress sex hormone production in both men and women.

Members of the family Asterinidae appear prone to rapid change in their reproductive life cycle and Cryptasterina hystera is one of several species that has recently diverged from its ancestral line. It has recently been recognised as a separate species from Cryptasterina pentagona, a morphologically similar species but with a different native range and a different method of reproduction. In a research study, embryos were removed from the gonads of Cryptasterina hystera and reared in the laboratory. It was found that the larvae developed normally and exhibited similar behaviour to that of the larvae of free-spawning starfish.

StAR is a mitochondrial protein that is rapidly synthesized in response to stimulation of the cell to produce steroid. Hormones that stimulate its production depend on the cell type and include luteinizing hormone (LH), ACTH and angiotensin II. At the cellular level, StAR is synthesized typically in response to activation of the cAMP second messenger system, although other systems can be involved even independently of cAMP. StAR has thus far been found in all tissues that can produce steroids, including the adrenal cortex, the gonads, the brain and the nonhuman placenta. One known exception is the human placenta.

Embryonal carcinomas, a rare tumor type usually found in mixed tumors, develop directly from germ cells but are not terminally differentiated; in rare cases they may develop in dysgenetic gonads. They can develop further into a variety of other neoplasms, including choriocarcinoma, yolk sac tumor, and teratoma. They occur in younger people, with an average age at diagnosis of 14, and secrete both alpha- fetoprotein (in 75% of cases) and hCG. Histologically, embryonal carcinoma appears similar to the embryonic disc, made up of epithelial, anaplastic cells in disorganized sheets, with gland-like spaces and papillary structures.

Participants at the third International Intersex Forum, Malta, in December 2013 Intersex people are born with sex characteristics, such as chromosomes, gonads, or genitals, that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies." Intersex people face stigmatisation and discrimination from birth, particularly when an intersex variation is visible. In some countries (particularly in Africa and Asia) this may include infanticide, abandonment and the stigmatization of families. Mothers in East Africa may be accused of witchcraft, and the birth of an intersex child may be described as a curse.

Gonadoblastoma is most often associated with an abnormal chromosomal karyotype, gonadal dysgenesis, or the presence of a Y chromosome in over 90% of cases. Gonadoblastoma has been found in association with androgen insensitivity syndrome, mixed gonadal dysgenesis and Turner syndrome, especially in the presence of Y chromosome-bearing cells. Women with Turner syndrome whose karyotype includes a Y chromosome (as in 45,X/46,XY mosaicism) are at increased risk for gonadoblastoma. Because of the risk of gonadoblastoma, individuals with Turner syndrome with detectable Y chromosome material (Mosaic Turner syndrome) should have their gonads prophylactically removed.

The pearlfish appears to be chemotaxic (responsive to chemical gradients in water) and is attracted to chemicals the coelomic fluid and Cuvierian tubules, which leads it to the sea cucumber's anus. Because the other species worm pearlfish prey on, H. atra, lack Cuvierian tubules, worm pearlfish are most likely not only attracted by the Cuvierian tubules. The anus of the sea cucumber contracts upon tactile stimulation by the worm pearlfish, but once it needs to respire and relax the anus again, pearlfish is able to penetrate the anus headfirst. Once inside, the worm pearlfish eats the sea cucumber's internal tissues – mostly the gonads.

Analysis of stomach contents show that Stemonidium hypomelas feed on crustaceans, mostly euphausiids but rarely also shrimps and amphipods. Reproduction is oviparous, with high reported fecundities ranging from 7,000 to almost 14,000 eggs per female. Female length at maturation varies from 22–30 cm, and the large size of their gonads relative to their bodies suggests that they may be semelparous, investing a high proportion of their available resources into a single, large batch of eggs. The males mature at 17.5–20 cm long; their better-developed nares and eyes may be an adaptation for finding widely scattered mates in the open ocean.

Anfesta was originally described by Mikhail Fedonkin as a free-swimming scyphozoa-like medusa. The branched furrows on the fossil were interpreted as imprints of a system of internal radial canals, and the three oval ridges as imprints of gonads. A year later, Fedonkin transferred such fossil animals as Anfesta, Albumares and Tribrachidium to the separate group Trilobozoa, populated by three-lobed, radially symmetric, coelenterate-grade animals that only superficially resemble cnidarians. Originally, Trilobozoa was established as a class within the phylum Coelenterata, but since Coelenterata was divided into separate phyla - Cnidaria and Ctenophora - the Trilobozoa have been transferred to rank of phylum.

In evolutionary context, it is assumed that human physiology has been modeled through natural selection to maximize reproductive success by allotting energy and resources through trade-offs. This period of reproductive maturation sees the onset of primary sexual characteristics, the production of gametes and hormones by the gonads, and secondary sexual characteristics. Secondary sexual characteristics include adolescent growth spurt, pubic and axillary hair, genital enlargement, breast development in girls, beard growth in boys, increase in subcutaneous fat, increase in muscle mass, and widening of the pelvis in girls. While there is variation among individuals, secondary sexual characteristics tend to develop in a sequence.

Gonadotropins are protein hormones that stimulate the gonads (testes and ovaries). For medication, they can be extracted from urine in postmenopausal women or through genetic modification and bacterial recombination. Examples of recombinant FSH are Follistim and Gonal F, while Luveris is a recombinant LH. FSH and recombinant FSH analogues are mainly used for controlled ovarian hyperstimulation as well as ovulation induction. There has been some controversy over the efficacy between extracted and recombinant FSH for ovulation induction; however, a meta-analysis of 14 trials among 1726 women found that there were no differences in clinical pregnancy or live birth outcomes.

A definite physiological explanation or reason for homosexual activity in animal species has not been agreed upon by researchers in the field. Numerous scholars are of the opinion that varying levels (either higher or lower) of the sex hormones in the animal, in addition to the size of the animal's gonads, play a direct role in the sexual behavior and preference exhibited by that animal. Others firmly argue no evidence to support these claims exists when comparing animals of a specific species exhibiting homosexual behavior exclusively and those that do not. Ultimately, empirical support from comprehensive endocrinological studies exist for both interpretations.

The taxon was erected by Danish marine biologist Paul Lassenius Kramp in 1938 to accommodate certain families of hydrozoans with biphasic life histories. It includes genera with medusae with ecto-endodermal statocysts and with gonads alongside their radial canals, and also genera which have polyps that are not covered by a theca. Molecular analysis performed by Collins in 2006 has since shown that the Limnomedusae are not monophylic. The family Armorhydridae, which contains a single genus and a single species, Armorhydra janowiczi, is found living in coarse sediment, has hollow tentacles and has no radial canals.

Estrogen is responsible for the mediation of puberty in females, and in girls with delayed puberty due to hypogonadism (low-functioning gonads, which can result in low sex hormone levels) such as in Turner syndrome, estradiol is used to induce the development of and maintain female secondary sexual characteristics such as breasts, wide hips, and a female fat distribution. It is also used to restore estradiol levels in adult premenopausal women with hypogonadism, for instance those with premature ovarian failure or who have undergone oophorectomy. It is used to treat women with hypogonadism due to hypopituitarism as well.

Natural spawning can occur in hatcheries during the regular spawning season however where more control over spawning time is required spawning of mature animals can be induced by a variety of methods. Some of the more common methods are: Manual stripping : For shellfish, gonads are generally removed and gametes are extracted or washed free. Fish can be manually stripped of eggs and sperm by stroking the anaesthetised fish under the pectoral fins towards the anus causing gametes to freely flow out. Environmental manipulation: Thermal shock, where cool water is alternated with warmer water in flow-through tanks can induce spawning.

Females and immature fish are silvery, like typical pelagic fish, but mature males develop stronger breeding colours, typically contrasting patterns of black, white and yellow. Females of several species have been found carrying eggs and young in their mouths and it is likely that all species are maternal mouthbrooders, like all other known haplochromine cichlids. Males in breeding dress with ripe gonads are often collected together in large numbers, along with a few ripe and mouthbrooding females, suggesting that these fishes gather together to breed in particular areas. Most species seem to breed between February and August.

Acorn worms are dioecious, having separate biological sexes, although at least some species are also capable of asexual reproduction. They have paired gonads, which lie close to the pharynx and release the gametes through a small pore near to the gill slits. The female lays a large number of eggs embedded in a gelatinous mass of mucus, which are then externally fertilized by the male before water currents break up the mass and disperse the individual eggs. Acorn worm life cycle by M. Singh In most species, the eggs hatch into planktonic larvae with elongated bodies covered in cilia.

Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. Appearance of Sertoli cells in males and granulosa cells in females can be thought of as the starting point for testicular or ovarian differentiation in many species. As male and female individuals develop from embryos into mature adults, sex differences at many levels develop, such as genes, chromosomes, gonads, hormones, anatomy, and psyche. Beginning with determination of sex by genetic and/or environmental factors, humans and other organisms proceed down different pathways of differentiation as they grow and develop.

The body cavity is composed of three major components: the perivisceral coelom which mainly surrounds the digestive system and the gonads; the perihaemal system, which consists of radial channels and forms a reduced circulatory system; and the water vascular system, which involves hundreds of tube feet, water channels, and the madreporite. Tube feet are involved in processes such as locomotion, adhesion, food collecting and excretion. The madreporite is a small calcified pore that is the location for drawing in and expelling water to fill the water vascular system. The digestive tract contains two stomachs, a large cardiac portion and a smaller pyloric portion.

