1000 Sentences With "homologous" | Random Sentence Generator

They have a hormonal information-processing system that's homologous to animals' neural network.

This type of gene disruption — called non-homologous end joining — is being used in sickle-cell and thalassemia trials.

The agency also allows what is known as "homologous use," deploying the cells in a way similar to their original function in the body.

By searching a database for homologous gene sequences she found sequences for asparaginase, also the name of the enzyme, and soon saw that many fungi contain this enzyme.

It's important to remember that the clit and glans (the head of the penis) are homologous, meaning they are structurally similar and made up of the same embryonic cells.

If examining the gut floras of autistic children and their mothers (whether or not those mothers are obese) even hinted at something homologous happening in human beings, then dosing infants who might be at risk with L. reuteri could be a sensible idea.

I have no idea how to read the piece "Dimensions and Indications of the Multidimensional Poverty Index" (2016), which consists of small, colored rectangles set in wooden frames, arranged side by side to create a kind of minimalist scheme of colors grouped in homologous families of hue.

The FDA nod was based on a trial that showed the benefit of using Zejula to treat tumours whether or not the women had mutated BRCA genes which hamper DNA repairs, but also in women with a wider range of genetic mutations, grouped together under the term homologous recombination deficiency (HRD).

In a "landmark" phase III clinical trial, presented at the European Society of Medical Oncology conference in Barcelona on Monday, the drug olaparib was shown to be safe and effective in delaying the progression of disease in men with both metastatic castrate-resistant prostate cancer and mutations in their homologous recombination repair, or HRR, genes.

Non-homologous end joining (NHEJ) and homologous recombination (HR) in mammals during DNA double-strand break Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as "non- homologous" because the break ends are directly ligated without the need for a homologous template, in contrast to homology directed repair, which requires a homologous sequence to guide repair. The term "non-homologous end joining" was coined in 1996 by Moore and Haber. NHEJ is typically guided by short homologous DNA sequences called microhomologies.

When the homologous DNA is absent, another process called non-homologous end joining (NHEJ) takes place instead.

In the fifth month the membrane degenerates but leaves a remnant called the hymen. Organs in the male and female with a shared common ancestry are said to be homologous. The clitoral glans is homologous to the male glans penis, and the clitoral body and the clitoral crura are homologous to the corpora cavernosa of the penis. The labia majora is homologous to the scrotum; the clitoral hood is homologous to the foreskin, and the labia minora is homologous to the spongy urethra.

Nilsson, A.S. and E. Haggård-Ljungquist, Detection of homologous recombination among bacteriophage P2 relatives. Molecular Phylogenetics and Evolution, 2001. 21(2): p. 259-269. Besides homologous recombination between related phages, non-homologous recombination is also a key mechanism for phage evolution.

Also, lack of Zmpste24 allows an increase in non- homologous end joining, but a deficiency in steps leading to homologous recombinational DNA repair.

Homologous recombination deficiency leads to Signature 3 substitution pattern, but also to increase burden of structural variants. In the absence of homologous recombination, non-homologous end joining leads to large structural variants such as chromosomal translocations, chromosomal inversions and copy number variants.

The core of the complex is structurally similar to cytochrome bc1 core. Cytochrome b6 and subunit IV are homologous to cytochrome b and the Rieske iron-sulfur proteins of the two complexes are homologous. However, cytochrome f and cytochrome c1 are not homologous.

Mitotic homologous recombination occurs mainly between sister chromatids subsequent to replication (but prior to cell division). Inter-sister homologous recombination is ordinarily genetically silent. During mitosis the incidence of recombination between non-sister homologous chromatids is only about 1% of that between sister chromatids.

Once the homologous sequence is found, the recombinases facilitate invasion of the ssDNA end into the homologous dsDNA to form a D-loop. After strand exchange, homologous recombination intermediates are processed by either of two distinct pathways (see diagram) to form the final recombinant chromosomes.

While parts of the hagfish skull are thought to be homologous with lampreys, they are thought to have very few homologous elements with jawed vertebrates.

The mechanism of conformational proofreading is utilized in the system of homologous recombination to discern between similar DNA sequences. Homologous recombination facilitates the exchange of genetic material between homologous DNA molecules. This crucial process requires detecting a specific homologous DNA sequence within a huge variety of heterologous sequences. The detection is mediated by RecA in E. coli, or members of its superfamily in other organisms.

After binding, Cas9 introduces a DNA double strand break, which is then followed by gene modification via homologous recombination (HDR) or non-homologous end joining (NHEJ).

In the second phase of prophase I, zygotene (from the Greek for "conjugation"), all maternally and paternally derived chromosomes have found their homologous partner. The homologous pairs then undergo synapsis, a process by which the synaptonemal complex (a proteinaceous structure) aligns corresponding regions of genetic information on maternally and paternally derived non-sister chromatids of homologous chromosome pairs. The paired homologous chromosome bound by the synaptonemal complex are referred to as bivalents or tetrads. Sex (X and Y) chromosomes do not fully synapse because only a small region of the chromosomes are homologous.

Brodmann-1909 regarded area 32 as topologically, but not cytoarchitecturally, homologous to the human dorsal anterior cingulate area 32; area 25 of Walker-1940 is topologically homologous to area 32.

Non- sister chromatids, on the other hand, refers to either of the two chromatids of paired homologous chromosomes, that is, the pairing of a paternal chromosome and a maternal chromosome. In chromosomal crossovers, non-sister (homologous) chromatids form chiasmata to exchange genetic material during the prophase I of meiosis (See Homologous chromosome pair).

NHEJ is a DNA repair mechanism which, unlike homologous recombination, does not require a long homologous sequence to guide repair. Whether homologous recombination or NHEJ is used to repair double-strand breaks is largely determined by the phase of cell cycle. Homologous recombination repairs DNA before the cell enters mitosis (M phase). It occurs during and shortly after DNA replication, in the S and G2 phases of the cell cycle, when sister chromatids are more easily available.

Figure 3. Homologous recombination repairs DNA before the cell enters mitosis (M phase). It occurs only during and shortly after DNA replication, during the S and G2 phases of the cell cycle. Double-strand breaks can be repaired through homologous recombination, polymerase theta-mediated end joining (TMEJ) or through non-homologous end joining (NHEJ).

The specific repair processes that require gap filling by DNA synthesis include nucleotide excision repair, base excision repair, mismatch repair, homologous recombinational repair, non-homologous end joining and microhomology-mediated end joining.

SUMOylation plays a role in the major DNA repair pathways of base excision repair, nucleotide excision repair, non-homologous end joining and homologous recombinational repair. SUMOylation also facilitates error prone translesion synthesis.

There are two main types of molecular mechanism for the formation of copy number variations: homologous based and non-homologous based. Although many suggestions have been put forward, most of these theories are speculations and conjecture. There is no conclusive evidence that correlates a specific copy number variation to a specific mechanism. Diagrammatic representation of non-allelic homologous recombination.

Their scales, called dermal denticles, and teeth are homologous organs.

This is the case with BRCA1 and BRCA2, two similar tumor suppressor genes whose malfunctioning has been linked with considerably increased risk for breast and ovarian cancer. Cells missing BRCA1 and BRCA2 have a decreased rate of homologous recombination and increased sensitivity to ionizing radiation, suggesting that decreased homologous recombination leads to increased susceptibility to cancer. Because the only known function of BRCA2 is to help initiate homologous recombination, researchers have speculated that more detailed knowledge of BRCA2's role in homologous recombination may be the key to understanding the causes of breast and ovarian cancer. Tumours with a homologous recombination deficiency (including BRCA defects) are described as HRD-positive.

Mammalian cells with mutant ERCC1–XPF are moderately more sensitive than normal cells to agents (such as ionizing radiation) that cause double- stranded breaks in DNA. Particular pathways of both homologous recombination repair and non-homologous end-joining rely on ERCC1-XPF function. The relevant activity of ERCC1–XPF for both types of double-strand break repair is the ability to remove non-homologous 3′ single-stranded tails from DNA ends before rejoining. This activity is needed during a single-strand annealing subpathway of homologous recombination. Trimming of 3’ single-stranded tail is also needed in a mechanistically distinct subpathway of non-homologous end-joining, dependent on the Ku proteins.

Homologous pairing of chromosomes involved using DNA strands that are highly similar to each other (~97%) and these strands must be longer than a certain length to avoid short but highly similar pairings. Non-homologous pairings, on the other hand, rely on only few base pairs of similarity between two strands, therefore it is possible for genetic materials to be exchanged or duplicated in the process of non-homologous based double stranded repairs. One type of non-homologous based mechanism is the non-homologous end joining or micro- homology end joining mechanism. These mechanisms are also involved in repairing double stranded breaks but require no homology or limited micro- homology.

Mammalian cells with mutant ERCC1–XPF are moderately more sensitive than normal cells to agents (such as ionizing radiation) that cause double-stranded breaks in DNA. Particular pathways of both homologous recombination repair and non-homologous end-joining rely on ERCC1-XPF function. The relevant activity of ERCC1–XPF for both types of double-strand break repair is the ability to remove non-homologous 3′ single-stranded tails from DNA ends before rejoining. This activity is needed during a single-strand annealing subpathway of homologous recombination. Trimming of 3’ single- stranded tails is also needed in a mechanistically distinct subpathway of non- homologous end-joining, independent of the Ku proteins Homologous integration of DNA, an important technique for genetic manipulation, is dependent on the function of ERCC1-XPF in the host cell.

Somatic cells of mice deficient in ATR have a decreased frequency of homologous recombination and an increased level of chromosomal damage. This finding implies that ATR is required for homologous recombinational repair of endogenous DNA damage.

Compared to homologous chromosomes, which are similar to another chromosome but often have different alleles, sister chromatids are an ideal template for homologous recombination because they are an identical copy of a given chromosome. When no homologous template is available or when the template cannot be accessed due to a defect in homologous recombination, the break is repaired via TMEJ in the S and G2 phases of the cell cycle. In contrast to homologous recombination and TMEJ, NHEJ is predominant in the G1 phase of the cell cycle, when the cell is growing but not yet ready to divide. It occurs less frequently after the G1 phase, but maintains at least some activity throughout the cell cycle.

Introducing genome alterations depends upon either of the two natural repair mechanisms of a cell: non-homologous end joining (NHEJ) and homology-directed repair (HDR). Repair through NHEJ comes about by the ligation of the end of the broken strands and, upon the occurrence of an error, can produce small insertions and deletions. HDR, on the other hand, uses a homologous DNA strand to repair—and gene making use of this repair mechanism and providing the desired nucleotide sequence allows for gene insertion or modification. In the absence of a homologous nucleotide base sequence that can be used by a homologous recombination mechanism, the main DSB repair pathway in mammals is through non-homologous end joining (NHEJ).

In the peripheral nervous system (PNS), a cluster of cell bodies of neurons (homologous to a CNS nucleus) is called a ganglion. The fascicles of nerve fibers in the PNS (homologous to CNS tracts) are called nerves.

During meiosis Rad51 interacts with another recombinase, Dmc1, to form a presynaptic filament that is an intermediate in homologous recombination. Dmc1 function appears to be limited to meiotic recombination. Like Rad51, Dmc1 is homologous to bacterial RecA.

SNX-482 is homologous to the spider peptides grammatoxin S1A and hanatoxin.

S. acidocaldarius possess a mechanism of replication homologous to the eukaryotic ESCRT.

HK1 is one of four highly homologous hexokinase isoforms in mammalian cells.

During meiosis, synapsis (the pairing of homologous chromosomes) ordinarily precedes genetic recombination.

This pathway will eventually recruit the necessary proteins for homologous recombination repair.

HK2 is one of four highly homologous hexokinase isoforms in mammalian cells.

The process of homologous recombinational repair (HRR) is a key DNA repair process that is especially effective for repairing double- strand damages, such as double-strand breaks. This process depends on a second homologous chromosome in addition to the damaged chromosome. During logarithmic growth, a DNA damage in one chromosome may be repaired by HRR using sequence information from the other homologous chromosome. Once cells approach stationary phase, however, they typically have just one copy of the chromosome, and HRR requires input of homologous template from outside the cell by transformation.

Rice gene OsDMC1 was found to be essential for pairing of homologous chromosomes during meiosis, and rice gene OsMRE11 was found to be required for both synapsis of homologous chromosomes and repair of double-strand breaks during meiosis.

However, U-type exchange can also occur for homologous chromosomes which creates an isochromosome with homologous arms. This exchange between homologues is most likely due to homologous sequences containing low copy repeats. Regardless of the chromosome involved in U-type exchange, the acentric fragment of the chromosome is lost, thus creating a partial monosomy of genes located in that portion of the acentric chromosome.

In this case, new combinations of alleles are not produced since the sister chromosomes are usually identical. In meiosis and mitosis, recombination occurs between similar molecules of DNA (homologous sequences). In meiosis, non-sister homologous chromosomes pair with each other so that recombination characteristically occurs between non-sister homologues. In both meiotic and mitotic cells, recombination between homologous chromosomes is a common mechanism used in DNA repair.

As such, the complex cleaves the links between two homologous chromosomes that form during homologous recombination. This allows the two linked chromosomes to resolve into two unconnected double-strand DNA molecules. The SLX4 interacting protein interacts with SLX4 in the DNA repair process, specifically in interstrand crosslink repair. SLX4 also associates with RAD1, RAD10 and SAW1 in the single-strand annealing pathway of homologous recombination.

Homologous proteins in mice have been called miwi (for _m_ ouse p _iwi_ ).

Felicia filifolia is a diploid having nine sets of homologous chromosomes (2n=18).

Condensin (despite dependent interactions with Topoisomerase II) is antagonistic to Drosophila homologous pairing.

The vestibular bulbs beneath the skin of the labia minora are homologous to the corpus spongiosum, the tissue of the penis surrounding the urethra, and to the bulb of the penis. Bartholin's glands are homologous to the bulbourethral glands in males.

Also, when two or more viruses infect a cell, genetic variation may be generated by homologous recombination. Homologous recombination can arise during viral genome replication by the RNA polymerase switching from one template to another, a process known as copy choice.

In the fourth phase of prophase I, diplotene (from the Greek for "twofold"), crossing-over is completed. Homologous chromosomes retain a full set of genetic information; however, the homologous chromosomes are now of mixed maternal and paternal descent. Visible junctions called chiasmata hold the homologous chromosomes together at locations where recombination occurred as the synaptonemal complex dissolves. It is at this stage where meiotic arrest occurs in many species.

A key event during meiosis in a diploid cell is the pairing of homologous chromosomes and homologous recombination (the exchange of genetic information) between homologous chromosomes. This process promotes the production of increased genetic diversity among progeny and the recombinational repair of damages in the DNA to be passed on to progeny. To explain the adaptive function of meiosis in flowering plants, some authors emphasize diversity and others emphasize DNA repair.

Therefore, the cell can replicate or segregate incorrect chromosomes. Faulty rearrangements can occur when homologous recombination fails to accurately repair double-stranded breaks. Since human chromosomes contain repetitive DNA sections, broken DNA segments from one chromosome can combine with similar sequences on a non-homologous chromosome. If repair enzymes do not catch this recombination event, the cell may contain non-reciprocal translocation where parts of non-homologous chromosomes are joined together.

The mechanisms behind mitotic recombination are similar to those behind meiotic recombination. These include sister chromatid exchange and mechanisms related to DNA double strand break repair by homologous recombination such as single-strand annealing, synthesis- dependent strand annealing (SDSA), and gene conversion through a double- Holliday Junction intermediate or SDSA. In addition, non-homologous mitotic recombination is a possibility and can often be attributed to non-homologous end joining.

UV irradiation of Halobacterium sp. strain NRC-1 induces several gene products employed in homologous recombination. For instance, a homolog of the rad51/recA gene, which plays a key role in recombination, is induced 7-fold by UV. Homologous recombination may rescue stalled replication forks, and/or facilitate recombinational repair of DNA damage. In its natural habitat, homologous recombination is likely induced by the UV irradiation in sunlight.

Patient's cells display chromosome rearrangements, micronuclei, sensitivity to DNA damage and defective homologous recombination.

The zooids are homologous to individual animals, but are connected physiologically to each other.

The gland somewhat resembles a caecum in structure but is not a homologous structure.

Some highly homologous variants of YPM have been characterized, including YPMa, YPMb, and YPMc.

Homologous recombination is conserved across all three domains of life as well as DNA and RNA viruses, suggesting that it is a nearly universal biological mechanism. The discovery of genes for homologous recombination in protists—a diverse group of eukaryotic microorganisms—has been interpreted as evidence that meiosis emerged early in the evolution of eukaryotes. Since their dysfunction has been strongly associated with increased susceptibility to several types of cancer, the proteins that facilitate homologous recombination are topics of active research. Homologous recombination is also used in gene targeting, a technique for introducing genetic changes into target organisms.

Down's syndrome, which is caused by an extra copy of chromosome 21, is one of many abnormalities that result from such a failure of homologous recombination in meiosis. Deficiencies in homologous recombination have been strongly linked to cancer formation in humans. For example, each of the cancer-related diseases Bloom's syndrome, Werner's syndrome and Rothmund-Thomson syndrome are caused by malfunctioning copies of RecQ helicase genes involved in the regulation of homologous recombination: BLM, WRN and RECQL4, respectively. In the cells of Bloom's syndrome patients, who lack a working copy of the BLM protein, there is an elevated rate of homologous recombination.

Homologous series are not unique to organic chemistry. Titanium, vanadium, and molybdenum oxides all form homologous series (e.g. VnO2n − 1 for 2 < n < 10), as do the silanes, SinH2n + 2 (with n up to 8) that are analogous to the alkanes, CnH2n + 2.

Homologous chromosomes are largely identical, in this case as a result of the chromosome replication.

The PPIase domain is homologous to PPIA and can be bound and inhibited by CsA.

Another tissue stress function is to regulate homologous tissue cell mass in various physiological conditions.

The paired pectoral and pelvic fins of fish are homologous with the limbs of tetrapods.

In the developing fetus, the genital tubercle develops into the glans of the penis in males and into the clitoral glans in females; they are homologous. The urogenital fold develops into the skin around the shaft of the penis and the urethra in males and into the labia minora in females.Keith L. Moore, T. V. N. Persaud, Mark G. Torchia, The Developing Human: Clinically Oriented Embryology 10th Ed. Elsevier Health Sciences, 2015 , pp 267-69 The corpora cavernosa are homologous to the body of the clitoris; the corpus spongiosum is homologous to the vestibular bulbs beneath the labia minora; the scrotum, homologous to the labia majora; and the foreskin, homologous to the clitoral hood. The raphe does not exist in females, because there, the two halves are not connected.

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.

Prophase I is by far the longest phase of meiosis (lasting 13 out of 14 days in mice). During prophase I, homologous maternal and paternal chromosomes pair, synapse, and exchange genetic information (by homologous recombination), forming at least one crossover per chromosome. These crossovers become visible as chiasmata (plural; singular chiasma). This process facilitates stable pairing between homologous chromosomes and hence enables accurate segregation of the chromosomes at the first meiotic division.

Non-Homologous Isofunctional Enzymes (NISE) are two evolutionarily unrelated enzymes that catalyze the same chemical reaction. Enzymes that catalyze the same reaction are sometimes referred to as analogous as opposed to homologous (Homology (biology), however it is more appropriate to name them as Non- homologous Isofunctional Enzymes, hence the acronym (NISE). These enzymes all serve the same end function but do so in different organisms without detectable similarity in primary and possibly tertiary structures.

Here, Gene X represents the gene of interest and the black line represents the chromosome. When the two homologous chromosomes are misaligned and recombination occurs, it may result in a duplication of the gene. One of the best-recognized theories that leads to copy number variations as well as deletions and inversions is non-allelic homologous recombinations. During meiotic recombination, homologous chromosomes pair up and form two ended double- stranded breaks leading to Holliday junctions.

Although SecY and SecE are conserved in all three domains of life, bacterial SecG is not homologous with eukaryotic Sec61β. The eukaryotic Sec61β is however homologous to the archaeal SecG, leading some authors to refer to the archaeal complex as SecYEβ instead of SecYEG.

S. oralis is competent for natural genetic transformation. Thus S. oralis cells are able to take up exogenous DNA and incorporate exogenous sequence information into their genomes by homologous recombination. These bacteria can employ a predatory fratricidal mechanism for active acquisition of homologous DNA.

S. mitis is competent for natural genetic transformation. Thus S. mitis cells are able to take up exogenous DNA and incorporate exogenous sequence information into their genome by homologous recombination. These bacteria can employ a predatory fratricidal mechanism for active acquisition of homologous DNA.

In addition, SIRT6 promotes the repair of DNA double-strand breaks. Furthermore, over-expression of SIRT6 can stimulate homologous recombinational repair. SIRT7 knockout mice display features of premature aging. SIRT7 protein is required for repair of double-strand breaks by non-homologous end joining.

Use of homologous recombination deficiency (HRD) score to enrich for niraparib sensitive high grade ovarian tumors.

Such genetic approaches rely on either linear or circular targeting vectors to carry out homologous recombination.

Included in this analysis was the observation of a homologous genomic organization in all three Epsilonretroviruses.

Note that exosortase and archaeosortase are functionally analogous, while not in any way homologous to sortase.

MinD is homologous to members in MinD of E. coli, a relative of the ParA family.

PhEVER is a database of homologous gene families between viral sequences and sequences from cellular organisms.

A homolog in archaea performs the same main task, while bacteria use the non-homologous Gre.

CNVs occur due to non-allelic homologous recombination mediated by low copy repeats (sequentially similar regions).

Therefore, accurate repair of the damage depends on retrieving the lost information from an undamaged homologous chromosome in the same cell. Retrieval can occur by pairing with a sister chromosome produced during a preceding round of replication. In a diploid cell retrieval may also occur by pairing with a non- sister homologous chromosome, as occurs especially during meiosis. Once pairing has occurred, the crosslink can be removed and correct information introduced into the damaged chromosome by homologous recombination.

While heterologous desensitization occurs rapidly at low agonist concentrations, homologous desensitization shows a dose dependent response and usually begins at significantly higher concentrations. Homologous desensitization serves as a mechanism for tachyphylaxis and helps organisms to maintain homeostasis. The process of homologous desensitization has been extensively studied utilizing G protein–coupled receptors (GPCRs). While the different mechanisms for desensitization are still being characterized, there are currently four known mechanisms: uncoupling of receptors from associated G proteins, endocytosis, degradation, and downregulation.

Diagram illustrating the movement of a branch point between two homologous pieces of DNA. Migration travels to the left and stops when it reaches the end of the homologous region. The second branch point on the right is free to move in either direction as well. Branch migration is the process by which base pairs on homologous DNA strands are consecutively exchanged at a Holliday junction, moving the branch point up or down the DNA sequence.

However, the Bacillus- plasmid RNA motif does not appear to be homologous to any such known RNA.

Therefore, recruitment of the ncPRC1.1 complex represents an early and critical regulatory step in homologous recombination repair.

Treatment includes antibiotics and collagenase inhibitors such as acetylcysteine and homologous blood serum. Surgery may be necessary.

TALENs can be used to edit genomes using non-homologous end joining (NHEJ) and homology directed repair.

Kallikrein is homologous to factor XI and consists of four apple domains and one serine protease domain.

However, the Rheotens is useful to compare the extensional flow properties of a homologous set of materials.

This makes sense due to the early homologous structures the Callorhinchidae possess relative to the other Chondrichthyes.

Calcineurin B homologous protein 1 is a protein encoded in humans by the CHP1 gene (formerly CHP).

This break is repaired by the natural repair mechanisms of the cell, specifically non-homologous end joining.

Significant similarity is strong evidence that two sequences are related by divergent evolution from a common ancestor. Alignments of multiple sequences are used to discover the homologous regions. Homology remains controversial in animal behaviour, but there is suggestive evidence that, for example, dominance hierarchies are homologous across the primates.

Steps 3,4,5,6 occur in rod cell outer segments; Steps 1, 2, and 7 occur in retinal pigment epithelium (RPE) cells. RPE65 isomerohydrolases are homologous with beta-carotene monooxygenases; the homologous ninaB enzyme in Drosophila has both retinal- forming carotenoid-oxygenase activity and all-trans to 11-cis isomerase activity.

Homologous recombination can be categorized as either in vivo or in vitro. In vitro homologous recombination mimics natural in vivo recombination. These in vitro recombination methods require high sequence homology between parental sequences. These techniques exploit the natural diversity in parental genes by recombining them to yield chimeric genes.

The methylation of histone lysine has an important role in choosing the pathway for repairing DNA double-strand breaks. As an example, tri-methylated H3K36 is required for homologous recombinational repair, while dimethylated H4K20 can recruit the 53BP1 protein for repair by the pathway of non-homologous end joining.

Double-strand break repair models that act via homologous recombination Homology directed repair (HDR) is a mechanism in cells to repair double-strand DNA lesions. The most common form of HDR is homologous recombination. The HDR mechanism can only be used by the cell when there is a homologous piece of DNA present in the nucleus, mostly in G2 and S phase of the cell cycle. Other examples of homology-directed repair include single-strand annealing and breakage-induced replication.

Cells are able to accurately repair DNA double-strand breaks using a process called homologous recombination. By this process DNA sequence information that is lost because of the breakage can be recovered from a second homologous DNA molecule. Homologous recombinational repair is important for removing DNA damage both during mitosis and meiosis. The repair process begins with the degradation of the 5’ end on either side of the double-strand break to yield 3’ single-stranded DNA tails (a process called end resection).

The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency. XRCC2 forms a four-part complex with three related paralogs: BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2) while two paralogs form a second complex CX3 (RAD51C-XRCC3). These two complexes act at two different stages of homologous recombinational DNA repair. The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites.

The Artemis:DNA-PKcs is also used for processing 5' and 3' ends in non-homologous DNA end joining.

Susceptibility of these chromosomes to nondisjunction may be due to reduced connections among homologous pairs in nonrecombinant chromosomes.

The MRN complex (MRX complex in yeast) is a protein complex consisting of Mre11, Rad50 and Nbs1 (also known as Nibrin in humans and as Xrs2 in yeast). In eukaryotes, the MRN/X complex plays an important role in the initial processing of double-strand DNA breaks prior to repair by homologous recombination or non-homologous end joining. The MRN complex binds avidly to double-strand breaks both in vitro and in vivo and may serve to tether broken ends prior to repair by non-homologous end joining or to initiate DNA end resection prior to repair by homologous recombination. The MRN complex also participates in activating the checkpoint kinase ATM in response to DNA damage.

The corresponding cobalt chelatases are not homologous. However, aerobic cobalt chelatase subunits CobN and CobS are homologous to Mg-chelatase subunits BchH and BchI, respectively. CobT, too, has been found to be remotely related to the third subunit of Mg-chelatase, BchD (involved in bacteriochlorophyll synthesis, e.g., in Rhodobacter capsulatus).

It was proposed that Saci-1497 and Saci-1500 function in an homologous recombination-based DNA repair mechanism that uses transferred DNA as a template. Thus it is thought that the ups system in combination with homologous recombination provide a DNA damage response which rescues Sulfolobales from DNA damaging threats.

This report further expands the phenotypic spectrum to include the possibility of normal intelligence as corroborated by formal, longitudinal psycho-educational testing. The presence of two homologous low copy repeats either side of the deletion break-point suggests that non-allelic homologous recombination is the likely mechanism underlying this syndrome.

Bioversity International. Vavilov also formulated the law of homologous series in variation.Popov I. Yu (2002). Periodical systems in biology .

The homologous protein (one that performs the same function) in yeast is Vacuolar protein sorting 29 homolog (S. cerevisiae).

This seems to match the ancestral condition, but it is not known for sure whether the circuitry is homologous.

These studies indicate that the pharyngeal slits found in hemichordates and chordates are indeed homologous in a molecular sense.

This suggests the two structures may be homologous, sclerotia being vestigial cleistothecia that lost the capacity to produce ascospores.

Low copy repeats (LCRs), also known as segmental duplications (SDs), are highly homologous sequence elements within the eukaryotic genome.

While homologous joints occur in other tetrapods, the term is generally restricted to mammals, particularly long-legged domesticated species.

It is 35 to 45% homologous to the human Epstein-Barr virus, which is classified in the same genus.

Sister chromatid interaction followed by homologous recombination appears to significantly contribute to the repair of DNA double- strand damages.

Because only homologous chromosomes pair, allopolyploids strictly exhibit bivalent formation at meiosis and undergo disomic inheritance for each locus.

The enzymes exist as homodimers. In eukaryotes, each monomer consisting of two major regions: an N-terminal oxygenase domain, which belongs to the class of heme-thiolate proteins, and a multi-domain C-terminal reductase, which is homologous to NADPH:cytochrome P450 reductase () and other flavoproteins. The FMN binding domain is homologous to flavodoxins, and the two domain fragment containing the FAD and NADPH binding sites is homologous to flavodoxin-NADPH reductases. The interdomain linker between the oxygenase and reductase domains contains a calmodulin-binding sequence.

The special chromosome separation in meiosis, homologous chromosomes separation in meiosis I and chromatids separation in meiosis II, requires special tension between homologous chromatids and non- homologous chromatids for distinguishing microtubule attachment and it relies on the programmed DNA double strand break (DSB) and repair in prophase I. Therefore meiotic recombination checkpoint can be a kind of DNA damage response at specific time spot. On the other hand, the meiotic recombination checkpoint also makes sure that meiotic recombination does happen in every pair of homologs.

More specifically, homologous proteins that exist in two distinct species are called orthologs. Whereas, homologous proteins encoded by the genome of a single species are called paralogs. The phylogenetic relationships of proteins are examined by multiple sequence comparisons. Phylogenetic trees of proteins can be established by the comparison of sequence identities among proteins.

Homologous recombination (HR) is an accurate process for repairing DNA double-strand breaks. HR is nearly absent in G1 phase, is most active in S phase, and declines in G2/M. Non-homologous end joining, a less accurate and more mutagenic process for repairing double strand breaks, is active throughout the cell cycle.

ArtAB toxin of Salmonella enterica has components similar to those found in two different families: the ArtA () subunit is homologous with pertussis toxin A, while the ArtB () subunit is homologous with subB as well as proteins found in other Salmonella strains. Under the categorize-by-A rule, it is a Ptx-family toxin.

It may be considered homologous to the supraoptic crest of mammals.Kuhlenbeck H. (1977). The central nervous system of vertebrates. Vol.

Competing theories include the Transformation theory, which was introduced as the Homologous theory by Čelakovský, and also renamed by Bower.

Since humans do not have a homologous protein, these enzymes are possible new targets for drug therapies against these diseases.

Epub 2006 Dec 18. PMID: 17178244 These mating type genes have high similarity to homologous genes in other ascomycete fungi.

The protein encoded by this gene is highly homologous to other family members; however, the enzymes have different substrate specificities.

The RecA/Rad51/DMC1 gene family plays a central role in homologous recombination during bacterial transformation as it does during eukaryotic meiosis and mitosis. For instance, the RecA protein is essential for transformation in Bacillus subtilis and Streptococcus pneumoniae, and expression of the RecA gene is induced during the development of competence for transformation in these organisms. As part of the transformation process, the RecA protein interacts with entering single- stranded DNA (ssDNA) to form RecA/ssDNA nucleofilaments that scan the resident chromosome for regions of homology and bring the entering ssDNA to the corresponding region, where strand exchange and homologous recombination occur. Thus the process of homologous recombination during bacterial transformation has fundamental similarities to homologous recombination during meiosis.

Modern anatomical texts show that the clitoris displays a hood that is the equivalent of the penis's foreskin, which covers the glans. It also has a shaft that is attached to the glans. The male corpora cavernosa are homologous to the corpus cavernosum clitoridis (the female cavernosa), the bulb of penis is homologous to the vestibular bulbs beneath the labia minora, the scrotum is homologous to the labia majora, and the penile urethra and part of the skin of the penis is homologous to the labia minora. Upon anatomical study, the penis can be described as a clitoris that has been mostly pulled out of the body and grafted on top of a significantly smaller piece of spongiosum containing the urethra.

They have been suggested to be homologous with the antennule of the euarthropods, or the chelicerae of chelicerates, although the latter possibility had been discounted by some authors. Later observations reject the homology of this two type of "great appendages", with neural structures clarifying the segmental affinities of radiodont frontal appendages as protocerebral (homologous to euarthropod's labrum), and megacheiran's short-great appendages as deutocerebral (homologous to euarthropod's antennule and chelicerae). Similar appendages also found in other Cambrian arthropods such as Isoxys and Occacaris, but their segmental affinities remain conjectural. On the other hand, a 2020 study suggested that the great/frontal appendages of Megacheirans, Isoxyids and Radiodontans to be homologous, and that the presence of a great appendage is the ancestral condition for Euarthropoda.

Fibrinogen and Cytochrome C divergence. Each data point on the graph represents a different species and that species homologous gene as identified through BLAST. BLAST searches were conducted using the human MGC50722, Fibrinogen and Cytochrome C gene and the percent identities were graphed against the actual divergence from humans for that species homologous gene.

1) have N-terminal, 12 TMS, sensor domains that regulate the C-terminal kinase domains. The latter are homologous to the kinase domain of NtrB and other sensor kinases. The N-terminal sensor domains are homologous, but distantly related to members of the SSS. The closest homologues are PutP of E. coli (2.A.21.2.

Chromomeres can be observed best when chromosomes are highly condensed. The chromomeres are present during leptotene phase of prophase I during meiosis. During zygotene phase of prophase I, the chromomeres of homologs align with each other to form homologous rough pairing (homology searching). These chromomeres helps provide a unique identity for each homologous pairs.

FAN1 has also been shown to increase the frequency of homologous recombination. This suggests that the gapped intermediate that forms following ICL unhooking may be repaired through HR when homologous chromosomes are present. FAN1 does not appear to be involved in other types of DNA repair, as it does not localize to DNA upon irradiation.

Prolegs do not have the same structure as modern adult insect legs, and there has been a great deal of debate as to whether they are homologous with them. Current evidence suggests that they are indeed homologous up to a very primitive stage in their embryological development, but that their emergence in modern insects was not homologous between the Lepidoptera and Symphyta. Such concepts are pervasive in current interpretations of phylogeny. In general the legs of larval insects, particularly in the Endopterygota, vary more than in the adults.

Nearby homologous regions of the template strand are often used for repair, which can give rise to either insertions or deletions in the genome if a non-homologous but complementary part of the template strand is used. Sequence similarity is a major player in crossover – crossover events are more likely to occur in long regions of close identity on a gene. This means that any section of the genome with long sections of repetitive DNA is prone to crossover events. The presence of transposable elements is another influential element of non- homologous crossover.

Non- homologous exon alignment by an iterative method (a), and by a phylogeny-aware method (b) Most multiple sequence alignment methods try to minimize the number of insertions/deletions (gaps) and, as a consequence, produce compact alignments. This causes several problems if the sequences to be aligned contain non-homologous regions, if gaps are informative in a phylogeny analysis. These problems are common in newly produced sequences that are poorly annotated and may contain frame-shifts, wrong domains or non-homologous spliced exons. The first such method was developed in 2005 by Löytynoja and Goldman.

During the diplotene stage, also known as diplonema, from Greek words meaning "two threads", the synaptonemal complex disassembles and homologous chromosomes separate from one another a little. However, the homologous chromosomes of each bivalent remain tightly bound at chiasmata, the regions where crossing-over occurred. The chiasmata remain on the chromosomes until they are severed at the transition to anaphase I to allow homologous chromosomes to move to opposite poles of the cell. In human fetal oogenesis, all developing oocytes develop to this stage and are arrested in prophase I before birth.

Homologous recombination also produces new combinations of DNA sequences during meiosis, the process by which eukaryotes make gamete cells, like sperm and egg cells in animals. These new combinations of DNA represent genetic variation in offspring, which in turn enables populations to adapt during the course of evolution. Homologous recombination is also used in horizontal gene transfer to exchange genetic material between different strains and species of bacteria and viruses. Although homologous recombination varies widely among different organisms and cell types, for double-stranded DNA (dsDNA) most forms involve the same basic steps.

The mechanisms that regulate homologous recombination and NHEJ throughout the cell cycle vary widely between species. Cyclin-dependent kinases (CDKs), which modify the activity of other proteins by adding phosphate groups to (that is, phosphorylating) them, are important regulators of homologous recombination in eukaryotes. When DNA replication begins in budding yeast, the cyclin-dependent kinase Cdc28 begins homologous recombination by phosphorylating the Sae2 protein. After being so activated by the addition of a phosphate, Sae2 uses its endonuclease activity to make a clean cut near a double-strand break in DNA.

Sycamore maple fruits have wings analogous but not homologous to a bird's. The opposite of homologous organs are analogous organs which do similar jobs in two taxa that were not present in their most recent common ancestor but rather evolved separately. For example, the wings of insects and birds evolved independently in widely separated groups, and converged functionally to support powered flight, so they are analogous. Similarly, the wings of a sycamore maple seed and the wings of a bird are analogous but not homologous, as they develop from quite different structures.

These mutations may be frameshift, missense, non-sense, or mutations of other kinds and are likely to cause deletions in the gene product. Apart from helicase activity that is common to all RecQ helices, it also acts to prevent inappropriate homologous recombination. During replication of the genome, the two copies of DNA, called sister chromatids, are held together through a structure called the centromere. During this time, the homologous (corresponding) copies are in close physical proximity to each other, allowing them to 'cross' and exchange genetic information, a process called homologous recombination.

The specificity of the sgRNA is determined by a 20-nt sequence, homologous to the genomic locus of interest, and the binding to Cas9 is mediated by a constant scaffold region of the sgRNA. The desired target site must be immediately followed (5’ to 3’) by a conserved 3 nucleotide protospacer adjacent motif (PAM). In order to repair the DSBs, the cell may use the highly error prone non-homologous end joining, or homologous recombination. By designing suitable sgRNAs, planned insertions or deletions can be introduced into the genome.

DNA strand breaks accumulate in long term hematopoietic stem cells during aging. This accumulation is associated with a broad attenuation of DNA repair and response pathways that depends on HSC quiescence. Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as "non-homologous" because the break ends are directly ligated without the need for a homologous template. The NHEJ pathway depends on several proteins including ligase 4, DNA polymerase mu and NHEJ factor 1 (NHEJ1, also known as Cernunnos or XLF).

Homoeologous (also spelled homeologous) chromosomes or parts of chromosomes are those brought together following inter-species hybridization and allopolyploidization to form a hybrid genome, and whose relationship was completely homologous in an ancestral species. In allopolyploids, the homologous chromosomes within each parental sub-genome should pair faithfully during meiosis, leading to disomic inheritance; however in some allopolyploids, the homoeologous chromosomes of the parental genomes may be nearly as similar to one another as the homologous chromosomes, leading to tetrasomic inheritance (four chromosomes pairing at meiosis), intergenomic recombination, and reduced fertility.

The homologous temperature of a substance is useful for determining the rate of steady state creep (diffusion dependent deformation). A higher homologous temperature results in an exponentially higher rate of diffusion dependent deformation. Additionally, for a given fixed homologous temperature, two materials with different melting points would have similar diffusion-dependent deformation behaviour. For example, solder (Tmp = 456 K) at 115 °C would have comparable mechanical properties to copper (Tmp = 1358 K) at 881 °C, because they would both be at 0.85Tmp despite being at different absolute temperatures.

