Image Chromosome Y.svg 125px right thumb Human Y chromatid The Ychromosome is one of the two Sex determination ... the gene SRY , which triggers testicle testis development if present. The human Ychromosome is composed of about 60 million base pairs . DNA in the Ychromosome is passed from father to son, and Y ..., the Ychromosome is one of the fastest evolving parts of the human genome. ref cite news ... one pair of sex chromosomes in each cell. Males have one Ychromosome and one X chromosome , while females have two X chromosomes. In mammals, the Ychromosome contains a gene, SRY , which triggers embryonic ... Before Ychromosome Many ectotherm ic vertebrates have no sex chromosomes. If they have different ... became the Ychromosome, while the other member of the pair became the X chromosome. Over time, genes ... on the Ychromosome, and females with unnecessary or even harmful genes previously only found on the Y ... Graves, J.A.M 2006 Over time, the Ychromosome changed in such a way as to inhibit the areas around ... 95 of the human Ychromosome is unable to recombine. Shrinking theory The human Ychromosome has ... of 4.6 genes per million years, the Ychromosome may potentially lose complete function within the next ... Ychromosome can conversion save it? journal Reproduction Fertility and Development volume 16 issue ... Y chromosomes show that the human Ychromosome has not lost any genes since the divergence of humans ... ago, ref http www.medicaldaily.com news 20120222 9163 ychromosomechromosome theory men extinct ... is flawed. High mutation rate The human Ychromosome is particularly exposed to high mutation rates due to the environment in which it is housed. The Ychromosome is passed exclusively through sperm , which ... the Ychromosome at a risk of mutation 4.8 times greater than the rest of the genome. ref name Graves, J.A.M 2006 Inefficient selection Without the ability to recombine during meiosis , the Ychromosome ... background selection . Due to this inability to sort through its gene content, the Ychromosome is particularly ... more details
The YChromosome Consortium YCC is a collection of scientists who work toward the understanding of Ychromosome Human Ychromosome human Y chromosomal phylogenetics and evolution. The consortium has the following objectives web resources that communicate information relating to the non recombinant region of the Ychromosome including new variants and changes in the nomenclature . ref name urlThe YChromosome Consortium cite web url http ycc.biosci.arizona.edu title The YChromosome Consortium format work accessdate ref The consortium sponsors literature regarding updates in the phylogenetics and wikt nomenclature nomenclature . ref name pmid18385274 cite journal author Karafet TM, Mendez FL, Meilerman MB, Underhill PA, Zegura SL, Hammer MF title New binary polymorphisms reshape and increase resolution of the human Y chromosomal haplogroup tree journal Genome Res. volume 18 issue 5 pages 830 8 year 2008 month May pmid 18385274 pmc 2336805 doi 10.1101 gr.7172008 url ref ref name pmid11827954 cite journal author title A nomenclature system for the tree of human Y chromosomal binary haplogroups journal Genome Res. volume 12 issue 2 pages 339 48 year 2002 month February pmid 11827954 pmc 155271 doi 10.1101 gr.217602 url last1 YChromosome first1 Consortium ref References reflist DEFAULTSORT YChromosome Consortium Category Scientific organizations ... more details
Ychromosome microdeletion YCM is a family of genetic disorder s caused by missing gene s in the Ychromosome ... edrv.endojournals.org cgi content full 22 2 226 Ychromosome microdeletions and alterations of spermatogenesis ... of mutation is not different for Ychromosome microdeletion. However, the ability to repair it differs from other chromosomes. The human Ychromosome is passed directly from father to son, and is not protected ... repair mechanism for the Ychromosome. Diagnosis Ychromosome microdeletion is currently ... 300 known genetic marker s for sequence tagged site s STS on the Ychromosome, and then using polymerase ... of a tiny part of the overall 23 million base pair long Ychromosome, therefore the sensitivity ..., but not the absence of any possible genetic defect on the chromosome. The gold standard test for genetic mutation, namely complete DNA sequencing of a patient s Ychromosome, is still far too expensive for use in epidemiologic research or even clinical diagnostics. Infertility Microdeletions in the Ychromosome have been found at a much higher rate in infertile men than in fertile controls ref name pmid16157049 cite journal author Song NH, Wu HF, Zhang W, et al. title Screening for Ychromosome ... testing techniques for the Ychromosome are developed. Much study has been focused upon the azoospermia ... Additional genes