The study showed that the extract worked against two forms of the parasite and scored a nine on the selectivity index, which indicates the extract is selective against the parasite. The extract reduced the size of lesions, and the amount of parasites without affecting the mice, however it did not cure the mice completely of the parasite. With further studies, this extract could prove to be an effective medicine against leishmaniasis. Another species within the genera, Echinaster brasiliensis, has been studied to examine the biochemical bases of circadian rhythms, and produces endogenous melatonin in their gonads.

At this time, glycogen storage in the main adductor muscle is depleted as energy is transferred from there to the gonads. When the spiny scallop's valves are parted for feeding and respiration, many tentacles protrude from each edge of the mantle. The longer ones have sensitive chemoreceptor cells at their tip which can taste the water and allow the mollusc to react appropriately to, for example, the "smell" of a starfish, by taking evasive action. The shorter ones, forming a ring all the way round the edge of the mantle, have simple eyes at their tips.

Aequorea victoria juvenile medusae are asexually budded off hydroid colonies in late spring; these free-living hydromedusae will spend all of their lives in the plankton. The medusa spends its first stage of life growing quickly, and after reaching approximately 3 cm will begin producing gametes for reproduction. Each medusa is either a male or a female. The eggs and spermatozoa mature daily in the medusa gonads, given enough food, and are free-spawned into the water column in response to a daily light cue, where they are fertilized and eventually settle out to form a new hydroid colony.

In animals, the different types of change are male to female (protandry), female to male (protogyny), female to hermaphrodite (protogynous hermaphroditism), and male to hermaphrodite (protandrous hermaphroditism). Both protogynous and protandrous hermaphroditism allow the organism to switch between functional male and functional female. These various types of sequential hermaphroditism may indicate that there is no advantage based on the original sex of an individual organism. Those that change gonadal sex can have both female and male germ cells in the gonads or can change from one complete gonadal type to the other during their last life stage.

Valproic acid has been found to be an antagonist of the androgen and progesterone receptors, and hence as a nonsteroidal antiandrogen and antiprogestogen, at concentrations much lower than therapeutic serum levels. In addition, the drug has been identified as a potent aromatase inhibitor, and suppresses estrogen concentrations. These actions are likely to be involved in the reproductive endocrine disturbances seen with valproic acid treatment. Valproic acid has been found to directly stimulate androgen biosynthesis in the gonads via inhibition of histone deacetylases and has been associated with hyperandrogenism in women and increased 4-androstenedione levels in men.

Individuals with 5-ARD are born with male gonads, including testicles and Wolffian structures. They can have normal male external genitalia, ambiguous genitalia, or external female appearing genitalia, but usually tend towards a female appearance. The development of the genital tubercle tissue (which by week 9 of a fetus' gestation becomes either a clitoris or a penis) tends towards a size qualifying it as an ambiguous macroclitoris/micropenis (large clitoris/small penis), and the urethra may attach to the phallus. If the condition has not already been diagnosed, it usually becomes apparent at puberty around age twelve with primary amenorrhoea and virilization.

The serrated bill is also well adapted for catching small spiders and insects, while the hooked tip of the males' bill is further suited for extracting prey from within rolled leaves and cavities. It has sometimes been seen rapidly gleaning below large leaves, while flicking its tail. Little is known about its breeding behavior, but individuals captured in Colombia in January–March have had enlarged gonads, indicating that they were in breeding condition. In Ecuador, it has been reported that males gather in leks in February–May, which is unusual among members of the subfamily Trochilinae, but frequent among the members of Phaethornithinae.

The proportions of crustaceans to molluscs can vary widely depending on the abundance of food items; hence in a 1999 field study, the soldier crab (Mictyris longicarpus) predominated in Cowan Creek while the black mussel did so in nearby Berowra Creek. Field experiments showed it was a consumer of oysters and the gastropod Bembicium auratum, and had a major impact on their numbers. Because it is a common estuarine fish, it has been used in studies of heavy metal contamination in coastal waters. Fish tested around Sydney showed uptake was highest in the gonads, then muscle, gills and liver.

It is unclear why metal concentrations were lower in toadfish livers (compared with studies of contamination in other fish) but their liver cells may be more effective at removing these elements. Lead, cadmium and nickel levels corresponded with those in the sediment from which the fish were taken, suggesting dietary intake. The gonads of male fish had twenty times as much arsenic as those of females, while the gills of female fish contained thirty times as much lead as those of males. Raised levels of arsenic, cobalt, cadmium and lead in gills suggested the fish absorbed these from the surrounding water.

Spermatozoa, in this case human, are a primary component in normal semen, and the agents of fertilization of female ova. Semen, also known as seminal fluid, is an organic fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa, and provide a medium through which they can move or "swim".

The study found that the digestive glands of infected bivalves appeared to be relatively normal when compared to full bodied, uninfected specimens. Within the sporocyst, the cercariae existed within a wide range of developmental stages, indicating that its development is asynchronous. It was also observed that heavy infection of the parasite led to host castration, which left the entire gonadal space often occupied by the sporocysts. By limiting the infection almost exclusively to the gonads, the parasites have developed an interesting strategy to only use the reproductive energy of their hosts, thereby minimizing the risk of host mortality.

In animals, the behavioral effects of gonad removal differ along lines of species and not sex, i.e. there are species where mating behavior ceases if the gonads are removed and other species where it does not cease, but removal of ovaries in females halt mating behavior in all of the same nonhuman animals in which male castration halts mating behavior. Therefore, some scientists argue that the notion that castration/spaying would drastically reduce sex drive in human males but not in human females is zoologically nonsensical, citing that humans belong to the animal kingdom.Robert Aunger, Valerie Curtis (2015)"Gaining Control: How human behavior evolved"(2015).

Intersex people are born with sex characteristics, such as chromosomes, gonads, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". "Because their bodies are seen as different, intersex children and adults are often stigmatized and subjected to multiple human rights violations". Discriminatory treatment includes Infanticide, abandonment, mutilation and neglect, as well as broader concerns regarding the right to life. Intersex people face discrimination in education, employment, healthcare, sport, with an impact on mental and physical health, and on poverty levels, including as a result of harmful medical practices.

There remains no clinical consensus about an evidence base, surgical timing, necessity, type of surgical intervention, and degree of difference warranting intervention. Such surgeries are the subject of significant contention due to consequences that include trauma, impact on sexual function and sensation, and violation of rights to physical and mental integrity. This includes community activism, and multiple reports by international human rights and health institutions and national ethics bodies. In the cases where gonads may pose a cancer risk, as in some cases of androgen insensitivity syndrome, concern has been expressed that treatment rationales and decision-making regarding cancer risk may encapsulate decisions around a desire for surgical "normalization".

The principal action of testolactone is reported to be inhibition of aromatase activity and the reduction in estrogen synthesis that follows. Androstenedione, a 19-carbon steroid hormone produced in the adrenal glands and the gonads, is where estrone synthesis originates and is the source of estrogen in postmenopausal women. In vitro studies report that the aromatase inhibition may be noncompetitive and irreversible, and could possibly account for the persistence of this drug's effect on estrogen synthesis after drug withdrawal. Testolactone at a dosage of 1,000 mg/day has been found to decrease estradiol levels in men by 25 to 50% after 6 to 10 days of use.

In humans, starting at about week 4 the gonadal rudiments are present within the intermediate mesoderm adjacent to the developing kidneys. At about week 6, sex cords develop within the forming testes. These are made up of early Sertoli cells that surround and nurture the germ cells that migrate into the gonads shortly before sex determination begins. In males, the sex-specific gene SRY that is found on the Y-chromosome initiates sex determination by downstream regulation of sex-determining factors, (such as GATA4, SOX9 and AMH), which leads to development of the male phenotype, including directing development of the early bipotential gonad down the male path of development.

Upon maturity, the tiny males of most species metamorphose into a parasitic form, which lacks both a lure and true teeth and is presumed not to feed. The parasitic males use their enlarged olfactory bulbs (as indicated by their enlarged nostrils) and sensitive eyes to home in on the pheromones and possibly the species-specific lures of females. The metamorphosed males attach themselves to the body of the female using their denticular hooks; the male's tissues then begin to coalesce with the female's, and the former's gonads begin to develop while all other organs degenerate. The male thus becomes inseparable from the female, deriving nourishment directly from her blood.

Parasitic castrators partly or completely destroy their host's ability to reproduce, diverting the energy that would have gone into reproduction into host and parasite growth, sometimes causing gigantism in the host. The host's other systems remain intact, allowing it to survive and to sustain the parasite. Parasitic crustaceans such as those in the specialised barnacle genus Sacculina specifically cause damage to the gonads of their many species of host crabs. In the case of Sacculina, the testes of over two-thirds of their crab hosts degenerate sufficiently for these male crabs to develop female secondary sex characteristics such as broader abdomens, smaller claws and egg-grasping appendages.

