Image HR in meiosis.svg thumb 275px alt Depiction of chromosome 1 after undergoing homologousrecombination in meiosis Figure 1. During meiosis , homologousrecombination can produce new combinations of genes ... 1 human chromosome 1 . Homologousrecombination is a type of genetic recombination in which nucleotide ... as double strand breaks. Homologousrecombination also produces new combinations of DNA sequences ... 48122761 57023651 69932405 ref Homologousrecombination is also used in horizontal gene transfer ... homologousrecombination varies widely among different organisms and cell types, most forms involve ... molecules. Depending on how the two junctions are cut by enzyme s, the type of homologousrecombination that occurs in meiosis results in either chromosomal crossover or non crossover. Homologousrecombination ... the damaged DNA molecule as it existed before the double strand break. Homologousrecombination ... homologousrecombination are topics of active research. Homologousrecombination is also ... a double strand chromosome break by homologousrecombination revisiting Robin Holliday s model ... a model now known as the Homologousrecombination DSBR pathway DSBR pathway , which accounted for observations ... , budding yeast and mammalian cells led to the emergence of other models of homologousrecombination, called Homologousrecombination SDSA pathway SDSA pathways , which do not always rely on Holliday junctions. ref name Haber 2004 In eukaryotes Homologousrecombination is essential to cell division ... , homologousrecombination repairs double strand breaks in DNA caused by ionizing radiation or DNA damaging ... 2000 publisher W. H. Freeman and Company isbn 0 7167 3136 3 chapter 12.5 Recombination between Homologous ... 85798 pmid 11242102 ref In addition to repairing DNA, homologousrecombination also helps produce ... within the cell cycle Image Cell Cycle 2.svg 250px thumb Figure 3. Homologousrecombination repairs ... be repaired through homologousrecombination or through non homologous end joining NHEJ . NHEJ is a DNA ... more details
Non allelic homologousrecombination NAHR is a form of homologousrecombination that occurs between two lengths of DNA that have high sequence homology biology homology , but are not allele s. ref name Hurles ref name pmid17637735 cite journal author Beckmann JS, Estivill X, Antonarakis SE title Copy number variants and genetic traits closer to the resolution of phenotypic to genotypic variability journal Nat. Rev. Genet. volume 8 issue 8 pages 639 46 year 2007 month August pmid 17637735 doi 10.1038 nrg2149 url ref It usually occurs between sequences of DNA that have been previously Segmental duplication duplicated through evolution, and therefore have low copy repeats LCRs . When non allelic homologousrecombination occurs between different LCRs, Deletion genetics deletions or further Gene duplication duplications of the DNA can occur. This can give rise to rare genetic disorder s, caused by the loss or increased copy number of genes within the deleted or duplicated region. It can also contribute to the copy number variation seen in some gene clusters. ref name pmid20333217 cite journal author Karn RC, Laukaitis CM title The mechanism of expansion and the volatility it created in three pheromone gene clusters in the mouse Mus musculus genome journal Genome Biol Evol volume 1 issue pages 494 503 year 2009 pmid 20333217 pmc 2839280 doi 10.1093 gbe evp049 url ref As LCRs are often ... name Hurles Citation last Hurles first Matthew, et al contribution Recombination Hotspots in Nonallelic HomologousRecombination title Genomic Disorders The Genomic Basis of Disease pages 341 355 publisher ... cite journal author Venturin M, Gervasini C, Orzan F, et al. title Evidence for non homologous end joining and non allelic homologousrecombination in atypical NF1 microdeletions journal Hum ... ref See also Genetic recombination Non homologous end joining References Reflist genetics stub DEFAULTSORT Non allelic homologousrecombination Category Genetics ... more details
wiktionary recombinationRecombination may refer to Genetic recombination , the process by which genetic material is broken and joined to other genetic material Recombination physics , in semiconductors, the elimination of mobile charge carriers electrons and holes Crossover genetic algorithm , also called recombination Plasma recombination , the formation of neutral atoms from the capture of free electrons by the cations in a plasma Recombination cosmology , the time at which protons and electrons formed neutral hydrogen in the timeline of the Big Bang Recombination chemistry , the opposite of dissociation, or disambig ar ca Recombinaci cs Rekombinace fr Recombinaison he hu Rekombin ci egy rtelm s t lap ja pl Rekombinacja ru sr sv Rekombination zh ... more details