Gene conversions and crossing over during homologous and homeologous ectopic recombination in saccharomyces cerevisae. Genetics 135: 5-16 Neither does it require high levels of homology between sequences—the lower limit required for it to occur has been estimated at as low as 2.2 kb of homologous stretches of DNA nucleotides. The role of transposable elements in ectopic recombination is an area of active inquiry. Transposable elements—repetitious sequences of DNA that can insert themselves into any part of the genome—can encourage ectopic recombination at repeated homologous sequences of nucleotides.

Dynamic chromosome pairing. The term “pairing” describes the spatial juxtaposition of entire homologous chromosomes, allelic sequences, and/or homologous sequences at non-allelic locations. (A, B) Homologous chromosomes can exist as paired throughout their entire length and the relative activities of pairing and anti-pairing factors determine the degree of global chromosome pairing. (C) Local pairing and anti-pairing factors can affect pairing status of specific genes or chromosomal regions. Local “pairing centers” can nucleate global pairing, but it is unclear whether factors regulating local pairing are different from global pairing factors.

When a double stranded break occurs in the genome unexpectedly the cell activates pathways that mediate the repair of the break. Errors in repairing the break, similar to non-allelic homologous recombination, can lead to an increase in copy number of a particular region of the genome. During the repair of a double stranded break, the broken end can invade its homologous chromosome instead of rejoining the original strand. As in the non-allelic homologous recombination mechanism, an extra copy of a particular region is transferred to another chromosome, leading to a duplication event.

However, most of these characteristics are considered homologous characteristics derived from common placoderm ancestors, and present also in basal cartilaginous fish.

Hu WS, Bowman EH, Delviks KA, Pathak VK. Homologous recombination occurs in a distinct retroviral subpopulation and exhibits high negative interference.

These findings suggested that the WRN protein takes part in homologous recombinational repair and in the processing of stalled replication forks.

OSR1 and OSR2 are homologous to the Odd-skipped class transcription factors in Drosophila, encoded by odd, bowl, sob and arm.

If the transferred genetic material provides sufficient DNA for homologous recombination, the genetic material will be inserted into the recipient chromosome.

The subnotochordal rod helps to stimulate development of the dorsal aorta. There is an opinion that these two structures are homologous.

The bone is also found in many other mammals, and is homologous with the "fourth distal carpal" of reptiles and amphibians.

The largest subunits of the Mrp complex (MrpA and MrpD) are homologous to subunits in NADH dehydrogenases (NDHs): ND2, ND4 and ND5 in the fungal NADH dehydrogenase complex and most other NDHs, as well as subunits in the F420H2 dehydrogenase of Methanosarcina mazei (TC#3.D.9.1.1). These homologous subunits may catalyze Na+/K+ and/or H+ transport.

The Insects: An Outline of Entomology. 4th edition. Blackwell Publishing The galea is a broad, scoop-like, lobe structure, which assists the maxillary palps in sampling items before ingestion. The maxillary palp is serially homologous to the walking leg while the cardo and stipes are regarded by most to be serially homologous to the first leg segment, the coxa.

In the first stage of prophase I, leptotene (from the Greek for "delicate"), chromosomes begin to condense. Each chromosome is in a haploid state and consists of two sister chromatids; however, the chromatin of the sister chromatids is not yet condensed enough to be resolvable in microscopy. Homologous regions within homologous chromosome pairs begin to associate with each other.

Genes homologous to FAM98A are predicted to occur in many taxa within Animalia, but there are other taxa outside of Animalia that may have homologous FAM98 genes in their genomes. Eukaryotes such as the opisthokonts Monosiga brevicollis (XP_00174505.1) and Capraspora owczarzaki (XP_004346371.1), and even the protist Chlorella variabilis (XP_005845167.1), a green alga, may contain FAM98 in their genomes.

Human MBL2 gene is located on chromosome 10q11.2-q21. Mice have two homologous genes, but in human the first of them was lost. A low level expression of an MBL1 pseudogene 1 (MBL1P1) was detected in liver. The pseudogene encodes a truncated 51-amino acid protein that is homologous to the MBLA isoform in rodents and some primates.

Using Darwin's theory evolutionary embryologists have since been able to distinguish between homologous and analogous structures between varying species. Homologous structures are those that the similarities between them are derived from a common ancestor, such as the human arm and bat wings. Analogous structures are those that appear to be similar but have no common ancestral derivation.

Geographically distinct lineages of the canine distemper virus are genetically diverse. This diversity arises from mutation, and when two genetically distinct viruses infect the same cell, from homologous recombinationYuan C, Liu W, Wang Y, Hou J, Zhang L, Wang G. Homologous recombination is a force in the evolution of canine distemper virus. PLoS One. 2017 Apr 10;12(4):e0175416.

Most recombination events appear to be the SDSA type. Meiotic chromosomal crossover (CO) recombination facilitates the proper segregation of homologous chromosomes. This is because, at the end of meiotic prophase I, CO recombination provides a physical link that holds homologous chromosome pairs together. These linkages are established by chiasmata, which are the cytological manifestations of CO recombination.

These 3 ncRNA appear to be highly homologous and are derived from a repeat region of the genome. Each of the ncRNA contains a short stretch homologous to boxC, a repeat element of unknown function present in 50 copies or more within the genome of E. coli.Bachellier, S., Gilson, E., Hofnung, M., and Hill, C.W. 1996. Repeated sequences.

This method generates chimeric genes directly from metagenomic samples. It begins with isolation of the desired gene by functional screening from metagenomic DNA sample. Next, specific primers are designed and used to amplify the homologous genes from different environmental samples. Finally, chimeric libraries are generated to retrieve the desired functional clones by shuffling these amplified homologous genes.

The α1 subunit has four homologous domains, each with six transmembrane segments. Within each homologous domain, the fourth transmembrane segment (S4) is positively charged, as opposed to the other five hydrophobic segments. This characteristic enables S4 to function as the voltage-sensor. Alpha-1D subunits belong to the Cav1 family, which is characterised by L-type calcium currents.

The most widely used banding methods are G-banding (Giemsa-banding) and R-banding (reverse-banding). These techniques produce a characteristic pattern of contrasting dark and light transverse bands on the chromosomes. Banding makes it possible to identify homologous chromosomes and construct chromosomal nomenclatures for many species. Banding of homologous chromosomes allows chromosome segments and rearrangements to be identified.

It consists of fifteen repeats homologous to the 157-residue CD-M6PR domain, two of which are responsible for binding to M6P.

In 2004, a protein homologous to cingulin was discovered and named JACOP (also known as paracingulin, or cingulin-like 1 protein; CGNL1).

The Rad51 protein plays a key role in homologous recombination, a process required for the accurate repair of DNA double-strand breaks.

UvsX, like RecA, can facilitate the assimilation of linear single-stranded DNA into an homologous DNA duplex to produce a D-loop.

Homologous integration of DNA, an important technique for genetic manipulation, is dependent on the function of ERCC1-XPF in the host cell.

A fourth miR-10 gene (mir-10d) is found elsewhere in the genome, at a location homologous to the pufferfish HoxDd cluster.

Because Crossover junction endodeoxyribonucleases perform Holliday Junction resolution, a crucial step of homologous recombination, they are therefore involved in repair of DSBs.

H3K36me3 is required for homologous recombinational repair of DNA damage such as double-strand breaks. The trimethylation is catalyzed by SETD2 methyltransferase.

The gene is located in a head-to-head orientation with HARS on chromosome five, where the homologous genes share a bidirectional promoter.

V. faba has a diploid (2n) chromosome number of 12 (six homologous pairs). Five pairs are acrocentric chromosomes and one pair is metacentric.

STAR is homologous to a family of proteins containing a 200- to 210-amino acid STAR-related lipid transfer (START) domain, including STARD5.

Genet Eng. 25:189-207 This increases the frequency of targeted homologous recombination by 4,000 fold compared to when no DSB is generated.

Crystal Structure of CRMP-1 CRMP1-5 are between 564-572 amino acids and these proteins are found to be approximately 95% conserved between mouse and human. The protein sequence of CRMP1-4 is approximately 75% homologous with each other, while CRMP5 is only 50-51% homologous with each of the other CRMPs. Additionally, CRMPs are homologs of Unc33 whose mutation causes impaired ability to form neural circuits and uncoordinated mobility in Caenorhabditis elegans. CRMP1-4 genes are roughly 60% homologous with the tetramer liver dihydropyrimidinase (DHPase), and also possess a similar structure to members of the metal-dependent amidohydrolases.

Figure 1. During meiosis, homologous recombination can produce new combinations of genes as shown here between similar but not identical copies of human chromosome 1. Homologous recombination is a type of genetic recombination in which nucleotide sequences are exchanged between two similar or identical molecules of double-stranded or single-stranded nucleic acids (usually DNA as in cellular organisms but may be also RNA in viruses). It is most widely used by cells to accurately repair harmful breaks that occur on both strands of DNA, known as double-strand breaks (DSB), in a process called homologous recombinational repair (HRR).

Homologous recombination (HR) is essential to cell division in eukaryotes like plants, animals, fungi and protists. In cells that divide through mitosis, homologous recombination repairs double-strand breaks in DNA caused by ionizing radiation or DNA-damaging chemicals. Left unrepaired, these double-strand breaks can cause large-scale rearrangement of chromosomes in somatic cells, which can in turn lead to cancer. In addition to repairing DNA, homologous recombination also helps produce genetic diversity when cells divide in meiosis to become specialized gamete cells—sperm or egg cells in animals, pollen or ovules in plants, and spores in fungi.

A common form of Genome editing relies on the concept of DNA double stranded break (DSB) repair mechanics. There are two major pathways that repair DSB; non-homologous end joining (NHEJ) and homology directed repair (HDR). NHEJ uses a variety of enzymes to directly join the DNA ends while the more accurate HDR uses a homologous sequence as a template for regeneration of missing DNA sequences at the break point. This can be exploited by creating a vector with the desired genetic elements within a sequence that is homologous to the flanking sequences of a DSB.

For example, in an aligned DNA sequence matrix, all of the A, G, C, T or implied gaps at a given nucleotide site are homologous in this way. Character state identity is the hypothesis that the particular condition in two or more taxa is "the same" as far as our character coding scheme is concerned. Thus, two Adenines at the same aligned nucleotide site are hypothesized to be homologous unless that hypothesis is subsequently contradicted by other evidence. Secondary homology is implied by parsimony analysis, where a character state that arises only once on a tree is taken to be homologous.

It has been suggested that some behaviours might be homologous, based either on sharing across related taxa or on common origins of the behaviour in an individual's development; however, the notion of homologous behavior remains controversial, largely because behavior is more prone to multiple realizability than other biological traits. For example, D. W. Rajecki and Randall C. Flanery, using data on humans and on nonhuman primates, argue that patterns of behaviour in dominance hierarchies are homologous across the primates. As with morphological features or DNA, shared similarity in behavior provides evidence for common ancestry Wenzel, John W. 1992. Behavioral homology and phylogeny.

The recombinase paralog rfs-1 is found in the round worm Caenorhabditis elegans, where it is not essential for homologous recombination. Among archaea the RadB and RadC recombinase paralogs are found in many organisms belonging to Euryarchaeota while a broader diversity of related recombinase paralogs seem to be found in the Crenarchaea including Ral1, Ral2, Ral3, RadC, RadC1, and RadC2. The RAD51 paralogs contribute to efficient DNA double-strand break repair by homologous recombination and depletion of any paralog often results in significant decreases in homologous recombination frequency. The paralogs form two identified complexes: BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2) and CX3 (RAD51C-XRCC3).

General pathways for GPCR homologous desensitization Homologous desensitization occurs when a receptor decreases its response to an agonist at high concentration. It is a process through which, after prolonged agonist exposure, the receptor is uncoupled from its signaling cascade and thus the cellular effect of receptor activation is attenuated. Homologous desensitization is distinguished from heterologous desensitization, a process in which repeated stimulation of a receptor by an agonist results in desensitization of the stimulated receptor as well as other, usually inactive, receptors on the same cell. They are sometimes denoted as agonist-dependent and agonist-independent desensitization respectively.

DNA repair and recombination protein RAD54-like is a protein that in humans is encoded by the RAD54L gene. The protein encoded by this gene belongs to the DEAD-like helicase superfamily, and shares similarity with Saccharomyces cerevisiae Rad54, a protein known to be involved in the homologous recombination and repair of DNA. This protein has been shown to play a role in homologous recombination related repair of DNA double-strand breaks. The binding of this protein to double-strand DNA induces a DNA topological change, which is thought to facilitate homologous DNA pairing, and stimulate DNA recombination.

Zinc finger nucleases (ZFNs) and Transcription Activator-Like Effector Nucleases (TALENs) are engineered DNA-binding proteins that facilitate targeted editing of the genome by creating double-strand breaks in DNA at user-specified locations. Double strand breaks are important for site-specific mutagenesis in that they stimulate the cell’s natural DNA-repair processes, namely homologous recombination and non-homologous end joining. When the cell uses the non- homologous end joining pathway to repair the double-strand break, the inherent inaccuracy of the repair often generates precisely targeted mutations. This results in embryos with targeted gene knockout.

Monotremes possess four or five (platypus) pairs of XY sex chromosomes, each pair consisting of sex chromosomes with homologous regions. The chromosomes of neighboring pairs are partially homologous, such that a chain is formed during mitosis. The first X chromosome in the chain is also partially homologous with the last Y chromosome, indicating that profound rearrangements, some adding new pieces from autosomes, have occurred in history. Platypus sex chromosomes have strong sequence similarity with the avian Z chromosome, (indicating close homology), and the SRY gene so central to sex-determination in most other mammals is apparently not involved in platypus sex-determination.

Within the doubly punctured plane this curve is homologous to zero but not homotopic to zero. Its winding number about any point is 0 despite the fact that within the doubly punctured plane it cannot be shrunk to a single point. Pochhammer cycle is homologous to zero: it is the boundary of the green area minus the boundary of the red one.

However, in the G2 phase of the cell cycle (following DNA replication), a second homologous DNA molecule is also present: the sister chromatid. Evidence indicates that, due to the special nearby relationship they share, sister chromatids are not only preferred over distant homologous chromatids as substrates for recombinational repair, but have the capacity to repair more DNA damage than do homologs.

M. smegmatis relies on DNA repair pathways to resist DNA damage. Double-strand breaks are especially threatening to bacterial viability. M. smegmatis has three options for repairing double-strand breaks; homologous recombination (HR), non-homologous end joining (NHEJ), and single-strand annealing (SSA). The HR pathway of M. smegmatis is the major determinant of resistance to ionizing radiation and oxidative DNA damage.

Synapsis during Meiosis. The circled area is the part where synapsis occurs, where the two chromatids meet before crossing over Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.

These methods use database information regarding structures to match homologous structures to the created protein sequences. These homologous structures are assembled to give compact structures using scoring and optimization procedures, with the goal of achieving the lowest potential energy score. Webservers for fragment information are I-TASSER, ROSETTA, ROSETTA @ home, FRAGFOLD, CABS fold, PROFESY, CREF, QUARK, UNDERTAKER, HMM, and ANGLOR.

This concept uses homologous superseries as a predictable path to new materials. Examples include as Cs4[Bi2n+4Te3n+6], CsPbmBi3Te5+m, Am[M1+lSe2+l]2m[M2l+nSe2+3l+n] (A = alkali metal, M = Sn, Pb, Sb, Bi), and (PbSe)n(Bi2Se3)m. Kanatzidis refers to these homologous superseries as "compound generating machines". Kanatzidis invented a new class of materials called chalcogels.

Tardigrades bear a circumoral nerve ring which has been homologised with the nerve ring of the ancestral ecdysozoan, and the arthropod (=Euarthropoda + Onychophora) protocerebrum, suggesting that the protocerebrum is homologous with the ancestral ecdysozoan brain. On this view, the stylet apparatus is homologous with the euarthropod labrum / onychophoran antennae, and the first pairs of walking legs correspond to the deutocerebral and tritocerebral appendages.

Lysophospholipid acyltransferase 5 is an enzyme that in humans is encoded by the LPCAT3 gene. It is homologous to other membrane-bound O-acyltransferases.

Externally and endogenously caused damages may be converted into mutations by inaccurate translesion synthesis or inaccurate DNA repair (e.g. by non-homologous end joining).

Endogenous antigens include xenogenic (heterologous), autologous and idiotypic or allogenic (homologous) antigens. Sometimes antigens are part of the host itself in an autoimmune disease.

This method introduces mutations into specific regions of genes while leaving other parts intact by utilizing the high frequency of homologous recombination in yeast.

It is unclear as to whether the Malpighian tubules of arachnids and those of the Uniramia are homologous or the result of convergent evolution.

Surprisingly, TopPred predicts a 12 TMS topology for the yeast Pho89 protein, but the homologous regions are not predicted to show similar topological features.

Thus it is thought that the ups system in combination with homologous recombination provide a DNA damage response which rescues Sulfolobales from DNA damaging threats.

HFM1 is a gene that in humans encodes a protein necessary for homologous recombination of chromosomes. Biallelic mutations in HFM1 cause recessive primary ovarian insufficiency.

The epithelial sodium (Na+) channel (ENaC) family belongs to the ENaC/P2X superfamily. ENaC and P2X receptors have similar 3-d structures and are homologous.

Thus it is thought that the ups system in combination with homologous recombination provide a DNA damage response which rescues Sulfolobales from DNA damaging threats.

Recombinases have a central role in homologous recombination in a wide range of organisms. Such recombinases have been described in archaea, bacteria, eukaryotes and viruses.

Aprataxin removes AMP from DNA ends following abortive ligation attempts by DNA Ligase IV during non-homologous end joining, thereby permitting subsequent attempts at ligation.

Several provincial governments, such as Ontario, Manitoba and Quebec, have also created homologous ministerial positions responsible for relations with other provinces and the federal government.

Repair of DNA double-strand breaks can occur by either of two processes, non-homologous end joining (NHEJ) or homologous recombination (HR). A-type lamins promote genetic stability by maintaining levels of proteins that have key roles in NHEJ and HR. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and are more sensitive to DNA damaging agents.

RecA is a 38 kilodalton protein essential for the repair and maintenance of DNA. A RecA structural and functional homolog has been found in every species in which one has been seriously sought and serves as an archetype for this class of homologous DNA repair proteins. The homologous protein is called RAD51 in eukaryotes and RadA in archaea. RecA has multiple activities, all related to DNA repair.

Spermatogenesis is the process in which spermatozoa are produced from spermatogonial stem cells by way of mitosis and meiosis. A major function of meiosis is homologous recombinational repair of this germline DNA. RNF8 plays an essential role in signaling the presence of DNA double-strand breaks. Male mice with a gene knockout for RNF8 have impaired spermatogenesis, apparently due to a defect in homologous recombinational repair.

The species infecting Sigmodontinae evolved in Brazil 400 years ago. Their ancestors may have been a Neotominae-associated virus from northern South America. The evolution of shrew-borne hantaviruses appears to have involved natural occurrences of homologous recombination events and the reassortment of genome segments. The evolution of Tula orthohantavirus carried by the European common vole also appears to have involved homologous recombination events.

Damage of nuclear DNA is a persistent problem arising from a variety of disruptive endogenous and exogenous sources. Eukaryotes have evolved a diverse set of DNA repair processes that remove nuclear DNA damages. These repair processes include base excision repair, nucleotide excision repair, homologous recombinational repair, non-homologous end joining and microhomology-mediated end joining. Such repair processes are essential for maintaining nuclear DNA stability.

The goal of transformation-associated recombination (TAR) technology in synthetic genomics is to combine DNA contigs by means of homologous recombination performed by the yeast artificial chromosome (YAC). Of importance is the CEN element within the YAC vector, which corresponds to the yeast centromere. This sequence gives the vector the ability to behave in a chromosomal manner, thereby allowing it to perform homologous recombination. Transformation-Associated Recombination.

The goal of Transformation-Associated Recombination (TAR) technology in synthetic genomics is to combine DNA contigs by means of homologous recombination performed by the Yeast Artificial Chromosome (YAC). Of importance is the CEN element within the YAC vector, which corresponds to the yeast centromere. This sequence gives the vector the ability to behave in a chromosomal manner, thereby allowing it to perform homologous recombination. Transformation-Associated Recombination.

In genetic genealogy, the term is used particularly concerning similar seeming events in Y chromosome DNA. This type of mutation happens within one chromosome, and does not involve a reciprocal transfer. Rather, one homologous segment "writes over" the other. The mechanism is presumed to be different from RecLOH events in autosomal chromosomes, since the target is the very same chromosome instead of the homologous one.

They each share about 25% amino acid sequence identity with RAD51 and each other. The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency. Two paralogs form a complex designated CX3 (RAD51C-XRCC3). Four paralogs form a second complex designated BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2).

It facilitates DNA repair by recombination. 4\. Recently many novel functions of cohesin have been discovered in many different cellular processes. Cohesin has been shown to be responsible for transcription regulation, DNA double strand break repair, chromosome condensation, pairing of homologous chromosomes during meiosis I, mono-orientation of sister kinetochores during meiosis I, non-homologous centromere coupling, chromosome architecture and rearrangement, DNA replication etc.

This cohesion is later broken by the enzyme separase, allowing the chiasmata to be broken and homologous chromosomes to segregate in a normal way. Age-related degeneration of the inhibitors and regulators of separase, may lead to inappropriate and premature cohesin degradation before anaphase. As a result, homologous chromosomes may align independently on the meiotic spindle, risking aneuploidy that represents a key mechanism of reduced reproductive success.

The Fusobacteriales-1 RNA motif is a conserved RNA structure that was discovered by bioinformatics. Fusobacteriales-1 motif RNAs are found in Fusobacteria. Most Fusobacteriales-1 RNAs are located upstream of genes homologous to the locus FSAG_00736, which encodes a hypothetical protein in Fusobacterium peridonticum. However, some Fusobacteriales-1 RNAs are located upstream of genes that do not appear to be homologous to FSAG_00736.

Compare sister chromatids to homologous chromosomes, which are the two different copies of a chromosome that diploid organisms (like humans) inherit, one from each parent. Sister chromatids are by and large identical (since they carry the same alleles, also called variants or versions, of genes) because they derive from one original chromosome. An exception is towards the end of meiosis, after crossing over has occurred, because sections of each sister chromatid may have been exchanged with corresponding sections of the homologous chromatids with which they are paired during meiosis. Homologous chromosomes might or might not be the same as each other because they derive from different parents.

The name "homologous series" is also often used for any collection of compounds that have similar structures or include the same functional group, such as the general alkanes (straight and branched), the alkenes (olefins), the carbohydrates, etc. However, if the members cannot be arranged in a linear order by a single parameter, the collection may be better called a "chemical family" or "class of homologous compounds" than a "series". The concept of homologous series was proposed in 1843 by the French chemist Charles Gerhardt.Charles Gerhardt (1843) "Sur la classification chimique des substances organiques" (On the chemical classification of organic substances), Revue scientifique et industrielle, 14 : 580–609.

The finding that WRN protein interacts with DNA-PKcs and the Ku protein complex, combined with evidence that WRN deficient cells produce extensive deletions at sites of joining of non-homologous DNA ends, suggests a role for WRN protein in the DNA repair process of non-homologous end joining (NHEJ). WRN protein also physically interacts with the major NHEJ factor X4L4 (XRCC4-DNA ligase 4 complex). X4L4 stimulates WRN exonuclease activity that likely facilitates DNA end processing prior to final ligation by X4L4. WRN protein appears to play a role in resolving recombination intermediate structures during homologous recombinational repair (HRR) of DNA double-strand breaks.

In other words, sperm cell flagella and Fallopian tube cilia are homologous structures. The testis- specific proteins that show the highest level of expression are protamines.

When Cas9 is expressed outside of meiosis, it seems like non-homologous end joining predominates, making this the biggest hurdle to practical application of gene drives.

Since the discovery of the tRNA cloverleaf, comparative analysis of numerous other homologous RNA molecules has led to the identification of common sequences and folding patterns.

Additionally, this weighted approach is able to identify BRCAness, which refers to mutational phenotypes displaying homologous recombination deficiency similar to tumors with BRCA1/BRCA2 germline defects.

On the top of the cypselae is a whorl of crown-like or free pappus bristles. C. congestum has eight homologous sets of chromosomes (2n=16).

Gray's Anatomy (1918). See infobox. The bone is also found in many other mammals, and is homologous with the "third distal carpal" of reptiles and amphibians.

Analyzing variable behavioral contingencies: Are certain complex skills homologous with locomotion? Behavioural Processes, 81, 316-321.Mechner, F. (2010). Anatomy of deception: a behavioral contingency analysis.

Neurotoxin B-IV belongs to a family of four homologous polypeptide neurotoxins designated B-I to B-IV which are produced by the marine worm Cerebratulus lacteus .

In the Tait–Bryan angles case, it is defined as the intersection of two non-homologous planes (perpendicular when Euler angles are zero; e.g. xy and YZ).

In other tetrapods, such as amphibians and reptiles, homologous bones to those of mammals, such as the quadrate, articular, columella, and entoglossus are part of the splanchnocranium.

Points which are collinear with respect to the homothetic center but are not homologous are said to be antihomologous, e.g., points Q and P′ in Figure 4.

Both reptin and pontin are essential for the acetylation function and the structural formation of the NuA4 complex. The repair stimulated by NuA4 is by homologous recombination.

Acanthotretella is a genus of brachiopods known from the Burgess Shale and the Guanshan fauna. Their spines are proposed to be homologous with those of the Siphonotretids.

Metamonads are unusual in having lost classical mitochondria—instead they have hydrogenosomes, mitosomes or uncharacterised organelles. The oxymonad Monocercomonoides is reported to have completely lost homologous organelles.

Ivory gene mutation is homologous to the D. melanogaster mutation vermillion and the M. domestica mutation green. S. barbata with ivory are less viable than wild-type.

In the alternative 'gill theory' wings are homologous with the 'gills' of mayfly larvae, implying that the first pterygotes were amphibiotic and that their ancestors were aquatic.

This feature makes it possible to catalyze a DNA synapsis reaction between a DNA double helix and a complementary region of single-stranded DNA. The RecA- ssDNA filament searches for sequence similarity along the dsDNA. A disordered DNA loop in RecA, Loop 2, contains the residues responsible for DNA homologous recombination. In some bacteria, RecA posttranslational modification via phosphorylation of a serine residue on Loop 2 can interfere with homologous recombination.

Genes MCM8 and MCM9 encode proteins that form a complex. This complex functions in homologous recombination and repair of DNA double-strand breaks. Inherited mutations in MCM8 and MCM9 can cause a chromosomal instability syndrome characterized by ovarian failure. The germline MCM8-MCM9 protein complex is most likely required for the resolution of double-strand breaks that occur during homologous recombination in the pachytene stage of meiosis I.

Prophase I is divided into five phases: leptotene, zygotene, pachytene, diplotene, and diakinesis. In addition to the events that occur in mitotic prophase, several crucial events occur within these phases such as pairing of homologous chromosomes and the reciprocal exchange of genetic material between these homologous chromosomes. Prophase I occurs at different speeds dependent on species and sex. Many species arrest meiosis in diplotene of prophase I until ovulation.

In meiosis, however, the recipient DNA tends to be from a similar but not necessarily identical homologous chromosome. A displacement loop (D-loop) is formed during strand invasion between the invading 3' overhang strand and the homologous chromosome. After strand invasion, a DNA polymerase extends the end of the invading 3' strand by synthesizing new DNA. This changes the D-loop to a cross-shaped structure known as a Holliday junction.

There are three main types of disease models: homologous, isomorphic and predictive. Homologous animals have the same causes, symptoms and treatment options as would humans who have the same disease. Isomorphic animals share the same symptoms and treatments. Predictive models are similar to a particular human disease in only a couple of aspects, but are useful in isolating and making predictions about mechanisms of a set of disease features.

Small GTPases, also known as small G-proteins, bind GTP and GDP likewise, and are involved in signal transduction. These proteins are homologous to the alpha (α) subunit found in heterotrimers, but exist as monomers. They are small (20-kDa to 25-kDa) proteins that bind to guanosine triphosphate (GTP). This family of proteins is homologous to the Ras GTPases and is also called the Ras superfamily GTPases.

In diploid eukaryotic cells, recombination can occur during the process of Meiosis. Homologous chromosomes pair up during meiosis before finally splitting, resulting in two haploid daughter cells each with a single copy of every chromosome. While homologous chromosomes are lined up, they are free to exchange corresponding segments of their own DNA with that of their homolog. This results in a chromosomes that carry both maternal and paternal DNA.

In molecular biology, the protein domain b1 refers to the domain b1 of Protein L. L is a bacterial protein with immunoglobulin (Ig) light chain-binding properties. It contains a number of homologous b1 repeats towards the N terminus. These repeats have been found to be responsible for the interaction of protein L with Ig light chains. N-terminus domain contains five homologous B1 repeats of 72-76 amino acids each.

The stapes is one of three ossicles in mammals. In non-mammalian four-legged animals, the bone homologous to the stapes is usually called the columella; however, in reptiles, either term may be used. In fish, the homologous bone is called the hyomandibular, and is part of the gill arch supporting either the spiracle or the jaw, depending on the species. The equivalent term in amphibians is the '.

In mice and humans, the BRCA2 complex primarily mediates orderly assembly of RAD51 on ssDNA, the form that is active for homologous pairing and strand invasion. BRCA2 also redirects RAD51 from dsDNA and prevents dissociation from ssDNA. However, in the presence of a BRCA2 mutation, human RAD52 can mediate RAD51 assembly on ssDNA and substitute for BRCA2 in homologous recombinational DNA repair, though with lower efficiency than BRCA2.

Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of NMT1 RNAs makes this scenario less likely. The most common type of gene that is apparently regulated by NMT1 RNAs is NMT1.

From page 588: "17. Nous appelons substances homologues celles qui jouissent des même propriétés chimiques et dont la composition offre certaines analogies dans les proportions relatives des éléments." (17. We call homologous substances those that have the same chemical properties and whose composition offers certain analogies in the relative proportions of elements.) A homologation reaction is a chemical process that converts one member of a homologous series to the next member.

Prekallikrein is homologous to factor XI, and similarly consists of four apple domains and a fifth, catalytic serine protease domain. The four apple domains create a disk-like platform around the base of the catalytic domain. However, unlike factor XI, prekallikrein does not form dimers. Prekallikrein is activated to form kallikrein by factor XII cleavage of a bond homologous to the corresponding bond cleaved during factor XI activation.

Oxidative DNA damage may block RNA polymerase II transcription and cause strand breaks. An RNA templated transcription- associated recombination process has been described that can protect against DNA damage. During the G1/G0 stages of the cell cycle, cells exhibit assembly of homologous recombination factors at double-strand breaks within actively transcribed regions. It appears that transcription is coupled to repair of DNA double-strand breaks by RNA templated homologous recombination.

Forelimbs in mammals have varying functions but are all homologous. A forelimb is an anterior limb (front arm, front leg, or similar appendage) on a terrestrial vertebrate's body. With reference to quadrupeds, the term foreleg is often used instead. (A forearm, however, is the part of the human arm or forelimb between the elbow and the wrist.) All vertebrate forelimbs are homologous, meaning that they all evolved from the same structures.

The first process, non-homologous end joining (NHEJ), can join the two broken ends of DNA in the G1, S and G2 phases of interphase. The second process, homologous recombinational repair (HRR), is more accurate than NHEJ in repairing double- strand breaks. HRR is active during the S and G2 phases of interphase when DNA replication is either partially accomplished or after it is completed, since HRR requires two adjacent homologs.

Studies have shown that charophytes have traits that are homologous to land plants. There are two main theories of the evolution of plant morphology, these theories are the homologous theory and the antithetic theory. The commonly accepted theory for the evolution of plant morphology is the antithetic theory. The antithetic theory states that the multiple mitotic divisions that take place before meiosis, cause the development of the sporophyte.

Yeast MetAP1 is 40 percent homologous to E. coli MetAP; within S. cerevisiae, MetAP2 is 22 percent homologous with the sequence of MetAP1; MetAP2 is highly conserved between S. cerevisiae and humans. In contrast to prokaryotes, eukaryotic S. cerevisiae strains lacking the gene for either MetAP1 or MetAP2 are viable, but exhibit a slower growth rate than a control strain expressing both genes. Figure 1. Active site structure of MetAP2.

Leaves are fragrant and a source of coumarin, a perfume ingredient. Extracts from this plant showed no antimicrobial activity against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, Trichophyton mentagrophytes and Cladosporium resinae. Analysis of the extracts revealed homologous very-long-chain 1,3-alkanediols, homologous series of C31, C33 and C35 alkanols, protoquercitol, methyl -D-fructopyranoside, palmitic acid, stearic acid, linoleic acid, linolenic acid and their methyl esters.

This name is derived from the Latin term mactator which means butcher or killer. Additionally, homologous proteins were found in Drosophila melanogaster (fruit fly) and Gallus gallus (chicken).

Sexual reproduction has been proposed to have evolved in both the Ascomycota and Basidiomycota as an adaptation for repair of DNA damage via homologous recombination under stressful conditions.

This antagonistic effect occurs because sumoylated PCNA recruits a DNA helicase called Srs2, which has a role in disrupting Rad51 nucleoprotein filaments fundamental for initiation of homologous recombination.

Leppanen V.M., Merckel M.C., Ollis D.L., Wong K.K., Kozarich J.W., Goldman A. Pyruvate formate lyase is structurally homologous to type I ribonucleotide reductase. 1999 Structure 7: 733-744.

The sequence of fibrillin-1 includes 47 six-cysteine EGF-like domains, 7 eight-cysteine domains homologous with latent TGF-beta binding protein, and a proline-rich region.

Protein S is structured into two domains. The two domains are highly homologous and have a Greek key structure. The domains share high similarity with other crystallin proteins.

Homologous pairs move together along the metaphase plate: As kinetochore microtubules from both spindle poles attach to their respective kinetochores, the paired homologous chromosomes align along an equatorial plane that bisects the spindle, due to continuous counterbalancing forces exerted on the bivalents by the microtubules emanating from the two kinetochores of homologous chromosomes. This attachment is referred to as a bipolar attachment. The physical basis of the independent assortment of chromosomes is the random orientation of each bivalent along the metaphase plate, with respect to the orientation of the other bivalents along the same equatorial line. The protein complex cohesin holds sister chromatids together from the time of their replication until anaphase.

Homologous recombination is an important method of integrating donor DNA into a recipient organism's genome in horizontal gene transfer, the process by which an organism incorporates foreign DNA from another organism without being the offspring of that organism. Homologous recombination requires incoming DNA to be highly similar to the recipient genome, and so horizontal gene transfer is usually limited to similar bacteria. Studies in several species of bacteria have established that there is a log-linear decrease in recombination frequency with increasing difference in sequence between host and recipient DNA. In bacterial conjugation, where DNA is transferred between bacteria through direct cell-to-cell contact, homologous recombination helps integrate foreign DNA into the host genome via the RecBCD pathway.

The ups (UV-induced pilus) operon of Sulfolobus species is highly induced by UV irradiation. The pili encoded by this operon are employed in promoting cellular aggregation, which is necessary for subsequent DNA exchange between cells, resulting in homologous recombination. A study of the Sulfolobales acidocaldarius ups operon showed that one of the genes downstream of the operon, saci-1497, encodes an endonuclease III that nicks UV-damaged DNA; and another gene of the operon, saci-1500, encodes a RecQ-like helicase that is able to unwind homologous recombination intermediates such as Holliday junctions. It was proposed that Saci-1497 and Saci-1500 function in an homologous recombination-based DNA repair mechanism that uses transferred DNA as a template.

The ups operon of Sulfolobus species is highly induced by UV irradiation. The pili encoded by this operon are employed in promoting cellular aggregation, which is necessary for subsequent DNA exchange between cells, resulting in homologous recombination. A study of the Sulfolobales acidocaldarius ups operon showed that one of the genes of the operon, saci-1497, encodes an endonuclease III that nicks UV-damaged DNA; and another gene of the operon, saci-1500, encodes a RecQ-like helicase that is able to unwind homologous recombination intermediates such as Holliday junctions. It was proposed that Saci-1497 and Saci-1500 function in an homologous recombination-based DNA repair mechanism that uses transferred DNA as a template.

Endogenous viral elements homologous to the nucleoprotein gene of BoDV-1 have been shown to exist in the genomes of several mammalian species, including humans and non-human primates.

The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites. RAD51 plays a major role in homologous recombinational repair of DNA during double strand break repair.

The 17β-aminoestrogens include the base or parent estrogen aminoestradiol (AE2) and the extended- chain derivatives butolame, hexolame, pentolame, prodiame, and prolame. They are a homologous series of steroids.

The amount of deformation is such that binding to homologous DNA sequences only slightly decreases, while binding to wrong sequences decreases significantly. This is exactly the conformational proofreading mechanism.

Brodmann found a cytoarchitecturally homologous area in the monkey (Cercopithecus), but it was so weakly developed that he omitted it from the cortical map of that species (Brodmann-1909).

The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites. RAD51 plays a major role in homologous recombinational repair of DNA during double strand break repair.

This protein is functionally uncharacterized and does not appear to be homologous to other holins. It does, however, show 31% identity to a heavy metal transporter from Dethiosulfovibrio peptidovorans.

The molecule is composed of multiple domains: one homologous to lectins, one to epidermal growth factor, and two to the consensus repeat units found in C3/C4-binding proteins.

Wiskott–Aldrich syndrome protein family member 1, also known as WASP-family verprolin homologous protein 1 (WAVE1), is a protein that in humans is encoded by the WASF1 gene.

The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites. RAD51 plays a major role in homologous recombinational repair of DNA during double strand break repair.

General bacterial porin family belongs to Porin Superfamily I. The homologous families Sugar Porin(SP) family and Rhodobacter PorCa Porin (RPP) Family also belong to the Porin Superfamily I.

The lobe- finned fish gave rise to the land-based tetrapods. Thus, the lungs of vertebrates are homologous to the gas bladders of fish (but not to their gills).

The protein contains a putative src homology 2 (SH2) domain, a hallmark of cellular tyrosine kinase signaling molecules, and is partly homologous to the cell division cycle protein CDC48.

At the same time, homologous recombination does not explain the multiple A → G gradients seen in plastomes. This shortcoming is one of the biggest for the linear structure theory.

Hz2V062 is most similar to GbNV odv-e56. Hz2V089 is homologous to baculovirus vp91. Hz2V108 is a homologue of MBV 38K protein gene, which is crucial for nucleocapsid assembly.

Double-strand breaks, both intentional and unintentional, regularly occur in cells. Unintentional breaks are commonly generated by ionizing radiation, various exogenous and endogenous chemical agents, and halted replication forks. Intentional breaks are generated as intermediaries in meiosis and V(D)J recombination, which are primarily repaired through homologous recombination and non-homologous end joining. Both cases require the ends in double strand breaks be processed by nucleases before repair can take place.