Many species of Talpid moles exhibit peniform clitorises that are tunneled by the urethra and are found to have erectile tissue, most notably species from the Talpa genus found in Europe. Unique to this clade are the presence of ovotestes, wherein the female ovary also is mostly made up of sterile testicular tissue that secretes testosterone with only a small portion of the gonad containing ovarian tissue. Genetic studies have revealed that females have an XX genotype and do not have any translocated Y-linked genes. Detailed developmental studies of Talpa occidentalis have revealed that the female gonads develop in a "testis-like pattern".

If the gonads are relatively "normal" testes, but the child is to be assigned and raised as female, (e.g., for intersex conditions with severe undervirilization, or major malformations involving an absent or unsalvageable penis) they must be removed before puberty to prevent virilization from rising testosterone. Testes in androgen insensitivity are a special case: if there is any degree of responsiveness to testosterone, they should be removed before puberty. On the other hand, if androgen insensitivity is complete, the testes may be left to produce estradiol (via testosterone) to induce breast development, but there is a slowly increasing risk of cancer in adult life.

The hormone of gonadotropins secreted by the anterior hypophyse gland effects on the gonads and play a crucial role in the process of gonadal development and function in vertebrates. In birds and mammals, luteinizinghormone (LH) regulates sex steroid production as well as ovulation, whereas follicle stimulating hormone (FSH) promotes spermatogenesis and ovarian follicle maturation. Since the isolation of gonadotropin-releasing hormone (GnRH), a hypothalamic decapeptide, from mammalian brain in the early 1970s, several other GnRHs have been identified in the brains of other vertebrates. Based on extensive studies in vertebrates, it was generally believed that GnRH is the only hypothalamic regulator of the release of pituitary gonadotropins.

Its members may act as coactivators and/or corepressors to modulate the activity of GATA transcription factors. That is, the ZFPM2 protein appears able to interact directly with and thereby either enhance or repress the ability of GATA transcription factors to stimulate the expression of their target genes; the direction of ZFPM2's actions depends on the contexts of the promoter sections of the various GATA target genes. The ZFPM2 protein interacts primarily with the GATA4 but also with GATA2, GATA5, and GATA6 transcription factors. ZFPM2 protein's interaction with GATA4 is notable for controlling the embryonic development of various tissues, particularly the heart, diaphragm, and gonads.

Among other mechanisms, her laboratory discovered that a polyadenylated tail is not required for gene regulation. Lehmann continued to focus her research efforts on germ cell differentiation well into the early 2000s. She played a substantial role in the discovery of germ cell migratory pathways (namely those involving gap junctions, G protein-coupled receptors like Tre-1, and isoprenoids), particularly those concerning migration into the ovaries and testis. In 2005, Lehmann’s laboratory published a paper relating the lipid phosphatases Wunen and Wunen 2 to germ cell migration and elimination, suggesting that germ cells are sorted into the gonads by a type of repellent mechanism.

On August 12, 2005, the mother of a child, Benjamín, filed a lawsuit against the Maule Health Service after the child's male gonads and reproductive system were removed without informing the parents of the nature of the surgery. The child had been raised as a girl. The claim for compensatory damages was initiated in the Fourth Court of Letters of Talca, and ended up in the Supreme Court of Chile. On November 14, 2012, the Court sentenced the Maule Health Service for "lack of service" and to pay compensation of 100 million pesos for moral and psychological damages caused to Benjamín, and another 5 million for each of the parents.

Taiwan's military is overwhelmingly male and only males are obligated to serve under conscription, this can cause complicated situations for intersex people. One noted case was in 1954 with the soldier Xie Jianshun who was originally assigned as a male at birth but was later discovered in the military to have many female characteristics. Xie had a penis but a very slim vaginal opening as well as internal gonads which contained both testicular and ovarian tissue, doctors determined that they could still produce eggs and that Xie's testicular tissue was deteriorating. Military doctors performed four surgeries despite Xie's desire to remain a man, afterwards Xie left the armed forces.

Chart of the generalized male reproductive system embryionic The genetic sex is determined by whether a Y bearing or next bearing sperm fertilizes the open; the presence or absence of a Y chromosome in turn determines whether the gonads of the embryo will be testes or ovaries; and the presence or absence of testes, finally, determines whether the sex accessory organs and external genitalia will be male or female. This sequence is understandable in light of the fact that both male and female embryos develop within the maternal environment - high in estrogen secreted by the mother's ovaries and the placenta. If estrogen determined the gender, all embryos would become feminized.

Intersex civil society organizations, and many human rights institutions, have criticized medical interventions designed to make intersex bodies more typically male or female. Some people who are intersex, such as some of those with androgen insensitivity syndrome, outwardly appear completely female or male, frequently without realizing they are intersex. Other kinds of intersex conditions are identified immediately at birth because those with the condition have a sexual organ larger than a clitoris and smaller than a penis. Some humans were historically termed true hermaphrodites if their gonadal tissue contained both testicular and ovarian tissue, or pseudohermaphrodites if their external appearance (phenotype) differed from sex expected from internal gonads.

As of 2010, over 400 AR mutations have been reported in the AR mutation database, and the number continues to grow. Inheritance is typically maternal and follows an X-linked recessive pattern; individuals with a 46,XY karyotype always express the mutant gene since they have only one X chromosome, whereas 46,XX carriers are minimally affected. About 30% of the time, the AR mutation is a spontaneous result, and is not inherited. Such de novo mutations are the result of a germ cell mutation or germ cell mosaicism in the gonads of one of the parents, or a mutation in the fertilized egg itself.

The males in some deep sea anglerfishes are much smaller than the females. When they find a female they bite into her skin, releasing an enzyme that digests the skin of their mouth and her body and fusing the pair down to the blood-vessel level. The male then slowly atrophies, losing first his digestive organs, then his brain, heart, and eyes, ending as nothing more than a pair of gonads, which release sperm in response to hormones in the female's bloodstream indicating egg release. This extreme sexual dimorphism ensures that, when the female is ready to spawn, she has a mate immediately available.

Ventral view with hyperiid amphipod Almost entirely transparent and colorless, and sometimes difficult to resolve, Aequorea victoria possess a highly contractile mouth and manubrium at the center of up to 100 radial canals that extend to the bell margin. The bell margin is surrounded by uneven tentacles, up to 150 of them in fully-grown specimens. The tentacles possess nematocysts that aid in prey capture, although they have no effect on humans. Specimens larger than 3 cm usually possess gonads for sexual reproduction, which run most of the length of the radial canals and are visible in the photos in this article as whitish thickenings along the radial canals.

This is consistent with studies in rats which found that gap junctions increased during lactation to facilitate prolactin demand. Additional studies in rats found that the number of gap junctions increases with anterior pituitary maturation, and this increase was prevented by castration in male rats which would prevent sexual maturation, and was restored to normal levels by hormone treatment. Similarly, gap junctions increase during pro-oestrus and oestrus phases of the oestrous cycle, and are decreased by fifty percent during di-oestrus. Evidently, the number of gap junctions is influenced by steroid hormone secretion from the gonads, and FS cells contribute to the pituitary-gonadal feedback loop.

Microphallus turgidus exclusively uses the snail Potamopyrgus antipodarum as the first intermediate host, a shrimp as the secondary intermediate host, and the final hosts are typically waterfowl. Embryonated Microphallus turgidus eggs are ingested from sediment and hatch in the snail's gut, penetrate the intestine, and migrate to the gonads and digestive gland. Following successful establishment, the parasite then undergoes asexual reproduction, replacing much of the host's reproductive tissue and digestive gland, which results in complete sterilization of the snail. The first visible parasite developmental stages (blastocercariae) are detectable after approximately 75 days post- exposure and metacercariae are common by 90 days post-exposure at 16 °C in the lab.

GnRH modulators are powerful antigonadotropins and hence functional antiandrogens. In both males and females, gonadotropin-releasing hormone (GnRH) is produced in the hypothalamus and induces the secretion of the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. The gonadotropins signal the gonads to make sex hormones such as testosterone and estradiol. GnRH modulators bind to and inhibit the GnRH receptor, thereby preventing gonadotropin release. As a result of this, GnRH modulators are able to completely shut-down gonadal sex hormone production, and can decrease testosterone levels in men and transgender women by about 95%, or to an equivalent extent as surgical castration.

The newborn mice will therefore be chimeras: some parts of their bodies result from the original stem cells, other parts from the knocked-out stem cells. Their fur will show patches of white and grey, with white patches derived from the knocked-out stem cells and grey patches from the recipient blastocyst. #Some of the newborn chimera mice will have gonads derived from knocked-out stem cells, and will therefore produce eggs or sperm containing the knocked-out gene. When these chimera mice are crossbred with others of the wild type, some of their offspring will have one copy of the knocked-out gene in all their cells.

The germ cell population (~40 in mice), after specification, migrate to the developing gonads where they differentiate further into gametogonia. Much of the research in germ cell development is done on animal models. Animal models are an effective research tool due to the commonality of sexual reproduction which is thought to have same or similar mechanisms across species. The majority of research is done on mice which has led to advances in understanding germ line differentiation across all mammal but there are some species specific mechanisms which have not been studied as extensively due to the difficulty of both obtaining human samples and the ethical limitations of human research.