Orphan date April 2012 Ectopic recombination is the Genetic recombinationrecombination between sequences like Leucine leu2 sequences present at different genomic locations. ref Meiotic Gene conversion Gene Conversion and Crossing Over Between Dispersed Homologous Sequences Occurs Frequently in Saccharomyces cerevisiae . Genetics 115 233 246 February, 1987 .Michael Lichten, Rhona H. Borts and James E. Haber ref Reference reflist Category Cellular processes Category Molecular genetics genetics stub ... more details
Homologous chromosomes also called homologs or homologues are chromosome pairs of approximately the same length, centromere position, and staining pattern, with genes for the same characteristics at corresponding Locus genetics loci . One Homology biology homologous chromosome is inherited from the organism s mother the other from the organism s father. ref name Campbell cite book author Reece, Jane Campbell, Neil title Biology publisher Benjamin Cummings location San Francisco year 2002 isbn 0 8053 6624 5 ref They are usually not identical. Homologous chromosomes pair synapsis synapse during meiosis the cell division that occurs as part of the creation of gamete s. Sections of the DNA can sometimes Chromosomal crossover cross over between homologous pairs. Each chromosome in the pair contains genes for the same biological features, such as eye color, at the same locations locus genetics loci on the chromosome. However, each can contain either the same allele e.g., both alleles for blue eyes or different alleles e.g., one allele for blue eyes and one allele for brown eyes for each feature. Homologous chromosomes are usually similar in length, except for the sex chromosome s in several ... share only small regions of homology biology homology . Humans have 22 pairs of homologous non sex ... to the 22 pairs of homologous autosomes, female humans have a homologous pair of sex chromosomes ... is the number of homologous versions it has of each chromosome. If the chromosomes of an organism ... chromosome in a diploid organism has exactly one homologous partner. Each chromosome from these pairs ... from two parents . In fact the chromosomes physically arrange themselves into homologous pairs ... have more than two homologous chromosomes. Sister chromatids In meiosis sister chromatid s are each strand of the conjoined chromosomes which result from the replication and crossover of homologous ... Homologous chromosome sr tr Homolog kromozom uk zh ... more details
Orphan date April 2012 Homologous desensitization occurs when a Receptor biochemistry receptor decreases its response to a signalling molecule when that agonist is in high concentration. ref cite web title homologous desensitization url http www.drugs.com dict homologous desensitization.html work Medical Dictionary publisher Drugs.com accessdate 18 May 2011 ref It is a process whereby after prolonged agonist exposure, the receptor is uncoupled from its signaling cascade, and thus the biological effect of receptor activation is attenuated. ref cite journal last Fehmann first HC coauthors Habener, JF title Homologous desensitization of the insulinotropic glucagon like peptide I 7 37 receptor on insulinoma HIT T15 cells. journal Endocrinology date 1991 Jun volume 128 issue 6 pages 2880 8 pmid 1645253 accessdate 18 May 2011 doi 10.1210 endo 128 6 2880 ref Homologous desensitization should not be confused with heterologous desensitisation , which is a different process whereby repeated stimulation of a receptor by one agonist results in desensitivity to a range of other agonists. Mechanism The mechanism of homologous desensitization is as follows using the Beta 2 adrenergic receptor sub 2 sub receptor as an example Agonist binds and activates receptor which changes to an active conformational state. Beta adrenergic receptor kinase BARK , a cytoplasmic kinase is activated and phosphorylation phosphorylates the C terminus of the sub 2 sub receptor. Such phosphorylation increases the affinity of arrestin arrestin for the receptor, resulting in uncoupling of the Gs alpha subunit subunit of the G proteins heterotrimeric G protein from the receptor producing desensitization. References reflist Category Membrane biology Category G protein coupled receptors Category Signal transduction sr Homologna desenzitizacija ... more details