Although Artemis exhibits 5' → 3' ssDNA exonuclease activity when alone, its complexing with DNA-PKcs allows for endonucleasic processing of the stem-loops. Defects of either protein confers severe immunodeficiency. Homologous recombination, on the other hand, involves two homologous DNA duplexes connected by D-loops or Holliday junctions. In bacteria, endonucleases like RuvC resolve Holliday junctions into two separate dsDNAs by cleaving the junctions at two symmetrical sites near the junction centre.

The recently-elucidated archaeal flagellum, or archaellum, is analogous—but not homologous—to the bacterial one. In addition to no sequence similarity being detected between the genes of the two systems, the archaeal flagellum appears to grow at the base rather than the tip, and is about 15 nanometers (nm) in diameter rather than 20. Sequence comparison indicates that the archaeal flagellum is homologous to Type IV pili. (pili are filamentous structures outside the cell).

SIRT6 is a chromatin-associated protein that is required for normal base excision repair of DNA damage in mammalian cells. Deficiency of SIRT6 in mice leads to abnormalities that overlap with aging-associated degenerative processes. SIRT6 also promotes the repair of DNA double-strand breaks by the process of non-homologous end joining and homologous recombination. SIRT6 stabilizes the repair protein DNA-PKcs (DNA-dependent protein kinase catalytic subunit) at chromatin sites of damage.

The RecF pathway, also called the RecFOR pathway, is a pathway of homologous recombination that repairs DNA in bacteria. It repairs breaks that occur on only one of DNA's two strands, known as single-strand gaps. The RecF pathway can also repair double-strand breaks in DNA when the RecBCD pathway, another pathway of homologous recombination in bacteria, is inactivated by mutations. Like the RecBCD pathway, the RecF pathway requires RecA for strand invasion.

Since the delitto perfetto technique is based on homologous recombination, this process must be functional in the cells for the technique to work. In Saccharomyces cerevisiae, the RAD52 gene is essential for homologous recombination, and thus is required for the delitto perfetto method. The method is useful only for applications where selectable markers are not necessary. For example, mutagenized yeast strains cannot be used for further genetic analysis such as tetrad analysis.

During meiosis DNA double-strand breaks and other DNA damages in a chromatid are repaired by homologous recombination using either the sister chromatid or a homologous non-sister chromatid as template. This repair can result in a crossover (CO) or, more frequently, a non- crossover (NCO) recombinant. In the yeast Schizosaccharomyces pombe the FANCM- family DNA helicase FmI1 directs NCO recombination formation during meiosis. The RecQ-type helicase Rqh1 also directs NCO meiotic recombination.

Reptin is a component of both the INO80 and the TIP60/NuA4 protein complexes, which function in repairing DNA double-stranded breaks. Such breaks may lead to cancer and other issues. Researchers have found that reptin is highly important in several functions of both of these complexes. The INO80 complex has been shown to directly participate in both the homologous recombination and the non-homologous end joining processes for fixing double stranded breaks.

Unequal Crossing Over Unequal crossing over is a type of gene duplication or deletion event that deletes a sequence in one strand and replaces it with a duplication from its sister chromatid in mitosis or from its homologous chromosome during meiosis. It is a type of chromosomal crossover between homologous sequences that are not paired precisely. Normally genes are responsible for occurrence of crossing over. It exchanges sequences of different links between chromosomes.

This convergence appears to depend on the ability of identical double-stranded DNA molecules to specifically identify each other, a process that culminates in the proximity of homologous sites along the paired chromosomes. Diverse stress conditions appear to prime bacteria to effectively cope with severe DNA damages such as double-strand breaks. The apposition of homologous sites associated with stress-induced chromosome condensation helps explain how repair of double- strand breaks and other damages occurs.

This process involves pairing of homologous genomes and recombination between them by a process referred to as multiplicity reactivation. Examples of viruses that undergo this process are herpes simplex virus, human immunodeficiency virus, and vaccinia virus. The sexual processes in bacteria, microbial eukaryotes, and viruses all involve recombination between homologous genomes that appears to facilitate the repair of genomic damage to the pathogens caused by the defenses of their respective target hosts.

DNA double-strand breaks (DSBs) are cytotoxic damages that can be repaired either by the homologous recombinational repair (HR) pathway or by the non-homologous end-joining (NHEJ) pathway. NHEJ, although faster than HR, is less accurate. The early divergent step between the two pathways is end resection, and this step is regulated by numerous factors. In particular, BRCA1 and 53BP1 play a role in determining the balance between the two pathways.

Sclerites are not homologous to a gastropod operculum. The sclerites of scaly-foot gastropods are also not homologous to the sclerites found in chitons (Polyplacophora). It has been hypothesized that the sclerites of Cambrian halwaxiids such as Halkieria may potentially be more analogous to the sclerites of this snail than are the sclerites of chitons or aplacophorans. As recently as 2015, detailed morphological analysis for testing this hypothesis had not been carried out.

Crossover junction endodeoxyribonuclease, also known as Holliday junction resolvase, Holliday junction endonuclease, Holliday junction-cleaving endonuclease, Holliday junction-resolving endoribonuclease, crossover junction endoribonuclease, and cruciform-cutting endonuclease, is an enzyme involved in DNA repair and homologous recombination. Specifically, it performs endonucleolytic cleavage that results in single-stranded crossover between two homologous DNA molecules at the Holliday junction to produce recombinant DNA products for chromosomal segregation. This process is known as Holliday junction resolution.

In the budding yeast Saccharomyces cerevisiae, mating-type is determined by two non-homologous alleles at the mating-type locus. S. cerevisiae has the capability of undergoing mating-type switching, that is conversion of some haploid cells in a colony from one mating-type to the other. Mating-type switching can occur as frequently as once every generation. Switching involves homologous recombinational repair of a site specific, programmed double-strand break, a highly organized process.

Each trunk segment of the Aegirocassis benmoulai specimen has both a ventral and a dorsal pair of flaps. Several details seen clearly in the specimen led to a review and reassessment of research of existing specimens and, most importantly, to the conclusion that the ventral pair are homologous with lobopodous walking limbs in arthropods, and the dorsal pair are homologous with the flaps of gilled lobopodians and exites of the Cambrian biramous limb.

Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of DUF805 RNAs makes this scenario less likely. However, the number of different gene classes found downstream of DUF805 RNAs is large in comparison to established cis-regulatory RNAs.

LOOT motif RNAs might function as cis-regulatory elements, in view of their positions upstream of protein-coding genes. Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of LOOT RNAs makes this scenario less likely.

This has shown how its structure is very similar to that of phenylalanine hydroxylase and tryptophan hydroxylase; together the three make up a family of homologous aromatic amino acid hydroxylases.

Each chromosome pair derived from the Triticum urartu parent is homoeologous to the opposite chromosome pair derived from the Aegilops speltoides parent, though each chromosome pair unto itself is homologous.

Single stranded DNA in the cell is bound by a well- conserved protein, DprA, which loads the DNA onto RecA, which mediates homologous recombination through the classic DNA repair pathway.

Similarly, during meiosis in the eukaryotic protist Tetrahymena Mre11 is required for repair of DNA damages, in this case double-strand breaks, by a process that likely involves homologous recombination.

For example, D. W. Rajecki and Randall C. Flanery, using data on humans and on nonhuman primates, argue that patterns of behaviour in dominance hierarchies are homologous across the primates.

For example, in protein engineering, "chimeragenesis (forming chimeras between proteins that are encoded by homologous cDNAs)" p. 424 is one of the "two major techniques used to manipulate cDNA sequences".

Because trivial 1-cycles are equivalent to 0 in H_1, the 1-cycle at right-middle is homologous to its sum with the boundary of the 2-simplex at left.

In: Nickoloff JA, Hoekstra MF (Eds.) DNA Damage and Repair, Vol.3. Advances from Phage to Humans. Humana Press, Totowa, NJ, pp. 1–19. UvsX is homologous to bacterial RecA.

I. Robert Lehman (born 1924) is an emeritus professor of biochemistry at the Stanford University School of Medicine who has made major contributions in characterizing the process of homologous recombination.

Most bird scales do not overlap significantly, except in the cases of kingfishers and woodpeckers. The scales of birds are thought to be homologous to those of reptiles and mammals.

CYTH2 exhibits GEP activity in vitro with ARF1, ARF3, and ARF6. CYTH2 protein is 83% homologous to CYTH1. Two transcript variants encoding different isoforms have been found for this gene.

Heptasartorite is a very rare mineral with formula Tl7Pb22As55S108. It belongs to sartorite homologous series.Topa, D., Stroeger, B., Makovicky, E., Berlepsch, P., and Stanley, C., 2015. Heptasartorite, IMA 2015-073.

Enneasartorite is a very rare mineral with formula Tl6Pb32As70S140. It belongs to sartorite homologous series.Topa, D., Berlepsch, P., Makovicky, E., Stroeger, B., and Stanley, C., 2015. Enneasartorite, IMA 2015-074.

Between taxa, not all osteodermic tissue develop by homologous processes. It is agreed upon that all osteoderms may share a deep homology, connected by the similar properties of their dermis.

Following this, more DNA synthesis occurs on the invading strand (i.e., one of the original 3' overhangs), effectively restoring the strand on the homologous chromosome that was displaced during strand invasion.

Because the male and female parts develop from the same tissues, this makes them homologous (different versions of the same structure). Sexual differentiation is complete at around 12 weeks of gestation.

It most likely represented a fused appendage pair originated from somite 7 (first opisthosomal segment), thus homologous to the chilaria of horseshoe crab and 4th walking leg pair of sea spider.

The N-terminal MSP-homologous part of VAPA is able to bind to the FFAT motif, a particular sequence motif shared by several lipid binding proteins including oxysterol- binding protein (OSBP).

Some DNA viruses encode a recombinase that facilitates homologous recombination. A well-studied example is the UvsX recombinase encoded by bacteriophage T4.Bernstein C, Bernstein H (2001). DNA repair in bacteriophage.

The CYTH1 is highly expressed in natural killer and peripheral T cells, and regulates the adhesiveness of integrins at the plasma membrane of lymphocytes. CYTH1 protein is 83% homologous to CYTH2.

It seems likely that this gene evolved by gene duplication and subsequent mutation of glycophorin A. The transition site from homologous to nonhomologous sequences can be localized within Alu repeat sequences.

In humans, the protein RAD51 is central to the homologous search and formation of the D-loop. In the bacterium Escherichia coli, a similar function is performed by the protein RecA.

The features are considered ancestral to molluscs and are present in monoplacophorans, but have been secondarily lost in the Heterobranchia. However, it is not certain that all oesophageal diverticulae are homologous.

Cartilaginous fish, such as sharks, also lack a true maxilla. Their upper jaw is instead formed from a cartilaginous bar that is not homologous with the bone found in other vertebrates.

The new combinations of DNA created during meiosis are a significant source of genetic variation alongside mutation, resulting in new combinations of alleles, which may be beneficial. Meiosis generates gamete genetic diversity in two ways: (1) Law of Independent Assortment. The independent orientation of homologous chromosome pairs along the metaphase plate during metaphase I and orientation of sister chromatids in metaphase II, this is the subsequent separation of homologs and sister chromatids during anaphase I and II, it allows a random and independent distribution of chromosomes to each daughter cell (and ultimately to gametes); and (2) Crossing Over. The physical exchange of homologous chromosomal regions by homologous recombination during prophase I results in new combinations of genetic information within chromosomes.

The gene targeting method in knockout mice uses mouse embryonic stem cells to deliver artificial genetic material (mostly of therapeutic interest), which represses the target gene of the mouse by the principle of homologous recombination. The mouse thereby acts as a working model to understand the effects of a specific mammalian gene. In recognition of their discovery of how homologous recombination can be used to introduce genetic modifications in mice through embryonic stem cells, Mario Capecchi, Martin Evans and Oliver Smithies were awarded the 2007 Nobel Prize for Physiology or Medicine. Advances in gene targeting technologies which hijack the homologous recombination mechanics of cells are now leading to the development of a new wave of more accurate, isogenic human disease models.

Acentric chromosome fragments may arise in a variety of ways. One way is that disrepair of DNA double-strand breaks can lead to symmetrical or asymmetrical chromatid and chromosome exchanges as well as chromatid and chromosome fragments. If DNA damage exceeds the repair capacity of the cell, unrepaired double-stranded DNA breaks may also result in acentric chromosome fragments. Another way eccentric chromosome fragments may arise is when defects in genes related to homologous recombinational repair (ex: ATM, BRCA1, BRCA2, and RAD51) result in a dysfunctional error-free homologous recombinational DNA repair pathway and causes the cell to resort to the error-prone non-homologous end-joining (NHEJ) repair pathway, increasing the likelihood of incorrect repair of DNA breaks, formation of dicentric chromosomes, and acentric chromosome fragments.

Comparative studies of pedipalpal morphology may suggest that leg-like pedipalps are primitive in arachnids. At present, the only reasonable alternative to this view is to assume that Xiphosurans reflect the morphology of the primitive arachnid pedipalp and to conclude that this appendage is primitively chelate. Pedipalps are traditionally thought to be homologous with mandibles in crustaceans and insects, although more recent studies (e.g. using Hox genes) suggest they are probably homologous with the crustacean second antennae.

However, in the first meiotic division the sister chromatids are held together by cohesins and segregated from their homologous pair of cohesion bound sister chromatids after resolution of recombination crossover points (chiasma) between the homologous pairs. The collision of mitosis and meiosis (first division) pathways could cause abnormal chiasma formation, abnormal cohesion expression, and mitotic/meiotic spindle defects that could result in insertions, deletions, abnormal segregation, DNA bridging, and potentially failure of cell division altogether resulting in polyploidy.

Peri-focal vaccination may not be effective for the combat of an outbreak, due to the rapidity of wild-IBDV spreading. Passive immunity may protect against challenge with homologous IBDV, as does previous infection with homologous avirulent strains. Breeder flocks may be immunised against IBD so that they would transfer protective antibodies to their progenies, such as broiler and pullet chicks. Low-attenuated vaccine strains may cause damage to the bursa of Fabricius and immunosuppression in susceptible chicks.

A structure can be homologous at one level, but only analogous at another. Pterosaur, bird and bat wings are analogous as wings, but homologous as forelimbs because the organ served as a forearm (not a wing) in the last common ancestor of tetrapods, and evolved in different ways in the three groups. Thus, in the pterosaurs, the "wing" involves both the forelimb and the hindlimb. Analogy is called homoplasy in cladistics, and convergent or parallel evolution in evolutionary biology.

Signature 3, seen in homologous recombination (HR) deficient tumour, is associated with increased burden of large indels (up to 50 nucleotides) with overlapping microhomology at the breakpoints. In such tumors, DNA double-strand breaks are repaired by the imprecise repair mechanisms of non-homologous end joining (NHEJ) or microhomology-mediated end joining (MMEJ) instead of high fidelity HR repair. Signature 6, seen in tumors with microsatellite instability, also features enrichment of 1bp indels in nucleotide repeat regions.

The α-δ subunits of these enzymes are homologous to proteins encoded within the genomes of archaea, such as Pyrococcus abyssi (Cohen et al., 2003). Consequently, NaT-DC family members may be present in archaea as well as bacteria. The α-subunits of the oxaloacetate and methylmalonyl-CoA decarboxylases are homologous to many biotin-containing enzymes including (1) pyruvate carboxylases, (2) homocitrate synthases, (3) biotin carboxyl carrier proteins, (4) isopropylmalate synthases and (5) acyl-CoA carboxylase.

The meiosis-specific recombinase, Dmc1, is required for efficient meiotic homologous recombination, and Dmc1 is expressed in Entamoeba histolytica. The purified Dmc1 from E. histolytica forms presynaptic filaments and catalyses ATP-dependent homologous DNA pairing and DNA strand exchange over at least several thousand base pairs. The DNA pairing and strand exchange reactions are enhanced by the eukaryotic meiosis- specific recombination accessory factor (heterodimer) Hop2-Mnd1. These processes are central to meiotic recombination, suggesting that E. histolytica undergoes meiosis.

Water molecules play a significant role in the interactions between proteins. The crystal structures of complexes, obtained at high resolution from different but homologous proteins, have shown that some interface water molecules are conserved between homologous complexes. The majority of the interface water molecules make hydrogen bonds with both partners of each complex. Some interface amino acid residues or atomic groups of one protein partner engage in both direct and water mediated interactions with the other protein partner.

The choice of which pathway is used for double strand break repair is complex. In most cases, MMEJ accounts for a minor proportion (10%) of double strand break repair, most likely in cases where the double strand break is resected but a sister chromatid is not available for homologous recombination. Cells which are deficient in either classical NHEJ or HR typically display increased MMEJ. Human homologous recombination factors suppress mutagenic MMEJ following double-strand break resection.

During unequal crossing over, homologous chromosomes exchange uneven portions of their DNA. This can lead to the transfer of one chromosome's gene to the other chromosome, leaving two of the same gene on one chromosome, and no copies of the gene on the other chromosome. Non-homologous duplications result from replication errors that shift the gene of interest into a new position. A tandem duplication then occurs, creating a chromosome with two copies of the same gene.

In mammals, one of the autosome pair, now Y, mutated its SOX3 gene into the SRY gene, causing that chromosome to designate sex. After this mutation, the SRY-containing chromosome inverted and was no longer completely homologous with its partner. The regions of the X and Y chromosomes that are still homologous to one another are known as the pseudoautosomal region. Once it inverted, the Y chromosome became unable to remedy deleterious mutations, and thus degenerated.

In sexually reproducing eukaryotes, homologous recombination (HR) ordinarily occurs during meiosis. The meiosis-specific recombinase, Dmc1, is required for efficient meiotic HR, and Dmc1 is expressed in E. histolytica. The purified Dmc1 from E. histolytica forms presynaptic filaments and catalyzes ATP-dependent homologous DNA pairing and DNA strand exchange over at least several thousand base pairs. The DNA pairing and strand exchange reactions are enhanced by the eukaryotic meiosis- specific recombination accessory factor (heterodimer) Hop2-Mnd1.

50px Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. The main alternative lengthening mechanism for telomeres is a type of homologous recombination called Break-induced Telomere Synthesis (or BITS). Normally, homologous recombination allows broken DNA strands to be repaired by lining up with a matching sequence of undamaged DNA, but in BITS, this mechanism is used to extend telomeres. Because telomeres are by nature repetitive, matching sequences are widely available.

Sex chromosomes also undergo synapsis; however, the synaptonemal protein complex that holds the homologous chromosomes together is only present at one end of each sex chromosome. This is not to be confused with mitosis. Mitosis also has prophase, but does not ordinarily do pairing of two homologous chromosomes. When the non-sister chromatids intertwine, segments of chromatids with similar sequence may break apart and be exchanged in a process known as genetic recombination or "crossing-over".

In sexually reproducing eukaryotes, homologous recombination (HR) ordinarily occurs during meiosis. The meiosis-specific recombinase, Dmc1, is required for efficient meiotic HR, and Dmc1 is expressed in E. histolytica. The purified Dmc1 from E. histolytica forms presynaptic filaments and catalyzes ATP-dependent homologous DNA pairing and DNA strand exchange over at least several thousand base pairs. The DNA pairing and strand exchange reactions are enhanced by the eukaryotic meiosis-specific recombination accessory factor (heterodimer) Hop2-Mnd1.

While many organisms are competent only under certain environmental conditions, such as starvation, H. pylori is competent throughout logarithmic growth. All organisms encode genetic programs for response to stressful conditions including those that cause DNA damage. In H. pylori, homologous recombination is required for repairing DNA double-strand breaks (DSBs). The AddAB helicase-nuclease complex resects DSBs and loads RecA onto single-strand DNA (ssDNA), which then mediates strand exchange, leading to homologous recombination and repair.

The MoFe protein can be replaced by alternative nitrogenases in environments low in the Mo cofactor. Two types of such nitrogenases are known: the vanadium-iron (VFe; Vnf) type and the iron-iron (FeFe; Anf) type. Both form an assembly of two α subunits, two β subunits, and two δ (sometimes γ) subunits. The delta subunits are homologous to each other, and the alpha and beta subunits themselves are homologous to the ones found in MoFe nitrogenase.

This method relies on PCR to differentially amplify non-homologous DNA regions between digested fragments of two nearly identical DNA species, that are called 'driver' and 'tester' DNA. Typically, tester DNA contains a sequence of interest that is non-homologous to driver DNA. When the two species are mixed, the driver sequence is added in excess to tester. During PCR, double stranded fragments first denature at ~95°C and then re-anneal when subjected to the annealing temperature.

Subsequently, the presence of native neuroligin dimers was confirmed in neurons through biochemical detection, which included heterodimers composed of different neuroligin species, increasing the potential heterogeneity of endogenous neuroligin core dimer complexes. The extracellular domain of NLGN consists mostly of a region that is homologous to acetylcholinesterases, but the amino acids important for catalysis in AChE are not conserved in NLGN, which lack esterase activity. Furthermore, this AChE homologous region is crucial for the proper function of NLGN.

These chromosomes (paired chromatids) then pair with the homologous chromosome (also paired chromatids) present in the same nucleus (see prophase I in the meiosis diagram). The process of alignment of paired homologous chromosomes is called synapsis (see Synapsis). During synapsis, genetic recombination usually occurs. Some of the recombination events occur by crossing over (involving physical exchange between two chromatids), but most recombination events involve information exchange but not physical exchange between two chromatids (see Synthesis-dependent strand annealing (SDSA)).

CSB and CSA proteins are considered to function in transcription coupled nucleotide excision repair (TC-NER). CSB and CSA deficient cells are unable to preferentially repair UV-induced cyclobutane pyrimidine dimers in actively transcribed genes, consistent with a failed TC- NER response. CSB also accumulates at sites of DNA double-strand breaks in a transcription dependent manner and influences double-strand break repair. CSB protein facilitates homologous recombinational repair of double-strand breaks and represses non-homologous end joining.

Plants are generally more capable of surviving, and indeed flourishing, as polyploids. Polyploid organisms have more than two sets of homologous chromosomes. For example, humans have two sets of homologous chromosomes, meaning that a typical human will have 2 copies each of 23 different chromosomes, for a total of 46. Wheat on the other hand, while having only 7 distinct chromosomes, is considered a hexaploid and has 6 copies of each chromosome, for a total of 42.

MSH5 mutants retain the competence to repair DNA double-strand breaks that are present during meiosis, but they accomplish this repair in a way that does not lead to crossovers between homologous chromosomes. The known mechanism of non- crossover recombinational repair is called synthesis dependent strand annealing (see homologous recombination). MSH5 thus appears to be employed in directing the recombinational repair of some double-strand breaks towards the cross over option rather than the non-cross over option.

In an article entitled "The Faculty of Language: What Is It, Who Has It, and How Did It Evolve?" Hauser, Chomsky, and Fitch present the three leading hypotheses for how language evolved and brought humans to the point where they have a universal grammar. The first hypothesis states that the faculty of language in the broad sense (FLb) is strictly homologous to animal communication. This means that homologous aspects of the faculty of language exist in non-human animals.

In crustaceans, the first pair are called maxillulae (singular maxillula). Modified coxae at the base of the pedipalps in spiders are also called "maxillae", although they are not homologous with mandibulate maxillae.

Similarity ultimately leads to homology, in that the more similar sequences are, the closer they are to being homologous. This similarity in sequences can then go on to help find common ancestry.

The transmembrane part is highly homologous with other members of the rhodopsin family of GPCRs. The C-terminal domain is intracellular and brief, rich in serine and threonine residues for possible phosphorylation.

Mating in these cases involves the pairing of individuals, accompanied by the pairing of their homologous chromosomes and then exchange of genomic information leading to formation of recombinant progeny (see mating systems).

DNA integration can be sustained through one of many processes. One is persistence as an episome, another is homologous recombination, and still another is illegitimate incorporation through lucky double-strand break repair.

Bulet, P., et al. 2004. Anti- microbial peptides: from invertebrates to vertebrates. Immunology Review 198:169–184. S100A7 is highly homologous to S100A15 (koebnerisin) but distinct in expression, tissue distribution and function.

However, in narwhals the male tusk is implanted in the left maxilla, whereas in Odobenocetops it is implanted in the right premaxilla. The tusks in these two genera are therefore not homologous.

The STT3B protein contains a highly immunogenic minor histocompatibility antigen epitope of 9 amino acids, B6(dom1). Like ITM1 (MIM 601134), STT3B is homologous to yeast STT3, an oligosaccharyltransferase essential for cell proliferation.

During meiosis, diploid cells divide twice to produce haploid germ cells. During this process, recombination results in a reshuffling of the genetic material from homologous chromosomes so each gamete has a unique genome.

Bianconi argued that homologous structures are explained on mechanical principles. Darwin briefly mentioned Bianconi and rejected his arguments in a footnote in his The Descent of Man.Darwin, Charles. (1888). The Descent of Man.

Oxalyl-CoA decarboxylase is structurally homologous to acetolactate synthase found in plants and other microorganisms, but OXC binds ADP in a region that is similar to the FAD-binding site in acetolactate synthase.

Synaptonemal complex protein 3 is a protein that in humans is encoded by the SYCP3 gene. It is a component of the synaptonemal complex formed between homologous chromosomes during the prophase of meiosis.

The bases of these mericarps each contain one hairless, brown, ellipse-shaped seed of about 5 mm long and 2 mm in diameter. P. peltatum has nine homologous sets of chromosomes (2x=18).

Aciculitins A-C Aciculitins are antifungal cyclic peptides isolated from a marine sponge. There are 3 Aciculitins that are isolated from the Lithistid sponge Aciculites orientalis that differ by their homologous lipid residues.

Significant similarity is strong evidence that two sequences are related by evolutionary changes from a common ancestral sequence. Alignments of multiple sequences are used to indicate which regions of each sequence are homologous.

While meiotic homologous pairing subsequently became well studied, somatic pairing remained neglected due to what has been described as "limitations in cytological tools for measuring pairing and genetic tools for perturbing pairing dynamics".

Because the stomata in mosses, hornworts and polysporangiophytes are viewed as homologous, it has been suggested they belong in a natural group named stomatophytes. The evolutionary history of plants is far from settled.

This PCR involves homologous fragments from different parental genes priming for each other, resulting in chimeric DNA. The chimeric DNA of parental size is then amplified using end terminal primers in regular PCR.

PGRPs contain at least one C-terminal peptidoglycan recognition domain, which is about 165 amino acids long. This peptidoglycan-binding type 2 amidase domain is homologous to bacteriophage and bacterial type 2 amidases.

Figure 4. Double-strand break repair models that act via homologous recombination Two primary models for how homologous recombination repairs double-strand breaks in DNA are the double- strand break repair (DSBR) pathway (sometimes called the double Holliday junction model) and the synthesis-dependent strand annealing (SDSA) pathway. The two pathways are similar in their first several steps. After a double- strand break occurs, the MRX complex (MRN complex in humans) binds to DNA on either side of the break.

Figure 6. Recombination via the SSA pathway occurs between two repeat elements (purple) on the same DNA duplex, and results in deletions of genetic material. (Click to view animated diagram in Firefox, Chrome, Safari, or Opera web browsers.) The single-strand annealing (SSA) pathway of homologous recombination repairs double-strand breaks between two repeat sequences. The SSA pathway is unique in that it does not require a separate similar or identical molecule of DNA, like the DSBR or SDSA pathways of homologous recombination.

Figure 10. Protein domains in homologous recombination-related proteins are conserved across the three main groups of life: archaea, bacteria and eukaryotes. While the pathways can mechanistically vary, the ability of organisms to perform homologous recombination is universally conserved across all domains of life. Based on the similarity of their amino acid sequences, homologs of a number of proteins can be found in multiple domains of life indicating that they evolved a long time ago, and have since diverged from common ancestral proteins.

In humans, RAD51 is a 339-amino acid protein that plays a major role in homologous recombination of DNA during double strand break repair. In this process, an ATP dependent DNA strand exchange takes place in which a template strand invades base-paired strands of homologous DNA molecules. RAD51 is involved in the search for homology and strand pairing stages of the process. Unlike other proteins involved in DNA metabolism, the RecA/Rad51 family forms a helical nucleoprotein filament on DNA.

Indeed, the RNAs are upstream of multiple genes that encode non- homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of COG2908 RNAs makes this scenario less likely. Genes apparently regulated by PGK RNAs include those encoding phosphoglycerate kinase and acetylglucosaminyltransferase of unknown substrate specificity (see also Glycosyltransferase), as well as less common gene classes.

He began his academic research career at Northwestern University Medical School in 1981 and later moved to the University of California at Davis in 1991. He is one of the world's foremost experts on RecA, the defining member of a ubiquitous class of DNA strand-exchange proteins that are essential for homologous recombination, a pathway that maintains genomic integrity by repairing broken DNA. His lab has made significant contributions to the fields of DNA repair, homologous recombination and the biophysics of DNA helicases.

This type of keratin, previously thought to be specific to feathers, is suppressed during embryological development of the alligator and so is not present in the scales of mature alligators. The presence of this homologous keratin in both birds and crocodilians indicates that it was inherited from a common ancestor. This may suggest that crocodilian scales, bird and dinosaur feathers, and pterosaur pycnofibres are all developmental expressions of the same primitive archosaur skin structures; suggesting that feathers and pycnofibers could be homologous.

It is difficult to match evolutionarily related proteins in distantly related species. While homologous DNA sequences can be found relatively easily, it is much more difficult to predict homologous interactions ("interologs") because the homologs of two interacting proteins do not need to interact. For instance, even within a proteome two proteins may interact but their paralogs may not. Each protein–protein interactome may represent only a partial sample of potential interactions, even when a supposedly definitive version is published in a scientific journal.

This gene encodes a member of the kleisin family of SMC (structural maintenance of chromosome) protein partners. The protein localizes to the axial elements of chromosomes during meiosis in both oocytes and spermatocytes. REC8 protein appears to participate with other cohesins STAG3, SMC1ß and SMC3 in sister chromatid cohesion throughout the whole meiotic process in human oocytes. In the mouse, the homologous protein is a key component of the meiotic cohesion complex, which regulates sister chromatid cohesion and recombination between homologous chromosomes.

MMS methylates DNA predominantly on N7-deoxyguanosine and N3-deoxyadenosine, and to a much lesser extent also methylates at other oxygen and nitrogen atoms in DNA bases, and also methylates the phosphodiester linkage. Originally, this action was believed to directly cause double-stranded DNA breaks, because homologous recombination-deficient cells are particularly vulnerable to the effects of MMS. However, it is now believed that MMS stalls replication forks, and cells that are homologous recombination-deficient have difficulty repairing the damaged replication forks.

Since driver and tester sequences are nearly identical, the excess of driver DNA fragments will anneal to homologous DNA fragments from the tester species. This blocks PCR amplification and there is no increase in homologous fragments. However, fragments that are different between the two species will not anneal to a complementary counterpart and will be amplified by PCR. As more cycles of RDA are performed, the pool of unique sequence fragment copies will grow faster than fragments found in both species.

PARP1 acts as a first responder that detects DNA damage and then facilitates choice of repair pathway. PARP1 contributes to repair efficiency by modulating chromatin structure and by interacting with and modifying multiple DNA repair factors. PARP1 is implicated in the regulation of several DNA repair processes including the pathways of nucleotide excision repair, non-homologous end joining, microhomology-mediated end joining, homologous recombinational repair, and DNA mismatch repair. PARP1 has a role in repair of single-stranded DNA (ssDNA) breaks.

Non-allelic homologous recombination (NAHR) is a form of homologous recombination that occurs between two lengths of DNA that have high sequence similarity, but are not alleles. It usually occurs between sequences of DNA that have been previously duplicated through evolution, and therefore have low copy repeats (LCRs). These repeat elements typically range from 10–300 kb in length and share 95-97% sequence identity. During meiosis or mitosis, LCRs can misalign and subsequent crossing-over can result in genetic rearrangement.

The RAD51C protein is one of five paralogs of RAD51, including RAD51B (RAD51L1), RAD51C (RAD51L2), RAD51D (RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other. The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency. RAD51C forms two distinct complexes with other related paralogs: BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2) and CX3 (RAD51C-XRCC3).

The iron binding site of PHD2. PHD2 is a 46-kDa enzyme that consists of an N-terminal domain homologous to MYND zinc finger domains, and a C-terminal domain homologous to the 2-oxoglutarate dioxygenases. The catalytic domain consists of a double-stranded β-helix core that is stabilized by three α-helices packed along the major β-sheet. The active site, which is contained in the pocket between the β-sheets, chelates iron(II) through histidine and aspartate coordination.

Coprinopsis cinerea can be transformed with exogenous DNA by transformation when the fungus is a protoplast. It was found that disrupting (knockout or RNAi silencing) ku70 homologue can increase gene targeting via increased homologous recombination. Either protoplasts derived from oidia or vegetative mycelium can be used, however, gene targeting was found to be higher by 2% (based on phenotyping) when using vegetative mycelium. Otherwise, insertion of integrative vectors ectopically and with small homologous regions can be used, likely with low transformation efficiency.

This is supported by gene expression data, which show that the jaws too are derived from a protocerebral or deuterocerebral segment. As all euarthropod antennae are deuterocerebral or tritocerebral, this implies that the onychophoran antennae are not homologous to any euarthropod ones. The tritocerebrum in arthropods is the first segment to express Hox genes; on this basis, it can be recognised as homologous to the third head segment in onychophora, which bears the slime glands (a pair of highly modified appendages).

Additionally, almost no incidence of cancer has ever been detected in naked mole rats. Nearly all of the differences found between these two organisms, which are otherwise rather genetically similar, was in somatic maintenance. Naked mole rats were found to have higher levels of superoxide dismutase, a reactive oxygen species clearing antioxidant. In addition, naked mole rats had higher levels of base excision repair, DNA damage response signaling, homologous recombination repair, mismatch repair, nucleotide excision repair, and non-homologous end joining.

Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of COG2908 RNAs makes this scenario less likely. However, the functions of the genes apparently regulated by COG2908 RNAs are largely unknown, and therefore no hypothesis of the biological function of this RNA motif has been advanced.

Off-target genome editing refers to nonspecific and unintended genetic modifications that can arise through the use of engineered nuclease technologies such as: clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9, transcription activator-like effector nucleases (TALEN), meganucleases, and zinc finger nucleases (ZFN). These tools use different mechanisms to bind a predetermined sequence of DNA (“target”), which they cleave (or "cut"), creating a double-stranded chromosomal break (DSB) that summons the cell's DNA repair mechanisms (non-homologous end joining (NHEJ) and homologous recombination (HR)) and leads to site-specific modifications. If these complexes do not bind at the target, often a result of homologous sequences and/or mismatch tolerance, they will cleave off-target DSB and cause non-specific genetic modifications. Specifically, off-target effects consist of unintended point mutations, deletions, insertions inversions, and translocations.

In proposed models for how BITS works, the process begins with the resection of a damaged telomere end: one of the strands is cut away to provide a single strand of DNA (the Guanosine-rich strand) that can bind to into a matching (homologous) template, forming a so- called displacement loop (D-loop) (Figure 1a). In ALT, there is evidence that this template consists of: (i) a centromere proximal sequence of the same chromosome (T-loop), (ii) circular extrachromosomal telomeric sequences (C-circles), (iii) homologous chromosomes, or (iv) other chromosomes (Figure 1b). ALT may arise from a combination of some or all of these templates. Importantly, because telomeres are highly repetitive, invasion between or within telomeres is not limited by the requirement for extended homology in homologous recombination.

Nevertheless, this mutant gave rise to spore viability patterns suggesting that segregation of non-exchange chromosomes occurred efficiently. Thus in S. cerevisiae proper segregation apparently does not entirely depend on crossovers between homologous pairs.

SLC41A1 is a protein that in humans is encoded by the gene SLC41A1. It is homologous to the prokaryotic Mg++ transfer protein MgtE Mutations in this gene have been associated to Nephronophthisis-like phenotypes.

There is evidence for recombination in some RNA viruses, specifically positive-sense ssRNA viruses like retroviruses, picornaviruses, and coronaviruses. There is controversy over whether homologous recombination occurs in negative-sense ssRNA viruses like influenza.

In biological terms the various forms are examples of evolutionary strategies and are largely analogous rather than homologous; the gonozooid phases of say, the Tunicata did not evolve from anything like say, a Bryozoan.

It was found that repair of DNA double-strand breaks is predominantly carried out by accurate homologous recombinational repair. Another less accurate process, microhomology-mediated end joining is also used to repair such breaks.

It is postulated that AIDS-like disease in African NHPs represents horizontal transmission of the virus from one or more homologous species in the recent evolutionary past, before equilibrium of co-adaptation has occurred.

Pelvic fins from a Java barb (Barbonymus gonionotus) Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods.

This has led to the PSI being termed a "swaposin" (a play-on-words of "swap" and "saposin") although the tertiary structure still remains homologous to saposin and other members of the SAPLIP family.

The nucleus is the most likely home of C16orf90's produced protein and is not a transmembrane protein. These results were verified by comparing the results of the homologous mouse and dolphin C16orf90 proteins.

Since this system increases the fitness of S. acidocaldarius cells after UV exposure, Wolferen et al. considered that transfer of DNA likely takes place in order to repair UV-induced DNA damages by homologous recombination.

Ghrelin O-acyltransferase (GOAT) also known as membrane bound O-acyltransferase domain containing 4 is an enzyme that in humans is encoded by the MBOAT4 gene. It is homologous to other membrane-bound O-acyltransferases.

HIS3 from Saccharomyces cerevisiae is not a fused IGP dehydratase and hisidinol phosphatase, but an IGPD only (homologous to hisB-N). Whereas HIS2 is the HP (analogous to hisB-C, called hisJ in some prokaryotes).

This method utilizes fast Fourier transform (FFT) that converts amino acid sequences into a sequence composed of volume and polarity values for each amino acid residue. This new sequence is used to find homologous regions.

This response may be a primitive form of sexual interaction, similar to the more well-studied bacterial transformation that is also associated with DNA transfer between cells leading to homologous recombinational repair of DNA damage.

He vigorously collected specimens for his museum, "prepared or otherwise provided, mainly by the work of my own hands, and at my own expense". The specimens were arranged to enable students to compare the anatomy of different animals. He intended the comparative anatomy exhibits to demonstrate evolution through the presence of homologous structures. For example, in mammals, the arm and hand of a human, the wing of a bird, the foreleg of a horse, and the flipper of a whale are all homologous forelimbs.

Single-progeny descent is only possible if the organism being studied is capable of asexual reproduction or self-fertilization. In cases where an organism is only capable of sexual reproduction (such as Drosophila melanogaster, which was the species used in many early MA experiments), organisms with balancer chromosomes are used. In MA experiments involving an obligate sexually reproducing species such as Drosophila, mutations are accumulated on only one of a pair of homologous chromosomes. The other homologous chromosome is a modified so-called balancer chromosome.