associated with spermatogenesis in men and reduced fertility upon Ychromosome deletions ... Acta Med Port year 1998 month April volume 11 issue 4 pages 365 72 title Ychromosome and male infertility ... NCBI NIH UW entry on YChromosome Infertility http cas.bellarmine.edu tietjen Ecology ychromosome as a battle ground .htm Bellarmine College The Ychromosome as a battle ground for sexual selection See also Infertility AZF1 Category Andrology Category Sex chromosome aneuploidies genetics stub disease ... month July year 2000 title Prognostic value of Y deletion analysis first Csilla last Krausz coauthors ... only discover certain types of deletions and mutations on a chromosome and give therefore no complete ... more details
File Haplogroups europe.png thumb 300px Y haplogroups in Europe genetic genealogy The following articles are lists of human Ychromosome DNA haplogroups found in populations and various ethnic groups by regions or continents around the world based on relevant studies, and the samples have been taken from individuals identified by linguistic designation. General Y DNA haplogroups by ethnic groups Europe Y DNA haplogroups in European populations Near East and North Africa Y DNA haplogroups by populations of Near East and North Africa Sub Saharan Africa Y DNA haplogroups by populations of Sub Saharan Africa Caucasus Y DNA haplogroups by populations of the Caucasus South Asia Y DNA haplogroups in South Asian populations Far East Y DNA haplogroups by populations of East and Southeast Asia Central Asia and Siberia Y DNA haplogroups in Central and North Asian populations Oceania Y DNA haplogroups in Oceanian populations Americas Y DNA haplogroups in Indigenous peoples of the Americas Famous haplotypes List of haplogroups of historical and famous figures See Also Recent African origin of modern humans Archaeogenetics of the Near East Genetics and archaeogenetics of South Asia Genetic history of Europe Genetic history of Italy Genetic history of North Africa Genetic history of indigenous peoples of the Americas Genetic history of the Iberian Peninsula Genetic history of the British Isles Y DNA External links Commons category Human Y DNA haplogroups http www.isogg.org tree ISOGG Y DNA Haplogroup Tree http www.scs.uiuc.edu mcdonald WorldHaplogroupsMaps.pdf Map of Y Haplogroups http www.eupedia.com europe european y dna haplogroups.shtml Distribution of European Ychromosome DNA Y DNA haplogroups by region in percentage Category Human Y DNA haplogroups ... more details
genetic genealogy In human genetics , a Human Ychromosome DNA haplogroup is a haplogroup defined by differences in the non genetic recombination recombining portions of DNA from the Ychromosome called Y DNA . The Ychromosome consortium has established a system of defining Y DNA haplogroup s by letters A through to T, with further subdivisions using numbers and lower case letters. ref ycc Y chromosomal ... of mtDNA and Ychromosome polymorphisms url journal European Journal of Human Genetics volume 10 issue ... Holmlund first4 Gunilla author separator , author name separator year 2006 title Ychromosome diversity ... 1 Ychromosome haplotype frequencies in 49 Eurasian populations, listed according to geographic region ... et al., The Eurasian Heartland A continental perspective on Ychromosome diversity, Proceedings ... tcga tcgapdf Bortolini AJHG 03 YAmer.pdf YChromosome Evidence for Differing Ancient Demographic ... years ago Britain See also Ychromosome haplogroups by populations Y DNA haplogroups by groups ... Genealogical DNA test Conversion table for Ychromosome haplogroups Y DNA References Reflist added under references heading by script assisted edit small note ycc http ycc.biosci.arizona.edu YChromosome Consortium note familytreedna http www.familytreedna.com haplotree.html 2005 Ychromosome Phylogenetic ... Tree http www.familytreedna.com PDF 2008 HaploChart GR lores.pdf FTDNA 2008 YChromosome Phylogenetic ... A YChromosome Perspective Paper that defined Eu haplogroups http www.worldfamilies.net yhapprojects ... Company STR Marker Comparison Chart Ychromosome haplogroups by populations Category Human Y DNA haplogroups ... of this common ancestor have varied significantly in different studies. Major Y DNA haplogroups Major Ychromosome haplogroups include Tree view Clade label1 Y chromosomal Adam Y DNA Adam 1 Clade 1 Haplogroup A Y DNA Haplogroup A0 2 Clade 1 Haplogroup A Y DNA Haplogroup A1 label2 Haplogroup BT Y DNA BT 2 Clade 1 Haplogroup B Y DNA Haplogroup B label2 Haplogroup CT Y DNA CT 2 Clade ... more details