When the germ cells reach the gonads, they undergo proliferation via mitosis and at 13.5 days of rat development they begin to undergo meiosis in the ovary but arrested at the mitotic stage in the testes. In the ovary, after mitosis, the gametogonium undergo meiosis, which is initiated by intrinsic competence factor DazL and extrinsic retinoic acid, excreted by the mesonephros. Retinoic acid is the major factor in meiosis, upregulating genes including ‘‘Stra8’‘, ‘‘Dmc1’‘ and ‘‘Sycp3’‘, which all have a role in meiosis. The male germ cells are protected from external signalling, like retinoic acid from the mesonephros, by the Leydig and Sertoli cells.

A Punnett square for one of Mendel's pea plant experiments - self-fertilization of the F1 generation, shows that inheritance is particulate, not blending. Blending inheritance was dismissed by the eventual widespread acceptance, after his death, of Gregor Mendel's theory of particulate inheritance, which he had presented in Experiments on Plant Hybridization (1865). In 1892, August Weismann set out the idea of a hereditary material, which he called the germ plasm, confined to the gonads and independent of the rest of the body (the soma). In Weismann's view, the germ plasm formed the body, but the body did not influence the germ plasm, except indirectly by natural selection.

As individuals with 46,XX/46,XY partially express the SRY gene, the normal process by which an embryo normally develops into a phenotypic male or phenotypic female may be significantly affected causing variation in the gonads, the reproductive tract and the genitals. Despite this, there have been cases of completely normal sex differentiation occurring in 46,XX/ 46,XY individuals reported in the medical literature. 46,XX/46,XY chimerism can be identified during pregnancy by prenatal screening or in early childhood through genetic testing and direct observation. The rate of incidence is difficult to determine as the majority of diagnoses go unreported in the literature.

Bulletin of Marine Science of the Gulf and Caribbean (1962) As part of the phylum Cnidaria they are mainly gelatinous with their most identifying characteristic being the gonads which, viewed from above, look like an X and then continue down the sides lining up with the radial canals. As a part of the zooplankton, it is incapable of sustained horizontal movement and relies on its tentacles to encounter and capture smaller organisms for food (feeds mainly on copepedites, selecting against naupilar stages).Purcell, J.E., Nemazie, D.A. “Quantitative Feeding Ecology of the Hydromedusan Nemopsis-Bachei in Chesapeake Bay”. Marine Biology 113:2 (1992): 305-311.

Although progesterone does not have significant AR-mediated androgenic or antiandrogenic activity, it is a precursor and intermediate, albeit distant, in the biosynthesis of androgens from cholesterol. For this reason, there has been some speculation that exogenous progesterone could be transformed into androgens by certain tissues that express the requisite enzymes. Progesterone is converted by 17α-hydroxylase into 17α-hydroxyprogesterone; 17α-hydroxyprogesterone is converted by 17,20-lyase into androstenedione; and androstenedione is converted by 17β-hydroxysteroid dehydrogenases into testosterone. CYP17A1, the cytochrome P450 gene that encodes 17α-hydroxylase and 17,20-lyase, is expressed mainly in the gonads (ovaries and testes) and the adrenal glands.

Participants at the third International Intersex Forum, Malta, in December 2013 Intersex people are individuals born with any of several variations in sex characteristics including chromosomes, gonads, sex hormones or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit the typical definitions for male or female bodies". This range of atypical variation may be physically obvious from birth – babies may have ambiguous reproductive organs, or at the other extreme range it is not obvious and may remain unknown to people all their lives. Intersex people were previously referred to as hermaphrodites or "congenital eunuchs".Nguyễn Khắc Thuần (1998), Việt sử giai thoại (History of Vietnam's tales), vol.

Intersex people are born with sex characteristics, such as genitals, gonads and chromosome patterns, "that do not fit typical binary notions of male or female bodies". Literary descriptions may use older or different language for intersex traits, including describing intersex people as hermaphrodites, neither wholly male or female, or a combination of male and female. This page examines intersex characters in fictional works as a whole, focusing on characters and tropes over time. For more information about fictional characters in other parts of the LGBTQ community, see the lists of lesbian (with sub-pages for characters in anime and animation), bisexual (with sub- sections for characters in anime and animation), non-binary, trans, and asexual characters.

The production of gametes is induced in both male and female mammals by the same two hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The production of these in turn is induced by a single releasing hormone, gonadotropin-releasing hormone (GnRH), which has been the focus of most of the research into immunocontraception against gamete production. GnRH is secreted by the hypothalamus in pulses and travels to the anterior pituitary gland through a portal venous system. There it stimulates the production of FSH and LH. FSH and LH travel through the general circulatory system and stimulate the functioning of the gonads, including the production of gametes and the secretion of sex steroid hormones.

Meiosis in the parents' gonads produces gametes that each contain only 23 chromosomes that are genetic recombinants of the DNA sequences contained in the parental chromosomes. When the nuclei of the gametes come together to form a fertilized egg or zygote, each cell of the resulting child will have 23 chromosomes from each parent, or 46 in total. In plants only, the diploid phase, known as the sporophyte, produces spores by meiosis that germinate and then divide by mitosis to form a haploid multicellular phase, the gametophyte, that produces gametes directly by mitosis. This type of life cycle, involving alternation between two multicellular phases, the sexual haploid gametophyte and asexual diploid sporophyte, is known as alternation of generations.

Antedon mediterranea Antedon mediterranea feeds by filtering out plankton and other small particles from the passing sea water. The food is then wrapped in mucus and passed by the tube feet down the ambulacral grooves on the arms to the central mouth which is on the upper side of the calyx. Antedon mediterranea can move around to a limited extent by creeping on its cirri, by "swimming", alternately raising and lowering its ten arms five at a time, or by "walking" along the seabed by propping itself up on its arm tips and heaving itself along. The sexes are separate in Antedon mediterranea and the gonads are located in the pinnules of the lower part of the arms.

DHEA and DHEA-S are produced in the zona reticularis of the adrenal cortex under the control of adrenocorticotropic hormone (ACTH). DHEA is synthesized from cholesterol via the enzymes cholesterol side-chain cleavage enzyme (CYP11A1; P450scc) and 17α-hydroxylase/17,20-lyase (CYP17A1), with pregnenolone and 17α-hydroxypregnenolone as intermediates. Then, DHEA-S is formed by sulfation of DHEA at the C3β position via the sulfotransferase enzymes SULT2A1 and to a lesser extent SULT1E1. Whereas DHEA is derived mostly from the adrenal cortex but is also secreted to a lesser extent by the gonads (10%), DHEA-S is almost exclusively produced and secreted by the adrenal cortex, with 95 to 100% originating from the adrenal cortex in women.

Rhizostomes, especially Rhopilema esculentum in China ( hǎizhé, "sea stingers") and Stomolophus meleagris (cannonball jellyfish) in the United States, are favored because of their larger and more rigid bodies and because their toxins are harmless to humans. Traditional processing methods, carried out by a jellyfish master, involve a 20- to 40-day multi- phase procedure in which, after removing the gonads and mucous membranes, the umbrella and oral arms are treated with a mixture of table salt and alum, and compressed. Processing makes the jellyfish drier and more acidic, producing a crispy texture. Jellyfish prepared this way retain 7–10% of their original weight, and the processed product consists of approximately 94% water and 6% protein.

A study was performed to model individual growth and explore the relationship of changes in local abundance with variation in environmental factors and the reproductive status of individuals.Geographical implications of seasonal reproduction in the bat star Asterina stellifera Elsevier, Journal of Sea Research Volume 85, January 2014, Pages 222-232 Pablo E. Merettaa, Tamara Rubilarb, Maximiliano Cledóna, C. Renato, R. Venturac. They studied the relationship between male and female organ wet weights with seawater temperature, salinity, monthly mean precipitation, and day-length. It was found that seawater temperature and day- length appear to influence the rapid increase of gonads and it was also found that gamete release failure is not the cause of the scarcity of new sea stars.

Prenatal androgen exposure has been associated with an increased chance of patient-initiated gender reassignment to male after being initially raised as female in early childhood or infancy. Gooren found that organizational effects of prenatal androgens are more prevalent in gender role behavior than in gender identity, and that there are preliminary findings that suggest evidence of a male gender identity being more frequent in patients with fully male-typical prenatal androgenization. Individuals with complete androgen insensitivity syndrome are almost always brought up as females, and the differentiation of gender identity/role is feminine. This example is important in demonstrating that chromosomes and gonads alone do not dictate gender identity and role.

Fetal gonads develop primarily based on the presence or absence of androgen hormones, mainly testosterone, dihydrotestosterone (DHT) and androstenedione; production of testosterone and conversion into dihydrotestosterone during weeks 6 to 12 of pregnancy are key factors in the production of a male fetus's penis, scrotum and prostate. In a female, on the other hand, absence of these levels of androgens results in development of typically female genitals. Following this, sexual differentiation of the brain occurs; sex hormones exert organizational effects on the brain that will be activated in puberty. As a result of these two processes occurring separately, the degree of genital masculinization does not necessarily relate to the masculinization of the brain.