Unreferenced stub auto yes date December 2009 Homologous temperature expresses the temperature of a material as a fraction of its melting point temperature using the Kelvin scale . For example, the homologous temperature of lead at room temperature is approximately 0.50 T sub H sub T T sub mp sub 298K 601K 0.50 . Solder T sub mp sub 183 C 456K at 0.85T sub mp sub or 115 C 388K , would thus be expected to have comparable properties to copper T sub mp sub 1085 C 1358K at 0.85T sub mp sub or 881 C 1154K . In electronics applications, where circuits typically operate over a 55 C to 125 C range, eutectic tin lead Sn63 solder is working at 0.48T sub mp sub to 0.87T sub mp sub . The upper temperature is high relative to the melting point from this we can deduce that solder will have limited mechanical strength as a bulk material and significant Creep deformation creep under stress. This is borne out by its comparatively low values for tensile strength, shear strength and modulus of elasticity. Citation needed date April 2009 Copper, on the other hand, has a much higher melting point, so foils are working at only 0.16T sub mp sub to 0.29T sub mp sub , and their properties are little affected by temperature. DEFAULTSORT Homologous Temperature Category Units of temperature Physics stub Measurement stub ... more details
In chemistry , a homologous series is a series of compounds with a similar General formula General forms for organic compounds general formula , possessing similar chemical properties due to the presence of the same functional group , and showing a gradation in physical properties as a result of increase in molecular size and mass see relative molecular mass . For example, ethane has a higher boiling point than methane since it has more Van der Waals forces intermolecular forces with neighbouring molecules. This is due to the increase in the number of atoms making up the molecule. Alkane s paraffin s , alkene s olefins , ethers , and alkyne s acetylene s form such series in which members differ in mass by 14 atomic mass units. For example, the alkane homologous series begins with methane CH sub 4 sub , ethane C sub 2 sub H sub 6 sub , propane C sub 3 sub H sub 8 sub , butane C sub 4 sub H sub 10 sub , and pentane C sub 5 sub H sub 12 sub , each member differing from the previous one by a CH sub 2 sub group or 14 atomic mass units . The CH sub 2 sub group is called Methylene Group. Similarly, there is the alcohol homologous series that starts with methanol CH sub 4 sub O , ethanol C sub 2 sub H sub 6 sub O , as primary alcohols, isopropanol C sub 3 sub H sub 8 sub O as a simple secondary alcohol, and a simple tertiary alcohol is tert butanol tert butanol C sub 4 sub H sub 10 sub O . Even though the general formula remains constant in a homologous series, specific members of the series ... groups . center table border 0 style text align center tr td Homologous series td td General ... reaction is any chemical process which converts one member of a homologous series to the next member. Inorganic Homologous Series Commons category Homologous series Homologous series are not unique to organic chemistry . Titanium , vanadium , and molybdenum oxides all form homologous series ... 2009 DEFAULTSORT Homologous Series Category Organic chemistry ar bg cs Homologick ... more details
Nonhomologous recombination main Non homologous end joining Recombination can occur between DNA sequences ... Animated guide to homologousrecombination. References Reflist NCBI scienceprimer Genetic ...Genetic recombination is a process by which a molecule of nucleic acid usually DNA , but can also be RNA is broken and then joined to a different one. Recombination can occur between Homology biology similar molecules of DNA, as in homologousrecombination , or dissimilar molecules, as in non homologous end joining . Recombination is a common method of DNA repair in both bacteria and eukaryotes . In eukaryotes, recombination also occurs in meiosis , where it facilitates chromosomal crossover . The crossover ... immune system , a type of genetic recombination called V D J recombination helps immune cells ... recombination is thought to have many advantages, as it is a major engine of genetic variation ... manner. In genetic engineering , recombination can also refer to artificial and deliberate recombination of disparate pieces of DNA, often from different organisms, creating what is called recombinant DNA . A prime example of such a use of genetic recombination is gene targeting , which ... on genetic recombination are also applied in protein engineering to develop new proteins of biological interest. Genetic recombination is catalysis catalyzed by many different enzyme s, called recombinase ... recombination, whereas the DMC1 gene DMC1 protein is specific to meiotic recombination. Chromosomal ... of crossing over 1916 Chromosomal crossover refers to recombination between the paired chromosome ..., homology biology homologous sites on two chromatids can mesh with one another, and may ... 8153 3218 3 ref Because recombination can occur with small probability at any location along chromosome, the recombination frequency frequency of recombination between two locations depends on their distance ... recombination are said to be linked. One gene in a linked pair can sometimes be used as a marker to deduce ... more details