CED-9 contains a BCL domain homologous to Bcl-2 domains BH1, BH2, and part of BH3 as well as a separate domain homologous to BH4 located near the N-terminus. CED-9 also includes a transmembrane domain on the C-terminal end of the structure that anchors the protein to the mitochondrial membrane. However, research shown that the C-terminal domain is not necessary for the protein's main function as an inhibitor of the CED-4 protein found in the same apoptosis signalling pathway.

Experiments in mice deficient in BLM have suggested that the mutation gives rise to cancer through a loss of heterozygosity caused by increased homologous recombination. A loss in heterozygosity refers to the loss of one of two versions—or alleles—of a gene. If one of the lost alleles helps to suppress tumors, like the gene for the retinoblastoma protein for example, then the loss of heterozygosity can lead to cancer. Decreased rates of homologous recombination cause inefficient DNA repair, which can also lead to cancer.

The protein encoded by this gene contains a RING finger motif and an FHA domain. This protein has been shown to interact with several class II ubiquitin-conjugating enzymes (E2), including UBE2E1/UBCH6, UBE2E2, and UBE2E3, and may act as a ubiquitin ligase (E3) in the ubiquitination of certain nuclear proteins. Alternatively spliced transcript variants encoding distinct isoforms have been reported. RNF8 promotes repair of DNA damage through three DNA repair pathways: homologous recombinational repair (HRR), non-homologous end joining (NHEJ), and nucleotide excision repair (NER).

Also a recessive genetic disposition on his Y chromosome - also hemizygot - can come to expression, because there is no homologous chromosome with an allele, which could overlay it. If there is no genetic information on the Y chromosome for a certain trait, the effect of the Y is neutral and the allele on his X chromosome, which would be recessive in a heterozygous woman, can now alone come to expression. Women have two homologous sex chromosomes (XX). Therefore, women can be carriers of X-linked genes.

The three small bones in the middle ear of mammals including humans, the malleus, incus, and stapes, are today used to transmit sound from the eardrum to the inner ear. The malleus and incus develop in the embryo from structures that form jaw bones (the quadrate and the articular) in lizards, and in fossils of lizard-like ancestors of mammals. Both lines of evidence show that these bones are homologous, sharing a common ancestor. Among the many homologies in mammal reproductive systems, ovaries and testicles are homologous.

The zinc finger domain of Gli1 in complex with DNA. The third, fourth and fifth zinc fingers of Gli1 are over 80% homologous to the zinc finger domain in Glis1, with fingers four and five making the most intimate interactions with DNA. Glis1 is an 84.3 kDa proline rich protein composed of 789 amino acids. No crystal structure has yet been determined for Glis1, however it is homologous to other proteins in many parts of its amino acid sequence whose structures have been solved.

Similar to B. subtilis and E. coli above, exposures of the archaeon Haloferax volcanii to stresses that damage DNA cause compaction and reorganization of the nucleoid. Compaction depends on the Mre11-Rad50 protein complex that catalyzes an early step in homologous recombinational repair of double-strand breaks in DNA. It has been proposed that nucleoid compaction is part of a DNA damage response that accelerates cell recovery by helping DNA repair proteins to locate targets, and by facilitating the search for intact DNA sequences during homologous recombination.

It is reported that when no double stranded breaks are generated, the number of cells that lose the CORE cassette in the absence of a targeting oligonucleotide is less than one transformant per 107 viable cells. In contrast, this number increases up to 100 transformants per 107 viable cells when a double stranded break is generated. In a diploid, the increased background mutation rates occur due to homologous recombination with the homologous chromosome decreasing targeted transformation events to only 4% of the total transformants.

Many forms of molecular phylogenetics are closely related to and make extensive use of sequence alignment in constructing and refining phylogenetic trees, which are used to classify the evolutionary relationships between homologous genes represented in the genomes of divergent species. The phylogenetic trees constructed by computational methods are unlikely to perfectly reproduce the evolutionary tree that represents the historical relationships between the species being analyzed. The historical species tree may also differ from the historical tree of an individual homologous gene shared by those species.

Non-homologous end joining a process of illegitimate recombination versus a homology driven recombination event. Illegitimate recombination, or nonhomologous recombination, is the process by which two unrelated double stranded segments of DNA are joined. This insertion of genetic material which is not meant to be adjacent tends to lead to genes being broken causing the protein which they encode to not be properly expressed. One of the primary pathways by which this will occur is the repair mechanism known as non- homologous end joining (NHEJ).

The homologous gene of Plutella xylostella was knocked out i.e. changed. This is a genetically-based approach that requires precise research to identify suitable genetic targets. Using the CRISPR/Cas9 system as a targeted gene to identify the abdominal segment, thus removing the harmful homologous gene (gene for cruciferous preference) in the diamondback moth. Field trials conducted by the UK biotechnology company Oxitec, released between 1,000 and 2,500 genetically modified males to a crop in New York state, during August and September 2017 on six occasions.

RECQL4 has a crucial role in DNA end resection that is the initial step required for homologous recombination (HR)-dependent double-strand break repair. When RECQL4 is depleted, HR-mediated repair and 5’ end resection are severely reduced in vivo. RECQL4 also appears to be necessary for other forms of DNA repair including non-homologous end joining, nucleotide excision repair and base excision repair. The association of deficient RECQL4-mediated DNA repair with accelerated aging is consistent with the DNA damage theory of aging.

Great appendages are interpret as raptorial limbs involved in predation, with those of some genus such as Yohoia are structurally comparable to the raptorial maxillipeds of mantis shrimp. While the great appendages of leanchoilid megacheirans such as Leanchoilia and Yawunik have elongated flagella, suggest a sensory role alongside predatory function. Radiodonts such as Anomalocaris have multi-segmented frontal appendages, which are suggested to be either homologous or non-homologous with the megacheiran's great appendages. Radiodont's frontal appendages have controversial relationships to those of the megacheirans.

According to the TAS concept, tissue stress possess the ability to regulate the cell mass of homologous tissue via executive mechanism described above – the CURD. As in the case of cells specialized functions regulation there are two ways of tissue-specific control of homologous tissue cell mass. These are cells unspecific resistance modulation and influencing the speed of physiological processes occurring in the cell. Tissue stress mechanism able to control tissue cell mass influencing both its mitotic and apoptotic (see Apoptosis) activities tissue-specifically.

Primordial follicles are immature primary oocytes surrounded by a single layer of granulosa cells. An enzyme system is present in oocytes that normally accurately repairs DNA double-strand breaks. This repair system is referred to as homologous recombinational repair, and it is especially active during meiosis. Meiosis is the general process by which germ cells are formed in eukaryotes, and it appears to be an adaptation for efficiently removing damages in germ line DNA by homologous recombinational repair (see Origin and function of meiosis).

When DNA polymerase encounters a direct repeat, it can undergo a replication slippage. Strand slippage may also occur during the DNA synthesis step of DNA repair processes. Within DNA trinucleotide repeat sequences, the repair of DNA damage by the processes of homologous recombination, non-homologous end joining, DNA mismatch repair or base excision repair may involve strand slippage mispairing leading to trinucleotide repeat expansion when the repair is completed. Slipped strand mispairing has also been shown to function as a phase variation mechanism in certain bacteria.

The breaks can lead to mutations that reposition a chromosome and can even lead to the entire loss of a chromosome. The mutations associated with double-stranded breaks have been linked to cancer and other deadly genetic diseases. RSC does not only repair double-stranded breaks by NHEJ, it also repairs this breaks using homologous recombination with the help of the SWI/SNF complex. SWI/SNF is recruited first, prior to two homologous chromosomes bind, and then RSC is recruited to help complete the repair.

The skull of Dimetrodon (an early synapsid with a single midline postparietal) in occipital view. Early synapsids inherited postparietals (sometimes paired) from their non-amniote ancestors. Embryological data indicates that the interparietal bone of mammals forms from the fusion of four bones during early development: a pair of medial neural crest elements edged by lateral mesoderm elements. The medial neural crest-derived pair are considered homologous to the postparietals of other vertebrates, while the lateral mesoderm bones are considered homologous to the tabular bones.

The Werner syndrome ATP-dependent helicase (WRN helicase) is unusual among RecQ DNA family helicases in having an additional exonuclease activity. WRN interacts with DNA-PKcs and the Ku protein complex. This observation, combined with evidence that WRN deficient cells produce extensive deletions at sites of joining of non-homologous DNA ends, suggests a role for WRN protein in the DNA repair process of non- homologous end joining (NHEJ). WRN also physically interacts with the major NHEJ factor X4L4 (XRCC4-DNA ligase 4 complex).

Figure B. The Human succinyl-CoA-Transferase enzyme is represented by the two joint blue and green bars at the top of the image. The alpha subunit of the Acetate-CoA- Transferase enzyme is homologous with the first half of the enzyme, represents by the blue bar. The beta subunit of the Acetate-CoA-Transferase enzyme is homologous with the second half of the enzyme, represents by the green bar. This mage was adapted from Uetz, P. & Pohl, E. (2018) Protein-Protein and Protein-DNA Interactions.

Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins. If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of sul1 RNAs makes this scenario less likely. Among the proteins encoded by genes that are apparently regulated by sul1 RNAs, the most common protein domains (whose gene is named sul1) is believed to function as a sulfate transporter.

If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of terC RNAs makes this scenario less likely. When considering the conserved protein domains contained in proteins that are encoded by terC-regulated genes, the most frequent are classified as TIGR03717 and TIGR03718, according to the Conserved domain database. Both TIGR03717 and TIGR03718 are homologous with the membrane-bound protein known as TerC.

Genes are commonly regarded as the basic units transferred through an HGT event. However it is also possible for HGT to occur within genes. For example, it has been shown that horizontal transfer between closely related species results in more exchange of ORF fragments, a type a transfer called gene conversion, mediated by homologous recombination. The analysis of a group of four Escherichia coli and two Shigella flexneri strains revealed that the sequence stretches common to all six strains contain polymorphic sites, consequences of homologous recombination.

Comparative chromosome painting allows a rapid and efficient comparison of many species and the distribution of homologous regions makes it possible to track the translocation of chromosomal evolution. When many species covering different mammalian orders are compared, this analysis can provide information on trends and rates of chromosomal evolution in different branches. However, homology is only detected qualitatively, and resolution is limited by the size of visualized regions. Thus, the method does not detect all minuscule homologous regions from multiple rearrangements (as between mouse and human).

The silent versions of this gene, PilS, can use homologous recombination to combine with parts of the PilE gene and thus create a different phenotype. This allows for up to 10,000,000 different phenotypes of the pili.

The main clinical sign is an increased level of the plasma enzyme lactate dehydrogenase (LDH). LDV has a remarkably narrow cell type specificity, meaning nothing homologous with LDV in mice has been found in another species.

As a result, Hox genes in most vertebrates are spread across multiple chromosomes: the HoxA–D clusters are the best studied. Dominance hierarchy behaviour, as in these weeper capuchin monkeys, may be homologous across the primates.

Lysophospholipid acyltransferase 7 also known as membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) is an enzyme that in humans is encoded by the MBOAT7 gene. It is homologous to other membrane-bound O-acyltransferases.

Makes it possible for homologous recombination to occur easily between different alleles. The repetitiveness of it, and the other members of the NBPF gene family is thought to have arisen from segmental duplications on chromosome 1.

Only occasionally have these food-induced allergies induced systemic responses. Researchers suspect that the cross-reactivity of latex with banana, avocado, kiwifruit, and chestnut occurs because latex proteins are structurally homologous with some other plant proteins.

Experimentally determined interactions usually provide the basis for computational methods to predict interactions, e.g. using homologous protein sequences across species. However, there are also methods that predict interactions de novo, without prior knowledge of existing interactions.

One additional contributory mechanism for the decline in the ovarian reserve with age appears to be a decreased gene expression of proteins involved in DNA repair by homologous recombination such as BRCA1, MRE11, Rad51 and ATM.

Regarding DSB repair, eukaryotes generally use two strategies: non-homologous end joining (NHEJ), which involves rapid reattachment of the broken ends; and homologous recombination (HR), which involves the use of a homologous DNA sequence to repair the break. Because HR requires a homologous sequence, its use is restricted to S/G2 phase. (Interestingly, as with many other aspects of the cell cycle, cyclin-dependent kinases are responsible for downregulating NHEJ during S/G2 phase to ensure use of the more accurate HR.) As shown in Figure 1A, telomere-shelterin complexes contain motifs that inhibit the DNA damage checkpoint, NHEJ, and HR. Initial work on the role of telomere-bound protein complexes in S. cerevisiae elucidated the mechanism by which these complexes prevent checkpoint activation and DSB repair of chromosome ends. The two major protein complexes that bind to telomeric DNA in S. cerevisiae are (1) the Cdc13-Stn1-Ten1 (CST) complex, which binds the single-stranded DNA (ssDNA) of the 3’ G-rich overhang at the end of the telomere, and (2) the Rif1-Rif2-Rap1 complex, which binds the double-stranded DNA (dsDNA) preceding the 3’ overhang.

Chording mycobacterium tuberculosis culture - luminescent microscope image Focusing his early researches on the molecular basis of homologous genetic recombination and employing RecA paradigm, Muniyappa demonstrated the effects of chromatization of DNA on homologous pairing and strand exchange and his studies are known to have assisted in exploring ways for gene targeting, cell senescence and genome stability. His studies on chromosome synapsis, genetic recombination and telomere dynamics attempted to widen the understanding of cellular recombination and Holliday junction and he is credited with the discovery of a negative regulatory mechanism of homologous recombination. His contributions in deciphering genetic recombination in mycobacterium tuberculosis are also reported to have influenced further researches on the mechanism of genetic exchange and lateral gene transfer. His researches have been published in a number of articles, 136 of which have been listed by ResearchGate, an online article repository.

Most recombination events appear to be the SDSA type. Conversion of one allele to the other is often due to base mismatch repair during homologous recombination: if one of the four chromatids during meiosis pairs up with another chromatid, as can occur because of sequence homology, DNA strand transfer can occur followed by mismatch repair. This can alter the sequence of one of the chromosomes, so that it is identical to the other. Meiotic recombination is initiated through formation of a double-strand break (DSB). The 5’ ends of the break are then degraded, leaving long 3’ overhangs of several hundred nucleotides. One of these 3’ single stranded DNA segments then invades a homologous sequence on the homologous chromosome, forming an intermediate which can be repaired through different pathways resulting either in crossovers (CO) or noncrossovers (NCO).

However, these nonliving vaccines did provide protection against the homologous organism. The living vaccines provided protection and cross-protection. as well. No protection was demonstrated against F. tularensis when using an F. novicida vaccine in any experiment.

This gene is homologous to the yeast gene SGT1, which encodes a protein involved in kinetochore function and required for the G1/S and G2/M transitions. Complementation studies suggest that the human protein has similar functions.

During meiosis up to one-third of all homology directed repair events occur between sister chromatids. The remaining two-thirds, or more, of homology directed repair occurs as a result of interaction between non-sister homologous chromatids.

Alpha- synuclein promotes the DSB repair pathway referred to as non-homologous end joining. The DNA repair function of alpha-synuclein appears to be compromised in Lewy body inclusion bearing neurons, and this may trigger cell death.

Frols et al. found that exposure of S. solfataricus to DNA damaging agents induces cellular aggregation, and suggested that cellular aggregation may enhance DNA transfer among cells to provide increased repair of damaged DNA via homologous recombination.

There are no known human DEPDC5 paralogs, but there are 64 human proteins containing a homologous DEP domain. There are also no identified paralogs for the yeast protein Iml1, the most distantly related ortholog of human DEPDC5.

Fülöppite forms a homologous series with other members of the plagionite group. The structures of these minerals differ by the thickness of a galena sheet which occurs in all of them. Fülöppite has the thinnest such sheet.

It is thought that DNMT3a and DNMT3b are the de novo methyltransferases that set up DNA methylation patterns early in development. DNMT3L is a protein that is homologous to the other DNMT3s but has no catalytic activity.

Machine learning algorithms have been able to enhance MSA analysis methods, especially for non-homologous proteins (ie. shallow MSA's). Predicted contact maps have been used in the prediction of membrane proteins where helix-helix interactions are targeted.

This may occur in addition to or instead of the secondary active transport mechanism established for ACR3 members noted above. Homologous ATPases are found in families TC# 3.A.4, TC# 3.A.19 and TC# 3.

Homologous genes could only be studied effectively using search tools that established like portions or local placement between two proteins or nucleic acid sequences. Homology was quantified by scores obtained from matching sequences, “mismatch and gap scores”.

This is the main reason for independent assortment. The equation to determine the number of possible combinations given the number of homologous pairs = 2x (x = number of homologous pairs) The Law of Independent Assortment states that alleles for separate traits are passed independently of one another.Big Medical Encyclopedia: Mendel' Laws - inheritance rules That is, the biological selection of an allele for one trait has nothing to do with the selection of an allele for any other trait. Mendel found support for this law in his dihybrid cross experiments.

Sister chromatid crossover events are known to occur at a rate of several crossover events per cell per division in eukaryotes. Most of these events involve an exchange of equal amounts of genetic information, but unequal exchanges may occur due to sequence mismatch. These are referred to by a variety of names, including non- homologous crossover, unequal crossover, and unbalanced recombination, and result in an insertion or deletion of genetic information into the chromosome. While rare compared to homologous crossover events, these mutations are drastic, affecting many loci at the same time.

When structures in different species are believed to exist and develop as a result of common, inherited genetic pathways, those structures are termed homologous. For example, the leaves of pine, oak, and cabbage all look very different, but share certain basic structures and arrangement of parts. The homology of leaves is an easy conclusion to make. The plant morphologist goes further, and discovers that the spines of cactus also share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well.

The IIA, IIB and IIC domains of the fructose- and mannitol-specific porters are demonstrably homologous. The IIB and IIC domains of the fructose porters appear to be dissimilar from each other as those of the mannitol porters. The IIB and IIC domains of these porters are homologous to those of the Glc family. However, the structure of the IIA domain of the mannitol porter of Escherichia coli has been determined, and it proved to possess an α2β2α3 secondary structure, a structure which is very different from the β-sandwich structure of IIAGlc.

Repair of DNA double-strand breaks can occur by either of two processes, non- homologous end joining (NHEJ) or homologous recombination (HR). A-type lamins promote genetic stability by maintaining levels of proteins that have key roles in NHEJ and HR. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased sensitivity to DNA damaging agents. In progeria, the inability to adequately repair DNA damages due to defective A-type lamin may cause aspects of premature aging (also see DNA damage theory of aging).

In Escherichia coli, homologous recombination events mediated by RecA can occur during the period after DNA replication when sister loci remain close. RecA can also mediate homology pairing, homologous recombination and DNA break repair between distant sister loci that had segregated to opposite halves of the E. coli cell. E. coli strains deficient in RecA are useful for cloning procedures in molecular biology laboratories. E. coli strains are often genetically modified to contain a mutant recA allele and thereby ensure the stability of extrachromosomal segments of DNA, known as plasmids.

Non-homologous end-joining factor 1 (NHEJ1), also known as Cernunnos or XRCC4-like factor (XLF), is a protein that in humans is encoded by the NHEJ1 gene. XLF was originally discovered as the protein mutated in five patients with growth retardation, microcephaly, and immunodeficiency. The protein is required for the non-homologous end joining (NHEJ) pathway of DNA repair. Patients with XLF mutations also have immunodeficiency due to a defect in V(D)J recombination, which uses NHEJ to generate diversity in the antibody repertoire of the immune system.

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division. There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate during meiosis II, and failure of sister chromatids to separate during mitosis. Nondisjunction results in daughter cells with abnormal chromosome numbers (aneuploidy). Calvin Bridges and Thomas Hunt Morgan are credited with discovering nondisjunction in Drosophila melanogaster sex chromosomes in the spring of 1910, while working in the Zoological Laboratory of Columbia University.

This technique was developed by a group at the National Institute of Environmental Health Sciences (NIEHS) composed of Michael A. Resnick, Francesca Storici (now at Georgia Institute of Technology), and L. Kevin Lewis (now at Southwest Texas State University). The method uses synthetic oligonucleotides in combination with the cellular process of homologous recombination. Consequently, it is well suited for genetic manipulation of yeast, which has highly efficient homologous recombination. The delitto perfetto approach has been used to produce single and multiple point mutations, gene truncations or insertions, and whole gene deletions (including essential genes).

Repair of DNA double-strand breaks can occur by one of two processes, non-homologous end joining (NHEJ) or homologous recombination (HR). A-type lamins promote genetic stability by maintaining levels of proteins which have key roles in NHEJ and HR. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased sensitivity to DNA damaging agents. In HGPS, the inability to adequately repair DNA damages due to defective A-type lamin may cause aspects of premature aging (see DNA damage theory of aging).

Mitotic recombination in the budding yeast Saccharomyces cerevisiae is primarily a result of DNA repair processes responding to spontaneous or induced damages that occur during vegetative growth.} (Also reviewed in Bernstein and Bernstein, pp 220–221). In order for yeast cells to repair damage by homologous recombination, there must be present, in the same nucleus, a second DNA molecule containing sequence homology with the region to be repaired. In a diploid cell in G1 phase of the cell cycle, such a molecule is present in the form of the homologous chromosome.

The structure and function of cytochrome b6f (in chloroplasts) is very similar to cytochrome bc1 (Complex III in mitochondria). Both are transmembrane structures that remove electrons from a mobile, lipid-soluble electron carrier (plastoquinone in chloroplasts; ubiquinone in mitochondria) and transfer them to a mobile, water-soluble electron carrier (plastocyanin in chloroplasts; cytochrome c in mitochondria). Both are proton pumps that produce a transmembrane proton gradient. In fact, cytochrome b6 and subunit IV are homologous to mitochondrial cytochrome b and the Rieske iron-sulfur proteins of the two complexes are homologous.

In 1984, David Julius, working in the laboratory of Jeremy Thorner, identified the product of the Kex2 gene as responsible for processing of the alpha factor mating pheromone. Robert Fuller, working with Thorner, identified the partial sequence of the Kex2-homologous Furin gene in 1989. In 1990 human Kex2-homologous genes were cloned by the Steiner group, Nabil Seidah and co-workers, Wim J.M. van de Ven and co-workers, Yukio Ikehara and co-workers, Randal Kaufman and co-workers, Gary Thomas and co-workers, and Kazuhisa Nakayama and co-workers.

The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of Isoxys and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to chelicerae and first antennae of other arthropods (which are deutocerebral), but not dinocaridid frontal appendages (protocerebral), A 2020 study suggests that the great appendages of megacheirans and radiodonts are homologous and casts doubt on the validity of suspected neuroanatomical evidences.

Her work there was funded by the Rockefeller Foundation. While studying and teaching at the University of Pennsylvania, Carothers traveled to the southern and southwestern regions of the United States on research expeditions, held in 1915 and 1919. During her time at the University of Iowa, she completed her most important work, in the field of genetics and cytology, using grasshopper embryos to study the independent assortment of heteromorphic homologous chromosomes. This was the first physical evidence that homologous chromosomes separated independently during meiosis, which is one source of genetic variation in sexually- reproducing organisms.

Recombination occurs not only during meiosis, but also as a mechanism for repair of double-strand breaks (DSBs) caused by DNA damage. These DSBs are usually repaired using the sister chromatid of the broken duplex and not the homologous chromosome, so they would not result in allelic conversion. Recombination also occurs between homologous sequences present at different genomic loci (paralogous sequences) which have resulted from previous gene duplications. Gene conversion occurring between paralogous sequences (ectopic gene conversion) is conjectured to be responsible for concerted evolution of gene families.

Segmental duplication are blocks of DNA ranging from 1 to 400 kb in length which recur at multiple sites within the genome, sharing greater than 90% similarity. Multiple studies have found a correlation between the location of segmental duplications and regions of chromosomal instability. This correlation suggests that they may be mediators of some genomic disorders. Segmental duplications are shown to be flanked on both sides by large homologous repeats, which exposes the region to recurrent rearrangement by nonallelic homologous recombination, leading to either deletion, duplication, or inversion of the original sequence.

Rad50 protein has been mainly studied in eukaryotes. However, recent work has shown that orthologs of the Rad50 protein are also conserved in extant prokaryotic archaea where they likely function in homologous recombinational repair. In the hyperthermophilic archeon Sulfolobus acidocaldarius, the Rad50 and Mre11 proteins interact and appear to have an active role in repair of DNA damages introduced by gamma radiation. These findings suggest that eukaryotic Rad50 may be descended from an ancestral archaeal Rad50 protein that served a role in homologous recombinational repair of DNA damage.

Furthermore, cohesin proteins are found to aid in the repair system of double stranded breaks through clamping the two ends in close proximity which prevents interchromosomal invasion of the ends. If for any reason, such as activation of ribosomal RNA, cohesin activity is affected then there may be local increase in double stranded break repair errors. The other class of possible mechanisms that are hypothesized to lead to copy number variations is non-homologous based. To distinguish between this and homologous based mechanisms, one must understand the concept of homology.

There are two known epigenetic causes of XRCC2 deficiency that appear to increase cancer risk. These are methylation of the XRCC2 promoter and epigenetic repression of XRCC2 by over- expression of EZH2 protein. The XRCC2 gene was found to be hypermethylated in the promoter region in 52 of 54 cases of cervical cancer. Promoter hypermethylation reduces gene expression, and thus would reduce the tumor suppressing homologous recombinational repair otherwise supported by XRCC2. Increased expression of EZH2 leads to epigenetic repression of RAD51 paralogs, including XRCC2, and thus reduces homologous recombinational repair.

The protein encoded by this gene is a member of the RAD51 protein family. RAD51 family members are highly similar to bacterial RecA and Saccharomyces cerevisiae Rad51, which are known to be involved in the homologous recombination and repair of DNA. This protein forms a complex with several other members of the RAD51 family, including RAD51L1, RAD51L2, and XRCC2. The protein complex formed with this protein has been shown to catalyze homologous pairing between single- and double-stranded DNA, and is thought to play a role in the early stage of recombinational repair of DNA.

Mice are often used as a model for human genetic behavior since mice and humans have homologous genes coding for homologous proteins that are used for similar functions at some biological levels. Mice aggression studies have led to some interesting insight in human aggression. Using reverse genetics, the DNA of genes for the receptors of many neurotransmitters have been cloned and sequenced, and the role of neurotransmitters in rodent aggression has been investigated using pharmacological manipulations. Serotonin has been identified in the offensive attack by male mice against intruder male mice.

Factor VIII protein consists of six domains: A1-A2-B-A3-C1-C2, and is homologous to factor V. The A domains are homologous to the A domains of the copper-binding protein ceruloplasmin. The C domains belong to the phospholipid-binding discoidin domain family, and the C2 domain mediate membrane binding. Activation of factor VIII to factor VIIIa is done by cleavage and release of the B domain. The protein is now divided to a heavy chain, consisting of the A1-A2 domains, and a light chain, consisting of the A3-C1-C2 domains.

Loss of him-14(MSH-4) function severely reduces crossing over, resulting in lack of chiasmata between homologs and consequent missegregation. Thus, in C. elegans, segregation apparently does depend on crossovers between homologous pairs. Him-14(MSH4) functions during the pachytene stage of meiosis, indicating that it is not needed for establishing the preceding stages of pairing and synapsis of homologous chromosomes. In an MSH4 mutant of rice, chiasma frequency was dramatically decreased to about 10% of the wild-type frequency, although the synaptonemal complex was normally installed.

RAD52 mediates RAD51 function in homologous recombinational repair (HRR) in both yeast Saccharomyces cerevisiae and in mammalian cells of mice and humans. However, the RAD52 protein has distinctly different functions in HRR of yeast and humans. In S. cerevisae, Rad52 protein, acting alone, facilitates the loading of Rad51 protein onto single- stranded DNA pre-coated with replication protein A in the presynaptic phase of recombination. In mice and humans, however, BRCA2 primarily mediates orderly assembly of RAD51 on ssDNA, the form that is active for homologous pairing and strand invasion.

In the strand invasion step that follows, an overhanging 3' end of the broken DNA molecule "invades" the DNA of a homologous chromosome that is not broken, forming a displacement loop (D-loop). After strand invasion, the further sequence of events may follow either of two main pathways leading to a crossover (CO) or a non-crossover (NCO) recombinant (see Genetic recombination and Homologous recombination). The pathway leading to a CO involves a double Holliday junction (DHJ) intermediate. Holliday junctions need to be resolved for CO recombination to be completed.

The formation of human gametes involves two separation events, known distinctly as Meiosis I, in which paired homologous chromosomes are separated, and Meiosis II, in which sister chromatids are divided. Meiosis I is a slightly elongated process, during which homologous chromosomes align, pair, and recombine. While male gametes (sperm) are continuously produced throughout life, the female ovarian reserve is fully formed during early development. Oocytes (but not spermatocytes) then undergo a prolonged arrest at the end of diplotene, until meiosis resumes at the beginning of the menstrual cycle.

Crystal structure of a homologous human malic enzyme highlights key residues involved in substrate binding and catalysis. Site II contains the GLGDLG motif, site V contains the other GXGXXG motif, the highlighted arginine residue interacts with both NADP+ and malate, and the highlighted lysine may possibly be involved in base catalysis. PDB file identity for image is 2aw5. Based on crystallography data of homologous NADP-dependent malic enzymes of mammalian origin, a 3D model for C4 pathway NADP-ME in plants has been developed, identifying the key residues involved in substrate-binding or catalysis.

A profile HMM modelling a multiple sequence alignment HMMER is a free and commonly used software package for sequence analysis written by Sean Eddy. Its general usage is to identify homologous protein or nucleotide sequences, and to perform sequence alignments. It detects homology by comparing a profile-HMM to either a single sequence or a database of sequences. Sequences that score significantly better to the profile-HMM compared to a null model are considered to be homologous to the sequences that were used to construct the profile-HMM.

The positioning of the stapes and the shape of the otic region suggests that the tympani of temnospondyls and frogs are homologous, but the tympani of these amphibians are no longer considered homologous with the hearing systems of reptiles, birds, and mammals. Therefore, ear structures in temnospondyls were not ancestral to those of all other tetrapods. The ability of the tympanum and stapes to effectively transmit vibrations is called impedance matching. Early tetrapods like temnospondyls have thick stapes with poor impedance matching, so it is now thought that they were not used for hearing.

FEN1 is over-expressed in the majority of cancers of the breast, prostate, stomach, neuroblastomas, pancreatic, and lung. FEN1 is an essential enzyme in an inaccurate pathway for repair of double-strand breaks in DNA called microhomology-dependent alternative end joining or microhomology- mediated end joining (MMEJ). MMEJ always involves at least a small deletion, so that it is a mutagenic pathway. Several other pathways can also repair double-strand breaks in DNA, including the less inaccurate pathway of non- homologous end joining (NHEJ) and accurate pathways using homologous recombinational repair (HRR).

Fet3p of S. cerevisiae is a multicopper oxidase (636 amino acyl residues) which spans the plasma membrane once (residues 561–584) and has two multicopper oxidase domains (residues 121–141 and 483–494), which possess the ferroxidase activity on the external surface of the plasma membrane. It is a member of the multicopper oxidase family and is therefore homologous to laccase (benzenediol:oxygen oxidoreductase or ligninolytic phenol oxidase), as well as L-ascorbate oxidase, ceruloplasmin and dihydrogeodin oxidase. Its copper binding domain is homologous to that of the PcoA copper binding protein of E. coli.

Werner syndrome is due to an inherited defect in an enzyme (a helicase and exonuclease) that acts in base excision repair of DNA (e.g. see Harrigan et al.). Huchinson–Gilford progeria is due to a defect in Lamin A protein which forms a scaffolding within the cell nucleus to organize chromatin and is needed for repair of double-strand breaks in DNA. A-type lamins promote genetic stability by maintaining levels of proteins that have key roles in the DNA repair processes of non-homologous end joining and homologous recombination.

This process generates single stranded DNA filaments coated by RAD51 and DMC1 which invade the homologous chromosomes, forming inter-axis bridges, and resulting in the pairing/co-alignment of homologues (to a distance of ~400 nm in mice).

Mice lacking the homologous gene Zfp423 have defects in midline brain development, especially in the cerebellum, as well as defects in olfactory development, and adipogenesis. Patients with mutations in ZNF423 have been reported in Joubert Syndrome and nephronophthisis.

Placoid scales as viewed through an electron microscope. Also called dermal denticles, these are structurally homologous with vertebrate teeth. Placoid (pointed, tooth-shaped) scales are found in the cartilaginous fishes: sharks, rays. They are also called dermal denticles.

This family of autolysin consist of only LytD itself. LytD functions for vegetative growth. Autolytic activity is found within the C-terminal region with catalytic domain homologous to the glucosaminidase domain. LytD is found in the cell wall.

The scientists showed that during DNA recombination of the cleaved strand, the homologous endogenous sequence HBD competes with the exogenous donor template. DNA repair in human embryos is much more complicated and particular than in derived stem cells.

HIRIP4 was isolated by virtue of its interaction with this protein; however, its exact function is not known. The sequence of HIRIP4 protein is highly homologous to the human DNJ3/CPR3, mouse Dj3 and rat Dj2 gene products.

This subfamily currently exists of six very homologous peptides, originating from scorpion venom: Aa1, AaTX1, AaTX2, AmmTX3, BmTx3 and Discrepin. Toxins of the α-KTX15 subfamily all seem to have an effect on the A-type potassium current.

The MCM heterohexamer arguably arose via MCM gene duplication events and subsequent divergent evolution. The pre-RC of Schizosaccharomyces pombe (S. pombe) is notably different from that of other eukaryotes; Cdc6 is replaced by the homologous Cdc18 protein.

Caddisflies also possess caudal cerci on the abdomen, a feature absent in the Lepidoptera. According to Scoble (2005), "morphologically, scales are macrotrichia, and thus homologous with the large hairs (and scales) that cover the wings of Trichoptera (caddisflies)".

However, homothallic meiosis may be maintained in fungi as an adaptation for surviving stressful conditions; a proposed benefit of meiosis is the promoted homologous meiotic recombinational repair of DNA damages that are ordinarily caused by a stressful environment.

Andrews, J. 1998. Bacteria as modular organisms. Annual Review of Microbiology, 52:105–126. The term has also been used in a broader sense in biology to refer to the reuse of homologous structures across individuals and species.

In addition to OGG1 and MYH, human cells contain three additional DNA glycosylases, NEIL1, NEIL2, and NEIL3. These are homologous to bacterial Nei, and their presence likely explains the mild phenotypes of the OGG1 and MYH knockout mice.

LIGHT stands for "homologous to lymphotoxin, exhibits inducible expression and competes with HSV glycoprotein D for binding to herpesvirus entry mediator, a receptor expressed on T lymphocytes". In the cluster of differentiation terminology it is classified as CD258.

Frols et al. and Ajon et al.(2011) hypothesized that cellular aggregation enhances species- specific DNA transfer between Sulfolobus cells in order to provide increased repair of damaged DNA by means of homologous recombination. Van Wolferen et al.

It has been suggested that ganoine is homologous to tooth enamel in vertebrates or even considered a type of enamel. Ganoine indeed contains amelogenin-like proteins and has a mineral content similar to that of tetrapod tooth enamel.

In recognition of their discovery of how homologous recombination can be used to introduce genetic modifications in mice through embryonic stem cells, Mario Capecchi, Martin Evans and Oliver Smithies were awarded the 2007 Nobel Prize for Physiology or Medicine.

The α-subunit of the glutaconate decarboxylase is homologous to propionyl-CoA carboxylase. The crystal structure of the carboxyltransferase at 1.7 Å resolution shows a dimer of TIM barrels with an active site metal ion, identified spectroscopically as Zn2+.

Crenezumab is a fully humanized monoclonal antibody against human 1-40 and 1-42 Beta amyloid, which is being investigated as a treatment of Alzheimer's disease. Crenezumab is highly homologous to solanezumab, another monoclonal antibody targeting amyloid-β peptides.

Preproghrelin (green and blue) and ghrelin (green). The GHRL gene produces mRNA which has four exons. Five products arise: the first is the 117-amino acid preproghrelin. It is homologous to promotilin; both are members of the motilin family.

Together with IRS2, IRS3 (pseudogene) and IRS4, it is homologous to the Drosophila protein chico, whose disruption extends the median lifespan of flies up to 48%. Similarly, Irs1 mutant mice experience moderate life extension and delayed age-related pathologies.

Both genera share an identical flower structure and a number of vegetative features. Within both Bartholina and Holothrix auricles (filament appendages) are absent. This differentiates them from all other Orchideae and Diseae. Instead their staminodes and gynostemium are homologous.

Conventional nomenclature labels the isoforms cryptdins-1 through -6 in order of discovery. The primary structures of cryptdin isoforms are highly homologous. Most differences between the isoforms lie in the identity of residues at the N- and C-termini.

Dystrobrevins are the product of two distinct genes coding for two highly homologous proteins, α- and β-dystrobrevin. Several different transcripts are derived from each gene by alternative splicing or initiation sites, generating a large family of dystrobrevin isoforms.

Non homologous end joining and Microhomology mediated end joining The most widely accepted and straightforward model for chromothripsis is that within a single chromosome, distinct chromosomal regions become fragmented/shattered almost simultaneously and subsequently rejoined in an incorrect orientation. Deletion of certain fragments, including deletions that are a few hundred base pairs long, and hence gene segments is possible and consequently the production of double minute chromosomes. When multiple chromosomes are involved in chromothripsis, fragments of both chromosomes are joined together by paired end joining and the exchange of fragments between the original chromosomes. Rejoining of fragments require very minimal or even no sequence homology and consequently suggesting that nonhomologous or microhomologous repair mechanisms such as non-homologous end joining (NHEJ) and microhomology-mediated break induced repair (MMBIR) dominate double stranded break repair and are involved in modelling the chromothriptic landscape, opposed to homologous recombination which requires sequence homology.

S. solfataricus cells aggregate preferentially with other cells of their own species. Frols et al. and Ajon et al. suggested that UV-inducible DNA transfer is likely an important mechanism for providing increased repair of damaged DNA via homologous recombination.

DNA2-like helicase is an enzyme that in humans is encoded by the DNA2 gene. Dna2, a homolog of DNA2KL present in budding yeast, possesses both helicase and nuclease activity, with which it helps catalyze early steps in homologous recombination.

PALB2 binds the single strand DNA and directly interacts with the recombinase RAD51 to stimulate strand invasion, a vital step of homologous recombination, PALB2 can function synergistically with a BRCA2 chimera (termed piccolo, or piBRCA2) to further promote strand invasion.

RNF8 appears to have other roles in HRR as well. RNF8, acting as a ubiquitin ligase, mono-ubiquitinates γH2AX to tether DNA repair molecules at DNA lesions. In particular, RNF8 activity is required to recruit BRCA1 for homologous recombination repair.

CCL1 is encoded by CCL1 gene which is one of the several chemokine genes clustered on the chromosome 17q11.2-q12 in humans. It is expressed by specifically activated T cells upon secondary stimulation. The homologous mouse gene is termed Tca-3.

This is the study of structures of proteins from parasites. Determination of parasitic protein structures may help to better understand how these proteins function differently from homologous proteins in humans. In addition, protein structures may inform the process of drug discovery.