When the bouillabaisse is done, the rouille is prepared: the stem of the garlic is removed; the garlic cloves are crushed into a fine paste with a pestle in a mortar; the egg yolk and saffron are added and blended with olive oil little by little to make a mayonnaise. The potatoes are peeled, cut into large slices and boiled in salted water for 15 to 20 minutes. The last step is to open the sea urchins with a pair of scissors, and to remove the corail (gonads) with a small spoon. The pieces of fish are then arranged on a platter, and the corail of the sea urchins is added to the broth and stirred.

Chemical castration is castration via anaphrodisiac drugs, whether to reduce libido and sexual activity, to treat cancer, or otherwise. Unlike surgical castration, where the gonads are removed through an incision in the body,"Can Castration Be a Solution for Sex Offenders? Man Who Mutilated Himself in Jail Thinks So, but Debate on Its Effectiveness Continues in Va., Elsewhere" by Candace Rondeaux for the Washington Post, July 5, 2006 chemical castration does not remove organs, nor is it a form of sterilization. Chemical castration is generally considered reversible when treatment is discontinued, although permanent effects in body chemistry can sometimes be seen, as in the case of bone density loss increasing with length of use of DMPA.

Peripheral precocious puberty caused by exogenous estrogens is evaluated by assessing decreased levels of gonadotrophins. Xenoestrogens in plastics, packaged food, drink trays and containers, (more so, when they've been heated in the Sun, or an oven), may interfere with pubertal development by actions at different levels – hypothalamic-pituitary axis, gonads, peripheral target organs such as the breast, hair follicles and genitals. Exogenous chemicals that mimic estrogen can alter the functions of the endocrine system and cause various health defects by interfering with synthesis, metabolism, binding or cellular responses of natural estrogens. Although the physiology of the reproductive system is complex, the action of environmental exogenous estrogens is hypothesized to occur by two possible mechanisms.

Xenoestrogens may temporarily or permanently alter the feedback loops in the brain, pituitary, gonads, and thyroid by mimicking the effects of estrogen and triggering their specific receptors or they may bind to hormone receptors and block the action of natural hormones. Thus it is plausible that environmental estrogens can accelerate sexual development if present in a sufficient concentration or with chronic exposure. The similarity in the structure of exogenous estrogens and the estrogens has changed the hormone balance within the body and resulted in various reproductive problems in females. The overall mechanism of action is binding of the exogenous compounds that mimic estrogen to the estrogen binding receptors and cause the determined action in the target organs.

Intersex, in humans and other animals, is a variation in sex characteristics including chromosomes, gonads, or genitals that do not allow an individual to be distinctly identified as male or female. Such variation may involve genital ambiguity, and combinations of chromosomal genotype and sexual phenotype other than XY-male and XX-female. Intersex persons are often subjected to involuntary "sex normalizing" surgical and hormonal treatments in infancy and childhood, often also including sterilization.Resolution 1952/2013, Provision version, Children’s right to physical integrity, Council of Europe, 1 October 2013Involuntary or coerced sterilisation of intersex people in Australia, Australian Senate Community Affairs Committee, October 2013.It's time to defend intersex rights, Morgan Carpenter at Australian Broadcasting Corporation, 15 November 2013.

Buserelin is a GnRH agonist, or an agonist of the GnRH receptor. It is a superagonist of the GnRH receptor with potency for induction of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion of about 20 to 170 times that of GnRH itself. By activating the GnRH receptor in the pituitary gland, buserelin induces the secretion of LH and FSH from the gonadotrophs of the anterior pituitary, which travel to the gonads through the bloodstream and activate gonadal sex hormone production as well as stimulate spermatogenesis in men and induce ovulation in women. With chronic administration of buserelin however, the GnRH receptor becomes desensitized and completely stops responding both to buserelin and to endogenous GnRH.

Medical terminology has shifted not only due to concerns about language, but also a shift to understandings based on genetics. Currently, hermaphroditism is not to be confused with intersex, as the former refers only to a specific phenotypical presentation of sex organs and the latter to a more complex combination of phenotypical and genotypical presentation. Using hermaphrodite to refer to intersex individuals is considered to be stigmatizing and misleading. Hermaphrodite is used for animal and plant species in which the possession of both ovaries and testes is either serial or concurrent, and for living organisms without such gonads but present binary form of reproduction, which is part of the typical life history of those species; intersex has come to be used when this is not the case.

Money and others controversially believed that children were more likely to develop a gender identity that matched sex of rearing than might be determined by chromosomes, gonads, or hormones. The primary goal of assignment was to choose the sex that would lead to the least inconsistency between external anatomy and assigned psyche (gender identity). Since advances in surgery have made it possible for intersex conditions to be concealed, many people are not aware of how frequently intersex conditions arise in human beings or that they occur at all. Dialog between what were once antagonistic groups of activists and clinicians has led to only slight changes in medical policies and how intersex patients and their families are treated in some locations.

"Gonadal cell lineages of the nematode Panagrellus redivivus and implications for evolution by the modification of cell lineage"(1981) Sternberg and Horvitz compared the gonadal cell lineages of Panagrellus redivivus to the gonadal lineages of C.elegans. They found that the death of Z4.pp is what probably prevents the posterior ovary in P. redivivus from developing which in C. elegans controls the development of that posterior ovary. This is thought to be the reason why there is a gross difference in the morphology of the P.redivivus female gonads and the C.elegans hermaphrodite. "Postembryonic nongonadal cell lineages of the nematode Panagrellus redivivus: Description and comparison with those of Caenorhabditis elegans" (1982) Horvitz and Sternberg looked at the postembryonic nongonodal cell lineages of P.redivivus and compared it to C.elegans.

It is at the seventh week of gestation that the bodies of unaffected individuals with the XY karyotype begin their masculinization: i.e, the Wolffian duct system is promoted and the Müllerian duct system is suppressed (the reverse happens with typically developing females). This process is triggered by androgens produced by the gonads, which in individuals with the XX karyotype had earlier become ovaries, but in XY individuals typically had become testicles due to the presence of the Y Chromosome. The cells of unaffected XY individuals then masculinize by, among other things, enlarging the genital tubercle into a penis, which in females becomes the clitoris, while what in females becomes the labia fuses to become the scrotum of males (where the testicles will later descend).

The syndrome is named after Henry Turner, an endocrinologist from Illinois, who described it in 1938. In Europe, it is often called Ullrich–Turner syndrome or even Bonnevie–Ullrich–Turner syndrome to acknowledge that earlier cases had also been described by European doctors. In Russian and USSR literature it is called Shereshevsky–Turner syndrome to acknowledge that the condition was first described as hereditary in 1925 by the Soviet endocrinologist , who believed that it was due to the underdevelopment of the gonads and the anterior pituitary gland and was combined with congenital malformations of internal development. The first published report of a female with a 45,X karyotype was in 1959 by Dr. Charles Ford and colleagues in Harwell near Oxford, and Guy's Hospital in London.

PBB Protein SRY image In an interview for the Rediscovering Biology website,Rediscovering Biology, Unit 11 - Biology of Sex and Gender, Expert interview transcripts, Link researcher Eric Vilain described how the paradigm changed since the discovery of the SRY gene: In mammals, including humans, the SRY gene is responsible with triggering the development of non-differentiated gonads into testes, rather than ovaries. However, there are cases in which testes can develop in the absence of an SRY gene (see sex reversal). In these cases, the SOX9 gene, involved in the development of testes, can induce their development without the aid of SRY. In the absence of SRY and SOX9, no testes can develop and the path is clear for the development of ovaries.

Mole paw Moles have polydactyl forepaws; each has an extra thumb (also known as a prepollex) next to the regular thumb. While the mole's other digits have multiple joints, the prepollex has a single, sickle-shaped bone that develops later and differently from the other fingers during embryogenesis from a transformed sesamoid bone in the wrist, independently evolved but similar to the giant panda thumb. This supernumerary digit is species-specific, as it is not present in shrews, the mole's closest relatives. Androgenic steroids are known to affect the growth and formation of bones, and a connection is possible between this species-specific trait and the "male" genital apparatus in female moles of many mole species (gonads with testicular and ovary tissues).

It begins gametogenesis in January and finishes in May, during which its gonads are nearly completely filled with gametes. Spawning usually occurs between May and June, but sometimes can take until October for all the urchins to finish releasing their eggs and sperm. The start and end times of these periods are not always rigid and can vary by a couple months. This data on H. mammillatus’ reproduction indicates a possible lunar or semilunar cycle in spawning and gametogenesis, meaning that H. mammillatus may take temporal cues from the moon. Given that spawning did not always happen during the same phase of moon, other factors may contribute to the timing of H. mammillatus’ reproductive stages (such as the tidal cycle, for example).

Kummerlöwe was the son of Arthur Kummerlöwe, a government inspector in Leipzig. He graduated in 1923 at the Humboldtschule and then went to the University of Leipzig, receiving a summa cum laude doctorate in philosophy on June 7, 1930. He initially worked towards a doctoral thesis under Johannes Meisenheimer on the gonads of female birds. Meisenheimer was a Jew while Kummerlöwe was an active National Socialist leading to differences and finally giving up study. By 1925 Kummerlöwe joined the Nazi party and in November he founded the first student union under the Nazis in Leipzig, the Leipziger Gruppe of the NS- Studentenbundes. In June 1926 he took part in the party day of the NSDAP and joined the Nazi Teaching Association.