Unreferenced stub auto yes date December 2009 Dissociative recombination is a process where a positive molecular ion recombines with an electron, and as a result, the neutral molecule dissociates. This reaction is important for extraterrestrial and atmospheric chemistry. On Earth , dissociative recombination is practically non existent, as free electrons would react with any molecule even neutral molecules they encounter. Even in the best laboratory conditions, dissociative recombination is hard to observe. In astrophysics , dissociative recombination is one of the main paths via which molecules are broken down, and other molecules are formed. The existence of dissociative recombination is possible due to the vacuum of the interstellar medium . A typical example of dissociative recombination in astrophysics is math CH 3 e rightarrow CH 2 H math See also Ionization DEFAULTSORT Dissociative Recombination Category Astrophysics Chem stub Astronomy stub fr Recombinaison dissociative nl Dissociatieve recombinatie ... more details
Unreferenced date October 2008 Plasma recombination is a process by which ion s of a Plasma physics plasma capture the free energetic electron s to form new neutral atom s. Recombination usually take place in the whole volume of a plasma volume recombination , although in some cases it is confined to some special region of it. Each kind of reaction is called a recombining mode and their individual rates are strongly affected by the properties of the plasma such as its energy heat , density of each species, pressure and temperature of the surrounding environment. Especially volume recombination is a very unlikely process at pressures below 1× 10 sup 4 sup Pa because of the conservation of energy and momentum. A third body is needed to satisfy the conservation laws. If the volume of the plasma is confined by a body the walls play the role of the third body. So recombination mostly occurs at the walls. Hydrogen recombination modes are of vital importance in the development of divertor regions for tokamak reactors. In fact they will provide a good way for extracting the energy produced in the core of the plasma. At the present time, it is believed that the most likely plasma losses observed in the recombining region are due to two different modes electron ion recombination EIR and molecular activated recombination MAR . physics stub Category Plasma physics Recombination, plasma ... more details
Recombination hotspots are regions in a genome that exhibit elevated rates of recombination, relative to a neutral expectation. The peak recombination rate within hotspots can be hundreds or thousands of times that of the surrounding region. ref Jeffreys, A.J., Kauppi, L., & Neumann, R., Intensely punctate meiotic recombination in the class II region of the major histocompatibility complex. , Nature Genetics 29, 217 222 2001 ref The PRDM9 protein is suspected to be a cause of hotspots in mammals. All hotspots so far characterized share similar morphology and are approximately 1.5 to 2.0 base pair Length measurements kb in width, which suggests a common causal process. Furthermore, recent studies have used patterns in linkage disequilibrium to identify over 25,000 hotspots in the human genome , ref Myers S., Bottolo L., Freeman C., McVean G. and Donnelly P., A Fine Scale Map of Recombination Rates and Hotspots Across the Human Genome , Science, Vol. 310. no. 5746, pp. 321 324 2005 ref suggesting that hotspots are a ubiquitous feature of the genome. See also Evolution Further reading http www.ox.ac.uk media news stories 2005 050211.html Researchers find surprising difference between human and chimp genomes Despite 99 DNA similarity between humans and our nearest relative, chimpanzees, the locations of DNA swapping between chromosomes, known as recombination hotspots, are almost entirely different. The surprising finding is reported in a paper published in 2005 in Science by Oxford University statisticians and US and Dutch geneticists. http biology.plosjournals.org perlserv?request get document&doi 10.1371 journal.pbio.0020190 What s so hot about recombination hotspots? A primer on recombination hotspots by Jody Hey in PLoS Biology References Reflist Category Molecular genetics Genetics stub de Hotspot Genetik ... more details