One says that relative homology is given by the relative cycles, chains whose boundaries are chains on A, modulo the relative boundaries (chains that are homologous to a chain on A, i.e., chains that would be boundaries, modulo A again).

The compound is stable indefinitely at low temperature, but decomposes before melting. In contrast, the homologous molecules with n = 4 or n = 5 have nearly straight backbones that stay at least 0.5 to 0.7 nm apart, and melt without decomposing.

They are not demonstrably homologous to members of other holin families and thus do not belong to one of the seven holin superfamilies. A representative list of proteins belonging to the LLHol family can be found in the Transporter Classification Database.

MMEJ repair is low in G0/G1 phase but is increased during S-phase and G2 phase of the cell cycle. In contrast, NHEJ operates throughout the cell cycle, and homologous recombination (HR) operates only in late S and G2.

It may protect them against the unspecific damaging influences as well as to increase stability of tissue specialized functions in the conditions of prolonged intensive functional activity. Simultaneously, the same mechanism performs intratissue control of cell mass of homologous tissue.

A comparison of homologous DNA indicates that L. salignum may be most closely related to L. lanigerum, followed by a clade consisting of L. flexuosum and L. discolor. It is called common sunshine conebush in English and knoppiesgeelbos in Afrikaans.

Valnoctamide (INN, USAN) has been used in France as a sedative-hypnotic since 1964. It is a structural isomer of valpromide, a valproic acid prodrug; unlike valpromide, however, valnoctamide is not transformed into its homologous acid, valnoctic acid, in vivo.

X-ray crystallography has shown that SLPI has two homologous domains of 53 and 54 amino acids, one of which exhibits anti-protease activity (C-terminal domain). The other domain (N-terminal domain) is not known to have any function.

B. licheniformis is naturally competent for genetic transformation. Natural genetic transformation is a sexual process involving DNA transfer from one bacterium to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination.

Poly(A)-binding protein interacting protein 2B, Paip2b, which represses mRNA translation, is mainly expressed in the oocytes and fertilized eggs in mice.UCSC genome browser Paip2b is a PAIP2 family protein, with 3 amino acids longer than its homologous Paip2a.

Scientists can purposefully "knockout" or cause the gene to be disrupted. To do this, they perform homologous recombination and eliminate the predicted start codon and the following 47 amino acids. Then the EcoRI restriction site is introduced into the chromosome.

These adaptations include an extremely efficient mechanism for repairing DNA double- strand breaks. This repair mechanism was studied in two Bdelloidea species, Adineta vaga, and Philodina roseola. and appears to involve mitotic recombination between homologous DNA regions within each species.

Monopolin is a protein complex that in yeast is composed of the four proteins CSM1, HRR25, LRS4, and MAM1. Monopolin is required for the segregation of homologous centromeres to opposite poles of a dividing cell during anaphase I of meiosis.

CCDC176 has no known paralogs and is orthologous in primates, mammals, birds, reptiles, amphibians, fish, all the way back to invertebrates, a fungi parasite and a proteobacteria. The domain found to be homologous is the DUF4515, a domain of unknown function.

Erb1 also known as the eukaryotic ribosome biogenesis protein 1 is a yeast protein required for maturation of the 25S and 5.8S ribosomal RNAs. It is a component of 66S pre-ribosomal particles and is homologous to the human protein BOP1.

Therefore, H4K20me3 serves an additional role in chromatin repression. Repair of DNA double-stranded breaks in chromatin also occurs by homologous recombination and also involves histone methylation (H3K9me3) to facilitate access of the repair enzymes to the sites of damage.

New genes are expected in the gaps. The area of 1q21.1 is one of the most difficult parts of the human genome to map. CNVs occur due to non- allelic homologous recombination mediated by low copy repeats (sequentially similar regions).

Hotspots diversify by rapid gene turnover; their chromosomal distribution depends on local contexts (neighboring core genes), and content in mobile genetic elements. Hotspots concentrate most changes in gene repertoires, reduce the trade-off between genome diversification and organization, and should be treasure troves of strain-specific adaptive genes. Most mobile genetic elements and antibiotic resistance genes are in hotspots, but many hotspots lack recognizable mobile genetic elements and exhibit frequent homologous recombination at flanking core genes. Overrepresentation of hotspots with fewer mobile genetic elements in naturally transformable bacteria suggests that homologous recombination and horizontal gene transfer are tightly linked in genome evolution.

The choice between NHEJ and homologous recombination for repair of a double-strand break is regulated at the initial step in recombination, 5' end resection. In this step, the 5' strand of the break is degraded by nucleases to create long 3' single-stranded tails. DSBs that have not been resected can be rejoined by NHEJ, but resection of even a few nucleotides strongly inhibits NHEJ and effectively commits the break to repair by recombination. NHEJ is active throughout the cell cycle, but is most important during G1 when no homologous template for recombination is available.

A subset of recombination events results in crossovers, which create physical links known as chiasmata (singular: chiasma, for the Greek letter Chi (X)) between the homologous chromosomes. In most organisms, these links can help direct each pair of homologous chromosomes to segregate away from each other during Meiosis I, resulting in two haploid cells that have half the number of chromosomes as the parent cell. During meiosis II, the cohesion between sister chromatids is released and they segregate from one another, as during mitosis. In some cases, all four of the meiotic products form gametes such as sperm, spores or pollen.

Homologous recombination has been most studied and is best understood for Escherichia coli. Double-strand DNA breaks in bacteria are repaired by the RecBCD pathway of homologous recombination. Breaks that occur on only one of the two DNA strands, known as single-strand gaps, are thought to be repaired by the RecF pathway. Both the RecBCD and RecF pathways include a series of reactions known as branch migration, in which single DNA strands are exchanged between two intercrossed molecules of duplex DNA, and resolution, in which those two intercrossed molecules of DNA are cut apart and restored to their normal double-stranded state.

A-type lamins promote genetic stability by maintaining the levels of proteins that have key roles in DNA double-strand break repair during the processes of non-homologous end joining and homologous recombination. Mutations in lamin A (LMNA) cause Hutchinson–Gilford progeria syndrome, a dramatic form of premature aging. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and are more sensitive to DNA damaging agents. The inability to adequately repair DNA damages when A-type lamins are defective is likely responsible for some of the aspects of premature aging.

Homing endonucleases insert themselves into the genome at the site homologous to the first insertion site, resulting in a conversion of a heterozygote into a homozygote bearing a copy of the homing endonuclease on both homologous chromosomes. This gives homing endonucleases an allele frequency dynamics rather similar to a segregation distortion system, and generally unless opposed by strong countervailing selection, they are expected to go to fixation in a population. CRISPR-Cas9 technology allows the artificial construction of homing endonuclease systems. These so-called "gene drive" systems pose a combination of great promise for biocontrol but also potential risk.

Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evolution, which occurs when two independent species evolve in the same direction and thus independently acquire similar characteristics; for instance, gliding frogs have evolved in parallel from multiple types of tree frog.

In the field of molecular phylogenetics, the distances and relationships between species are investigated by looking at the DNA, RNA or amino acid sequences of an organism. When phylogenetic trees are constructed without considering possible saturation, the possibility of multiple substitutions can cause the distance between taxa to appear much smaller than the true distance. Multiple sequence alignment, a common technique to construct phylogenies, relies on the comparison of homologous sequences. It can easily be confounded by genetic saturation because the homologous loci under investigation show no indication whether or not more than one substitution on each nucleotide separates the taxa being described.

Homologous sequences are orthologous if they are descended from the same ancestral sequence separated by a speciation event: when a species diverges into two separate species, the copies of a single gene in the two resulting species are said to be orthologous. The term "ortholog" was coined in 1970 by the molecular evolutionist Walter Fitch. Homologous sequences are paralogous if they were created by a duplication event within the genome. For gene duplication events, if a gene in an organism is duplicated to occupy two different positions in the same genome, then the two copies are paralogous.

Thus H. influenzae may protect its genome against the reactive oxygen species produced by the host's phagocytic cells through recombinational repair of oxidative DNA damages.} As PDF Recombinational repair of a damaged site of a chromosome requires, in addition to rec1, a second homologous undamaged DNA molecule. Individual H. influenzae cells are capable of taking up homologous DNA from other cells by the process of transformation. Transformation in H. influenzae involves at least 15 gene products, and is likely an adaptation for repairing DNA damages in the resident chromosome (as suggested in Transformation (genetics)#Transformation, as an adaptation for DNA repair).

Snf3 is homologous to multiple sugar transporters, it shares high similarity to the glucose transporters of rat brain cells and human HepG2 hepatoma cells, as well as to the arabinose and xylose transporters (AraE and XylE) of Escherichia coli.Celenza JL, Marshall-Carlson L, Carlson M (1988). The yeast SNF3 gene encodes a glucose transporter homologous to the mammalian protein. PNAS 85, 2130-2134 Based on this homology and on genetic studies, Snf3 was initially thought to be a high affinity glucose transporter. Later, it was found that Snf3 is not a glucose transporter, but rather a high affinity glucose sensor.

Alignment of UBact (EES53751) and Pup (EES52728) from the bacterium Leptospirillum ferrodiazotrophum to assess their similarity. Figure 3. Demonstration of UBact C-terminus conservation across tremendous evolutionary distance. In spite of the large difference in sequence, UBact is homologous to Pup and shares several characteristics with it: (i) same genomic location within a cluster of genes homologous to Mpa -> Dop -> Pup/UBact -> PrcB -> PrcA -> PafA, (ii) C-terminal sequence that ends exclusively with glutamine or glutamate across bacterial species, (iii) short size (similar to that of ubiquitin) and, (iv) high sequence conservation across tremendous evolutionary distance (a characteristic also in common with ubiquitin).

In this process, an ATP dependent DNA strand exchange takes place in which a single strand invades base-paired strands of homologous DNA molecules. RAD51 is involved in the search for homology and strand pairing stages of the process. Although the structures of the BRCA1 and BRCA2 genes are very different, at least some functions are interrelated. The proteins made by both genes are essential for repairing damaged DNA (see Figure of recombinational repair steps). BRCA2 binds the single strand DNA and directly interacts with the recombinase RAD51 to stimulate and maintain strand invasion, a vital step of homologous recombination.

Additionally, ß-arrestins are better at inactivating ßARK-phosphorylated receptors rather than protein kinase A-phosphorylated receptors, which suggests that the arrestins preferentially mediate homologous desensitization. The mechanism of homologous desensitization for the β2 receptor is as follows: # Agonist binds and activates the receptor, which changes to an active conformational state. # Beta adrenergic receptor kinase (βARK), a cytoplasmic kinase is activated and phosphorylates the C-terminus of the β2 receptor. # This phosphorylation increases the affinity of β-arrestin for the receptor, resulting in uncoupling of the α subunit of the heterotrimeric G-protein from the receptor, producing desensitization.

Apart from its original function in bacterial immunity, the Cas9 protein has been heavily utilized as a genome engineering tool to induce site-directed double-strand breaks in DNA. These breaks can lead to gene inactivation or the introduction of heterologous genes through non-homologous end joining and homologous recombination respectively in many laboratory model organisms. Alongside zinc finger nucleases and Transcription activator-like effector nuclease (Talen) proteins, Cas9 is becoming a prominent tool in the field of genome editing. Cas9 has gained traction in recent years because it can cleave nearly any sequence complementary to the guide RNA.

Microhomology-mediated end joining (MMEJ), also known as alternative nonhomologous end-joining (Alt-NHEJ) is one of the pathways for repairing double-strand breaks in DNA. As reviewed by McVey and Lee, the foremost distinguishing property of MMEJ is the use of microhomologous sequences during the alignment of broken ends before joining, thereby resulting in deletions flanking the original break. MMEJ is frequently associated with chromosome abnormalities such as deletions, translocations, inversions and other complex rearrangements. There are multiple pathways for repairing double strand breaks, mainly non-homologous end joining (NHEJ), homologous recombination (HR), and MMEJ.

Ectopic recombination is an atypical form of recombination in which crossing over occurs at non-homologous, rather than along homologous, loci. Such recombination often results in dramatic chromosomal rearrangement, which is generally harmful to the organism.Montgomery, E., B. Charlesworth, and C. H. Langley. 1987. A test for the role of natural selection in the stabilization of transposable element copy number in a population of Drosophila melanogaster. Genet. Res. 49:31–41 Some research, however, has suggested that ectopic recombination can result in mutated chromosomes that benefit the organism.Bush, G.L., S.M. Case, A.C. Wilson and J.L. Patton. 1977.

Hemagglutinin is the major antigen of the virus against which neutralizing antibodies are produced, and influenza virus epidemics are associated with changes in its antigenic structure. This was originally derived from pigs, and should technically be referred to as "pig flu". The evolution of avian influenza virus has been influenced by genetic variation in the virus population due to genome segment reassortment and mutation. Also homologous recombination occurs in viral genes, suggesting that genetic variation generated by homologous recombination has also played a role in driving the evolution of the virus and potentially has affected virulence and host range.

According to tissue adaptive syndrome (TAS) concept, this adaptive mechanism (see adaptation) comes into effect in damaged tissue (see Tissue (biology)) as a result of concurrence of two events. The first one is accumulation of TAS effectors in tissue (comutons, chalones, and contactins), which possess a unique feature of tissue specificity in their action on homologous tissue cells without species specificity. The second one is increase in sensitivity of damaged cells to these regulators, as it was demonstrated on the example of comuton. These effectors cause tissuespecific self-damage of homologous cells via disturbance of their ion homeostasis and energy-production processes.

The lectin pathway is homologous to the classical pathway, but with the opsonin, mannose-binding lectin (MBL), and ficolins, instead of C1q. This pathway is activated by binding of MBL to mannose residues on the pathogen surface, which activates the MBL-associated serine proteases, MASP-1, and MASP-2 (very similar to C1r and C1s, respectively), which can then split C4 into C4a and C4b and C2 into C2a and C2b. C4b and C2b then bind together to form the classical C3-convertase, as in the classical pathway. Ficolins are homologous to MBL and function via MASP in a similar way.

Cyanobacteria are capable of natural genetic transformation. Natural genetic transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous DNA from its surroundings. For bacterial transformation to take place, the recipient bacteria must be in a state of competence, which may occur in nature as a response to conditions such as starvation, high cell density or exposure to DNA damaging agents. In chromosomal transformation, homologous transforming DNA can be integrated into the recipient genome by homologous recombination, and this process appears to be an adaptation for repairing DNA damage.

Not all β-glucoside PTS porters are in this class, as the PTS porter first described as the cellobiose β-glucoside porter is the diacetylchitobiose porter in the Lac family. The IIA, IIB and IIC domains of all of the group translocators listed below are demonstrably homologous. These porters (the IIC domains) show limited sequence similarity with and are homologous to members of the Fru family and less with members of the Lac family. The IIC domains of the glucose and glucoside subfamilies are as distant from each other as they are from the Fru, Mtl and Lac families.

From various genome analyses, it was concluded that the double-strand breaks (DSB) can be repaired via homologous recombination by at least two different but related pathways. In case of major pathway, homologous sequences on both sides of the DSB will be employed which seems to be analogous to the conservative DSB repair model that was originally proposed for meiotic recombination in yeast. where as the minor pathway is restricted to only one side of the DSB as postulated by nonconservative one-sided invasion model. However, in both cases the sequence of the recombination partners will be absolutely conserved.

However, in the aberrant mechanism, during the formation of Holliday junctions, the double-stranded breaks are misaligned and the crossover lands in non-allelic positions on the same chromosome. When the Holliday junction is resolved, the unequal crossing over event allows transfer of genetic material between the two homologous chromosomes, and as a result, a portion of the DNA on both the homologues is repeated. Since the repeated regions are no longer segregating independently, the duplicated region of the chromosome is inherited. Another type of homologous recombination based mechanism that can lead to copy number variation is known as break induced replication.

Autotransfusion is intended for use in situations characterized by the loss of one or more units of blood and may be particularly advantageous for use in cases involving rare blood groups, risk of infectious disease transmission, restricted homologous blood supply or other medical situations for which the use of homologous blood is contraindicated. Autotransfusion is commonly used intraoperatively and postoperatively. Intraoperative autotransfusion refers to recovery of blood lost during surgery or the concentration of fluid in an extracorporeal circuit. Postoperative autotransfusion refers to the recovery of blood in the extracorporeal circuit at the end of surgery or from aspirated drainage.

This gene encodes a member of the RecA/Rad51-related protein family that participates in homologous recombination to maintain chromosome stability and repair DNA damage. This gene is involved in the repair of DNA double-strand breaks by homologous recombination and it functionally complements Chinese hamster irs1, a repair-deficient mutant that exhibits hypersensitivity to a number of different DNA-damaging agents. The XRCC2 protein is one of five human paralogs of RAD51, including RAD51B (RAD51L1), RAD51C (RAD51L2), RAD51D (RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other.

A further plate composed of four pairs of bones forms the roof of the mouth; these include the vomer and palatine bones. The base of the cranium is formed from a ring of bones surrounding the foramen magnum and a median bone lying further forward; these are homologous with the occipital bone and parts of the sphenoid in mammals. Finally, the lower jaw is composed of multiple bones, only the most anterior of which (the dentary) is homologous with the mammalian mandible. In living tetrapods, a great many of the original bones have either disappeared or fused into one another in various arrangements.

Of 21 genes in the homologous recombinational repair pathway and 7 genes in the non-homologous end joining pathway examined, the only SNPs found in microRNA binding regions which were both at high enough frequency to evaluate and which affected risks of colon cancer, were the two in RAD52 and one in MRE11A. DNA damage appears to be the primary underlying cause of cancer, and deficiencies in DNA repair appear to underlie many forms of cancer. If DNA repair is deficient, DNA damage tends to accumulate. Such excess DNA damage may increase mutational errors during DNA replication due to error-prone translesion synthesis.

Meiotic recombination protein DMC1/LIM15 homolog is a protein that in humans is encoded by the DMC1 gene. Meiotic recombination protein Dmc1 is a homolog of the bacterial strand exchange protein RecA. Dmc1 plays the central role in homologous recombination in meiosis by assembling at the sites of programmed DNA double strand breaks and carrying out a search for allelic DNA sequences located on homologous chromatids. The name "Dmc" stands for "disrupted meiotic cDNA" and refers to the method used for its discovery which involved using clones from a meiosis-specific cDNA library to direct knock-out mutations of abundantly expressed meiotic genes.

When a double-stranded DNA molecule has suffered a break in both strands, one repair mechanism available in diploid eukaryotic cells is homologous recombination repair. This makes use of the intact chromosome homologous to the broken one as a template to bring the two double- stranded pieces into correct alignment for rejoining. Early in this process, one strand of one piece is matched to a strand of the intact chromosome and that strand is used to form a D-loop at that point, displacing the intact chromosome's other strand. Various ligation and synthesis steps follow to effect the rejoining.

Partially overlapping fragments are then used for synthesis of homologous regions through a moving D-loop that can continue extension until they find complementary partner strands. In the final step there is crossover by means of RecA-dependent homologous recombination. Topoisomerases introduce both single- and double- strand breaks in the course of changing the DNA's state of supercoiling, which is especially common in regions near an open replication fork. Such breaks are not considered DNA damage because they are a natural intermediate in the topoisomerase biochemical mechanism and are immediately repaired by the enzymes that created them.

CRISPR allows the construction of artificial homing endonucleases, where the construct produces guide RNAs that cut the target gene, and homologous flanking sequences then allow insertion of the same construct harboring the Cas9 gene and the guide RNAs. Such gene drives ought to have the ability to rapidly spread in a population (see Gene drive systems), and one practical application of such a system that has been proposed is to apply it to a pest population, greatly reducing its numbers or even driving it extinct. This has not yet been attempted in the field, but gene drive constructs have been tested in the lab, and the ability to insert into the wild-type homologous allele in heterozygotes for the gene drive has been demonstrated. Unfortunately, the double-strand break that is introduced by Cas9 can be corrected by homology directed repair, which would make a perfect copy of the drive, or by non-homologous end joining, which would produce "resistant" alleles unable to further propagate themselves.

As FA is now known to affect DNA repair, specifically homologous recombination, and given the current knowledge about dynamic cell division in the bone marrow, patients are consequently more likely to develop bone marrow failure, myelodysplastic syndromes, and acute myeloid leukemia (AML).

In humans, a chromosome breakage syndrome characterized by severe lung disease in early childhood is associated with a mutation in a component of the SMC-5/6 complex. Patient’s cells display chromosome rearrangements, micronuclei, sensitivity to DNA damage and defective homologous recombination.

IP receptors bind with ionophores that induce ADP and serotonin secretion. PGE1 inhibits the secretion of factors that stimulate platelet aggregation by competitive inhibition. Kistrin is a protein inhibitor of platelet aggregation. It belongs to the homologous family of glycoprotein IIb- IIa antagonists.

This will result in the desired change being inserted at the site of the DSB. While HDR based gene editing is similar to the homologous recombination based gene targeting, the rate of recombination is increased by at least three orders of magnitude.

Accessory olfactory cortical areas are portions of the human amygdala that are homologous to those areas in other species that receive afferents from the accessory olfactory bulb. They include the caudal part of the medial amygdalar nucleus, and the cortical amygdalar nucleus.

To Change their cultural crisis there are few apparent choices. The Okinawan people can commit a genocide of culture and forget their distinct differences and history to be accepted nationally, or accept their differences and become an outcast to the Japanese homologous society.

This means that they share a general fold, but the amino-terminal sequence of one is homologous to the C-terminus of the other, and vice versa. Thus the Catalytic tyrosines of TraI and TrwC are amino-terminal rather than carboxy-terminal.

They also share similar capsid and nucleocapsid proteins/domains. Caulimoviruses also share some features with belpaoviruses, metaviruses, pseudoviruses, and retroviruses such a homologous aspartate protease. On the other hand, Hepadnaviridae family appears to be more distantly related to the above- mentioned families.

Delitto Perfetto is a two step method for in vivo mutagenesis. In the initial step, the CORE cassette is inserted in the region of interest by homologous recombination. Subsequently, the CORE cassette is replaced with DNA containing the mutation of interest. Figure 1.

Dernburg found that in Caenorhabditis elegans, double-strand breaks are required for recombination and for chromosome segregation during meiosis, but not for homologous pairing and synapsis. The finding suggested that there may be more diversity in meiotic mechanisms than was previously expected.

Bernstein C. Deoxyribonucleic acid repair in bacteriophage. Microbiol Rev. 1981;45(1):72-98 Prophage reactivation can occur by recombination between a UV-damaged infecting phage λ chromosome and a homologous phage genome integrated into the bacterial DNA and existing in a prophage state.

This leads to gene synthesis since one copy of the allele is copied across from the homologous chromosome and then synthesized into the breach on the damaged chromosome. The net effect of this would be one heterozygous chromosome and one homozygous chromosome.

Recombination rates exceeded those of uninduced cultures by up to three orders of magnitude. Frols et al. and Ajon et al. hypothesized that the UV-inducible DNA transfer process and subsequent homologous recombinational repair represents an important mechanism to maintain chromosome integrity.

The scientists used injection of Cas9 protein complexed with the relevant sgRNAs and homology donors into human embryos. The scientists found homologous recombination-mediated alteration in HBB and G6PD. The scientists also noted the limitations of their study and called for further research.

When the grafts were rejected, Woodruff determined that rejection must be controlled by additional factors. In 1951 Woodruff was awarded a Hunterian Professorship of the Royal College of Surgeons of England for his lecture The transplantation of homologous tissue and its surgical application.

S. sanguinis is naturally competent for genetic transformation. Natural genetic transformation is a sexual process involving DNA transfer from one bacterial cell to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination.

In mouse, deletion of this homologous gene causes congenital heart disorder known as noncompaction of left ventricular myocardium. There is evidence of multiple alternatively spliced transcript variants for this gene, but the full length nature of some variants has not been determined.

The act of hibernating or going to sleep for the winter months. Hirsute. Covered with hairs, as some snails. Hispid. Same as hirsute. Homologous. Having the same position or value, as the wing of a bird and of a bat. Hyaline. Glassy. Imperforate.

Meitinger, F. and S. Palani. (2016). Actomyosin ring driven cytokinesis in budding yeast. Seminars in Cell & Developmental Biology 53:19-27. In most bacteria and many archaea a homologous structure called the z-ring forms out of FtsZ, a homolog of tubulin.

I. Cortical projection of the mediodorsal nucleus. II. Efferent connections. Brain Research, 12, 321-343 provided an anatomical basis for this possibility, leading to Kolb's demonstration that rodents have frontal areas that appear homologous to prefrontal areas in the primate.Kolb, B. (1984).

Recombination rates exceeded those of uninduced cultures by up to three orders of magnitude. Frols et al. and Ajon et al. hypothesized that the UV-inducible DNA transfer process and subsequent homologous recombinational repair represents an important mechanism to maintain chromosome integrity.

400x400px Three homologous genes, Cnn1, Cnn2 and Cnn3, have evolved in vertebrates, encoding three isoforms of calponin: calponin 1, calponin 2, calponin 3, respectively. Protein sequence alignment shows that calponin 1 is highly conserved in mammals but more diverged among lower vertebrates.

The Enzyme Commission refers to this family as SARS coronavirus main proteinase (Mpro; ). The 3CL protease corresponds to coronavirus nonstructural protein 5 (nsp5). The "3C" in the common name refers to the 3C protease (3Cpro) which is a homologous protease found in picornaviruses.

While NAAA operates much like fatty acid amide hydrolase (HUGO gene symbol: FAAH), the two enzymes are not homolgous. On the other hand, NAAA is homologous to acid ceramidase (HUGO gene symbol: ASAH1), sharing 30% sequence identity at the amino acid level in humans ENSEMBL.

Isolation of homologous genes by Edward de Robertis and William McGinnis revealed that numerous genes from a variety of species contained the homeobox. Subsequent phylogenetic studies detailing the evolutionary relationship between homeobox-containing genes showed that these genes are present in all bilaterian animals.

The homologous domain in FAM98A is the DUF2465 (Domain of Unknown Function 2465) domain. The function of this domain, like the gene itself, is largely unknown, though it has been reported that it preferentially binds to RNA, targeting mRNA in FAM98A and tRNA in FAM98B.

Additionally, sequences homologous to all tRNAs necessary for translation were present in 16s and 23s rRNAs, and synthetases to load these tRNAs were also found, indicating that many of the functions of transcription and translation present in more modern life exist in rRNA, if vestigially.

Brodmann Area 15 is one of Brodmann's subdivisions of the cerebral cortex in the brain. Area 15 was defined by Brodmann in the guenon monkey, but he found no equivalent structure in humans. However, functional imaging experiments have found structures that may be homologous.

Can f 1 or canis familiaris allergen 1 is a lipocalinMajor allergen Can f 1 UniProtKB. allergen produced by dogsGrammer, Leslie C. and Paul A. Greenberger (2009), Patterson's Allergic Diseases p. 97. in their tongue epithelial tissue. It is homologous with the human lipocalin LCN1.

These breaks can be caused by natural radiation or other exposures, but also occur when chromosomes exchange genetic material (homologous recombination, e.g., "crossing over" during meiosis). The BRCA2 protein, which has a function similar to that of BRCA1, also interacts with the RAD51 protein.

In most mammals (excluding primates and species that have a cloaca), the urogenital sinus refers to the sinus in which the openings to the female's urethra and vagina are found. The urogenital sinus of non-primates is homologous to the vulval vestibule of primates.

Indiana University Press. These bundles are organized in rough "staircases" of hairs of increasing length order. This use of mechanosensitive hairs is homologous to the functioning of hair cells in the auditory and vestibular systems, indicating a close link between these systems.FLOCK, A. (1967).

Figure 2 RecBCD pathway of homologous recombination where ATP is in excess. Both the RecD and RecB subunits are helicases, i.e., energy-dependent molecular motors that unwind DNA (or RNA in the case of other proteins). The RecB subunit in addition has a nuclease function.

Crotamine has a number of biological actions: it acts on cell membrane's sodium channels, is slightly analgesic and is myotoxic, i.e., it penetrates the cells of muscles and promotes necrosis. Crotamine is homologous with other venom myotoxins and is similar to α-,β-defensins.

Human glucokinase is coded for by the GCK gene on chromosome 7. This single autosomal gene has 10 exons. Genes for glucokinase in other animals are homologous to human GCK. A distinctive feature of the gene is that it begins with two promoter regions.

Polyploidy is a characteristic of the bacterium Deinococcus radiodurans and of the archaeon Halobacterium salinarum. These two species are highly resistant to ionizing radiation and desiccation, conditions that induce DNA double-strand breaks. This resistance appears to be due to efficient homologous recombinational repair.

In humans, each cell nucleus contains 23 pairs of chromosomes, a total of 46 chromosomes. The first 22 pairs are called autosomes. Autosomes are homologous chromosomes i.e. chromosomes which contain the same genes (regions of DNA) in the same order along their chromosomal arms.

Most bacteria have a homologous structure, FtsZ. Prosthecobacter are the exception to this, containing genes that have higher sequence-homology to eukaryotic tubulin than FtsZ. These genes are called bacterial tubulin a (BtubA) and bacterial tubulin b (BtubB). The properties are not exactly same.

The last step of DNA repair involves DNA ligase which brings the final DNA strands together in a phosphodiester bond. There are many mechanisms for the repair of damaged double stranded DNA. PARP1 may function as a synapsis factor in alternative non-homologous end joining.

Beta is a protein that binds to single stranded DNA and assists homologous recombination by promoting annealing between the homology regions of the inserted DNA and the chromosomal DNA. Gam functions to protect the DNA insert from being destroyed by native nucleases within the cell.

Clearly, such vivipary repeatedly has developed independently in the evolutionary history of the Scincidae and the different examples are not ancestral to the others. In particular, placental development of whatever degree in lizards is phylogenetically analogous, rather than homologous, to functionally similar processes in mammals.

EZH2 targets RAD51C, reducing RAD51C mRNA and protein expression (and also represses other RAD51 paralogs RAD51B, RAD51D, XRCC2 and XRCC3). Increased expression of EZH2, leading to repression of RAD51 paralogs and consequent reduced homologous recombinational repair, was proposed as a cause of breast cancer.

It returns only red blood cells suspended in saline and is rarely associated with any clinical complications. Discontinuous autotransfusion can practically eliminate the need for exposure to homologous blood in elective surgical patients and can greatly reduce the risk of exposure to emergency surgical patients.

RECQL4 also appears to be necessary for other forms of DNA repair including non-homologous end joining, nucleotide excision repair and base excision repair. The association of deficient RECQL4 mediated DNA repair with accelerated aging is consistent with the DNA damage theory of aging.

Exosome complex exonuclease RRP44 or Dis3 is an enzyme that in humans is encoded by the DIS3 gene. Its protein product is an RNase enzyme homologous to the yeast protein Rrp44, and can be part of the exosome complex in the nucleus of eukaryotic cells.

Yunnanxane is a bioactive taxane diterpenoid first isolated from Taxus wallichiana. Yunnanxane was later isolated from cell cultures of Taxus cuspidata and Taxus chinensis. Four homologous esters of yunnanxane have also been isolated from Taxus. Yunnanxane is reported to have anticancer activity in vitro.

The most homologous gene is found in the Ectoropis oblique nucleopolyhedrovirus (NPV). Hz2V070 has the most similarity to the xeroderma pigmentosum G (XPG) enzyme, which is related to other enzymes playing roles in nucleotide-excision repair and transcription- coupled repair of oxidative DNA damage.

Vaccines containing trophozoites inactivated with formalin and prepared in oil adjuvants have been developed and have shown good protection against the homologous serotype. Several P. dicentrarchi serotypes have been described. However, the protection induced against heterologous isolates appears to be very low or non-existent.

As a homologous structure in lemuriforms, the toothcomb serves variable biological roles, despite its superficially stereotypic shape and appearance. It is primarily used as a toiletry device or grooming comb. Additionally, some species use their toothcomb for food procurement or to gouge tree bark.

The RecA nucleoprotein filament then searches for a homologous DNA and exchanges places with the identical or nearly identical strand in the homologous DNA. Although the proteins and specific mechanisms involved in their initial phases differ, the two pathways are similar in that they both require single-stranded DNA with a 3' end and the RecA protein for strand invasion. The pathways are also similar in their phases of branch migration, in which the Holliday junction slides in one direction, and resolution, in which the Holliday junctions are cleaved apart by enzymes. The alternative, non-reciprocal type of resolution may also occur by either pathway.

Crosslinked DNA is repaired in cells by a combination of enzymes and other factors from the nucleotide excision repair (NER) pathway, homologous recombination, and the base excision repair (BER) pathway. To repair interstrand crosslinks in eukaryotes, a 3’ flap endonuclease from the NER, XPF-ERCC1, is recruited to the crosslinked DNA, where it assists in ‘unhooking’ the DNA by cleaving the 3’ strand at the crosslink site. The 5’ strand is then cleaved, either by XPF-ERCC1 or another endonuclease, forming a double-strand break (DSB), which can then be repaired by the homologous recombination pathway. DNA crosslinks generally cause loss of overlapping sequence information from the two strands of DNA.

The term "homology" was first used in biology by the anatomist Richard Owen in 1843 when studying the similarities of vertebrate fins and limbs, defining it as the "same organ in different animals under every variety of form and function", and contrasting it with the matching term "analogy" which he used to describe different structures with the same function. Owen codified 3 main criteria for determining if features were homologous: position, development, and composition. In 1859, Charles Darwin explained homologous structures as meaning that the organisms concerned shared a body plan from a common ancestor, and that taxa were branches of a single tree of life.

Females can produce full clones of themselves through a modification of the normal meiosis process used to produce haploid egg cells for sexual reproduction. The female's germ cells undergo a process of premeiotic genome doubling, or endoreduplication, so that two consecutive division cycles in the process of meiosis result in a diploid, rather than haploid, genome. Whereas homologous chromosomes pair and separate during meiosis I in sexual species, identical duplicate sister chromosomes, produced through premeiotic replication, pair and separate during meiosis I in true parthenotes. Pairing of identical sister chromosomes, in comparison to the alternative of pairing homologous chromosomes, maintains heterozygosity in obligate parthenotes.

Double-strand break (DSB) repair by homologous recombination is initiated by 5' to 3' strand resection (DSB resection). In humans, the DNA2 nuclease cuts back the 5'-to-3' strand at the DSB to generate a 3' single-strand DNA overhang strand. A number of paralogs (see Figure) of RAD51 are essential for RAD51 protein recruitment or stabilization at damage sites in vertebrates. Protein domains in homologous recombination-related proteins are conserved across the three main groups of life: archaea, bacteria and eukaryotes. In vertebrates and plants, five paralogs of RAD51 are expressed in somatic cells, including RAD51B (RAD51L1), RAD51C (RAD51L2), RAD51D (RAD51L3), XRCC2 and XRCC3.

ZFNs can be used to disable dominant mutations in heterozygous individuals by producing double-strand breaks (DSBs) in the DNA (see Genetic recombination) in the mutant allele, which will, in the absence of a homologous template, be repaired by non-homologous end-joining (NHEJ). NHEJ repairs DSBs by joining the two ends together and usually produces no mutations, provided that the cut is clean and uncomplicated. In some instances, however, the repair is imperfect, resulting in deletion or insertion of base-pairs, producing frame-shift and preventing the production of the harmful protein. Multiple pairs of ZFNs can also be used to completely remove entire large segments of genomic sequence.

Unlike the above assumption of a fundamental split between prokaryotes and eukaryotes, the most important difference between biota may be the division between bacteria and the rest (archaea and eukaryota). For instance, DNA replication differs fundamentally between bacteria and archaea (including that in eukaryotic nuclei), and it may not be homologous between these two groups. Moreover, ATP synthase, though common (homologous) in all organisms, differs greatly between bacteria (including eukaryotic organelles such as mitochondria and chloroplasts) and the archaea/eukaryote nucleus group. The last common antecessor of all life (called LUCA, last universal common ancestor) should have possessed an early version of this protein complex.

UV-irradiation increases the frequency of recombination due to genetic exchange in S. acidocaldarius. The ups operon of Sulfolobus species is highly induced by UV irradiation. The pili encoded by this operon are employed in promoting cellular aggregation, which is necessary for subsequent DNA exchange between cells, resulting in homologous recombination. A study of the Sulfolobales acidocaldarius ups operon showed that one of the genes of the operon, saci-1497, encodes an endonuclease III that nicks UV-damaged DNA; and another gene of the operon, saci-1500, encodes a RecQ-like helicase that is able to unwind homologous recombination intermediates such as Holliday junctions.

Structure-Based Assignment (SBA) is a technique to accelerate the resonance assignment which is a key bottleneck of NMR (Nuclear magnetic resonance) structural biology. A homologous (similar) protein is used as a template to the target protein in SBA. This template protein provides prior structural information about the target protein and leads to faster resonance assignment . By analogy, in X-ray Crystallography, the molecular replacement technique allows solution of the crystallographic phase problem when a homologous structural model is known, thereby facilitating rapid structure determination.. Some of the SBA algorithms are CAP which is an RNA assignment algorithm which performs an exhaustive search over all permutations,.

In animals and humans, however, the capability of DSB repair in germline cells depends on the oogenetic and spermatogenetic stage, nonetheless, due to the low repair activity, mature sperms are incapable of DSB repair. Additionally, DSB can also be repaired by homologous recombination (HR), which is more accurate and introduces fewer errors in the process of repair, while, has not yet seen in the process of mtDNA insertion;. Apart from canonical NHEJ, DSBs are repaired via a mechanism that involves sequences containing a few homologous nucleotides at the ends of a DSB to be ligated. This mechanism is known as microhomology-mediated end joining abbreviated as MMEJ.

A protein complex known as shelterin serves to protect the ends of telomeres from being recognised as double-strand breaks by inhibiting homologous recombination (HR) and non-homologous end joining (NHEJ). Telomeres are found at the termini of chromosomes. The end of a telomere inserts back into the main body of the telomere to form a T-loop In most prokaryotes, chromosomes are circular and thus do not have ends to suffer premature replication termination. A small fraction of bacterial chromosomes (such as those in Streptomyces, Agrobacterium, and Borrelia) are linear and possess telomeres, which are very different from those of the eukaryotic chromosomes in structure and functions.

It commonly occurs with G protein- coupled receptors where it is mediated by the G protein-coupled receptor kinases (GRK) and arestins that are mobilized during the receptor's activation. Homologous desensitization also occurs with cytokine and other types of receptors, such as those of the epidermal growth factor receptor type, but in these cases desensitization is mediated by other types of receptor kinases. Homologous desensitization serves to limit or restrain a cell's responses to stimuli. However, some stimuli cause cells to activate protein kinase Cs that act to desensitize multiple types of receptors thereby rendering a cell unresponsive to agonists of multiply receptor types.

In this model, portions of genes or non-coding regions can accidentally serve as templates during repair of double stranded breaks (DSBs) occurring in Helitrons during their transposition. Low-fidelity repair of DSB by Non-Homologous End Joining is more frequent in plants and mammals than repair through homologous recombination, and is often accompanied by insertions of 100–4000 bp long “filler DNA” copied from diverse genomic or extra-chromosomal DNA regions into DSB. This model predicts that 2 to 8 bp regions of microhomology exist between the regions that flank the DSB in the Helitron and that flank the original host sequence captured by the Helitron.