WAGR syndrome (also known as WAGR complex, Wilms tumour-aniridia syndrome, aniridia-Wilms tumour syndrome) is a rare genetic syndrome in which affected children are predisposed to develop Wilms tumour (a tumour of the kidneys), Aniridia (absence of the coloured part of the eye, the iris), Genitourinary anomalies, and mental Retardation. The G is sometimes instead given as "gonadoblastoma," since the genitourinary anomalies can include tumours of the gonads (testes or ovaries). Some WAGR syndrome patients show severe childhood obesity and hyperphagia; the acronym WAGRO (O for obesity) has been used to describe this category and may be associated with the coinciding loss of BDNF a gene that is also on chromosome 11. The condition, first described by Miller et al.

St. Mary has also collaborated on the study of the effect of agriculture (and agricultural contaminants) on gonadal form and function in the giant cane toad Bufo marinus (also known as Rhinella marina), which found that toads living on land used for agriculture had increased incidences of gonadal abnormalities and intersex gonads. Males were feminized or demasculinized with altered testosterone levels corresponding to the level of agricultural land use. She also helped publish another study of the giant toad species which demonstrated reduced spermatogenesis in toads living in agricultural areas due to endocrine disrupting chemicals. Other studies authored in this field include the ecological determinants of settlement choice in coral reef fish larvae, and the effects of hatchery rearing of Florida largemouth bass.

Werner syndrome patients exhibit growth retardation, short stature, premature graying of hair, alopecia (hair loss), wrinkling, prematurely aged faces with beaked noses, skin atrophy (wasting away) with scleroderma-like lesions, lipodystrophy (loss of fat tissues), abnormal fat deposition leading to thin legs and arms, and severe ulcerations around the Achilles tendon and malleoli (around ankles). Other symptoms include change in voice (weak, hoarse, high-pitched), atrophy of gonads leading to reduced fertility, bilateral cataracts (clouding of lens), premature arteriosclerosis (thickening and loss of elasticity of arteries), calcinosis (calcium deposits in blood vessels), atherosclerosis (blockage of blood vessels), type 2 diabetes, osteoporosis (loss of bone mass), telangiectasia, and malignancies. The prevalence of rare cancers, such as meningiomas, are increased in individuals with Werner syndrome.

When underweight or sickly children present with pubertal delay, it is warranted to search for illnesses that cause a temporary and reversible delay in puberty. Chronic conditions such as sickle cell disease and thalassemia, cystic fibrosis, HIV/AIDS, hypothyroidism, chronic kidney disease, and chronic gastroenteric disorders (such as coeliac disease and inflammatory bowel disease) cause a delayed activation of the hypothalamic region of the brain to send signals to start puberty. Childhood cancer survivors can also present with delayed puberty secondary to their cancer treatments, especially males. The type of treatment, amount of exposure/dosage of drugs, and age during treatment determine the level by which the gonads are affected with younger patients at a lower risk of negative reproductive effects.

Screening studies include a complete blood count, an erythrocyte sedimentation rate, and thyroid studies. Hypogonadism can be differentiated between hyper- and hypo-gonadotropic hypogonadism by measuring serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) (gonadotropins to measure pituitary output), and estradiol in girls (to measure gonadal output). By the age of 10-12, children with failure of the ovaries or testes will have high LH and FSH because the brain is attempting to jump-start puberty, but the gonads are not responsive to these signals. Stimulating the body by administering an artificial version of gonadotropin-releasing hormone (GnRH, the hypothalamic hormone) can differentiate between constitutional delay of puberty and a GnRH deficiency in boys, although no studies have been done in girls to prove this.

For example, 18 species of trematodes are known to parasitically castrate the California horn snail, Cerithidea californica. Certain other effects of a parasite on its host may appear similar to parasitic castration, such as the host's immune system diverting energy from reproduction in response to numerous parasites that singly would have no impact on fecundity or fertility, or parasitoids that may consume reproductive organs first. A parasite that ends the reproductive life of its host theoretically liberates a significant fraction of the host's resources, which can now be used to benefit the parasite. Lafferty points out that the fraction of intact host energy spent on reproduction includes not just gonads and gametes but also secondary sexual characteristics, mate- seeking behavior, competition, and care for offspring.

The origin of this asymmetry, at least for the gonads, is possibly influenced by the direction of the basal coiling in the tubarium, by some intrinsic biological mechanisms in pterobranchs, or solely by environmental factors. Hedgehog (hh), a highly conserved gene implicated in neural developmental patterning, was analyzed in Hemichordates, taking Rhabdopleura as a pterobranch representative. It was found that hedgehog gene in pterobranchs is expressed in a different pattern compared to other hemichordates as the enteropneust Saccoglossus kowalevskii. An important conserved glycine–cysteine–phenylalanine (GCF) motif at the site of autocatalytic cleavage in hh genes, is altered in R. compacta by an insertion of the amino acid threonine (T) in the N-terminal, and in S. kowalesvskii there is a replacement of serine (S) for glycine (G).

Leydig cell hypoplasia (or aplasia) (LCH), also known as Leydig cell agenesis, is a rare autosomal recessive genetic and endocrine syndrome affecting an estimated 1 in 1,000,000 genetic males. It is characterized by an inability of the body to respond to luteinizing hormone (LH), a gonadotropin which is normally responsible for signaling Leydig cells of the testicles to produce testosterone and other androgen sex hormones. The condition manifests itself as pseudohermaphroditism (partially or fully underdeveloped genitalia), hypergonadotropic hypogonadism (decreased or lack of production of sex steroids by the gonads despite high circulating levels of gonadotropins), reduced or absent puberty (lack of development of secondary sexual characteristics, resulting in sexual infantilism if left untreated), and infertility. Leydig cell hypoplasia does not occur in biological females as they do not have either Leydig cells or testicles.

John Money, a pediatric clinical psychologist in the new "Psychohormonal Research Unit" at Hopkins and his partners, John and Joan Hampson, analyzed these assignments and reassignments in an attempt to learn the timing and sources of gender identity. In most of these patients, gender identity seemed to follow the sex of assignment and sex of rearing more closely than it did genes or hormones. This apparent primacy of social learning over biology became part of the intellectual underpinning of the feminist movement of the 1960s. In its application to children with intersex conditions, this thesis that sex was a many-faceted social construction changed the management of ambiguous genitalia from determination of the baby's real sex (by checking gonads or chromosomes) to determination of what sex should be assigned.

Although their exact pathways are not fully understood, they have been proven to be essential for the continued expression of SOX9 at the levels necessary for testes development. SOX9 and TDF are believed to be responsible for the cell- autonomous differentiation of supporting cell precursors in the gonads into Sertoli cells, the beginning of testes development. These initial Sertoli cells, in the center of the gonad, are hypothesized to be the starting point for a wave of FGF9 that spreads throughout the developing XY gonad, leading to further differentiation of Sertoli cells via the up-regulation of SOX9. SOX9 and TDF are also believed to be responsible for many of the later processes of testis development (such as Leydig cell differentiation, sex cord formation, and formation of testis-specific vasculature), although exact mechanisms remain unclear.

Within 3 to 4 years, hair fills the pubic area (stage 4) and becomes much thicker and darker, and by 5 years extends to the near thighs and upwards on the abdomen toward the umbilicus (stage 5). Tanner scale-male Other areas of the skin are similarly, though slightly less, sensitive to androgens and androgenic hair typically appears somewhat later. In rough sequence of sensitivity to androgens and appearance of androgenic hair, are the armpits (axillae), perianal area, upper lip, preauricular areas (sideburns), periareolar areas (nipples), middle of the chest, neck under the chin, remainder of chest and beard area, limbs and shoulders, back, and buttocks. Although generally considered part of the process of puberty, pubarche is distinct and independent of the process of maturation of the gonads that leads to sexual maturation and fertility.

Like monoamine oxidase (MAO), VAP-1 can deaminate short-chain primary amines, but SSAO enzymes, including VAP-1, can tolerate several selective flavin-dependent MAO-A and MAO-B inhibitors like clorgiline, pargyline, and deprenyl, but are still sensitive to semicarbazide and other hydrazines, hydroxylamine and propargylamine. VAP-1 is found in the smooth muscle of blood vessels and various other tissues, and can mostly be found in two forms: tissue-bound and soluble isoforms. The tissue- bound SSAO is primarily located in the leukocytes, adipocytes, and the endothelium of highly vascularized tissues, including the kidney, liver, and gonads. Thus, this form participates in cellular differentiation, deposition of the ECM (extracellular matrix) in smooth muscle cells, lipid trafficking in adipocytes and control of muscular tone, by mechanisms that are not completely understood.

46,XX/ 46,XY is associated with a wide spectrum of different physical presentations, ranging from what was formerly known as "true hermaphroditism" to a completely normal male or female phenotype. Due to this variation, genetic testing is the only way to reliably make a diagnosis. 46,XX/46,XY is possible if there is direct observation of one or more of the following: # Small phallus midway in size between a clitoris and a penis # Incompletely closed urogenital opening (shallow vagina) # Abnormal urethra opening on the perineum As individuals with 46,XX/46,XY possess both ovarian tissue and testicular tissue, depending on the individual, gonads (ovaries or testes) may function fully, partly or not at all. At puberty, a mix of male and female characteristics may emerge.