Physical cosmology In cosmology , recombination refers to the epoch astronomy epoch at which charged ... hydrogen atom s. ref group nb Note that the term recombination is a misnomer, considering that it represents ... in the universe, which leads to recombination sometimes being called photon decoupling , although recombination ... observe today as cosmic microwave background radiation . Recombination occurred when the universe was roughly 300,000 years old, or at a redshift of z val 1100 . Derivation of recombination epoch It is possible to find a rough estimate of the redshift of the recombination epoch, starting by considering that during the era preceding recombination, the photons were primarily coupled to matter ... . math ref Ryden 2003 , p. 158. ref Solving this equation for a 50 percent ionization yields a recombination ... or 0.3 eV. ref Longair 2006 , p. 279. ref A different statement of this is that recombination ... relied on the assumptions of thermodynamic equilibrium and recombination directly to the ground state of hydrogen, each of which simplifies the calculation but also modifies the result. Recombination to an excited state of hydrogen means that recombination proceeds more slowly than that predicted ... of recombination yields a value closer to z val 1100 . ref Galli et al. 2008 , p.1. ref Impact Prior to recombination, photons were not able to freely travel through the universe ... causes a loss of information, and there is therefore a photon barrier at a redshift near that of recombination .... ref Longair 2006 , p. 280. ref Once recombination had occurred, however, the mean free path of photons greatly increased due to the lower number of free electrons. Shortly after recombination, the photon ..., recombination is closely associated with the last scattering surface, which is the name for the last ... for the baryon to photon ratio and matter density, recombination and photon decoupling need not have ... cite journal author Galli, S. Bean, R. Melchiorri, A. Silk, J. title Delayed recombination and cosmic ... more details
completely on homologousrecombination to repair double strand breaks. NHEJ proteins have been identified ... 10.1016 j.molcel.2006.07.009 url ref Unlike homologousrecombination , which has been studied extensively ... Mre11 roles in DNA repair beyond homologousrecombination journal Nat. Struct. Mol. Biol. volume ... end joining and V D J recombination. 2002 Cell 108, 781 794. PMID 11955432 ref Mre11 has nuclease activity, but it seems to be involved in homologousrecombination , not NHEJ. The DNA polymerase ... in directing DNA double strand breaks to homologous and non homologous repair paths. 1999 Curr. Biol. 9 767 70. PMID 10421582 ref Regulation The choice between NHEJ and homologousrecombination for repair ...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 homologousrecombination , which requires a homologous sequence to guide repair. The term non homologous end joining was coined in 1996 by Moore and Haber. ref name Moore and Haber ... 73. PMID 8628283 ref NHEJ typically utilizes short homologous DNA sequences called microhomologies ... doi 10.1016 j.molcel.2004.05.008 url ref In budding yeast Saccharomyces cerevisiae , however, homologousrecombination dominates when the organism is grown under common laboratory conditions. When ... cycle in a stationary haploid phase, in which a template for recombination is not available. ref ... on DNA ends during V D J recombination , a specific type of NHEJ, and may also participate in end .... A. Sibling rivalry competition between Pol X family members in V D J recombination and general double .... Yeast DNA ligase IV mediates non homologous DNA end joining. 1997 Nature 388, 495 498. DOI 10.1038 41365 PMID 9242411 ref XLF Protein XLF , also known as Cernunnos, is homologous to yeast Nej1 and is also ... dot DNA ligase IV Complex and Is Homologous to the Yeast Nonhomologous End joining Factor Nej1. J Biol ... more details
it is present must find its complement. Since HomologousRecombination occurs after DNA replication ...Refimprove date March 2010 Cre Lox recombination is a site specific recombinase technology widely used ... enzyme, Cre recombinase that Site specific recombination recombines a pair of short target sequences ... lox system is very similar in action and in usage to the FLP FRT recombination system. History The Cre Lox recombination is a special type of Site specific recombinase technology site specific recombination ... specific recombination system in the yeast Saccharomyces cerevisiae , Mol Cell Biol 7 2087 2096 ref ref Sauer, B. and Henderson, N. 1988 Site specific DNA recombination in mammalian cells by the Cre ... of Dr. Jamey Marth showed that Cre Lox recombination could be used to delete loxP flanked .... ref Orban, P.C., Chui, D., and Marth, J.D. 1992 Tissue and site specific recombination in transgenic ... switch recombination at individual switch regions evidenced through Cre loxP mediated ... of Drs. Marth and Rajewsky showed in 1994 that Cre lox recombination could be used for conditional gene ... the Max Delbr ck medal to Dr. Klaus Rajewsky for his role in developing Cre Lox recombination. Cre Lox recombination involves the targeting of a specific sequence of DNA and splicing it with the help ... embryonic lethality, Cre Lox recombination is commonly used to circumvent this problem. In addition, Cre Lox recombination provides the best experimental control that presently exists in transgenic animal ... The Cre lox system is used as a genetic tool to control site specific Genetic recombinationrecombination events in genomic DNA. This system has allowed researchers to manipulate a variety of genetically ... catalyse the recombination of DNA between specific sites in a DNA molecule. These sites, known ... where recombination can occur. When cells that have loxP sites in their genome express Cre, a recombination .... The result of recombination depends on the orientation of the loxP sites. For two lox sites on the same ... more details