The mutation frequencies for cells throughout the different stages of spermatogenesis in mice is similar to that in female germline cells, that is 5 to 10-fold lower than the mutation frequency in somatic cells Thus low mutation frequency is a feature of germline cells in both sexes. Homologous recombinational repair of double-strand breaks occurs in mouse during sequential stages of spermatogenesis, but is most prominent in spermatocytes. The lower frequencies of mutation in germ cells compared to somatic cells appears to be due to more efficient removal of DNA damages by repair processes including homologous recombination repair during meiosis. Mutation frequency during spermatogenesis increases with age.

Besides its role as a genome caretaker, NHEJ is required for joining hairpin-capped double-strand breaks induced during V(D)J recombination, the process that generates diversity in B-cell and T-cell receptors in the vertebrate immune system. Homologous recombination requires the presence of an identical or nearly identical sequence to be used as a template for repair of the break. The enzymatic machinery responsible for this repair process is nearly identical to the machinery responsible for chromosomal crossover during meiosis. This pathway allows a damaged chromosome to be repaired using a sister chromatid (available in G2 after DNA replication) or a homologous chromosome as a template.

In fact, an MFS gene has never before been found in a viral genome; it is found exclusively in living species genomes. The protein it encodes for likely facilitates the enhanced metabolism necessary for the cell proliferation in the infected hosts' reproductive tissues Hz2V034 is relatively similar to the guanosine monophosphate kinase (GMPK) and most homologous with the hypothetical protein of monodon baculovirus. GMPK transfers the terminal phosphate group of ATP and GMP in order to make ADP and GDP, a critical step in the biosynthesis of GTP. Hz2V039 has homology with the baculovirus 19K protein gene (AcMNPV ORF 96) and is most homologous with GbNV ORF 87.

Concerted evolution is the phenomenon where paralogous genes within one species are more closely related to one another than to members of the same gene family in closely related species. It is possible that this might occur even if the gene duplication event preceded the speciation event . High sequence similarity between paralogs may be maintained by homologous recombination events that lead to gene conversion, effectively copying some sequence from one and overwriting the homologous region in the other. Another possible hypothesis that has yet to be disproved is that rapid waves of gene duplication are responsible for the apparently "concerted" homogeneity of tandem and unlinked repeats seen in concerted evolution.

In jawless fishes a series of gills opened behind the mouth, and these gills became supported by cartilaginous elements. The first set of these elements surrounded the mouth to form the jaw. There are ample evidences For example: (1) both sets of bones are made from neural crest cells (rather than mesodermal tissue like most other bones); (2) both structures form the upper and lower bars that bend forward and are hinged in the middle; and (3) the musculature of the jaw seem homologous to the gill arches of jawless fishes. (Gilbert 2000) that vertebrate jaws are homologous to the gill arches of jawless fishes.

One of the key ideas in bioinformatics is the notion of homology. In the genomic branch of bioinformatics, homology is used to predict the function of a gene: if the sequence of gene A, whose function is known, is homologous to the sequence of gene B, whose function is unknown, one could infer that B may share A's function. In the structural branch of bioinformatics, homology is used to determine which parts of a protein are important in structure formation and interaction with other proteins. In a technique called homology modeling, this information is used to predict the structure of a protein once the structure of a homologous protein is known.

A number of muscles in the human body are thought to be vestigial, either by virtue of being greatly reduced in size compared to homologous muscles in other species, by having become principally tendonous, or by being highly variable in their frequency within or between populations.

Meiosis involves two rounds of chromosome segregation and thus undergoes prophase twice, resulting in prophase I and prophase II. Prophase I the most complex phase in all of meiosis because homologous chromosomes must pair and exchange genetic information. Prophase II is very similar to mitotic prophase.

Some evidence suggests that the 2-oxoadipate dehydrogenase complex (OADHc), which is structurally homologous to the E1 subunit of the oxoglutarate dehydrogenase complex (OGDHc) (E.C 1.2.4.2), is responsible for the decarboxylation reaction. Finally, glutaryl-CoA is oxidatively decarboxylated to crotony-CoA by glutaryl-CoA dehydrogenase (E.

A conception cap can assist to protect semen from the vaginal cavity and allow semen to pool against the cervical os.Pregnancy following use of the cervical cup for home artificial insemination utilizing homologous semen. MP Diamond et al. Fertility and Sterility, 1983 Apr:39(4): 480-4.

SNJ1 genome replicates by the rolling-circle mechanism and is initiated by the virus- encoded RepA protein, which is homologous to the replication-initiation proteins of archaeal plasmids and bacterial transposases of the IS91 family insertion sequences. The virus is released by lysis of the infected cells.

It is generally located nearby to the Shine-Dalgarno sequence of the downstream gene. Presumably, the RNAs function as cis-regulatory elements, however the poor sequence conservation makes it difficult to determine if there are more diverged homologous sequences that might occur in different genetic locations.

This gene encodes a gap junction protein. Gap junction proteins are members of a large family of homologous connexins and comprise 4 transmembrane, 2 extracellular, and 3 cytoplasmic domains. This gene plays a key role in central myelination and is involved in peripheral myelination in humans.

The alternative argument is that during meiosis I, looping and homologous recombination within a sister chromatid can cause this rearrangement. A rough estimation approximates that neocentromere formation on inverted duplicated chromosomes happens every 70,000–200,000 live births. However, this statistic does not include Class II rearrangements.

The Putative Acholeplasma Phage L2 Holin (L2 Holin) Family (TC# 1.E.59) consists of a putative holin (TC# 1.E.59.1.1; 81 amino acyl residues (aas) and 2 transmembrane segments (TMSs)) and a homologous uncharacterized protein (TC# 1.E.59.1.2; 75 aas and 2 TMSs).

Also, because eukaryotic constructs rely on illegitimate recombination—a process by which the transgene is integrated into the genome without similar genetic sequences—and not homologous recombination, they cannot be targeted to specific locations within the genome, unless the transgene is co-delivered with genome editing reagents.

1) and PanF of E. coli (2.A.21.1.1). Homologous regulatory domains are found in Agrobacterium, Mesorhizobium, Sinorhizobium, Vibrio cholerae and Bacillus species. While it is clear that these domains function as sensors, it is not known if they also transport the small molecules they sense.

The Sec7 domain is responsible for the GEF catalytic activity in ARF GTPases. ARF proteins function in vesicle trafficking. Though ARF GEFs are divergent in their overall sequences, they contain a conserved Sec 7 domain. This 200 amino acid region is homologous to the yeast Sec7p protein.

Paxinos has published 46 research books, 145 refereed journal articles, 30 book chapters, and 17 CDROMs. He has identified 90 nuclei (areas) in the rat and human brains. Comparing rats and humans, he has identified 61 homologous nuclei. He has identified 180 nuclei and homologies in birds.

L. infantum produces proteins BRCA1 and RAD51 that interact with each other to promote homologous recombinational repair. These proteins play a key role in meiosis. Thus, meiotic events provide the adaptive advantage of efficient recombinational repair of DNA damages even when they do not lead to outcrossing.

This suggests that the evolution of a non-coding piece of DNA that regulates the transcription of nearby genes can be the reason behind similar phenotypic coloration between distant species, making it hard to determine if the trait is homologous or simply the result of convergent evolution.

Unlike many bacterial deazaflavin photolyases that accepts FMN as well as 8-HDF, one such enzyme from the fruit fly only accepts 8-HDF. The FeS-BCP N-terminal domain is homologous to this domain. Instead of an organic cofactor, its chromophore is an iron-sulphur cluster.

Furthermore, many genes that are present in clusters are not homologous. How did evolutionary non- related genes come in close proximity in the first place? Either there is a force that brings functionally related genes near to each other, or the genes came near by change.

NMR structure family of Agouti Signalling Protein, C-terminal knotting domain. PDB entry Agouti signalling peptide adopts an inhibitor cystine knot motif. Along with the homologous Agouti-related peptide, these are the only known mammalian proteins to adopt this fold. The peptide consists of 131 amino acids.

In anatomy, two anatomical structures are considered to be analogous when they serve similar functions but are not evolutionarily related, such as the legs of vertebrates and the legs of insects. Analogous structures are the result of convergent evolution and should be contrasted with homologous structures.

The only vertebrates lacking a spleen are the lampreys and hagfishes. Even in these animals, there is a diffuse layer of haematopoietic tissue within the gut wall, which has a similar structure to red pulp, and is presumed to be homologous to the spleen of higher vertebrates.

Right: Finally, completion of Holliday Junction Resolution results in recombinant DNA. Diagram generated based on Wyatt et. al. Crossover junction endodeoxyribonucleases also play key roles in DNA repair. During cell growth and meiosis, DNA double-strand breaks (DSBs) often occur, and are usually repaired by homologous recombination.

DIS3-like exonuclease 1 (Dis3L1 or Dis3L) is an enzyme that in humans is encoded by the DIS3L gene. Its protein product is an RNase enzyme homologous to the yeast protein Rrp44, and can be part of the exosome complex in the cytoplasm of eukaryotic cells.

Mammalian mRNAs contain AU-rich elements (AREs) within their three prime untranslated regions. In yeast, 3-prime-to-5-prime mRNA degradation is mediated by the exosome, a multisubunit particle. EXOSC2 (which is homologous to the yeast Rrp4 protein) is a component of the human exosome.

The abducens nerve controls the movement of a single muscle, the lateral rectus muscle of the eye. In most other mammals it also innervates the musculus retractor bulbi, which can retract the eye for protection. Homologous abducens nerves are found in all vertebrates except lampreys and hagfishes.

Calponin 3 is known as acidic calponin. Among three isoforms of calponin, less is known for the gene regulation and function of calponin 3. Nonetheless, much has been learned from extensive studies on the homologous genes CNN1 and CNN2 that encode calponin 1 and calponin 2.

The DNA-binding domain at exons 3 and 4 of the NR4A1 gene is conserved among all members of the nuclear receptor. NR4A1 has homologous genes in a range of species including neuronal growth factor- induced clone B in rats, Nur77 in mice and TR3 in humans.

Cancer incidence was not increased in the mutant mice. Ku70 and Ku80 form the heterodimer Ku protein essential for the non-homologous end joining (NHEJ) pathway of DNA repair, active in repairing DNA double-strand breaks. This suggests an important role of NHEJ in longevity assurance.

Given this transformation, it is likely, under this theory, that the remnant of the great appendage/primary antenna is the labrum of extant arthropods. Because in this view Fuxianhuia possesses both a hypostome and a great appendage, the hypostome cannot be straightforwardly homologous with the labrum.

E. coli bacteria are a well-studied example of a cellular organism with diverse well- defined DNA repair processes. These include: (1) nucleotide excision repair, (2) DNA mismatch repair, (3) non-homologous end joining of double-strand breaks, (4) recombinational repair and (5) light-dependent repair (photoreactivation).

The α-dystrobrevin structure is homologous to the cysteine-rich carboxy-terminal domain of dystrophin. This protein is expressed predominantly in skeletal muscle, heart, lung, and central nervous system. It is thought to be involved in synaptic transmission at the neuromuscular junction and in intracellular signaling.

The secondary oocyte is the cell that is formed by meiosis I in oogenesis.Biochem Thus, it has only one of each pair of homologous chromosomes. In other words, it is haploid. However, each chromosome still has two chromatids, making a total of 46 chromatids (1N but 2C).

The telopodite is recognizably leglike in structure and consists of three segments plus an apical claw. The second maxillae also have a metameric pore, which is the opening of the maxillary gland and maxillary nephridium homologous to those of millipedes.Lewis, J. G. E. 1981. The Biology of Centipedes.

Vulva structures with labels The labia majora (singular: labium majus) are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva. The labia majora are homologous to the male scrotum.

TPC2 is homologous to TPC1, the best characterized member of the TPC family. The structure of a TPC1 ortholog from Arabidopsis thaliana has been solved by two laboratories. The structures were solved using X-ray crystallography and contained the fold of a voltage- gated ion channel and EF hands.

As 5' and 3' LTRs are identical upon insertion, the difference between paired LTRs can be used to estimate the age of ancient retroviral insertions. This method of dating is used by paleovirologists, though it fails to take into account confounding factors such as gene conversion and homologous recombination.

Other homologies exist, such as the fact that all papillomaviruses have repeated sequences in the noncoding parts of their genomes. CRPV has some notable repeats, some as long as 32 base pairs. Many pairs up stream of the transcription locations are homologous with promoter sequences in of SV40.

The enzyme converts glutamine to glutamate, with the release of ammonia. Members tend to be described as glutaminase A (glsA), where B (glsB) is unknown and may not be homologous (as in Rhizobium etli; some species have two isozymes that may both be designated A (GlsA1 and GlsA2).

Most recently his lab created a new transposable element (MiMIC) that permits even more downstream manipulations via RMCE (recombinase-mediated cassette exchange), such as protein tagging and knockdown and large scale homologous recombination. His research constantly evolves with the changing technology to meet the needs of the Drosophila community.

The per gene was first discovered using forward genetics in Drosophilla melanogaster in 1971. Mammalian Per2 was discovered by in 1997 through a search for homologous cDNA sequences to PER1. It is more similar to Drosophila per than its paralogs. Later experiments in also identified Per2 in humans.

Amphibians have unique inner ear structures. There are two sensory papillae involved in hearing, the basilar (higher frequency) and amphibian (lower frequency) papillae, but it is uncertain whether either is homologous to the hearing organs of lepidosaurs, archosaurs and mammals and we have no idea when they arose.

Just before each crus of the penis meets its fellow, it presents a slight enlargement, which Georg Ludwig Kobelt named the bulb of the corpus cavernosum penis. The bulb of penis is also known as the urethral bulb. The bulb is homologous to the vestibular bulbs in females.

2010 U.S. Patent. Fusion of Bacterial Protoplasts of Five Strains of Clostridium to Produce a Unique Thermophilic that Produces Bio-fuels and Other Chemicals Like Butanole in a Single Bioreactor. 2012 U.S Patent # 018293.00016 HIV replication inhibition using viral gene fragments and homologous microRNAs. 2014 U.S. Patent (#8,669,082 B1).

Some essential genes can tolerate mutations that are deleterious, but not wholly lethal, since they do not completely abolish the gene's function. Computational analysis can reveal many properties of proteins without analyzing them experimentally, e.g. by looking at homologous proteins, function, structure etc. (see also below, Predicting essential genes).

Anti-XRCC4 antibodies including phosphospecific antibodies to pS260 and pS318 in XRCC4 have been developed.; Antibodies to XRCC4 can have a variety of uses, including use in immunoassays to conduct research in areas such as DNA damage and repair, non-homologous end joining, transcription factors, epigenetics and nuclear signaling.

Gametology denotes the relationship between homologous genes on non-recombining, opposite sex chromosomes. The term was coined by García-Moreno and Mindell. 2000\. Gametologs result from the origination of genetic sex determination and barriers to recombination between sex chromosomes. Examples of gametologs include CHDW and CHDZ in birds.

The complex they from promotes homologous recombination DNA repair. The timeless protein is thought to directly connect the cell cycle with the circadian rhythm in mammals. In this model. referred to as a “direct coupling,” the two cycles share a key protein whose expression exhibits a circadian pattern.

Diagram showing homologous bones of the skulls of a monitor lizard and a crocodile. Jugal bone labelled Ju, in pale green, at centre left. The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic.

Humans also express two paralogs of FPR1 vis., FPR2 and FPR3. Mice express no fewer than 7 Fpr receptors and encoding genes that are homologous to FPR1 although no single one of these FPRs appears to perform exactly the same functions as any one of the human FPRs.

Squirrel gliders are able to curl their tails around branches to hold on. This feature is homologous to the ring tail possum (order of Diprodontia) which use their tail as an extra limb to grab hold of trees. It is longer but the squirrel gliders tail is bushier.

Expression of the ATM gene, as well as other key DSB repair genes, declines with age in mouse and human oocytes and this decline is paralleled by an increase of DSBs in primordial follicles. These findings indicate that ATM- mediated homologous recombinational repair is a crucial function of meiosis.

Since the cryptochromes were discovered in plants, several labs have identified homologous genes and photoreceptors in a number of other organisms, including humans, mice and flies. There are blue light photoreceptors that are not a part of photomorphogenesis. For example, phototropin is the blue light photoreceptor that controls phototropism.

Following its activation, EP4 undergoes homologous desensitization. That is, EP4 becomes insensitive to further activation and internalizes. This effect limits the duration and extent to which EP4 can stimulate cells. Agents which activate certain isoforms of protein kinase C can also desensitize EP4 by a process termed heterologous desensitization.

Z histone is found on the first nucleosome at the beginning of genes. The INO80 subfamily of remodelers will also be recruited to the H2A.X histone in the homologous recombination repair pathway. In addition to this function, the INO80 subfamily plays a role in transcriptional regulation and genomic recombination.

This in vitro technique was one of the first techniques in the era of recombination. It begins with the digestion of homologous parental genes into small fragments by DNase1. These small fragments are then purified from undigested parental genes. Purified fragments are then reassembled using primer-less PCR.

Sarcomeric mitochondrial creatine kinase has 80% homology with the coding exons of ubiquitous mitochondrial creatine kinase. This gene contains sequences homologous to several motifs that are shared among some nuclear genes encoding mitochondrial proteins and thus may be essential for the coordinated activation of these genes during mitochondrial biogenesis.

No common breakpoints for the deletion were identified indicating that the 2q37 rearrangement is unlikely to be mediated by non-homologous recombination and low-copy repeats. In a study of 20 patients, no clear relationship was found between clinical features and the size or position of the monosomic region.

Among bovine, rat, and human it has been shown to be 95% homologous, with the central 'C' domain evolutionarily conserved. This phosphoprotein is loosely associated with the vesicular membrance and is easily dissociated by treatment with a salt, versus a detergent being required for its removal from the membrane.

The trapezium is distinguished by a deep groove on its anterior surface. It is situated at the radial side of the carpus, between the scaphoid and the first metacarpal bone (the metacarpal bone of the thumb). It is homologous with the first distal carpal of reptiles and amphibians.

They are often located nearby to integrase genes that most resemble the homologous gene found in the P4 phage. int-alpA RNAs also often occur nearby to alpA genes, a gene that is also related to phages. Thus the RNA motif seems to function as part of phages.

However, a subset of breaks (at least one per chromosome) form crossovers between non- sister (homologous) chromosomes resulting in the exchange of genetic information. Sex chromosomes, however, are not wholly identical, and only exchange information over a small region of homology called the pseudoautosomal region. The exchange of information between the homologous chromatids results in a recombination of information; each chromosome has the complete set of information it had before, and there are no gaps formed as a result of the process. Because the chromosomes cannot be distinguished in the synaptonemal complex, the actual act of crossing over is not perceivable through an ordinary light microscope, and chiasmata are not visible until the next stage.

The DSBR pathway is unique in that the second 3' overhang (which was not involved in strand invasion) also forms a Holliday junction with the homologous chromosome. The double Holliday junctions are then converted into recombination products by nicking endonucleases, a type of restriction endonuclease which cuts only one DNA strand. The DSBR pathway commonly results in crossover, though it can sometimes result in non-crossover products; the ability of a broken DNA molecule to collect sequences from separated donor loci was shown in mitotic budding yeast using plasmids or endonuclease induction of chromosomal events. Because of this tendency for chromosomal crossover, the DSBR pathway is a likely model of how crossover homologous recombination occurs during meiosis.

The discovery of Dmc1 in several species of Giardia, one of the earliest protists to diverge as a eukaryote, suggests that meiotic homologous recombination—and thus meiosis itself—emerged very early in eukaryotic evolution. In addition to research on Dmc1, studies on the Spo11 protein have provided information on the origins of meiotic recombination. Spo11, a type II topoisomerase, can initiate homologous recombination in meiosis by making targeted double-strand breaks in DNA. Phylogenetic trees based on the sequence of genes similar to SPO11 in animals, fungi, plants, protists and archaea have led scientists to believe that the version Spo11 currently in eukaryotes emerged in the last common ancestor of eukaryotes and archaea.

Voltage-gated sodium ion channels (VGSC) are essential in producing and propagating action potentials. Tetrodotoxin, a toxin found in pufferfish, is able to block some VGSCs and therefore is used to distinguish the different subtypes. There are three TTX-resistant VGSC: Nav1.5, Nav1.8 and Nav1.9. Nav1.8 and Nav1.9 are both expressed in nociceptors (damage-sensing neurons). Nav1.7, Nav1.8 and Nav1.9 are found in the DRG and help mediate chronic inflammatory pain. Nav1.8 is an α-type channel subunit consisting of four homologous domains, each with six transmembrane regions, of which one is a voltage sensor. Structure of Nav1.8, an α-type subunit with four homologous domains, each with six transmembrane regions. Each domain has a voltage sensor (purple).

Rb is able to be localize to sites of DNA breaks during the repair process and assist in non-homologous end joining and homologous recombination through complexing with E2F1. Once at the breaks, Rb is able to recruit regulators of chromatin structure such as the DNA helicase transcription activator BRG1. Rb has been shown to also be able to recruit protein complexes such as condensin and cohesin to assist in the structural maintenance of chromatin. Such findings suggest that in addition to its tumor suppressive role with E2F, Rb is also distributed throughout the genome to aid in important processes of genome maintenance such as DNA break-repair, DNA replication, chromosome condensation, and heterochromatin formation.

The principle of homology: The biological relationships (shown by colours) of the bones in the forelimbs of vertebrates were used by Charles Darwin as an argument in favor of evolution. In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of four-legged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod structure. Evolutionary biology explains homologous structures adapted to different purposes as the result of descent with modification from a common ancestor.

Meiosis is the general process in eukaryotic organisms by which germ cells are formed, and it is likely an adaptation for removing DNA damages, especially double-strand breaks, from germ line DNA. (Also see article Meiosis). Homologous recombinational repair employing BRCA1 is especially promoted during meiosis. It was found that expression of 4 key genes necessary for homologous recombinational repair of DNA double-strand breaks (BRCA1, MRE11, RAD51 and ATM) decline with age in the oocytes of humans and mice, leading to the hypothesis that DNA double-strand break repair is necessary for the maintenance of oocyte reserve and that a decline in efficiency of repair with age plays a role in ovarian aging.

Protein A is produced and purified in industrial fermentation for use in immunology, biological research and industrial applications (see below). Natural (or native) protein A can be cultured in Staphylococcus aureus and contains the five homologous antibody binding regions described above and a C-terminal region for cell wall attachment. Today, protein A is more commonly produced recombinantly in Escherichia coli. (Brevibacillus has also been shown to be an effective host.) Recombinant versions of protein A also contain the five homologous antibody binding domains but may vary in other parts of the structure in order to facilitate coupling to porous substrates Engineered versions of the protein are also available, the first of which was rProtein A, B4, C-CYS.

Human β-glucuronidase is homologous to the Escherichia coli enzyme β-galactosidase. This homologous relationship, along with the knowledge that glycosidases often perform hydrolysis catalyzed by two acidic residues, enabled the development of a mechanistic hypothesis. This hypothesis proposes that the two glutamic acid residues Glu540 and Glu451 are the nucleophilic and acidic residues, respectively, and that the tyrosine residue Tyr504 is also involved in catalysis. In support of this hypothesis, experimental mutations in any of these three residues result in large decreases of enzymatic activity. Increased activity of an E451A mutant enzyme (where Glu451 is replaced with an alanine residue) after addition of azide is consistent with Glu451 as the acid/base residue.

In eukaryotes, the MRN complex (through cooperation of its subunits) has been identified as a crucial player in many stages of the repair process of double-strand DNA breaks: initial detection of a lesion, halting of the cell cycle to allow for repair, selection of a specific repair pathway (i.e., via homologous recombination or non-homologous end joining) and providing mechanisms for initiating reconstruction of the DNA molecule (primarily via spatial juxtaposition of the ends of broken chromosomes). Initial detection is thought to be controlled by both Nbs1 and MRE11. Likewise, cell cycle checkpoint regulation is ultimately controlled by phosphorylation activity of the ATM kinase, which is pathway dependent on both Nbs1 and MRE11.

The gene pool of Elymus canadensis can provide information on promoting disease resistance in Hordeum vulgare (barley). In two different Elymus canadensis × Hordeum vulgare hybrid groups, the ones with Elymus canadensis cytoplasm were missing a chromosome that was homologous to the barley chromosome 7, and the ones with the Hordeum vulgare cytoplasm were missing a chromosome homologous to barley chromosome 3. The lack of each of the chromosomes in the hybrids was not random, and were caused by differences in DNA methylation. Thus, further research can use these differences in order to figure out what exactly makes Elymus canadensis so hardy, and be able to integrate its hardiness into barley so that the crop can withstand more environmental stress.

Engineered zinc finger arrays are often fused to a DNA cleavage domain (usually the cleavage domain of FokI) to generate zinc finger nucleases. Such zinc finger-FokI fusions have become useful reagents for manipulating genomes of many higher organisms including Drosophila melanogaster, Caenorhabditis elegans, tobacco, corn, zebrafish, various types of mammalian cells, and rats. Targeting a double-strand break to a desired genomic locus can be used to introduce frame-shift mutations into the coding sequence of a gene due to the error-prone nature of the non-homologous DNA repair pathway. If a homologous DNA "donor sequence" is also used then the genomic locus can be converted to a defined sequence via the homology directed repair pathway.

Protein threading, also known as fold recognition, is a method of protein modeling which is used to model those proteins which have the same fold as proteins of known structures, but do not have homologous proteins with known structure. It differs from the homology modeling method of structure prediction as it (protein threading) is used for proteins which do not have their homologous protein structures deposited in the Protein Data Bank (PDB), whereas homology modeling is used for those proteins which do. Threading works by using statistical knowledge of the relationship between the structures deposited in the PDB and the sequence of the protein which one wishes to model. The prediction is made by "threading" (i.e.

The arcopallium refers to regions of the avian brain which partially overlap regions homologous to the amygdala of mammals. These regions have formerly been referred to as archistriatum, and before this epistriatum or amygdaloid complex, and a recent change of nomenclature has divided the region into the arcopallium and posterior pallial amygdala. The new nomenclature, adopted in 2004, reflects a modern understanding that the avian brain is broadly similar to the mammalian brain, containing large regions homologous to the mammalian neocortex, claustrum, and pallial amygdala. The outdated nomenclature it replaced perceived the avian brain as consisting almost entirely of enlarged basal ganglia, to which more complex outer layers had been added during a progress toward mammalian intelligence.

Protein S is partly homologous to other vitamin K-dependent plasma coagulation proteins, such as protein C and factors VII, IX, and X. Similar to them, it has a Gla domain and several EGF-like domains (four rather than two), but no serine protease domain. Instead, there is a large C-terminus domain that is homologous to plasma steroid hormone-binding proteins such as sex hormone-binding globulin and corticosteroid-binding globulin. It may play a role in the protein functions as either a cofactor for activated protein C (APC) or in binding C4BP. Additionally, protein S has a peptide between the Gla domain and the EGF-like domain, that is cleaved by thrombin.

Likewise, neither compares homologous points, and global change is always given more weight than local variation (which may have large biological consequences). Eigenshape analysis requires an equivalent starting point to be set for each specimen, which can be a source of error EFA also suffers from redundancy in that not all variables are independent. On the other hand, it is possible to apply them to complex curves without having to define a centroid; this makes removing the effect of location, size and rotation much simpler. The perceived failings of outline morphometrics are that it doesn't compare points of a homologous origin, and that it oversimplifies complex shapes by restricting itself to considering the outline and not internal changes.

All subunits are homologous to the subunits in other members of this monovalent cation (K+ or Na+):proton antiporter-3 (CPA3) family as well as subunits in the archaeal hydrogenases (TC#s 3.D.1.4.1 and 3.D.1.4.2), which share several subunits with NADH dehydrogenase subunits (3.D.1).

As of March 2015 there was no crystal structure of RubA although a structure of the homologous protein from a cryptomonad was determined using NMR. Investigation of the gene however indicates that it differs from other known rubredoxins in being bound to the thylakoid membrane via a C-terminal transmembrane helix.

The current organization was approved in 1987 by the Generalitat, when three categories of homologous territorial demarcation were established. Article 65 of the 2006 Statute of Autonomy provides the first legislative foundation for the comarques, although, as of April 2007, the enabling legislation has not been passed by the Corts Valencianes.

The police forces of the autonomous governments of Biscay (1784–1877) and Gipuzkoa (1796–1936) were known as Miqueletes. Their homologous police forces in Álava and Navarre, called Miñones and Policía foral, managed to survive beyond the Spanish Civil War for the siding of these provinces with the military uprising.

The gene for factor V is located on the first chromosome (1q24). It is genomically related to the family of multicopper oxidases, and is homologous to coagulation factor VIII. The gene spans 70 kb, consists of 25 exons, and the resulting protein has a relative molecular mass of approximately 330kDa.

This mechanism is still the leading theory today; however, a second theory suggests that most cpDNA is actually linear and replicates through homologous recombination. It further contends that only a minority of the genetic material is kept in circular chromosomes while the rest is in branched, linear, or other complex structures.

BRD3 is a member of the Bromodomain and Extra-Terminal motif (BET) protein family. Like other BET family members it contains two tandem homologous bromodomains and an "Extra-Terminal" motif. BRD3, similar to BRD2, does not have a long C-terminal domain as BET family proteins BRD4 and BRDT do.

Other studies have been able to induce transcription of Cas9 with a small molecule, doxycycline. Small molecules can also be used to improve homology directed repair, often by inhibiting the non-homologous end joining pathway. These systems allow conditional control of CRISPR activity for improved precision, efficiency, and spatiotemporal control.

They share a homologous region of about 400 residues (residues 206-623 in PKD2; residues 3656-4052 in PKD1) which includes five TMSs of both proteins. This may well be the channel domain. PKD2 and polycystin-L have been shown to exhibit voltage-, pH- and divalent cation-dependent channel activity.

The ACD of CyaA shares a similar structure and mechanism of activation with anthrax edema factor (EF). However, the interactions of CyaA with calmodulin completely diverge from those of EF. This provides molecular details of how two structurally homologous bacterial toxins evolved divergently to bind calmodulin, an evolutionarily conserved calcium sensor.

In 2010, a team led by Edward Marcotte developed an algorithm that identifies deeply homologous genetic modules in unicellular organisms, plants, and animals based on phenotypes (such as traits and developmental defects). The technique aligns phenotypes across organisms based on orthology (a type of homology) of genes involved in the phenotypes.

Mitotic crossover may enable recombination, i.e., an exchange of genetic material between homologous chromosomes. The chromosome number may then be restored to its haploid state by nuclear division, with each daughter nuclei being genetically different from the original parent nuclei. Alternatively, nuclei may lose some chromosomes, resulting in aneuploid cells.

Homoploid means "at the same ploidy level", i.e. having the same number of homologous chromosomes. For example, homoploid hybridization is hybridization where the offspring have the same ploidy level as the two parental species. This contrasts with a common situation in plants where chromosome doubling accompanies or occurs soon after hybridization.

Conversely, rats do not express a splice variant homologous to the h5-HT7(d), as the rat 5-HT7 gene lacks the exon necessary to encode this isoform. Drug binding affinities are similar across the three human splice variants; however, inverse agonist efficacies appear to differ between the splice variants.

SEC24 family, member A (S. cerevisiae) is a protein that in humans is encoded by the SEC24A gene. The protein belongs to a protein family that are homologous to yeast Sec24. It is a component of coat protein II (COPII)-coated vesicles that mediate protein transport from the endoplasmic reticulum.

Schizophrenia PPI. Using experimental data as a starting point, homology transfer is one way to predict interactomes. Here, PPIs from one organism are used to predict interactions among homologous proteins in another organism ("interologs"). However, this approach has certain limitations, primarily because the source data may not be reliable (e.g.

These kinases initiate the DNA damage response pathway which participates in NKG2D ligand upregulation. DNA damage response thus participate in alerting the immune system to the presence of potentially dangerous cells. All NKG2D ligands are homologous to MHC class I molecules and are divided into two families: MIC and RAET1/ULBP.

The glans (,OED 2nd edition, 1989.Entry "glans" in Merriam-Webster Online Dictionary. plural "glandes" ; from the Latin word for "acorn")"glans" at merriam-webster.com is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals.

Others, like the ostrich, have only two toes (didactyl feet). The first digit, called the hallux, is homologous to the human big toe. The claws are located on the extreme phalanx of each toe. They consist of a horny keratinous podotheca, or sheath, and are not part of the skeleton.

Gene conversion is the process by which one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion event. Gene conversion can be either allelic, meaning that one allele of the same gene replaces another allele, or ectopic, meaning that one paralogous DNA sequence converts another.

Obestatin is encoded by the same gene that encodes ghrelin, a peptide hormone. The mRNA produced from the GHRL gene has four exons. Five products of similar structure and function arise: the first is the 117-amino acid preproghrelin. (It is homologous to promotilin; both are members of the motilin family).

In 2017, Fantini et al. showed that DDB2, in association with XRCC5 and XRCC6 (otherwise known as Ku80 and Ku70, which make up the Ku heterodimer), has transcriptional activities. The DDB2/Ku effects on transcription are separate from the actions of the Ku heterodimer in non- homologous end joining DNA repair.

Large species with an anterior opisthosomal sternal complex of themale consisting of three digit- like apophyses pointing backward, densely ornamented with conspicuous gland openings. The sternal organ seems to be homologous to Huitaca ventralis and Huitaca tama. The male specimen has a dark brown body with lighter legs.Benavides & Giribet, 2013, p.

Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs. snoZ199 is predicted to be a methylation guide for sites on 18S and 25S ribosomal RNA (rRNA). Oryza sativa snoZ199 is reported to be homologous to Arabidopsis thaliana snoR13.

These methods are based upon the homology of proteins. These methods are also known as comparative modeling. The first step in homology modeling is generally the identification of template sequences of known structure which are homologous to the query sequence. Next the query sequence is aligned to the template sequence.

GTx1-15 displays sequence homology with other ion channel toxins from several spider species. It is homologous in sequence with sodium channel blocker PaurTx3 by 76.5%, and it also shares similarities in sequence with HnTx-IV (60%), CcoTx2 (55.9%), TLTx1 (55.6%), ω-GrTx SIA (40%), GsAFII (38.2%) and GsMTx2 (38.2%).

It is likely that MSH4 interacts with MSH5 to promote the majority of crossovers during rice meiosis. In general it appears that MSH4 acts during meiosis to direct the recombinational repair of some DNA double-strand breaks towards the crossover option rather than the non-cross over option (see Homologous recombination).

The protein domain, SWIB/MDM2, short for SWI/SNF complex B/MDM2 is an important domain. This protein domain has been found in both SWI/SNF complex B and in the negative regulator of the p53 tumor suppressor MDM2. It has been shown that MDM2 is homologous to the SWIB complex.

Externally and endogenously caused damages may be converted into mutations by inaccurate translesion synthesis or inaccurate DNA repair (e.g. by non-homologous end joining). In addition, DNA damages can also give rise to epigenetic alterations during DNA repair. Both mutations and epigenetic alterations (epimutations) can contribute to progression to cancer.

This gene is one of two genes that encode the V1 domain C subunit proteins and is found ubiquitously. This C subunit is analogous but not homologous to gamma subunit of F-ATPases. Previously, this gene was designated ATP6D. In melanocytic cells ATP6V1C1 gene expression may be regulated by MITF.

Evidence suggests that other forms of DNA repair including non- homologous end joining, nucleotide excision repair and base excision repair also depend on RECQL4 function. In the Rothmund-Thomson syndrome, the association of deficient RECQL4-mediated DNA repair and premature aging is consistent with the DNA damage theory of aging.

Very rarely, such a configuration of a large eustachian valve may mimic a right atrial cystic tumor.Malaterre HR, Kallee K, Perier Y. Eustachian valve mimicking a right atrial cystic tumor. Int J Card Imaging 2000;16(4):305–7. The superior vena cava (SVC) does not have any homologous valve or valvule.

Additionally, Symons compares human play to that of non-human animals, attempted to explain differences in play between male and female rhesus macaques in terms of reproductive strategies, and argues that human warfare and animal fighting, as well as the developmental processes upon which they are based, are not homologous.

The 3D structure of human serum albumin has been determined by X-ray crystallography to a resolution of . Albumin is a 65–70 kDa protein. Albumin comprises three homologous domains that assemble to form a heart- shaped protein. Each domain is a product of two subdomains that possess common structural motifs.

Rhodium(0) complexes are binary carbonyls, the principal examples being tetrarhodium dodecacarbonyl, Rh4(CO)10, and hexadecacarbonylhexarhodium, Rh6(CO)16. These compounds are obtained by reductive carbonylation of rhodium(III) salts or Rh2Cl2(CO)4. In contrast to the stability of the homologous Co2(CO)8, Rh2(CO)8 is very labile.

It is common among protists that the sexual cycle is inducible by stressful conditions such as starvation. Such conditions often cause DNA damage. A central feature of meiosis is homologous recombination between non-sister chromosomes. In T. thermophila this process of meiotic recombination may be beneficial for repairing DNA damages caused by starvation.

Most of ATP7B protein is located in the trans-Golgi network (TGN) of hepatocytes, which is different from its homologous protein ATP7A. Small amount of ATP7B is located in the brain. As a copper-transporting protein, one major function is delivering copper to copper dependent enzymes in Golgi apparatus (e.g. holo-ceruloplasmin (CPN)).

Comparison of homologous DNA has increased the insight in the phylogenetic relationships between the Senecioneae. It shows that Phaneroglossa is most closely related to Austrosynotis rectirama, Oresbia heterocarpa and the genus Dendrosenecio. Further research that includes more species and more or other genes may change these insights. The following tree represents current insights.

Unlike chondromodulin-1, TNMD does not have a processing signal for furin protease. The extracellular part, prior the putative cleavage site, contains a BRICHOS extracellular domain found also in several other unrelated proteins. This domain consists of a homologous sequence of approximately 100 amino acids containing a pair of conserved cysteine residues.

This protein, and a homologous mouse sequence, are very similar to the Drosophila sidekick gene product but the specific function of this superfamily member is not yet known. Evidence for alternative splicing at this gene locus has been observed but the full-length nature of additional variants has not yet been determined.

Although most proteins showing cooperative binding are multimeric complexes of homologous subunits, some proteins carry several binding sites for the same ligand on the same polypeptide. One such example is calmodulin. One molecule of calmodulin binds four calcium ions cooperatively. Its structure presents four EF-hand domains, each one binding one calcium ion.

EGFR gain-of-function mutation and EGFR inhibitor treatment in colorectal cancer ). More recently, mutational signatures profiling has proven successful in guiding oncological management and use of targeted therapies (e.g. immunotherapy in mismatch repair deficient of diverse cancer types, platinum and PARP inhibitor to exploit synthetic lethality in homologous recombination deficient breast cancer).