Out of date article date October 2010 Ychromosome haplogroup s are a frequent topic of discussion in human population genetics and genetic genealogy . Men in the same Y DNA haplogroup share a set of differences, or markers, on their Ychromosome, which distinguish them from men in other haplogroups. Often these Unique event polymorphism UEP s, or markers used to define haplogroups, are Single nucleotide polymorphism SNP mutation s. YChromosome Haplogroups all form family tree s or phylogeny phylogenies , with both branches or sub clade s diverging from a common haplogroup ancestor, and also with all haplogroups themselves linked into one family tree which traces back ultimately to the most recent shared male line ancestor of all men alive today, the so called YChromosome Adam . In 2002, the Ychromosome consortium published a widely used proposal to standardize the naming of all Ychromosome haplogroups. ref Citation doi 10.1101 gr.217602 author YChromosome Consortium YCC year 2002 title A Nomenclature System for the Tree of Human Y Chromosomal Binary Haplogroups periodical Genome Research volume 12 pages 339 348 url http www.genome.org cgi content abstract 12 2 339 issue 2 pmid 11827954 pmc 155271 ref The below table is mainly based upon this work, but with updates from a later 2007 publication by the same team, as well as the widely cited webpage of the International Society of Genetic Genealogy ISOGG , which keeps an updated summary. ref Citation last Karafet et al. first1 TM last2 Mendez first2 FL last3 Meilerman first3 MB last4 Underhill first4 PA last5 Zegura first5 SL last6 Hammer first6 MF title New binary polymorphisms reshape and increase resolution of the human Y chromosomal haplogroup tree journal Genome Research volume 18 issue 5 pages 830 8 year 2008 url http www.genome.org cgi content abstract gr.7172008v1 doi 10.1101 gr.7172008 month May pmid 18385274 ... Table For YChromosome Haplogroups Category Human Y DNA haplogroups ... more details
34,893,953 X chromosome X sex chromosome 1,846 154,913,754 151,058,754 YchromosomeY sex chromosome ... system X chromosome X chromosome X inactivation YchromosomeYchromosomeY chromosomal Aaron Y chromosomal Adam Lampbrush chromosome Polytene chromosome References FolBiolKrak w56 241. reflist ... Diagram of a replicated and condensed metaphase eukaryotic chromosome. 1 Chromatid one of the two identical parts of the chromosome after S phase . 2 Centromere the point where the two chromatids touch, and where the microtubules attach. 3 Short arm. 4 Long arm. A chromosome is an organized ... P, Salse J, et al. title A Physical Map of the 1 Gigabase Bread Wheat Chromosome 3B journal Science ... there are many exceptions to this rule. Also, cells may contain more than one type of chromosome ... leading to the progression of cancer . In practice chromosome is a rather loosely defined term .... However, a large body of work uses the term chromosome regardless of chromatin content. In prokaryotes ... lack structural proteins. Citation needed date February 2012 explain The word chromosome comes from ... sutton.png right thumb 190px Walter Sutton left and Theodor Boveri right independently developed the chromosome ... original. Citation needed date April 2009 Wilhelm Roux suggested that each chromosome carries a different ... around 1902 by naming the chromosome theory of inheritance the Boveri Sutton Chromosome Theory Sutton ... Morgan , all of a rather dogmatic turn of mind. Eventually, complete proof came from chromosome ... In eukaryotes See also Eukaryotic chromosome fine structure Eukaryotes cell biology cells with nuclei ... in the cell s nucleus. Each chromosome has one centromere , with one or two arms projecting ... chromosome length is an estimate as well, based on the estimated size of unsequenced heterochromatin ... pairs in mega base pairs on each human chromosome. class wikitable sortable style text align right Chromosome Genes Total Nucleobase base pairs Sequenced base pairs ref Sequenced percentages are based ... more details
Mechanism of Rearrangement , Molecular Cytogenetics 2008, 1 16 ref . See also Chromosome abnormalities References Schmidt et al. 1981. Ring chromosome 14 a distinct clinical entity. Journal of Medical ... more details
Artificial chromosome may refer to Yeast artificial chromosome Bacterial artificial chromosome Human artificial chromosome P1 derived artificial chromosome disambig Long comment to avoid being listed on short pages ... more details
Supernumerary chromosome could refer to B chromosome in some animals and plants Small supernumerary marker chromosome sSMC in humans disambig ... more details