The meiotic recombination checkpoint monitors the Meiotic recombination In eukaryotes meiotic recombination during meiosis , and blocks the entry into Metaphase I Metaphase I metaphase I if the recombination is not efficiently processed. Meitotic recombination contributes to the cells in two different ways. First, to achieve proper segregation, each pair of homologous chromosomes must be linked to each other to maintain a certain level of tension between them. Such tension is supposed to help the assembly of spindles and generally depends on meitotic recombination. Secondly, Meitotic recombination increases the genetic diversity of gametes, making them readily adapt to new environment. Overview Image Malik meiotic recombination.JPG thumb right alt See caption Spo11 catalyzes a double strand break in one of the two homologous chromosomes to induce meiotic recombination. DSB dependent meiotic recombination checkpoint monitors the repair of these DSBs while DSB independent meiotic recombination checkpoint examines the Synapsis asynapsis of each homolog pair which is the consequence of uncompleted DSB induction. Generally speaking, the cell cycle regulation of meiosis is similar to that of mitosis ... and APC sup Cdc20 sup can initiate the metaphase I. The special chromosome separation in meiosis, homologous ... tension between homologous chromatids and non homologous chromatids for distinguishing microtubule ... break DSB and repair in prophase I. Therefore meiotic recombination checkpoint can be a kind of DNA ..., the meiotic recombination checkpoint also makes sure that meiotic recombination does happen in every ... phosphorylation and marking Wee1 to be degraded. Meiotic recombination begins with a double strand break ... as classical DNA damage response and is the part we know the best in meiotic recombination checkpoint ... of Different Recombination Defects in Mouse Spermatocytes Yields Distinct Responses despite Elimination ... responses drive the loss of oocytes in recombination defective mouse mutants first6 M last6 Jasin ... more details
V D J recombination , also known as somatic recombination , is a mechanism of genetic recombination in the early ... system . V D J recombination takes place in the primary lymphoid tissue the bone marrow for B cells , and Thymus for T cells .V D J recombination nearly randomly combines V ariable, D iverse, and J oining ... with B lineage acute lymphoblastic leukemia implications for the mechanisms of VDJ recombination ... D J recombination of immunoglobulin heavy chains Heavy chain In the developing B cell , the first recombination event to occur is between one D and one J gene segment of the heavy chain locus. Any DNA between these two genes is deleted. This D J recombination is followed by the joining of one V gene ..., the first step of recombination for the light chains involves the joining of the V and J chains to give ... undergo essentially the same sequence of ordered recombination events as that described for immunoglobulins. D to J recombination occurs first in the chain of the TCR. This process can involve either ... of the D sub sub 2 gene segment to one of seven J sub sub 2 segments. DJ recombination is followed ... of T cell s. Mechanism Recombination signal sequences The regional genes V, D, J are flanked by Recombination Signal Sequences RSSs that are recognized by a group of enzymes known collectively ... as the 12 23 rule of recombination or one turn two turn rule . VDJ recombinase VDJ recombinase ... in many cell types. The initial steps of VDJ recombination are carried out by critical lymphocyte specific enzymes, called recombination activating gene 1 and 2 RAG1 and RAG2 . These enzymes associate ... in DNA repair following the activity of RAG1 and RAG2. RAG1 is homologous to transposase ref cite journal author V.V. Kapitonov and J. Jurka year 2005 title RAG1 core and V D J recombination signal ... end joining and V D J recombination journal Cell volume 108 pages 781 794 pmid 11955432 .... van der Burg year 2007 title Non homologous end joining, a sticky affair journal Oncogene volume 26 ... more details