Zebrafish pancreas development is very homologous to mammals, such as mice. The signaling mechanisms and way the pancreas functions are very similar. The pancreas has an endocrine compartment, which contains a variety of cells. Pancreatic PP cells that produce polypeptides, and β-cells that produce insulin are two examples of those such cells.

What homologues can be identified? The general conclusion from the study by Butler, et al., is that some of the major theories for the mammalian brain also appear to be valid for the avian brain. The structures assumed to be critical for consciousness in mammalian brains have homologous counterparts in avian brains.

There is a good correlation between the genotype and phenotype. As a result, the CYP21A2 genotyping has high diagnostic value. However, the genotyping of the CYP21A2 gene is prone to errors, especially due to the closely located and highly homologous pseudogene CYP21A1P and the complex duplications, deletions and rearrangements within the chromosome 6p21.3.

FAD-dependent urate hydroxylase (, HpxO enzyme, FAD-dependent urate oxidase, urate hydroxylase) is an enzyme with systematic name urate,NADH:oxygen oxidoreductase (5-hydroxyisourate forming). A non-homologous isofunctional enzyme (NISE) to HpxO was found, and named HpyO. HpyO was determined to be a typical Michaelian enzyme. These FAD-dependent urate hydroxylases are flavoproteins.

A balancer chromosome contains large inversions ([B,C,D] and [G]). Normal genetic recombination (blue X) is suppressed (red X) at these sites. To suppress crossing over, balancer chromosomes are the products of multiple, nested chromosomal inversions so that synapsis between homologous chromosomes is disrupted. This construct is called a crossover suppressor.

DBH-like monooxygenase protein 1, also known as monooxygenase X, is an enzyme that in humans is encoded by the MOXD1 gene. DBH-like 1 maintains many of the structural features of dopamine beta-monooxygenase DBH. Since Peptidylglycine alpha-hydroxylating monooxygenase (PHM; EC 1.14.17.3) is homologous to dopamine beta-monooxygenase (DBM; EC 1.14.

As segment eleven is reduced or absent in the majority of arthropods, in such cases, the cerci emerge from the tenth abdominal segment. It is not clear that other structures so named are homologous. In the Symphyla they are associated with spinnerets.Tiegs, O. W. The post-embryonic development of Hanseniella agilis (Symphyla).

Chromosomal reciprocal translocation of the 4th and 20th chromosome. In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation. Reciprocal translocation is a chromosome abnormality caused by exchange of parts between non-homologous chromosomes.

In eukaryotes, when DUE-B's are knocked out, the cell will not go into S phase of its cycle, where DNA replication occurs. Increased apoptosis will result. But, activity can be rescued by re-addition of the DUE-B's, even from a different species. This is because DUE-B's are homologous between species.

Three of the principal members of the pentraxin family are serum proteins: namely, C-reactive protein (CRP), serum amyloid P component protein (SAP), and female protein (FP). PTX3 (or TSG-14) protein is a cytokine-induced protein that is homologous to CRPs and SAPs, but its function has not yet been determined.

Di Gregorio was born to Chilean parents in the city of Mendoza in Argentina's homologous province. Then, he began his career in the football academy of Chilean giants Club Deportivo Universidad Católica. Nevertheless, he left Católica for join to Coquimbo Unido. In 2001, he was sent on loan to Club Deportivo Huachipato.

I-CreI has already been used successfully to induce homologous recombination in Drosophila melanogaster, an extremely popular eukaryotic model organism. It seems very likely that advances in molecular biological techniques and generation of a library of I-CreI-derived novel endonucleases will eventually allow for the targeting of many genes of etiological significance.

Blood transfusions use as sources of blood either one's own (autologous transfusion), or someone else's (allogeneic or homologous transfusion). The latter is much more common than the former. Using another's blood must first start with donation of blood. Blood is most commonly donated as whole blood obtained intravenously and mixed with an anticoagulant.

This response may be a primitive form of sexual interaction, similar to the more well-studied bacterial transformation that is also associated with DNA transfer between cells leading to homologous recombinational repair of DNA damage. In another related species, Sulfolobus acidocaldarius, UV-irradiation also increases the frequency of recombination due to genetic exchange.

The Holliday junction can be resolved into linear DNA by the RuvABC complex or dissociated by the RecG protein. Each of these events can generate intact DNA with new combinations of genetic markers by which the parental DNAs may differ. This process, homologous recombination, completes the repair of the double-stranded DNA break.

The host organism can be a bacterium, yeast, mammalian cell, or plant cell. This host is called the "expression system". Homologous expression, on the other hand, refers to the overexpression of a gene in a system from where it originates. Genes are subjected to heterologous expression often to study specific protein interactions.

It consists in the formation of the protective phase of this physiological reaction. Meanwhile, under tissue stress, its protective function may be carried out both the “passive” and “active” CURD-induced mechanisms. Thus, the cell stress mechanism is just one of the two instruments with which TAS protects the cells of homologous tissue.

The ectotympanic, or tympanicum, is a bony ring in the tympanic part of the temporal bone that holds the eardrum, or tympanic membrane. Its position and attachment to the skull vary within mammals, and particularly primates, and can be either inside or outside the auditory bulla. It is homologous with the angular bone.

It is homologous to the Epstein-Barr virus membrane antigen gp350/220. MuHV-68 is more closely related to the Kaposi's Sarcoma-associated herpesvirus (KSHV) than it is to the Epstein-Barr virus. Glycoprotein K8.1 is the KSHV homolog of MuHV-68 gp150. MuHV-68 is a very close relative of MuHV-72.

Allelic gene conversion occurs during meiosis when homologous recombination between heterozygotic sites results in a mismatch in base pairing. This mismatch is then recognized and corrected by the cellular machinery causing one of the alleles to be converted to the other. This can cause non-Mendelian segregation of alleles in germ cells.

Although many natural waxes contain esters, paraffin waxes are hydrocarbons, mixtures of alkanes usually in a homologous series of chain lengths. These materials represent a significant fraction of petroleum. They are refined by vacuum distillation. Paraffin waxes are mixtures of saturated n- and iso- alkanes, naphthenes, and alkyl- and naphthene-substituted aromatic compounds.

In some species, melons are more specialized than in others. The sperm whale has the largest nose of any animal in the world. The bulk of that nose is composed of two large, fatty structures, the spermaceti organ and the "junk". The junk is structurally the same as the melon (homologous to it).

Phasing is the process of identifying the individual complement of homologous chromosomes. Methods for phasing include pedigree analysis, allele-specific PCR, linkage emulsion PCR haplotype analysis,Linking emulsion PCR haplotype analysis. Wetmur JG, Chen J. Methods Mol Biol. 2011;687:165-75. polony PCR,Long-range polony haplotyping of individual human chromosome molecules.

This technique does not require prior knowledge of the protein structure and function relationship. Directed evolution utilizes random or focused mutagenesis to generate libraries of mutant proteins. Random mutations can be introduced using either error prone PCR, or site saturation mutagenesis. Mutants may also be generated using recombination of multiple homologous genes.

Suggested relationship between saposin and swaposin. They could have evolved from a similar gene. Both consist of four alpha helices with the order of helices being permuted relative to each other. Among plants, APs between different species are generally homologous exhibiting high sequence identity whilst maintaining a similar tertiary structure to pepsin.

Agrin is a large proteoglycan whose best-characterised role is in the development of the neuromuscular junction during embryogenesis. Agrin is named based on its involvement in the aggregation of acetylcholine receptors during synaptogenesis. In humans, this protein is encoded by the AGRN gene. This protein has nine domains homologous to protease inhibitors.

Mol Microbiol. 2000 Apr;36(2):437-46. This repair of double-strand breaks is facilitated by the gene 2.5 protein that promotes the annealing of homologous complementary strands of DNA.Yu M, Masker W. T7 single strand DNA binding protein but not T7 helicase is required for DNA double strand break repair.

Natural genetic transformation in bacteria is a sexual process involving the transfer of DNA from one cell to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination. A. tumefaciens can undergo natural transformation in soil without any specific physical or chemical treatment.

Phenotype selection of the inability to fruit can indict that insertion led to disruption of vital genes. All in all, homologous recombination provides more specificity when creating a mutant strain. Depending on the mutant, auxotrophy markers (requires lost gene to be inserted) or prototrophy (when causing essential gene deletion) be used for selection.

Recent research suggests that H2AZ is incorporated into the nucleosome using a Swr1, a Swi2/Snf2- related adenosine triphosphatase. Another H2A variant that has been identified is H2AX. This variant has a C-terminal extension that’s utilized for DNA repair. The method of repair this variant employs is non-homologous end joining.

Male sex hormones are secreted by the testes later in embryonic life to cause the development of secondary sex organs. The scrotum is developmentally homologous to the labia majora. The raphe does not exist in females. Reproductive organs and tissues develop in females and males begin during the fifth week after fertilization.

The hya RNA motif is a conserved RNA structure that was discovered by bioinformatics. hya motif RNAs are found in Actinobacteria. hya motif RNAs likely function as cis-regulatory elements, in view of their positions upstream of protein-coding genes. Indeed, the RNAs are upstream of multiple genes that encode non-homologous proteins.

Double- strand breaks (DSBs) at specific sites can be induced by transfecting cells with a plasmid encoding I-SceI endonuclease (a homing endonuclease). Multiple DSBs can be induced by irradiating sensitized cells (labeled with 5'-bromo-2'-deoxyuridine and with Hoechst dye) with 780 nm light. These DSBs can be repaired by the accurate homologous recombinational repair or by the less accurate non-homologous end joining repair pathway. Here we describe the early steps in homologous recombinational repair (HRR). After treating cells to introduce DSBs, the stress-activated protein kinase, c-Jun N-terminal kinase (JNK), phosphorylates SIRT6 on serine 10. This post-translational modification facilitates the mobilization of SIRT6 to DNA damage sites with half-maximum recruitment in well under a second. SIRT6 at the site is required for efficient recruitment of poly (ADP-ribose) polymerase 1 (PARP1) to a DNA break site and for efficient repair of DSBs. PARP1 protein starts to appear at DSBs in less than a second, with half maximum accumulation within 1.6 seconds after the damage occurs. This then allows half maximum recruitment of the DNA repair enzymes MRE11 within 13 seconds and NBS1 within 28 seconds.

The causal relationship of DNA damage to spontaneous mutation is illustrated by aerobically growing E. coli bacteria, in which 89% of spontaneously occurring base substitution mutations are caused by reactive oxygen species (ROS)-induced DNA damage. In yeast, more than 60% of spontaneous single-base pair substitutions and deletions are likely caused by trans-lesion synthesis. An additional significant source of mutations in eukaryotes is the inaccurate DNA repair process non-homologous end joining, that is often employed in repair of double strand breaks. In general, it appears that the main underlying cause of spontaneous mutation is error prone trans-lesion synthesis during DNA replication and that the error- prone non-homologous end joining repair pathway may also be an important contributor in eukaryotes.

ATCC27551 and Pseudomonas diminuta is highly conserved (100% sequence homology), although the plasmids where the genes are found have very different sequences apart from a 5.1Kb conserved region where the gene is found. A closer look on the organization of the opd gene from Flavobacterium suggests a potential transposon-like architecture, which accounts for the widespread distribution of the gene among other microbial species that might have occurred through lateral DNA transfer. The opd gene is flanked by transposition insertion sequences, characteristic of Tn3 family of transposons. Moreover, a transposase-like sequence (homologous to TnpA) and a resolvase-like sequence (homologous to TnpR) were also identified in regions upstream of the opd gene, which are characteristics of class II transposons such as Tn3.

The two pathways for homologous recombination in eukaryotes, showing the formation and resolution of Holliday junctions The Holliday junction is a key intermediate in homologous recombination, a biological process that increases genetic diversity by shifting genes between two chromosomes, as well as site-specific recombination events involving integrases. They are additionally involved in repair of double-strand breaks. In addition, cruciform structures involving Holliday junctions can arise to relieve helical strain in symmetrical sequences in DNA supercoils. While four- arm junctions also appear in functional RNA molecules, such as U1 spliceosomal RNA and the hairpin ribozyme of the tobacco ringspot virus, these usually contain unpaired nucleotides in between the paired double-helical domains, and thus do not strictly adopt the Holliday structure.

Much of the genetic work done on hemichordates has been done to make comparison with chordates, so many of the genetic markers identified in this group are also found in chordates or are homologous to chordates in some way. Studies of this nature have been done particularly on S. kowalevskii, and like chordates S. kowalevskii has dorsalizing bmp-like factors such as bmp 2/4, which is homologous to Drosophila’s decapentaplegic dpp. The expression of bmp2/4 begins at the onset of gastrulation on the ectodermal side of the embryo, and as gastrulation progresses its expression is narrowed down to the dorsal midline but is not expressed in the post anal tail. The bmp antagonist chordin is also expressed in the endoderm of gastrulating S. kowalevskii.

To create a stable mutant line, gene targeting can be used to insert a gene of interest into a particular location of the C. merolae genome via homologous recombination. By including regions of DNA several hundred base pairs long on the ends of the gene of interest that are complementary to a sequence within the C. merolae genome, the organism’s own DNA repair machinery can be used to insert the gene at these regions. The same transformation procedure as is used for transient expression can be used here, except with the homologous DNA segments to allow for genome integration. Freeze fracture deep etch electron microscopy image of C. merolae, showing two cells, one in which the plastid has begun to divide.

In general, although D. discoideum generally reproduces asexually, D. discoideum is still capable of sexual reproduction if certain conditions are met. D. discoideum has three different mating types and studies have identified the sex locus that specifies these three mating types. Type I strains are specified by the gene called MatA, Type II strains have three different genes: MatB (homologous to Mat A), Mat C, and Mat D, and Type III strains have Mat S and Mat T genes (which are homologous to Mat C and Mat D). These sexes can only mate with the two different sexes and not with its own. When incubated with their bacterial food supply, heterothallic or homothallic sexual development can occur, resulting in the formation of a diploid zygote.

After two or three months of song learning and rehearsal (depending on species), the juvenile produces a crystallized song, characterized by spectral and temporal stereotypy (very low variability in syllable production and syllable order). Some birds, such as zebra finches, which are the most popular species for birdsong research, have overlapping sensory and sensorimotor learning stages. Research has indicated that birds' acquisition of song is a form of motor learning that involves regions of the basal ganglia. Further, the PDP (see Neuroanatomy below) has been considered homologous to a mammalian motor pathway originating in the cerebral cortex and descending through the brain stem, while the AFP has been considered homologous to the mammalian cortical pathway through the basal ganglia and thalamus.

This displaced strand pops up to form a 3' overhang in the original double-stranded break duplex, which can then anneal to the opposite end of the original break through complementary base pairing. Thus DNA synthesis fills in gaps left over from annealing, and extends both ends of the still present single stranded DNA break, ligating all remaining gaps to produce recombinant non-crossover DNA. SDSA is unique in that D-loop translocation results in conservative rather than semiconservative replication, as the first extended strand is displaced from its template strand, leaving the homologous duplex intact. Therefore, although SDSA produces non-crossover products because flanking markers of heteroduplex DNA are not exchanged, gene conversion does occur, wherein nonreciprocal genetic transfer takes place between two homologous sequences.

The possible presence of organelle DNA inside the nuclear genome was suggested after finding of homologous structure to the mitochondrial DNA, which was shortly after the discovery of the presence of an independent DNA within the organelles in 1967. This topic stayed untouched until the 1980s. Initial evidence that DNA could move among cell compartments came when fragments of chloroplast DNA were found in the maize mitochondrial genome with the help of cross-hybridization, between chloroplast and mitochondrial DNA, and physical mapping of homologous regions. After this initial observation, Ellis coined the name "promiscuous DNA" in order to signify the transfer of DNA intracellularly from one organelle to the other and is the presence of organelle DNA in multiple cellular compartments.

Dual oxidases are characterized by a defining N-terminal, extracellular domain exhibiting considerable sequence identity with the mammalian peroxidases, a transmembrane (TM) segment appended to an EF-hand calcium-binding cytosolic region and a NOX2 homologous structure (six TMs tethered to NADPH oxidase). Topological studies place this peroxidase domain on the opposite side of the membrane from the NADPH oxidase domain. hDUOX1 and hDUOX2 are 83% homologous, ~190 kDa in size (after extensive glycosylation contributing ~30 kDa in mass), and require maturation factors (DUOXA1 and DUOXA2) to achieve heterologous expression in full-length, active form. Mature DUOX enzymes produce H2O2; this activity is regulated by Ca2+ concentration through triggered dissociation of NOXA1 and possibly other as yet unidentified interacting proteins.

The protein encoded by this gene is essential for meiotic homologous recombination. Genetic recombination in meiosis plays an important role in generating diversity of genetic information and facilitates the reductional segregation of chromosomes that must occur for formation of gametes during sexual reproduction. Like other members of the Rad51/RecA family, Dmc1 stabilizes strand exchange intermediates (Rad1/RecA-stretched DNA, or RS-DNA) in stretched triplets similar to B form DNA. Each molecule of the protein binds a triplet of nucleotides, and the strength of that binding, as assessed by the change in Gibbs free energy, can be assessed by the length of time that a labelled dsDNA probe with a short homologous sequence remains bound to a DNA containing a short region of homology to it.

The analysis of 630 human primary tumors in 11 tissues shows that WRN promoter hypermethylation (with loss of expression of WRN protein) is a common event in tumorigenesis. The WRN gene promoter is hypermethylated in about 38% of colorectal cancers and non-small-cell lung carcinomas and in about 20% or so of stomach cancers, prostate cancers, breast cancers, non-Hodgkin lymphomas and chondrosarcomas, plus at significant levels in the other cancers evaluated. The WRN helicase protein is important in homologous recombinational DNA repair and also has roles in non-homologous end joining DNA repair and base excision DNA repair. Topoisomerase inhibitors are frequently used as chemotherapy for different cancers, though they cause bone marrow suppression, are cardiotoxic and have variable effectiveness.

This requirement follows not only from the discussion above but also from in vivo evidence showing the function of this checkpoint in precancerous lesions and its dysfunction in late-stage tumors. Second, to survive after disabling the DNA damage checkpoint, precancerous cells must activate mechanisms to extend their telomeres. As a result of the continued division past the point of normal senescence, the telomeres of these cells become too short to prevent NHEJ(Non Homologous End Joining) and HR(Homologous Recombination) of chromosome ends, causing a state known as crisis. The application of these DSB (double strand breaks)repair mechanisms to chromosome ends leads to genetic instability, and while this instability can promote carcinogenesis, it induces apoptosis if experienced for too long.

FK506 binding protein 6, also known as FKBP6, is a human gene. The encoded protein shows structural homology to FKBP immunophilins, which bind to the immunosuppressants FK506 and rapamycin. FKBP6 is essential for homologous chromosome pairing in meiosis during spermatogenesis. Targeted inactivation of FKBP6 in mice results in infertile males, but apparently normal females.

An ortholog is defined as two or more homologous genes between species that are evolutionarily related by linear descent. Bone morphogenetic protein (BMP), a growth factor that plays a significant role in embryonic neural development, is highly conserved amongst vertebrates, as is sonic hedgehog (SHH), a morphogen that inhibits BMP to allow neural crest development.

In this form of phase variation. The promoter region of the genome can move from one copy of a gene to another through homologous recombination. This occurs with Campylobacter fetus surface proteins. The several different surface antigen proteins are all silent apart from one and all share a conserved region at the 5' end.

Natural genetic transformation in bacteria is a sexual process involving transfer of DNA from one cell to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination. B. japonicum cells are able to undergo transformation. They become competent for DNA uptake during late log phase.

Natural infection and the attenuated vaccine induce antibodies that enhance the update of the homologous virus and H1N1 virus isolated several years later, demonstrating that a primary influenza A virus infection results in the induction of infection enhancing antibodies. ADE was suspected in infections with influenza A virus subtype H7N9, but knowledge is limited.

One is called PAGAN that was developed by the same team as PRANK. The other is ProGraphMSA developed by Szalkowski. Both software packages were developed independently but share common features, notably the use of graph algorithms to improve the recognition of non-homologous regions, and an improvement in code making these software faster than PRANK.

Expression of shoot processes in leaf development of Polemonium caeruleum. Botanische Jahrbücher für Systematik 119: 563-582. Consequently, they appear partially homologous with shoots as postulated by Agnes Arber in her partial- shoot theory of the leaf. They appear to be part of a continuum between morphological categories, especially those of leaf and shoot.

Four different mouse models with Col3a1 defects have been reported. Inactivation of the murine Col3a1 gene using homologous recombination technique led to a shorter life span in homozygous mutant mice. The mice died prematurely from a rupture of major arteries mimicking the human vEDS phenotype. These mice also had a severe malformation of the brain.

This protein belongs to the HHIP family and is one of three members found in humans. HHIPL1 contains a SRCR domain and an N-terminal signal peptide. Processing of the signal peptide leads to this protein's secretion. As an HHIP member, it also contains a conserved HHIP-homologous (HIPH) domain composed of 18 cysteine residues.

Detail of a human metaphase spread. A region in the pseudoautosomal region of the short arms of the X chromosome (left) and the Y chromosome (top right) was detected by fluorescent in situ hybridization (green). Chromosomes counterstained in red. The pseudoautosomal regions, PAR1, PAR2, are homologous sequences of nucleotides on the X and Y chromosomes.

PADs are found in chordates but not in lower animals. In mammals five PAD isotypes – PAD1, PAD2, PAD3, PAD4 and PAD6 – have been found. PAD5 was thought to be a unique isotype in humans, however it was shown to be homologous to PAD4. These isotypes differ in terms of their tissue and cellular distributions.

Genetic code logo of the Globobulimina pseudospinescens mitochondrial genome. The logo shows the 64 codons from left to right, predicted alternatives in red (relative to the standard genetic code). Red line: stop codons. The height of each amino acid in the stack shows how often it is aligned to the codon in homologous protein domains.

2014; The phosphorylation site of Parkin, at S65, is homologous to the site where ubiquitin is phosphorylated. This phosphorylation activates Parkin by inducing dimerization, an active state. This allows for Parkin-mediated ubiquitination on other proteins. Because of its PINK1-mediated recruitment to the mitochondrial surface, Parkin can ubiquitylate proteins in the outer mitochondrial membrane.

They also reduce the mitochondrial membrane potential in mammalian cells. Tissue specificity occurs for the different UCPs and the exact methods of how UCPs transfer H+/OH- are not known. UCPs contain the three homologous protein domains of MACPs. This gene is widely expressed in many tissues with the greatest abundance in brain and testis.

Nav1.6 is encoded by the SCN8A gene which contains 27 exons and measures 170 kb. The voltage gated sodium channel is composed of 1980 residues. Like other sodium channels, Nav1.6 is a monomer composed of four homologous domains (I-IV) and 25 transmembrane segments. SCN8A encodes S3-S4 transmembrane segments which form an intracellular loop.

A homologous domain is found in YscM (Yop secretion protein M), which acts as a Yop protein translocation protein. Several Yop proteins are involved in pathogenesis. YscM is produced by the virulence operon virC, which encodes thirteen genes, yscA-M. Transcription of the virC operon was subjected to the same regulation as the yop genes.

Annual Review of Ecology and Systematics 23:361-381. The hypothesis that a behavioral character is not homologous should be based on an incongruent distribution of that character with respect to other features that are presumed to reflect the true pattern of relationships. This is an application of Willi Hennig's Hennig, W. 1966. Phylogenetic Systematics.

Aureusidin synthase is homologous to plant polyphenol oxidase, but contains certain significant modifications. Aurone synthase catalyzes the formation of aurones. Aurone synthase purified from Coreopsis grandiflora shows weak tyrosinase activity against isoliquiritigenin, but the enzyme does not react with the classic tyrosinase substrates L-tyrosine and tyramine and must therefore be classified as catechol oxidase.

It is the primordial vascular channel from which the aortic arches arise (and eventually the dorsal aortae) and is homologous to the ventral aorta of gill-bearing vertebrates. Genes dHAND and eHAND are expressed during the development of the aortic bulb and the arteries which arise from it.Richard P. Harvey, Nadia Rosenthal (ed). Heart Development.

RAD51 is a eukaryotic gene. The enzyme encoded by this gene is a member of the RAD51 protein family which assists in repair of DNA double strand breaks. RAD51 family members are homologous to the bacterial RecA, Archaeal RadA and yeast Rad51. The protein is highly conserved in most eukaryotes, from yeast to humans.

Cells from a person with Bloom syndrome exhibit a striking genomic instability that includes excessive crossovers between homologous chromosomes and sister chromatid exchanges (SCEs). The condition was discovered and first described by New York dermatologist Dr. David Bloom in 1954. Bloom syndrome has also appeared in the older literature as Bloom–Torre–Machacek syndrome.

Gerald J. Cox, John H. Ferguson, and Mary L. Dodds (1933): "III. Technology of Sucrose Octaäcetate and Homologous Esters". Industrial & Engineering Chemistry, volume 25, issue 9, pages 968–970. Charles D. Hurd and K. M. Gordon (1941): "Propionyl Derivatives of Sugars". Journal of the American Chemical Society, volume 63, issue 10, pages 2657–2659.

These glands secrete mucus and a vaginal and vulval lubricant. They are homologous to the bulbourethral glands in the male. The lesser vestibular glands known as Skene's glands, are found on the anterior wall of the vagina. They are homologues of the male prostate gland and are also referred to as the female prostate.

Aureusidin synthase is a 39 kDa monomeric glycoprotein containing binuclear copper. The addition of phenylthiourea, which competitively binds to binuclear copper, inhibits the enzyme's productivity overall. Because of this, it is likely that the active site contains the binuclear copper. Aureusidin synthase is homologous to plant polyphenol oxidase (PPO), but contains certain significant modifications.

For GPCRs generally, each mechanism of homologous desensitization begins with receptor phosphorylation by an associated G protein-coupled receptor kinase (GRK). GRKs selectively modify activated receptors such that no heterogeneous desensitization will occur. This phosphorylation then acts to recruit other proteins, such as arrestins, that participate in one or more of the following mechanisms.

Homologous subfamily of ADAMTSL (ADAMTS-like) proteins, which lack enzymatic activity, has also been described. Most cases of thrombotic thrombocytopenic purpura arise from autoantibody-mediated inhibition of ADAMTS13. Like ADAMs, the name of the ADAMTS family refers to its disintegrin and metalloproteinase activity, and in the case of ADAMTS, the presence of a thrombospondin motif.

Swastika with 24 beads, primarily used in Malaysian Buddhism. In Buddhism, the swastika is considered to symbolize the auspicious footprints of the Buddha. It is an aniconic symbol for the Buddha in many parts of Asia and homologous with the dharma wheel. The shape symbolizes eternal cycling, a theme found in samsara doctrine of Buddhism.

The complex locks the RNAP clamp into a closed state to prevent the elongation complex (EC) from dissociating. The Spt5 NGN domain helps anneal the two strands of DNA upstream. The single KOW domain in bacteria and archaea anchors a ribosome to the RNAP. In bacteria, the homologous complex only contains NusG, a Spt5 homolog.

Zinc finger protein 366, also known as DC-SCRIPT (Dendritic cell-specific transcript), is a protein that in humans is encoded by the ZNF366 gene. The ZNF366 gene was first identified in a DNA comparison study between 85 kb of Fugu rubripes sequence containing 17 genes with its homologous loci in the human draft genome.

Doubly indirect interactions, mediated by two water molecules, are more numerous in the homologous complexes of low affinity. Carefully conducted mutagenesis experiments, e.g. changing a tyrosine residue into a phenylalanine, have shown that water mediated interactions can contribute to the energy of interaction. Thus, water molecules may facilitate the interactions and cross-recognitions between proteins.

There are several theories on how mitotic crossover occurs. In the simple crossover model, the two homologous chromosomes overlap on or near a common Chromosomal fragile site (CFS). This leads to a double- strand break, which is then repaired using one of the two strands. This can lead to the two chromatids switching places.

Traditionally, homologous recombination was the main method for causing a gene knockout. This method involves creating a DNA construct containing the desired mutation. For knockout purposes, this typically involves a drug resistance marker in place of the desired knockout gene. The construct will also contain a minimum of 2kb of homology to the target sequence.

This may be done imperfectly, therefore sometimes causing insertions or deletions of base pairs, which cause frameshift mutations. These mutations can render the gene in which they occur nonfunctional, thus creating a knockout of that gene. This process is more efficient than homologous recombination, and therefore can be more easily used to create biallelic knockouts.

The protein product of ABHD18 in humans is predicted to be a secreted product. It is ubiquitously expressed at low to moderate levels. In humans, the protein is found at high levels the digestive tract and parathyroid gland. The homologous mouse protein 3110057O12Rik is expressed at high levels in the granule layer of the cerebellum.

HoxA and HoxD, that regulate finger and toe formation in mice, control the development of ray fins in zebrafish; these structures had until then been considered non-homologous. There is a possible deep homology among animals that use acoustic communication, such as songbirds and humans, which may share unmutated versions of the FOXP2 gene.

Webbed feet have arisen in all major vertebrate lineages with limbed animals. Most webbed-footed species spend part of their time in aquatic environments, indicating that this homologous structure provides some advantage to swimmers. Some examples from each class are highlighted here, but this is not a complete listing. A phylogenetic tree of vertebrate taxa.

A characteristic central feature of meiosis is recombination between homologous chromosomes. This process is associated with repair of DNA damage, particularly double-strand breaks. The ability of C. neoformans and U. maydis to undergo meiosis may contribute to their virulence by repairing the oxidative DNA damage caused by their host's release of reactive oxygen species.

When consensus nucleotides and alternative ones were compared, homologous regions were "boxed" by the researchers. The boxing in of sequences sheds light on the origin of the term "box". The TATA box was first identified in 1978 as a component of eukaryotic promoters. Transcription is initiated at the TATA box in TATA-containing genes.

Jawed vertebrates are typified by paired appendages, fins or legs, which may be secondarily lost. The limbs of vertebrates are considered to be homologous because the same underlying skeletal structure was inherited from their last common ancestor. This is one of the arguments put forward by Charles Darwin to support his theory of evolution.

In female Drosophila melanogaster fruit flies, meiotic chromosome synapsis occurs in the absence of recombination. Thus synapsis in Drosophila is independent of meiotic recombination, consistent with the view that synapsis is a precondition required for the initiation of meiotic recombination. Meiotic recombination is also unnecessary for homologous chromosome synapsis in the nematode Caenorhabditis elegans.

High throughput experiments using expressed sequence tags (ESTs) or DNA microarrays can be a powerful tool for genome annotation—a general aspect of genomics. ; Sequence analysis :Sequence clustering is used to group homologous sequences into gene families. This is a very important concept in bioinformatics, and evolutionary biology in general. See evolution by gene duplication.

Production of siderophores also exhibited in some plant-infecting bacteria, such as Agrobacterium tumefaciens. The enzyme is controlled by gene cluster agb and the production of 2,3-diDHB dehydrogenase is controlled by the gene agbA. The enzyme AgbA is homologous to the EntA enzyme in E. coli, the same enzyme that produces 2,3-diDHB dehydrogenase.

BLAST can be used for several purposes. These include identifying species, locating domains, establishing phylogeny, DNA mapping, and comparison. ;Identifying species: With the use of BLAST, you can possibly correctly identify a species or find homologous species. This can be useful, for example, when you are working with a DNA sequence from an unknown species.

The gene encoding mDia1 is located on Chromosome 18 of Mus musculus and named Diap1. mDia1 is highly homologous to Drosophila diaphanous, regulating the cytokinetic ring during cytokinesis. Homologues in other species are known as well, like the human DIAP1, budding yeast Bni1 or fission yeast Cdc12p. The gene has been knocked-out in mice.

The gene clusters are also homologous, and these subunits are interchangeable to some degree. All nitrogenases use a similar Fe-S core cluster, and the variations come in the cofactor metal. The Anf nitrogenase in Azotobacter vinelandii is organized in an anfHDGKOR operon. This operon still requires some of the Nif genes to function.

Genetic variation in FOXO3 has been shown to be associated with healthspan and longevity in humans. It is found in most centenarians across a variety of ethnic groups around the world. The homologous genes daf-16 in the nematode C. elegans and dFOXO in the fruit fly are also associated with longevity in those organisms.

This protein has been shown to interact with and be involved in the phosphorylation of tumor suppressor protein Rb. Knockout studies of the homologous gene in mouse suggest the essential roles of this gene in ovarian granulosa and germ cell proliferation. High level expression of this gene was observed in ovarian and testicular tumors.

In sharks, this includes a rectal gland that secretes salt to help the animal maintain osmotic balance with the seawater. The gland somewhat resembles a caecum in structure, but is not a homologous structure. As with many aquatic animals, most fish release their nitrogenous wastes as ammonia. Some of the wastes diffuse through the gills.

Two taxa, the corallines and Hildenbrandiaceae, bear conceptacles, although the striking difference between their formation indicates that the conceptacles are not homologous. Similar structures also exist: cryptostomata are similar to conceptacles but differ having only hairs and are sterile; caecostomata, are found only in Fucus distichus, in these the ostiole becomes blocked during development.

C1QBP is 282 amino acid in length and has three homologous subunit with its N-terminal 73 amino acid residues cleaved off to produce mature C1QBP. C1QBP appears as a monomer around 33 kDa on SDS-PAGE gel under both reducing and nonreducing condition but migrates as a trimer on size- exclusion chromatography (gel filtration).

These two complexes act at two different stages of homologous recombinational DNA repair. The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites. The BCDX2 complex appears to act by facilitating the assembly or stability of the RAD51 nucleoprotein filament. The CX3 complex acts downstream of RAD51 recruitment to damage sites.

Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Gamma-crystallins are a homogeneous group of highly symmetrical, monomeric proteins typically lacking connecting peptides and terminal extensions. They are differentially regulated after early development.

In each nostril only a single nasal opening is visible, perhaps homologous to "Aperture A" in related species. Behind a narrow pair of nasal armour plates, rows of caputegulae stretch to the rear. The two front rows consists of pairs of rectangular plates. Part of the third row is a small central hexagonal caputegula.

This component is homologous to the genomes of all other geminiviruses. The proteins encoded on it are required for replication (Rep), control of gene expression, overcoming host defenses, encapsidation (coat protein) and insect transmission. The DNA B segment encodes two different movement proteins. These proteins have functions in intra- and intercellular movement in host plants.

Two views are presented. This structure represents p97 in an ADP bound state. The N-D1 ring is larger (162 Å in diameter) than the D2 ring (113 Å) due to the laterally attached N-domains. The D1 and D2 domains are highly homologous in both sequence and structure, but they serve distinct functions.

The signalling of the D1–D2 receptor heteromer is distinct from that of the parent receptor monomers. It comprises Gq/11 coupling, phospholipase C activation, intracellular calcium release from inositol trisphosphate receptor-sensitive stores, CaMKII activation and BDNF production. In comparison, signalling of the homologous D5–D2 receptor heteromer involves the influx of extracellular calcium.

In literature, "nor" is sometimes called the "next lower homologue", although in this context "homologue" is an inexact term. "Nor" only refers to the removal of one carbon atom with the accompanying hydrogen, not the removal of other units. "Nor" compares two related compounds; it does not describe the relation to a homologous series.

Hendekasartorite is a very rare thallium sulfosalt mineral with formula Tl2Pb48As82S172. It is one of recently approved new members of sartorite homologous series,Topa, D., Makovicky, E.,, Berlepsch, P., Stroeger, B., and Stanley, C., 2015. Hendekasartorite, IMA 2015-075. CNMNC Newsletter No. 28, December 2015, 1861; Mineralogical Magazine 79, 1859–1864 by enneasartorite and heptasartorite.

The UQCC2 gene is located on the p arm of chromosome 6 in position 21.31 and spans 14,990 base pairs. The gene produces a 14.9 kDa protein composed of 126 amino acids. This protein has no homologous domains with other known proteins. It is associated with the mitochondrial nucleoid, likely located in the peripheral region.

The dfrA-dnaX RNA motif is a conserved RNA structure that was discovered by bioinformatics. dfrA-dnaX motifs are found in Parvimonas. It is ambiguous whether dfrA-dnaX RNAs function as cis-regulatory elements or not. dfrA-dnaX RNAs are apparently located in the 5' untranslated regions (UTRs) of a variety of non-homologous genes.

If all examples of the RNA were upstream of homologous genes, there is the possibility that the RNAs were conserved in that position simply by inheritance. The non-homology of the genes downstream of hya RNAs makes this scenario less likely. The genes presumably regulated by hya RNAs are subunits of nickel-iron hydrogenase I.

It is homologous to the second half of p64. Structural studies showed that in the soluble form, CLIC proteins adopt a GST fold with an active site exhibiting a conserved glutaredoxin monothiol motif, similar to the omega class GSTs. Al Khamici et al. demonstrated that CLIC proteins have glutaredoxin-like glutathione-dependent oxidoreductase enzymatic activity.

Other efforts have engineered systems by expressing a chalcomycin synthase genes along with the TYLS system. This points to the potential of coexpressing homologous PKS systems for the production of new products, however the high specificity of protein-protein interactions limits chimeric PKS engineering. TYLS KR1 with Loading Module loop indicated. The loop facilitates intermodular interaction.

Multiple MMR pathways have been implicated in the maintenance of complex organism genome stability, and any of many possible malfunctions in the MMR pathway result in DNA editing and correction errors. Therefore, while it is not certain precisely what mechanisms lead to errors of non-homologous crossover, it is extremely likely that the MMR pathway is involved.

Chelate or sub-chelate (pincer-like) pedipalps are found in several arachnid groups (Ricinulei, Thelyphonida, scorpions and pseudoscorpions) but the chelae in most of these groups may not be homologous with those found in Xiphosura. The pedipalps are distinctly raptorial (i.e., modified for seizing prey) in the Amblypygi, Thelyphonida, Schizomida, and some Opiliones belonging to the laniatorid group.

Two adult siblings, both heterozygous for two particular NBS1 nonsense mutations displayed cellular sensitivity to radiation, chromosome instability and fertility defects, but not the developmental defects that are typically found in other NBS patients. These individuals appear to be primarily defective in homologous recombination, a process that accurately repairs double-strand breaks, both in somatic cells and during meiosis.

D5 receptor is highly homologous to the D1 receptor. Their amino acid sequences are 49% to 80% identical. D5 receptor has a long C-terminus of 93 amino acids, accounting for 26% of the entire protein. In spite of the high degree of homology between D5 and D1 receptors, their c-terminus tails have little similarity.

H. salinarum is polyploid and highly resistant to ionizing radiation and desiccation, conditions that induce DNA double-strand breaks. Although chromosomes are initially shattered into many fragments, complete chromosomes are regenerated by making use of over-lapping fragments. Regeneration occurs by a process involving DNA single-stranded binding protein, and is likely a form of homologous recombinational repair.

Santiago Pérez Fernández (born 5 August 1977 in Vega de Peridiello, Asturias) is a Spanish professional road bicycle racer, who last rode for . In March 2005, it was announced that he would be suspended for 2 years after having failed a test for homologous blood transfusion during the 2004 Vuelta a España. He returned to cycling in 2007 with .