It mediates its antiandrogenic effects by 1) stimulating the production of sex hormone-binding globulin (SHBG) in the liver, which decreases free and thus bioactive concentrations of testosterone in the blood; and by 2) suppressing luteinizing hormone (LH) secretion from the pituitary gland, which decreases production of testosterone by the gonads. Birth control pills that contain EE are useful in the treatment of androgen-dependent conditions like acne and hirsutism by virtue of their antiandrogenic effects. Birth control pills containing EE have been found to increase circulating SHBG levels by 2- to 4-fold in women and to reduce free testosterone concentrations by 40 to 80%. Birth control pills containing high doses of EE can increase SHBG levels in women by as much as 5- to 10-fold.

It is notable that gynecomastia has been observed in patients in whom estradiol levels are within the normal range. This has been suggested to be due to in situ conversion of adrenal androgens into estrone and then estradiol (via local 17β-HSD) in breast tissue (where aromatase activity may be particularly high). The symptoms of AEXS, in males, include heterosexual precocity (precocious puberty with phenotypically-inappropriate secondary sexual characteristics; i.e., a fully or mostly feminized appearance), severe prepubertal or peripubertal gynecomastia (development of breasts in males before or around puberty), high-pitched voice, sparse facial hair, hypogonadism (dysfunctional gonads), oligozoospermia (low sperm count), small testes, micropenis (an unusually small penis), advanced bone maturation, an earlier peak height velocity (an accelerated rate of growth in regards to height), and short final stature due to early epiphyseal closure.

Adult male and female medusa spawn daily, and can be entrained with controlled light conditions to spawn at specific times. The oocytes, eggs, embryos, and planulae of Clytia are easily visualized under a microscope and, much like those of popular model organisms like sea urchins, the zygotes of C. hemisphaerica are relatively large (around 200 um in diameter) and can be microinjected to form transgenic planulae, polyp colonies, and medusa. Clytia is also unique in that its gonads can function autonomously; a gonad separated from an adult medusa will undergo oocyte development and ovulation under the same entrained light cues as would a gonad still attached to a medusa. Clytia medusa that are produced from a single polyp colony are also genetically identical, presenting a huge advantage for gene function analysis as well as genome sequencing.

Ishmael, an African American detective originally from Madison, Wisconsin, relocates to Kenya and starts a detective agency called the Black Star Agency with his associate, O (short for Odhiambo). Ishmael and O’s initial investigations involve odd cases, such as recovering “stolen” male gonads and cases of witchcraft; the only reason that the detectives are willing to take on these cases is that they are desperate for cash. They suddenly jump at the opportunity to investigate a new case involving a man who has been murdered and discarded in the Ngong Forest. They eventually realize that the man’s murder might be linked to a later bombing of the Norfolk Hotel in downtown Nairobi, which leaves ten Americans dead. Over the course of the novel, Ishmael and O’s case becomes more complicated when the results of the presidential election prompt tribal violence.

The part of the Y-chromosome which is responsible for maleness is the sex-determining region of the Y-chromosome, the SRY. The SRY activates Sox9, which forms feedforward loops with FGF9 and PGD2 in the gonads, allowing the levels of these genes to stay high enough in order to cause male development; for example, Fgf9 is responsible for development of the spermatic cords and the multiplication of Sertoli cells, both of which are crucial to male sexual development. The ZW sex-determination system, where males have a ZZ (as opposed to ZW) sex chromosome may be found in birds and some insects (mostly butterflies and moths) and other organisms. Members of the insect order Hymenoptera, such as ants and bees, are often determined by haplodiploidy, where most males are haploid and females and some sterile males are diploid.

The males of the Astatotilapia burtoni come in two phenotypes that are reversible. The males can readily switch between being territorial and non-territorial based on the social environment they are in: dominant, territorial males possess bright coloration, aggressive behavior while defending territory, and an active role in sexually reproducing with the females; on the other hand, subordinate and non-territorial males possess coloration similar that of the females, lack initiative to pursue female counterparts, and are reproductively suppressed due to regressed gonads. The transitions between different social roles cause several changes in the brain and reproductive system, such that the social transformation affects them both behaviorally and physically. To expand on reversibility, if a territorial male is placed with an individual that is significantly larger in size, it will then rapidly socially transform into the non-territorial type.

A GnRH modulator, or GnRH receptor modulator, also known as an LHRH modulator or LHRH receptor modulator, is a type of medication which modulates the GnRH receptor, the biological target of the hypothalamic hormone gonadotropin- releasing hormone (GnRH; also known as luteinizing-releasing hormone, or LHRH). They include GnRH agonists and GnRH antagonists. These medications may be GnRH analogues like leuprorelin and cetrorelix – peptides that are structurally related to GnRH – or small-molecules like elagolix and relugolix, which are structurally distinct from and unrelated to GnRH analogues. GnRH modulators affect the secretion of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn affects the gonads, influencing their function and hence fertility as well as the production of sex steroids, including that of estradiol and progesterone in women and of testosterone in men.

The alae appears to be a neural receptor responsive to just a handful of molecules particular to each species of nematode. Up to half a dozen types of receptors may be present at any one time on the alae and each type would be very numerous. The target molecules in the environment that stimulate each type of receptor may then be measured for their concentration and a threshold reached before an action is instigated. These actions may instigate entry into the dauer state (L1 alae), exiting of the dauer state (pheromone and or presence of an indicator for food availability), for sexual reproduction where the area around the vulva and gonads of the female and male use this family of receptors (RAM-5) where the nematode is likely to identify that reproductive organs are in contact.

The eggs develop in gonads of female medusae, which are located in the walls of the manubrium (stomach). Mature eggs are presumably spawned and fertilized in the sea by sperm produced and released by male medusae, as is the case for most hydromedusae, although the related species Turritopsis rubra seems to retain fertilized eggs until the planula stage. Fertilized eggs develop into planula larvae, which settle onto the sea-floor (or even the rich marine communities that live on floating docks), and develop into polyp colonies (hydroids). The hydroids bud new jellyfishes, which are released at about one millimetre in size and then grow and feed in the plankton, becoming sexually mature after a few weeks (the exact duration depends on the ocean temperature; at it is 25 to 30 days and at it is 18 to 22 days).

Signals for somite differentiation are derived from surroundings structures, including the notochord, neural tube and epidermis. The intermediate mesoderm connects the paraxial mesoderm with the lateral plate, eventually it differentiates into urogenital structures consisting of the kidneys, gonads, their associated ducts, and the adrenal glands. The lateral plate mesoderm give rise to the heart, blood vessels and blood cells of the circulatory system as well as to the mesodermal components of the limbs. Some of the mesoderm derivatives include the muscle (smooth, cardiac and skeletal), the muscles of the tongue (occipital somites), the pharyngeal arches muscle (muscles of mastication, muscles of facial expressions), connective tissue, dermis and subcutaneous layer of the skin, bone and cartilage, dura mater, endothelium of blood vessels, red blood cells, white blood cells, and microglia, Dentine of teeth, the kidneys and the adrenal cortex.

The same process of sex differentiation concerns other male and female reproductive organs (see List of related male and female reproductive organs), with some organs of both sexes developing similar, yet not identical, structure and functions (like the gonads - male testicles and female ovaries, like male and female urethras, erectile corpus cavernosum penis and prepuce in the penis (foreskin) and the corpus cavernosum clitoridis in the clitoris and (clitoral hood) and their frenula). But other male and female sex organs become absolutely different and unique, like the internal female genitalia. The scrotum and labia majora develop to have both similarities and crucial differences. Like the scrotum, labia majora after puberty may become of a darker color than the skin outside them, and, similarly, also grow pubic hair on their external surface (the female genitals on accompanying photos are shaved to show their structure clearer).

These reassignments were rarely successful, leading John Money and other influential psychologists and physicians to conclude that gender identity was (1) unrelated to chromosomes, (2) primarily a result of social learning, and (3) could not be easily changed after infancy. By the 1960s, CAH was well understood, karyotyping was routine, and standard management was to assign and raise all children with CAH according to their gonads and karyotypes, no matter how virilized. Markedly virilized girls were usually referred to a pediatric surgeon, often a pediatric urologist for a reconstructive vaginoplasty and clitoral reduction or recession—surgery to create or enlarge a vaginal opening and reduce the size or protrusion of the clitoris. This approach was designed to preserve fertility for both sexes and remains the standard management, but two aspects of this management have been challenged: assignment of completely virilized genetic females and the value and age of corrective surgery.

In his opinion the differences between the narrower first tooth-row and slightly wider second one in both Odontogriphus and Wiwaxia were unlike those of a molluscan radula, in which the much more numerous tooth-rows are identical; instead he argued that these two rows resembled the permanent lower jaw and moltable upper jaw of modern dorvilleid polychaetes. While Butterfield agreed that the dark patches round the foot served as gills, he denied that they were similar in structure and mode of development to molluscan ctenidia. In his opinion the flattened remains of Odontogriphus were formed by relatively tough extracellular secretions, such as jaws, bristles and toughened skin, and do not include purely or primarily cellular tissues, such as muscles or gonads. He therefore thought the respiratory organs round the edge of Odontogriphus’ foot could not be molluscan ctenidia, since these are covered by purely cellular tissue.