Homologousrecombination References reflist Category Molecular biology Category Cellular processes ... recombination , also known as conservative site specific recombination , is a type of genetic recombination ... specific recombination systems just a recombinase recombinase enzyme and the recombination sites ... sites are also needed. Site specific recombination systems are highly specific, fast and efficient ... in Genetics isbn 978 0 12 017655 7 ref Recombination sites are typically between 30 and 200 nucleotide ... binds, and which flank a central crossover sequence at which the recombination takes place. The pairs of sites between which the recombination occurs are usually identical, but there are exceptions ... Recombination journal Annual Reviews in Biochemistry volume 58 issue 1 pages 913 41 doi 10.1146 annurev.bi.58.070189.004405 pmid 2528323 ref Mechanism Recombination between two DNA sites begins by the recognition ... energy rich Cofactor biochemistry cofactors such as adenosine triphosphate ATP . The recombination ... sites and vice versa. This causes the recombination sites to be reconstituted in the recombination ..., such as Cre recombinase Cre or FLP FRT Recombination FLP , cleave one DNA strand at a time at points ... view of tyrosine recombinase site specific recombination pages 93 117 publisher ASM Press ref ... mediated site specific recombination in vitro DNA cleavage and protein DNA linkage at the recombination ... Resolvase mediated recombination intermediates contain a serine residue covalently linked to DNA journal ... . ref name Stark1989 cite journal last1 Stark first1 M.W. year 1989 title Site specific recombination ... and inversions occur if the recombination takes place between two sites that are found on the same molecule intramolecular recombination , and if the sites are in the same direct repeat or in an opposite orientation inverted repeat , respectively. Insertions on the other hand take place if the recombination occurs on sites that are situated on two different DNA molecules intermolecular recombination ... more details
Orphan date April 2012 refimprove date February 2011 Recombination detection program RDP is a computer program used to analyse nucleotide sequence data and identify evidence of genetic recombination. Besides applying a large number of different recombination detection methods it also implements various phylogenetic tree construction methods and recombination hotspot tests. See also Computational phylogenetics External links http darwin.uvigo.es rdp rdp.html Homepage for the program Categories DEFAULTSORT Recombination Detection Program Category Molecular biology Category Science software biology stub genetics stub science software stub ... more details
Unreferenced date January 2009 The regional genes V, D, J , used to generate T cell receptor T cell receptors and Antibody Immunoglobulin molecules , are flanked by Recombination Signal Sequences RSSs that are recognized by a group of enzymes known collectively as the VDJ recombinase. RSSs are composed of seven conserved nucleotides a heptamer that reside next to the gene encoding sequence followed by a spacer containing either 12 or 23 unconserved nucleotides followed by a conserved nonamer 9 base pairs . The RSSs are present on the Directionality molecular biology 3 side downstream of a V region and the Directionality molecular biology 5 side upstream of the J region. These are the sides that will be involved in the joining. Only a pair of dissimilar spacer RSSs are efficiently genetic recombination recombined i.e. one with a spacer of 12 nucleotides will be recombined with one that has a spacer containing 23 nucleotides . This is known as the 12 23 rule of recombination or the one turn two turn rule . See also VDJ recombination Category Immune system immunology stub ... more details
Unreferenced date October 2007 Generation Recombination noise , or g r noise , is a type of electrical signal noise caused statistically by the fluctuation of the generation and Carrier generation and recombinationrecombination of electrons in semiconductor based photon detectors. See also Noise Noise audio residual low level hiss or hum Noise electronic related to electronic circuitry. Noise figure the ratio of the output noise power to attributable thermal noise. Signal noise in science, fluctuations in the signal being received. Thermal noise sets a fundamental lower limit to what can be measured. Weighting filter ITU R 468 noise weighting A weighting List of noise topics science stub Category Noise ... more details