Upon co-infection, the unmodified genome is cut and repaired by homologous recombination, producing new gene drive viruses that can progressively replace the naturally occurring population. In cell culture experiments, it was shown that a viral gene drive can spread into the viral population and strongly reduce the infectivity of the virus, which opens novel therapeutic strategies against herpesviruses.

Natural genetic transformation in bacteria is a process involving transfer of DNA from one cell to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination. Methylobacterium organophilum cells are able to undergo genetic transformation and become competent for DNA uptake near the end of the exponential growth phase.

G. intestinalis contains two functionally equivalent nuclei that are inherited independently during mitosis. In the giardial cyst these nuclei fuse (karyogamy) and undergo homologous recombination facilitated by meiosis gene homologs. The recombination associated with karyogamy may primarily function to repair DNA damage. G. intestinalis is divided into eight assemblages based on host specificities and genetic divergence of marker genes.

It has 530 amino acid residues with 10–12 transmembrane segments, and is not homologous to other known monoamine transporters, such as the high-affinity SERT, DAT, and NET, or the low- affinity SLC22A OCT family. It was initially identified by a search of the draft human genome database by its sequence homology to ENTs (equilibrative nucleoside transporters).

In molecular biology, the presence of amylase can serve as an additional method of selecting for successful integration of a reporter construct in addition to antibiotic resistance. As reporter genes are flanked by homologous regions of the structural gene for amylase, successful integration will disrupt the amylase gene and prevent starch degradation, which is easily detectable through iodine staining.

The archaeon Halobacterium salinarium is polyploid and, like Deinococcus radiodurans, is highly resistant to X-ray irradiation and desiccation, conditions that induce DNA double-strand breaks. Although chromosomes are shattered into many fragments, complete chromosomes can be regenerated by making use of overlapping fragments. The mechanism employs single-stranded DNA binding protein and is likely homologous recombinational repair.

The formula used for the prediction of the normal boiling point shows another problem. Joback assumed a constant contribution of added groups in homologous series like the alkanes. This doesn't describe the real behavior of the normal boiling points correctly.Stein S. E., Brown R. L., "Estimation of Normal Boiling Points from Group Contributions", J. Chem. Inf. Comput. Sci.

The pachytene stage ( ), also known as pachynema, from Greek words meaning "thick threads". is the stage at which all autosomal chromosomes have synapsed. In this stage homologous recombination, including chromosomal crossover (crossing over), is completed through the repair of the double strand breaks formed in leptotene. Most breaks are repaired without forming crossovers resulting in gene conversion.

Figure 9. Joining of single-ended double strand breaks could lead to rearrangements Without proper homologous recombination, chromosomes often incorrectly align for the first phase of cell division in meiosis. This causes chromosomes to fail to properly segregate in a process called nondisjunction. In turn, nondisjunction can cause sperm and ova to have too few or too many chromosomes.

Exosome complex exonuclease MTR3 is an enzyme that in humans is encoded by the EXOSC6 gene. This gene product constitutes one of the subunits of the multisubunit particle called the exosome complex, which mediates mRNA degradation. The composition of human exosome is similar to its yeast counterpart. This protein is homologous to the yeast Mtr3 protein.

Two pore segment channel 1 (TPC1) is a human protein encoded by the TPCN1 gene. The protein encoded by this gene is an ion channel. In contrast to other calcium and sodium channels which have four homologous domains, each containing 6 transmembrane segments (S1 to S6), TPCN1 only contains two domains (each containing segments S1 to S6).

Two pore segment channel 2 (TPC2) is a protein which in humans is encoded by the TPCN2 gene. TPC2 is an ion channel, however, in contrast to other calcium and sodium channels which have four homologous domains, each containing 6 transmembrane segments (S1 to S6), TPCN1 only contains two domain (each containing segments S1 to S6).

Functionality of syndecan is contributed by glycosaminoglycans which help in the interaction with different extracellular ligands. Depending upon the cellular localization of syndecan, glycosaminoglycans have different structures to accommodate the functional needs of the region. The syndecans are known to form homologous oligomers that may be important for their functions. Functions of syndecan can be categorized in four ways.

Most homologous papillomaviruses are actually CRPV and HPV1a. This is possibly because both of these viruses target the skin. From an evolutionary perspective, CRPV and HPV1a could have diverged recently, or they could have converged due to their similar target. CRPV is a member of the papillomaviruses so it is related to all viruses in this family.

The first description of Toll-like receptors involved in the response to infection was performed in Drosophila. culminating in a Nobel prize in 2011. The Toll pathway in Drosophila is homologous to Toll-like pathways in mammals. This regulatory cascade is initiated following pathogen recognition by pattern recognition receptors, particularly by Gram-positive bacteria, parasites, and fungal infection.

For diploid organisms such as humans and maize, each organism has two copies of a chromosome - one each from the two parents. The two copies are highly similar to each other. A haplotype is the sequence of nucleotides in a chromosome. the haplotype phasing problem is focused on the nucleotides where the two homologous chromosomes differ.

KMT2D is homologous to Trithorax-related (Trr), which is a Trithorax-group protein. The mouse and human KMT2D proteins are 5,588 and 5,537 amino acids in length, respectively. Both species of the protein weigh about 600 kDa. KMT2D contains an enzymatically active C-terminal SET domain that is responsible for its methyltransferase activity and maintaining protein stability in cells.

They also reduce the mitochondrial membrane potential in mammalian cells. Tissue specificity occurs for the different UCPs and the exact methods of how UCPs transfer H+/OH- are not known. UCPs contain the three homologous protein domains of MACPs. Transcripts of this gene are detected only in brain tissue and are specifically modulated by various environmental conditions.

Men cannot be carriers because they only have one X chromosome. The Y chromosome is not a really homologous chromosome. For this reason, the genetic make-up of the observed trait is not twofold. If a man has a certain recessive genetic disposition on his X chromosome, this is called hemizygot and it gets phenotypically expressed.

A chemical formula used for a series of compounds that differ from each other by a constant unit is called a general formula. It generates a homologous series of chemical formulae. For example, alcohols may be represented by the formula CnH(2n + 1)OH (n ≥ 1), giving the homologs methanol, ethanol, propanol for n=1–3.

The word homology, coined in about 1656, is derived from the Greek ὁμόλογος homologos from ὁμός homos "same" and λόγος logos "relation". Similar biological structures or sequences in different taxa are homologous if they are derived from a common ancestor. Homology thus implies divergent evolution. For example, many insects (such as dragonflies) possess two pairs of flying wings.

Additional research on sponge proteins found that of 42 sponge proteins that were analysed, all of them had homologous proteins that are found in humans. An identity score of 53% was given to the similarity among sponge and human proteins, compared to a score of 42% when the same sequence was compared to that of C. elegans.

Homologous genes MenB exist in many different organisms, such as; Galium mollugo, Geobacillus kaustophilus, Mycobacterium phlei, Mycobacterium tuberculosis, Spinacia oleracea, and Staphylococcus aureus. MenB is only found in biosynthesis pathways in plants and bacteria, it does not exist in any other organisms. However, mammals require vitamin K in their diet because it is vital in the blood clotting process.

Spurious low-scoring spaced-word matches are discarded, evolutionary distances between the input sequences are estimated based on the nucleotides aligned to each other at the don't-care positions of the remaining, homologous spaced-word matches. FSWM has been adapted to estimate distances based on unassembled NGS reads, this version of the program is called Read-SpaM.

The first definition allows for "chromatins" to be defined in other domains of life like bacteria and archaea, using any DNA-binding proteins that condenses the molecule. These proteins are usually referred to nucleoid-associated proteins (NAPs); examples include AsnC/LrpC with HU. In addition, some archaea do produce nucleosomes from proteins homologous to eukaryotic histones.

In addition, CV-N is active against rhinoviruses, human parainfluenza virus, respiratory syncytial virus, and enteric viruses. The virucidal activity of CV-N against influenza virus is directed towards viral haemagglutinin. CV-N has a complex fold composed of a duplication of a tandem repeat of two homologous motifs comprising three-stranded beta sheet and beta hairpins.

In addition to the potent antimicrobial activity, cytotoxicity against tumour cells and spermicidal action of maximins, maximin 3 possessed a significant anti-Simian-Human immunodeficiency virus (HIV) activity. Maximins 1 and 3 have been found to be toxic to mice. Peptides in the second group, termed maximins H1, H2, H3 and H4, are homologous with bombinin H peptides.

Signature 3 displays high mutation counts of multiple mutation classes and is associated with germline and somatic (biology) BRCA1 and BRCA2 mutations in several cancer types (e.g. breast, pancreatic, ovarian, prostate). This signature results from DNA double-strand break repair deficiency (or homologous recombination deficiency). Signature 3 is associated with high burden of indels with microhomology at the breakpoints.

All four members of the Casuariidae are large flightless birds. The northern cassowary and the emu share homologous features. For example, both have a blue patch of colour on their face/neck, but the functions of these differ. The emu's patch is of a paler colour and is used as a form of camouflage where it is located.

The breast cancer susceptibility protein BRCA2 and PALB2 controls the function of Rad51 in the pathway for DNA repair by homologous recombination. In addition to the data listed in Table 1, increased RAD51 expression levels have been identified in metastatic canine mammary carcinoma, indicating that genomic instability plays an important role in the carcinogenesis of this tumor type.

Fanconi anemia (FA) is a hereditary condition characterized by cellular hypersensitivity to DNA cross- linking agents. A dominant negative mutation in the Rad51 gene has been reported to give rise to an FA-like phenotype with features of mental retardation. This report included evidence that Rad51-mediated homologous recombinational repair likely has an important role in neurodevelopment.

Sgs1, also known as slow growth suppressor 1, is a DNA helicase protein found in Saccharomyces cerevisiae. It is a homolog of the bacterial RecQ helicase. Like the other members of the RecQ helicase family, Sgs1 is important for DNA repair. In particular, Sgs1 collaborates with other proteins to repair double- strand breaks during homologous recombination in eukaryotes.

ETS homologous factor is a protein that in humans is encoded by the EHF gene. This gene encodes a protein that belongs to an ETS transcription factor subfamily characterized by epithelial-specific expression (ESEs). The encoded protein acts as a transcriptional repressor and may be associated with asthma susceptibility. This protein may be involved in epithelial differentiation and carcinogenesis.

Molecular phylogenetics (based on homologous DNA sequences) establishes a sister group relationship between the Riodinidae and the Lycaenidae accepted almost unanimously.Dana L. Campbell and Naomi E. Pierce (2003): Phylogenetic relationships of the Riodinidae: Implications for the evolution of ant association. In: C. Boggs, P. Ehrlich, W.B. Watt (editors). Butterflies as Model Systems. Chicago University Press: 395-408.

It houses a brain and may be homologous to the prostomium of other annelids. The proboscis has rolled-in margins and a groove on the ventral surface. The distal end is sometimes forked. The proboscis can be very long; in the case of the Japanese species Ikeda taenioides, the proboscis can be long while the body is only .

Jones was involved in the early stage of development of the CATH database, with Christine Orengo and Janet Thornton which is a hierarchical domain classification of protein structures in the Protein Data Bank, where the 4 major levels in hierarchy are: Class, Architecture, Topology, and Homologous superfamily. The CATH database employs a combination of automatic and manual techniques.

Cannabidiolic acid synthase consists of a single protein with a molecular mass of 74 kDa. Its amino acid sequence is partly (40-50%) homologous to several other oxidoreductases, such as berberine bridge enzyme in Eschscholzia californica and Nectarin V in Nicotiana langsdorffii X N. sanderae. CBDA synthase has four binding sites; two for FAD and two for the substrate.

Diglyceride acyltransferase (or O-acyltransferase), DGAT, catalyzes the formation of triglycerides from diacylglycerol and Acyl-CoA. The reaction catalyzed by DGAT is considered the terminal and only committed step in triglyceride synthesis and to be essential for intestinal absorption (i.e. DGAT1) and adipose tissue formation (i.e. DGAT2). The protein is homologous to other membrane-bound O-acyltransferases.

The peripheral stalk differs in subunit composition between mitochondrial, chloroplast and bacterial F-ATPases. In bacterial and chloroplast F-ATPases, the peripheral stalk is composed of one copy of the delta subunit (homologous to OSCP in mitochondria), and two copies of subunit b in bacteria, or one copy each of subunits b and b' in chloroplasts and photosynthetic bacteria.

The spindle assembly checkpoint (SAC) is a molecular safe-guarding mechanism that governs proper chromosome segregation in eukaryotic cells. SAC inhibits progression into anaphase until all homologous chromosomes (bivalents, or tetrads) are properly aligned to the spindle apparatus. Only then, SAC releases its inhibition of the anaphase promoting complex (APC), which in turn irreversibly triggers progression through anaphase.

A transpoviron is a plasmid-like genetic element found in the genomes of giant DNA viruses. They are linear DNA elements of approximately 7 kilobases that encompass six to eight protein encoding genes. Two of these genes are homologous to virophage genes. Transpovirons encode a superfamily 1 helicase, which encompasses an inactivated family B DNA polymerase domain.

As noted above, the BRCA1 protein plays a key role in homologous recombinational repair. This is the only known cellular process that can accurately repair DNA double-strand breaks. DNA double-strand breaks accumulate with age in humans and mice in primordial follicles. Primordial follicles contain oocytes that are at an intermediate (prophase I) stage of meiosis.

Segregation of homologous chromosomes to opposite poles of the cell occurs during the first division of meiosis. Proper segregation is essential for producing haploid meiotic products with a normal complement of chromosomes. The formation of chiasmata (crossover recombination events) appears to generally facilitate proper segregation. However, in the fission yeast Schizosaccharomyces pombe, when chiasmata are absent, dynein promotes segregation.

Sertoli cells are capable of repairing DNA damage. This repair likely employs the process of non-homologous end joining involving XRCC1 and PARP1 proteins that are expressed in Sertoli cells. Sertoli cells have a higher mutation frequency than spermatogenic cells. Compared to spermatocytes, the mutation frequency is about 5 to 10-fold higher in Sertoli cells.

The fluorinase catalyses the reaction between fluoride ion and the co-factor S-adenosyl-L-methioinine (SAM) to generate 5'-fluoro-5'-deoxyadenosine (FDA) and L-methionine (L-Met).A homologous chlorinase enzyme, which catalyses the same reaction with chloride rather than fluoride ion, has been isolated from Salinospora tropica, from the biosynthetic pathway of salinosporamide A.

Repeated fertilizations within the ovary are accompanied by maturation of the ovary to form the tomato fruit. Homologs of the recA gene, including rad51, play a key role in homologous recombinational repair of DNA during meiosis. A rad51 homolog is present in the anther of tomato (Lycopersicon esculentum), suggesting that recombinational repair occurs during meiosis in tomato.

Two detached fragments of two different chromosomes are switched. Robertsonian translocation occurs when two non-homologous chromosomes get attached, meaning that given two healthy pairs of chromosomes, one of each pair "sticks" together. A gene fusion may be created when the translocation joins two otherwise-separated genes. It is detected on cytogenetics or a karyotype of affected cells.

Previous studies discussed the gizzard (i.e. a muscular oesophageal crop lined with cuticula) with gizzard plates as homologous apomorphic structures supporting a clade composed of Cephalaspidea s.s., Pteropoda and Anaspidea. A gizzard with gizzard plates probably originated in herbivorous taxa in which it worked like a grinding mill, thus might be secondarily reduced in carnivorous groups within Cephalaspidea s.s.

Similar to the pentadactyl limb in mammals, the earliest dinosaurs split into two distinct orders—the saurischia and ornithischia. They are classified as one or the other in accordance with what the fossils demonstrate. Figure 2d, shows that early saurischians resembled early ornithischians. The pattern of the pelvis in all species of dinosaurs is an example of homologous structures.

Red Brangus receive their unique coat colour from a mutation within the animal's genome. The distinctive red colouring occurs when an animal receives a receive red gene from its parents. An animal must have 2 recessive alleles in order for the animal's phenotype to display a red coat. This means that the animal will be homologous.

Some members of the family, Homologous rhodopsin-like pigments, i.e. bacteriorhodopsin (of which there are more than 800 types) have Sensory Functions like opsins, integral for visual phototransduction. Many of these sensory functions are unknown – for example, the function of Neuropsin in the human retina. Members are known to have different absorption spectra including green and blue visible light.

Changes in the regulation of gene networks are a common mechanism for prokaryotic evolution. An example of the effects of different regulatory environments for homologous proteins is the DNA-binding protein OmpR, which is involved in response to osmotic stress in E. coli but is involved in response to acidic environments in the close relative Salmonella Typhimurium.

Polysomic inheritance occurs during meiosis when chiasmata form between more than two homologous partners, producing multivalent chromosomes. Autopolyploids may show polysomic inheritance of all the linkage groups, and their fertility may be reduced due to unbalanced chromosome numbers in the gametes. In tetrasomic inheritance, four copies of a linkage group rather than two (tetrasomy) assort two-by-two.

In structural bioinformatics, de novo modeling, also known as ab initio modeling, refers to approaches for obtaining three-dimensional structures from sequences without the necessity of a homologous known 3D structure. Despite the new algorithms and methods proposed in the last years, de novo protein structure prediction is still considered one of the remain outstanding issues in modern science.

The comparative aspects of such approach resides in the analogy between animals with brain lesions and human patients with lesions in homologous areas of the brain. One example is represented by the comparison between the brain of laboratory animals (primarily non human primates and mice) with the one of people with damages resulting from alcohol abuse.

Catenin beta-1, also known as β-catenin, is a protein that in humans is encoded by the CTNNB1 gene. β-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcription. In humans, the CTNNB1 protein is encoded by the CTNNB1 gene. In Drosophila, the homologous protein is called armadillo.

Approximately half of all ovarian cancers are deficient in homologous recombination (HR). These HR-deficient tumors upregulate polymerase theta (POLQ), resulting in an increase in MMEJ. These tumors are hyper-reliant upon MMEJ, so that knockdown of polymerase theta results in substantial lethality. In most cell types, MMEJ makes a minor contribution to double strand break repair.

Expression of four key DNA repair genes that are necessary for homologous recombinational repair during meiosis (BRCA1, MRE11, Rad51, and ATM) decline with age in oocytes. This age-related decline in ability to repair DNA double-strand damages can account for the accumulation of these damages, that then likely contributes to the depletion of the ovarian reserve.

As women (and mice) age, double-strand breaks accumulate in their primordial follicle reserve. These follicles contain primary oocytes that are arrested in prophase of the first cell division of meiosis. Double- strand breaks are accurately repaired during meiosis by searching for, and building off of, the matching strand (termed “homologous recombinational repair”). Titus et al.

Liver glucokinase occurs widely but not universally throughout vertebrate species. The gene structure and amino acid sequence are highly conserved among most mammals (e.g., rat and human glucokinase is more than 80% homologous). However, there are some unusual exceptions: For example, it has not been discovered in cats and bats, though some reptiles, birds, amphibians, and fish have it.

Amphibians have a skeletal system that is structurally homologous to other tetrapods, though with a number of variations. They all have four limbs except for the legless caecilians and a few species of salamander with reduced or no limbs. The bones are hollow and lightweight. The musculoskeletal system is strong to enable it to support the head and body.

Drosophila Titin, also known as Kettin or sallimus (sls), is kinase-free. It has roles in the elasticity of both muscle and chromosomes. It is homologous to vertebrate titin I-band and contains Ig PEVK domains, the many repeats being a hot target for splicing. There also exists a titin homologue, ttn-1, in C. elegans.

The N-terminal domain contains a three-layer alpha/beta/alpha sandwich that is homologous with the Rossmann fold (CATH class 3.40.50.170) of which the major feature is a long beta sheet that is composed of nine mostly parallel beta strands. SurEstructural domain has a similar topology to the N-terminal protein domain of the glutaminase/asparaginase family.

Zebende, G. and Moret, M. Phys. Rev. E 75, 011920 (2007) He has proved the superiority of this scale against other scales for numerous (especially heptad) transmembrane proteins. Using profile smoothing methods he has found otherwise inaccessible correlations between protein properties and thousands of amino acid sequences, based on homologous globular features of water film packages.

GamEvac-Combi () is a heterologous VSV- and Ad5-vectored Ebola vaccine. There is also a version called GamEvac which is a homologous Ad5-vectored vaccine. GamEvac-Combi was developed by Gamaleya Research Institute of Epidemiology and Microbiology. the vaccine has been licensed in Russia for emergency use, on the basis of Phase 1 and Phase 2 clinical trials.

The Germ line is the gametic line where the gamete formation takes place. The number of chromosomes during this line is different in males and females. In the formation sperms of males the 1st spermatocystic division is monocentric mitosis, the maternal and paternal homologous chromosomes are separated. Then few limited chromosomes are eliminated not all of them.

Another method is to identify homologous sequences based on other known gene sequences (Tools see Table 4.3). The two methods described here are focused on the sequence. However, the shape feature of these molecules such as DNA and protein have also been studied and proposed to have an equivalent, if not higher, influence on the behaviors of these molecules.

Steroid hormones are converted from their parent compound, cholesterol. Mammalian steroid hormones can be grouped into five groups by the receptors to which they bind: glucocorticoids, mineralocorticoids, androgens, estrogens, and progestogens. Some forms of vitamin D, such as calcitriol, are steroid-like and bind to homologous receptors, but lack the characteristic fused ring structure of true steroids.

In bioinformatics, sequence clustering algorithms attempt to group biological sequences that are somehow related. The sequences can be either of genomic, "transcriptomic" (ESTs) or protein origin. For proteins, homologous sequences are typically grouped into families. For EST data, clustering is important to group sequences originating from the same gene before the ESTs are assembled to reconstruct the original mRNA.

Homologous animals have the same causes, symptoms and treatment options as would humans who have the same disease. Isomorphic animals share the same symptoms and treatments, only. Predictive models are similar to a particular human disease in only a couple of aspects. However, these are useful in isolating and making predictions about mechanisms of a set of disease features.

Many LCRs are concentrated in "hotspots", such as the 17p11-12 region, 27% of which is composed of LCR sequence. NAHR and non-homologous end joining (NHEJ) within this region are responsible for a wide range of disorders, including Charcot–Marie–Tooth syndrome type 1A, hereditary neuropathy with liability to pressure palsies, Smith–Magenis syndrome, and Potocki–Lupski syndrome.

CENP-B is an 80kDa DNA binding protein involved in the folding of heterochromatin. CENP-C is a 140kDa protein involved in kinetochore assembly. CENP-D is a 50kDa protein of unknown function, but may be homologous to another protein involved in chromatin condensation, RCC1. CENP-E is a 312kDa protein from the kinesin motor protein family.

This bears a small pseudobranch that resembles a gill in structure, but only receives blood already oxygenated by the true gills. The spiracle is thought to be homologous to the ear opening in higher vertebrates.Laurin M. (1998): The importance of global parsimony and historical bias in understanding tetrapod evolution. Part I-systematics, middle ear evolution, and jaw suspension.

The superior colliculus (Latin for "upper hill") is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form tectal is commonly used for both structures. In mammals, the superior colliculus forms a major component of the midbrain.

These two complexes act at two different stages of homologous recombinational DNA repair. The CX3 complex acts downstream of RAD51, after its recruitment to damage sites. The CX3 complex associates with Holliday junction resolvase activity, probably in a role of stabilizing gene conversion tracts. The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites.

There is an epigenetic cause of XRCC3 deficiency that appears to increase cancer risk. This is the repression of XRCC3 by over- expression of EZH2 protein. Increased expression of EZH2 leads to epigenetic repression of RAD51 paralogs, including XRCC3, and thus reduces homologous recombinational repair. This reduction was proposed to be a cause of breast cancer.

Hemocyanin is homologous to the phenol oxidases (e.g. tyrosinase) since both proteins share type 3 Cu active site coordination. In both cases inactive proenzymes such as hemocyanin, tyrosinase, and catcholoxidase must be activated first. This is done by removing the amino acid that blocks the entrance channel to the active site when the proenzyme is not active.

Li et al. showed that overexpression of HMGA2 delayed the release of DNA-PKcs (needed for non-homologous end joining DNA repair) from double strand break sites. Overexpression of HMGA2 alone was sufficient to induce chromosomal aberrations, a hallmark of deficiency in NHEJ-mediated DNA repair. These properties implicate HMGA2 in the promotion of genome instability and tumorigenesis.

The intergeniculate leaflet is a relatively small area found dorsal to the vLGN. Earlier studies had referred to the IGL as the internal dorsal division of the vLGN. Several studies have described homologous regions in several species, including humans. The vLGN and IGL appear to be closely related based on similarities in neurochemicals, inputs and outputs, and physiological properties.

The RydB RNA is a non-coding RNA originally identified in E. coli in an RNA screen. This gene is only 67 nucleotides in length and is composed of a hairpin like structure. RydB lies between the ydiC and ydiH in E. coli. Homologous RNA genes have been found in other species such as Shigella flexneri and Salmonella species.

The duplication is believed to arise de novo as a result of non-allelic homologous recombination (NAHR) between the proximal and distal ORDRs. NAHR is also thought to give rise to the reciprocal microdeletion syndrome, the polymorphic inversion between the ORDRs and a variety of other large scale abnormalities involving the short arm of chromosome 8.

Pol λ is a member of the X family of DNA polymerases. It is thought to resynthesize missing nucleotides during non-homologous end joining (NHEJ), a pathway of DNA double-strand break (DSB) repair. NHEJ is the main pathway in higher eukaryotes for repair of DNA DSBs. Chromosomal DSBs are the most severe type of DNA damage.

Mi-III, Mi-VI and Mi-X are due to rearrangements of glycophorin A and B in the order GlyA (alpha)-GlyB (delta)-GlyA (alpha). Mil-IX in contrast is a reverse alpha-delta-alpha hybrid gene. Mi-V, MiV(J.L.) and Sta are due to unequal but homologous crossing-over between alpha and delta glycophorin genes.

This method begins with alignment of homologous genes, followed by identification of regions of polymorphism. Next the top strand of the gene is divided into small degenerate oligonucleotides. The bottom strand is also digested into oligonucleotides to serve as scaffolds. These fragments are combined in solution are top strand oligonucleotides are assembled onto bottom strand oligonucleotides.

The Bartholin's glands (also called Bartholin glands or greater vestibular glands) are two pea sized compound alveolar glandsManual of Obstetrics. (3rd ed.). Elsevier. pp. 1-16. . located slightly posterior and to the left and right of the opening of the vagina. They secrete mucus to lubricate the vagina and are homologous to bulbourethral glands in males.

There are two pathways for homologous recombinational repair of double-strand breaks. The major pathway depends on BRCA1, PALB2 and BRCA2 while an alternative pathway depends on RAD52. Pre-clinical studies, involving epigenetically reduced or mutated BRCA-deficient cells (in culture or injected into mice), show that inhibition of RAD52 is synthetically lethal with BRCA- deficiency.

Patrocladograms are graphs that assert hypotheses of similarity whereas phylogenetic trees are graphs that assert hypotheses of common ancestry. When a patrocladogram does not logically match with a comparable phylogenetic tree hypothesis it should not be used to define monophyletic groups. The usage of patrocladograms can skew interpretations of novel evolution or depict homologous traits as homoplastic.

Repair of these double-strand breaks appears to use an RNA template-based recombination mechanism dependent on RAD52. The Cockayne Syndrome B protein (CSB) (coded for by ERCC6) localizes at double-strand breaks at sites of active transcription, followed by RAD51, RAD51C and RAD52 to carry out homologous recombinational repair using the newly synthesized RNA as a template.

Mi-III, Mi-VI and Mi-X are due to rearrangements of glycophorin A and B in the order GlyA (alpha)-GlyB (delta)-GlyA (alpha). Mil-IX in contrast is a reverse alpha-delta-alpha hybrid gene. Mi-V, MiV(J.L.) and Sta are due to unequal but homologous crossing-over between alpha and delta glycophorin genes.

Some texts consider it to be found only in males, and cite the vaginal artery as the homologous structure in females. Other texts consider it to be present in both males and females. \- "The Female Pelvis: Branches of Internal Iliac Artery" In these contexts, the inferior vesical artery in females is a small branch of a vaginal artery.

Kallikrein-related peptidase 7 (KLK7) is a serine protease that in humans is encoded by the KLK7 gene. KLK7 was initially purified from the epidermis and characterised as stratum corneum chymotryptic enzyme (SCCE). It was later identified as the seventh member of the human kallikrein family, which includes fifteen homologous serine proteases located on chromosome 19 (19q13).

NHEJ can also introduce mutations during repair. Loss of damaged nucleotides at the break site can lead to deletions, and joining of nonmatching termini forms insertions or translocations. NHEJ is especially important before the cell has replicated its DNA, since there is no template available for repair by homologous recombination. There are "backup" NHEJ pathways in higher eukaryotes.

A polycomb repressive complex (PRC); PRC2, mediates the tri-methylation of histone 3 on lysine 27 through histone methyl transferase activity. This mark can recruit PRC1 which will bind and contribute to the compaction of the chromatin. H3K27me3 is linked to the repair of DNA damages, particularly repair of double-strand breaks by homologous recombinational repair.

He wrote that "Societies are based on practices that derived from many distinct structures, which exist at different levels, operate in different modalities, and are themselves based on widely varying types and quantities of resources. ...It is never true that all of them are homologous."Sewell, Jr., W. H. (1992). A theory of structure: duality, agency, and transformation.

Cospin, is the first fungal trypsin inhibitor with a determined 3D structure, it utilizes a different loop for trypsin inhibition compared to other beta-trefoil inhibitors.Sasakawa H., Yoshinaga S., Kojima S., Tamura A. (2002): Structure of POIA1, a homologous protein to the propeptide of subtilisin. Implication for protein foldability and the function as an intramolecular chaperone. J. Mol. Biol.

SIRT1, SIRT6 and SIRT7 proteins are employed in DNA repair. SIRT1 protein promotes homologous recombination in human cells and is involved in recombinational repair of DNA breaks. SIRT6 is a chromatin-associated protein and in mammalian cells is required for base excision repair of DNA damage. SIRT6 deficiency in mice leads to a degenerative aging-like phenotype.

Thus these cells have an influx transporter on one side and an efflux transporter on the other side of the cell to permit the effective transcellular transport of the nutrient. ArsA proteins are homologous to nitrogenase iron (NifH) proteins 2 of bacteria and to protochlorophyllide reductase iron sulfur ATP-binding proteins of cyanobacteria, algae and plants.

There are two pathways for homologous recombinational repair of double-strand breaks. The major pathway depends on BRCA1, PALB2 and BRCA2 while an alternative pathway depends on RAD52. Pre-clinical studies, involving epigenetically reduced or mutated BRCA-deficient cells (in culture or injected into mice), show that inhibition of RAD52 is synthetically lethal with BRCA-deficiency.

Total human chromosomes or their arms can efficiently paint extended chromosome regions in many placentals down to Afrotheria and Xenarthra. Gene localization data on human chromosomes can be extrapolated to the homologous chromosome regions of other species with high reliability. Usefully, humans express conserved syntenic chromosome organization similar to the ancestral condition of all placental mammals.

ETEC is the type of E. coli that most vaccine development efforts are focused on. Antibodies against the LT and major CFs of ETEC provide protection against LT-producing, ETEC-expressing homologous CFs. Oral inactivated vaccines consisting of toxin antigen and whole cells, i.e. the licensed recombinant cholera B subunit (rCTB)-WC cholera vaccine Dukoral, have been developed.

Genes in E. coli are usually named by 4-letter acronyms that derive from their function (when known) and italicized. For instance, recA is named after its role in homologous _rec_ ombination plus the letter A. Functionally related genes are named recB, recC, recD etc. The proteins are named by uppercase acronyms, e.g. RecA, RecB, etc.

Scales on talons of a Steller's sea eagle (Haliaeetus pelagicus) Birds' scales are found mainly on the toes and metatarsus, but may be found further up on the ankle in some birds. The scales and scutes of birds were thought to be homologous to those of reptiles, but are now agreed to have evolved independently, being degenerate feathers.

Such "multi-subunit" assemblies usually involve a circular arrangement of identical or homologous proteins closely packed around a water-filled pore through the plane of the membrane or lipid bilayer. For most voltage-gated ion channels, the pore-forming subunit(s) are called the α subunit, while the auxiliary subunits are denoted β, γ, and so on.

The genome of P. patens has been sequenced, which has allowed several genes involved in DNA repair to be identified. P. patens mutants that are defective in key steps of homologous recombination have been used to work out how the repair mechanism functions in plants. For example, a study of P. patens mutants defective in RpRAD51, a gene that encodes a protein at the core of the recombinational repair reaction, indicated that homologous recombination is essential for repairing DNA double-strand breaks in this plant. Similarly, studies of mutants defective in Ppmre11 or Pprad50 (that encode key proteins of the MRN complex, the principal sensor of DNA double- strand breaks) showed that these genes are necessary for repair of DNA damage as well as for normal growth and development.

In the field of organic chemistry, a homologous series is a sequence of compounds with the same functional group and similar chemical properties in which the members of the series can be branched or unbranched. This can be the length of a carbon chain, for example in the straight-chained alkanes (paraffins), or it could be the number of monomers in a homopolymer such as amylose. Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties. (For example, the series of primary straight-chained alcohols has a hydroxyl at the end of the carbon chain.) These properties typically change gradually along the series, and the changes can often be explained by mere differences in molecular size and mass.

It seems that conversion tracts accompanying crossover are longer (mean length = ∼460 bp) than conversion tracts without crossover (mean length = 55–290 bp). In the studies of human globulin genes, it has long been supported that the gene conversion event or branch migration events can either be promoted or inhibited by the specific motifs that exist in the vicinity of the DNA sequence (Papadakis and Patrinos, 1999). Another basic classification of gene conversion events is the interlocus (also called nonallelic) and interallelic gene conversions. The cis or trans nonallelic or interlocus gene conversion events occur between nonallelic gene copies residing on sister chromatids or homologous chromosomes, and, in case of interallelic, the gene conversion events take place between alleles residing on homologous chromosomes (Adapted from Chen et al.

In this case therefore the separation of homologous chromosomes follows the segregation of sister chromatids. However, in order to have a successful inverted meiosis, it is necessary that a bipolar orientation of sister kinetochores occurs, together with their attachment to microtubules from opposite spindle poles in meiosis I. This allows the segregation of sister chromatids to opposite poles in anaphase I (equational division), but it requests a mechanism to align and pair homologous chromosomes during the second meiotic division. Interestingly, the presence of inverted meiosis can also facilitate the proper chromosome segregation in hybrids from parental species with differences in their karyotypes or derived by populations with rearranged karyotype allowing rescue of the fertility and viability of hybrids and promoting a fast karyotype evolution and possibly chromosomal speciation, as reported in Lepidoptera.

The most unusual feature was that the dorsal surface also had two thick ossifications, with smooth surfaces and wide bases, which cannot be part of the parietal bone. This demonstrates the existence of paired ossifications between the supraoccipital and the parietal, which can only be homologous to the postparietals of basal amniotes. There may be something similar in some species of Cymbospondylus.

Fms-related tyrosine kinase 3 ligand (FLT3LG) is a protein which in humans is encoded by the FLT3LG gene. Flt3 ligand (FL) is a hematopoietic four helical bundle cytokine. It is structurally homologous to stem cell factor (SCF) and colony stimulating factor 1 (CSF-1). In synergy with other growth factors, Flt3 ligand stimulates the proliferation and differentiation of various blood cell progenitors.

DNA interstrand cross-links (ICLs) cause replication stress by blocking replication fork progression. This blockage leads to failure of DNA strand separation and a stalled replication fork. Repair of ICLs can be accomplished by sequential incisions, and homologous recombination. In vertebrate cells, replication of an ICL-containing chromatin template triggers recruitment of more than 90 DNA repair and genome maintenance factors.

This process brings the incoming DNA to the corresponding site in the B. subtilis chromosome where informational exchange occurs. Michod et al. have reviewed evidence that RecA-mediated transformation is an adaptation for homologous recombinational repair of DNA damage in B. subtilis, as well as in several other bacterial species (i.e. Neisseria gonorrhoeae, Hemophilus influenzae, Streptococcus pneumoniae, Streptococcus mutans and Helicobacter pylori).

Proteins that are considered to be INAVA paralogs are not consistent between databases. A multiple sequence alignment (MSA) of potentially paralogous proteins was made to determine the likelihood of a truly paralogous relationship. The sequences were retrieved from a BLAST search in humans with the C1orf106 protein. The MSA suggests the proteins share a homologous domain, DUF3338, which is found in eukaryotes.

However, a homologous IIC protein from Listeria monocytogenes has been shown to be required for D-arabitol fermentation. It presumably functions together with IIAGat and IIBGat homologues. IICGat is distantly related to IICSgc of E. coli; IIAGat is distantly related to IIASga and IIASgcof E. coli as well as IIAMtl and IIAFru. IIBGat is distantly related to IIBSga and IIBSgc of E. coli.

The rod domain connects to the head domain. The head domain 84 amino acids with many arginine, serine, and aromatic residues is important in filament assembly and dimer-dimer interactions. The tail domain is responsible for the integration of filaments and interaction with proteins and organelles. Desmin is only expressed in vertebrates, however homologous proteins are found in many organisms.

Even though these RAB family proteins are highly homologous to each other (RAB2A and RAB2B have 85.8% amino acid identity), the knockdown of any of them (from RAB1A to RAB8A) causes Golgi complex to disperse through the cell's cytoplasm. Because of this, the RAB2B-GARIL5 complex stops functioning properly, affecting the IFN response and enhancing the replication of many viruses, as seen previously.

From the large intestine, a rectum ascends towards the anus. Despite the names, the small and large intestines of sea urchins are in no way homologous to the similarly named structures in vertebrates. Digestion occurs in the intestine, with the caecum producing further digestive enzymes. An additional tube, called the siphon, runs beside much of the intestine, opening into it at both ends.

Crystal structure of a RecA protein filament bound to DNA.; A 3' overhang is visible to the right of center. Homologous recombination is a major DNA repair process in bacteria. It is also important for producing genetic diversity in bacterial populations, although the process differs substantially from meiotic recombination, which repairs DNA damages and brings about diversity in eukaryotic genomes.

True flies are insects of the order Diptera. The name is derived from the Greek di- = two, and ptera = wings. Most insects of this order have two wings (not counting the halteres, club-like limbs which are homologous to the second pair of wings found on insects of other orders). Wingless flies are found on some islands and other isolated places.

The recently available Acanthamoeba genome sequence revealed several orthologs of genes employed in meiosis of sexual eukaryotes. These genes included Spo11, Mre11, Rad50, Rad51, Rad52, Mnd1, Dmc1, Msh and Mlh. This finding suggests that Acanthamoeba is capable of some form of meiosis and may be able to undergo sexual reproduction. In sexually reproducing eukaryotes, homologous recombination (HR) ordinarily occurs during meiosis.

Unlike yeast, several human homologs of the ERD2 gene, constituting the KDEL receptor gene family, have been described. KDELR3 was the third member of the family to be identified, and it encodes a protein highly homologous to KDELR1 and KDELR2 proteins. Two transcript variants of KDELR3 that arise by alternative splicing, and encode different isoforms of KDELR3 receptor, have been described.