Follicle-stimulating hormone (FSH) insensitivity, or ovarian insensitivity to FSH in females, also referable to as ovarian follicle hypoplasia or granulosa cell hypoplasia in females, is a rare autosomal recessive genetic and endocrine syndrome affecting both females and males, with the former presenting with much greater severity of symptomatology. It is characterized by a resistance or complete insensitivity to the effects of follicle- stimulating hormone (FSH), a gonadotropin which is normally responsible for the stimulation of estrogen production by the ovaries in females and maintenance of fertility in both sexes. The condition manifests itself as hypergonadotropic hypogonadism (decreased or lack of production of sex steroids by the gonads despite high circulating levels of gonadotropins), reduced or absent puberty (lack of development of secondary sexual characteristics, resulting in sexual infantilism if left untreated), amenorrhea (lack of menstruation), and infertility in females, whereas males present merely with varying degrees of infertility and associated symptoms (e.g., decreased sperm production).

OII was established to give voice to intersex people, including those speaking languages other than just English, for people born with bodies which have atypical sexual characteristics such as gonads, chromosomes, and/or genitals. OII acknowledges intersex as a normal human biological variation, and rejects the terminology of disorder, as in DSD/Disorders of Sex Development, utilized by some other intersex groups, as well as the sexualization of intersex (as in Intersexuality). They acknowledge intersex people's own distinct sexuality, as people who may identify as gay, lesbian, bisexual, queer, trans, straight, or other, in alliance with other members of the LGBTI population.. Sociologist Georgiann Davis describes OII and (the now defunct) Intersex Society of North America as "activist organisations". The objective of OII is to achieve equality and human rights for intersex people, and end human rights violations against them, particularly the practice of non-consensual genital surgeries on infants and minors.

"Pseudohermaphroditism" has, until very recently, been the term used in the medical literature to describe the condition of an individual whose gonads and karyotype do not match the external genitalia in the gender binary sense. For example, 46,XY individuals who have a female phenotype, but also have testes instead of ovaries—a group that includes all individuals with CAIS, as well as some individuals with PAIS—are classified as having "male pseudohermaphroditism", while individuals with both an ovary and a testis (or at least one ovotestis) are classified as having "true hermaphroditism". Use of the word in the medical literature antedates the discovery of the chromosome, thus its definition has not always taken karyotype into account when determining an individual's sex. Previous definitions of "pseudohermaphroditism" relied on perceived inconsistencies between the internal and external organs; the "true" sex of an individual was determined by the internal organs, and the external organs determined the "perceived" sex of an individual.

A survey of the research literature from 1955–2000 suggests that more than one in every hundred individuals may have some intersex characteristic. An intersex human or other animal is one possessing any of several variations in sex characteristics including chromosomes, gonads, sex hormones, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". An intersex variation may complicate initial sex assignment and that assignment may not be consistent with the child's future gender identity. Reinforcing sex assignments through surgical and hormonal means may violate the individual's rights. A 2005 study on the gender identity outcomes of female-raised 46,XY persons with penile agenesis, cloacal exstrophy of the bladder, or penile ablation, found that 78% of the study subjects were living as female, as opposed to 22% who decided to initiate a sex change to male in line with their genetic sex.

The vitamin D receptor belongs to the nuclear receptor superfamily of steroid/thyroid hormone receptors, and VDRs are expressed by cells in most organs, including the brain, heart, skin, gonads, prostate, and breast. VDR activation in the intestine, bone, kidney, and parathyroid gland cells leads to the maintenance of calcium and phosphorus levels in the blood (with the assistance of parathyroid hormone and calcitonin) and to the maintenance of bone content. One of the most important roles of vitamin D is to maintain skeletal calcium balance by promoting calcium absorption in the intestines, promoting bone resorption by increasing osteoclast number, maintaining calcium and phosphate levels for bone formation, and allowing proper functioning of parathyroid hormone to maintain serum calcium levels. Vitamin D deficiency can result in lower bone mineral density and an increased risk of reduced bone density (osteoporosis) or bone fracture because a lack of vitamin D alters mineral metabolism in the body.

Fathers exposed to medical diagnostic x-rays are more likely to have infants who contract leukemia, especially if exposure is closer to conception or includes two or more X-rays of the lower gastrointestinal (GI) tract or lower abdomen. In medical radiography the x-ray beam is adjusted to expose only the area of which an image is required, so that generally shielding is applied to the patient to avoid exposing the gonads, whereas in an airport backscatter scan, the testicles of men and boys will be deliberately subjected to the direct beam in order to check for weapons in the underpants, and some radiation will also reach the ovaries of female subjects. A linear dose- response relationship has been observed between x-ray dose and double-strand breaks in DNA in human sperm. Extrapolations of cancer risk from minuscule exposures to radiation across large populations, however, are not supported by analysis by the National Council on Radiation Protection (NCRP).

Intersex people are born with sex characteristics, such as chromosomes, gonads, or genitals that, according to the United Nations Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". According to the Asia Pacific Forum of National Human Rights Institutions, few countries have provided for the legal recognition of intersex people. The Asia Pacific Forum states that the legal recognition of intersex people is firstly about access to the same rights as other men and women, when assigned male or female; secondly it is about access to administrative corrections to legal documents when an original sex assignment is not appropriate; and thirdly it is not about the creation of a third sex or gender classification for intersex people as a population but it is, instead, about self determination. The Asia Pacific Forum, the Council of Europe, and the Malta declaration of the Third International Intersex Forum have called for non-binary gender classifications to be available on a voluntary, opt-in basis.

Individuals affected by CAIS develop a normal external female habitus, despite the presence of a Y chromosome, but internally, they will lack a uterus, and the vaginal cavity will be shallow, while the gonads, having been turned into testicles rather than ovaries in the earlier separate process also triggered by their Y chromosome, will remain undescended in the place where the ovaries would have been. This results not only in infertility individuals with CAIS, but also presents a risk of gonadal cancer later on in life. CAIS is one of the three categories of androgen insensitivity syndrome (AIS) since AIS is differentiated according to the degree of genital masculinization: complete androgen insensitivity syndrome (CAIS) when the external genitalia is that of a typical female, mild androgen insensitivity syndrome (MAIS) when the external genitalia is that of a typical male, and partial androgen insensitivity syndrome (PAIS) when the external genitalia is partially, but not fully masculinized. Androgen insensitivity syndrome is the largest single entity that leads to 46, XY undermasculinization.

She considered LeVay's account of "the embryonic development of gonads and genitalia" an example of this weakness, describing it as "extremely unsophisticated", and accusing LeVay of making inaccurate claims. She criticized LeVay's views on gender differences, including his belief "that female development is passive and preprogrammed ... and male development active", and for failing to cite critiques of that viewpoint. She gave LeVay credit for bringing "a wider range of evidence to bear in examining the interactions among hormones, the brain, and behavior" and citing less well-known work on this topic, and praised LeVay for "declaring his own gay identity", and called his treatment of the relevance of biology to homosexuality "appropriately cautious". Horton described the book as persuasive and credited LeVay, along with other researchers, with helping make a strong but not definitive case that biological influences play an important or even decisive role in "determining sexual preference among males", and with "taking a "broad philosophical perspective in his discussion of human sexuality by placing his research in the context of animal evolution.

The Adriatic sturgeon is a tetraploid fish (has four sets of chromosomes) and research based on mitochondrial and microsatellite information is applied on the breeding stock to establish how best to increase the genetic diversity of the fish used in the breeding programme. It has been reported by researchers that, despite the release of captive-bred fish, no signs of spawning have been observed in the wild; however, considering that Adriatic sturgeon needs at least twelve years to attain sexual maturity and matures gonads in alternate years, and considering the release of captive small fish started in 2004, it was probably premature to look for wild fingerlings at the time of the publication of the report (2011). About the southwestern population, it was reported that Adriatic sturgeon was seen for the last time in Greece in 1977, and in Albania in 1997 in the Buna River, but has not been seen there since; however, in 2003 a study published genetic data of several specimens especially caught in Buna river, below the confluence with Lake Skadar.

Intersex people are born with sex characteristics, such as chromosomes, gonads, or genitals that, according to the UN Office of the High Commissioner for Human Rights, "do not fit typical binary notions of male or female bodies". A sex and gender distinction is not universal, and Peletz's description of gender as designating biological variations as well as cultural practices is not unique. In a study of arguments that intersex people fit into a third gender classification, intersex scholar Morgan Holmes argues that much analysis of a third sex or third gender is simplistic: Like non- intersex people, some intersex individuals may not identify themselves as either exclusively female or exclusively male, but most appear to be men or women. A clinical review suggests that between 8.5–20% of people with intersex conditions may experience gender dysphoria, while sociological research in Australia, a country with a third 'X' sex classification, shows that 19% of people born with atypical sex characteristics selected an "X" or "other" option, while 52% are women, 23% men and 6% unsure. Alex MacFarlane is believed to be the first person in Australia to obtain a birth certificate recording sex as indeterminate, and the first Australian passport with an 'X' sex marker in 2003.