unreferenced date March 2010 Non radiative recombination is a process in phosphor s and semiconductor s, whereby charge carrier s carrier generation and recombination recombine without releasing photon s. A phonon is released instead. Non radiative recombination in optoelectronics and phosphors is an unwanted process, lowering the light generation efficiency and increasing heat losses. Shockley Read Hall SRH process The electron in transition between electronic band structure bands passes through a new energy state created within the band gap by an impurity in the crystal lattice . The impurity state can absorb differences in momentum between the carriers, and so this process is the dominant generation and recombination process in silicon and other indirect bandgap materials. It can also dominate in direct bandgap materials under conditions of very low charge carrier density carrier densities very low level injection . The energy is exchanged in the form of lattice vibration, or a phonon exchanging thermal energy with the material. Various impurities and dislocation s create energy level s within the band gap corresponding to neither donor nor acceptor levels, forming deep level trap s. Non radiative recombination occurs primarily at such sites. Category Charge carriers ... more details
see also Recombinase mediated cassette exchange In genetics , FLP FRT recombination is a site specific recombination site directed recombination technology used to manipulate an organism s DNA under controlled conditions in vivo . It is analogous to Cre Lox recombination . It involves the recombination of sequences between short Flippase Recognition Target FRT sites by the Flippase recombination enzyme FLP or Flp derived from the 2 m plasmid of the baker s yeast Saccharomyces cerevisiae . The 34bp long FRT site sequence is 5 GAAGTTCCTATTCtctagaaaGTATAGGAACTTC 3 . Flippase flp binds to the 13 bp 5 GAAGTTCCTATTC 3 and to the reverse complement of 5 GTATAGGAACTTC 3 5 GAAGTTCCTATAC 3 . The FRT site is cleaved just before 5 tctagaaa 3 , the 8bp asymmetric core region , on the top strand and behind this sequence on the bottom strand. ref cite journal author Zhu XD, Sadowski PD title Cleavage dependent Ligation by the FLP Recombinase journal Journal of Biological Chemistry volume 270 pages 23044 54 year 1995 pmid 7559444 issue 39 doi 10.1074 jbc.270.39.23044 ref Several variant FRT sites exist. Recombination can occur between two identical FRT sites but generally not between non identical FRT sites ref cite journal author Schlake T, Bode J title Use of mutated FLP recognition target FRT sites for the exchange of expression cassettes at defined chromosomal loci journal Biochemistry volume 33 issue 43 pages 12746 12751 year 1994 pmid 7947678 doi 10.1021 bi00209a003 ref Many available constructs include the sequence 5 GAAGTTCCTATTCC 3 immediately upstream the FRT site resulting in 5 GAAGTTCCTATTCCGAAGTTCCTATTCtctagaaaGTATAGGAACTTC 3 but this sequence is dispensable for recombination. Because the recombination activity can be targeted to only one target organ, or a low level of recombination activity can be used to consistently alter the DNA of only a subset of cells, FLP FRT can ... can also be studied over time, by using an inducible promoter to trigger the recombination activity ... more details
In the solid state physics of semiconductor s, carrier generation and recombination are processes by which mobile charge carrier semiconductor charge carrier s electron s and electron hole s are created and eliminated. Carrier generation and recombination processes are fundamental to the operation of many optoelectronic semiconductor device s, such as photodiode s, LED s and laser diode s. They are also critical to a full analysis of p n junction devices such as bipolar junction transistor s and p n junction diode s. The electron hole pair is the fundamental unit of generation and recombination, corresponding to an electron transitioning between the valence band and the conduction band. Band structure Like other solids, semiconductor materials have electronic band structure determined by the crystal properties of the material. The actual energy distribution among the electrons is described by the Fermi energy and the temperature of the electrons. At absolute zero temperature, all of the electrons ... band, producing two mobile carriers while recombination describes processes by which a conduction ... band. In a material at thermal equilibrium generation and recombination are balanced, so that the net ... . Generation and recombination processes Carrier generation and recombination result from interaction ... and recombination File diffusion center.gif thumb 350px right The following image shows change ... differences in momentum between the carriers, and so this process is the dominant generation and recombination ... deep level trap s. Photon exchange During radiative recombination , a form of spontaneous emission ... recombination is significant only in direct bandgap materials. When photons are present in the material ... stimulate a recombination event, resulting in a generated photon with similar properties to the one ... diode s. Auger recombination The energy is given to a third carrier, which is excited to a higher ... in the unstable high energy state. The Auger recombination can be calculated from the equation ... more details
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