Ychromosome, for the next letter in the alphabet, after it was discovered later. ref name nyt angier cite web url http www.nytimes.com 2007 05 01 science 01angi.html title For Motherly X Chromosome ... in each cell. Females have two X chromosomes, whereas males have one X and one Ychromosome . Both males and females retain one of their mother s X chromosomes, and females retain their second X chromosome from their father. Since the father retains his X chromosome from his mother, a human female has one X chromosome from her paternal grandmother father s side , and one X chromosome from her mother. Identifying genes on each chromosome is an active area of genetic research. Because researchers ... Macmillan Science Library title Genetics on X Chromosome year 2001 ref genes compared to the Ychromosome containing 78 ref name Harris cite web author Richard Harris title Scientists Decipher YChromosome ... and has a more active euchromatin region than its Ychromosome counterpart. Further comparison of the X ... a genetic degeneration for Y in that region. Because males have only one X chromosome, they are more ... of two X chromosomes and one Ychromosome 47,XXY . It is less common for affected males to have ... the SRY region of the Ychromosome has recombined to be located on one of the X chromosomes. As a result ... q22 See also Ychromosome Sex linkage List of X STR markers References CytogenetGenomeRes101 266 ...Image Chromosome X.svg 125px thumb right Scheme of the X chromatid Image Sd4hi unten crop.jpg thumb Nucleus of a female amniotic fluid cell. Top Both X chromosome territories are detected by Fluorescence ... . The X chromosome is one of the two sex determination system sex determining chromosome s in many animal species, including mammals the other is the Ychromosome and is found in both males and females. It is a part of the XY sex determination system and X0 sex determination system . The X chromosome ... 01 accessdate 2007 05 01 ref In humans Function The X chromosome in humans spans more than 153 million ... more details
. Homologous chromosomes are similar in length sex chromosome s in several taxa , where the X chromosome is considerably larger than the Ychromosome . These sex chromosomes share only small regions ...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 ... loci on the chromosome. However, each can contain either the same allele e.g., both alleles for blue ... , and one pair of sex chromosome s, making a total of 46 chromosomes in a genetically normal human ... autosomes, female humans have a homologous pair of sex chromosomes X chromosome two Xs , while males have an X chromosome X and a Ychromosome . Ploidy The ploidy of an organism is the number of homologous versions it has of each chromosome. If the chromosomes of an organism were separated ... and animals are diploid organisms. Their chromosomes come in pairs each chromosome in a diploid organism has exactly one homologous partner. Each chromosome from these pairs is biological inheritance ... are each strand of the two identical conjoined chromosomes the product of chromosome replication ... Homology resources, and Comparative Chromosome Maps of the Human, Mouse, and Rat. http www.ncbi.nlm.nih.gov ... kromosomer pl Chromosomy homologiczne pt Cromossomos hom logos simple Homologous chromosome ... more details
Multiple issues orphan March 2011 unreferenced October 2010 expert subject March 2011 The polycentric chromosome is when more than 2 chromosome are present e.g. par ascaris 2 chromosome Mucor hiemalis in plant s have 2 chromosome. Adder s tongue fern have 1262 chromosome. In auto cantha or radiolorian there are 1682 chromosome. DEFAULTSORT Polycentric Chromosome Category Chromosomes genetics stub ... more details
Orphan date February 2009 A derivative chromosome der is a structurally rearranged chromosome generated either by a rearrangement involving two or more chromosomes or by multiple aberrations within a single chromosome e.g. an inversion and a deletion of the same chromosome, or deletions in both arms of a single chromosome . http ghr.nlm.nih.gov ghr glossary derivativechromosome The term always refers to the chromosome that has an intact centromere. Derivative chromosomes are designated by the abbreviation der when used to describe a Karyotype . The derivative chromosome must be specified in parentheses followed by all aberrations involved in this derivative chromosome. The aberrations must be listed from pter to qter and not be separated by a comma. For example, 46,XY,der 4 t 4 8 p16 q22 t 4 9 q31 q31 would refer to a derivative chromosome 4 which is the result of a translocation between the short arm of chromosome 4 at band 16 and the long arm of chromosome 8 at band 22, and a translocation between the long arm of chromosome 4 at band 31 and the long arm of chromosome 9 at band 31. Derivative chromosomes and other abnormalities could be drawn online using CyDAS online tools Hiller B, Bradtke J, Balz H and Rieder H 2004 CyDAS Online Analysis Site , http www.cydas.org OnlineAnalysis References An International System for Human Cytogenetic Nomenclature, Shaffer, L.G., Tommerup N. eds S. Karger, Basel 2005 Category Chromosomes genetics stub ... more details
Unreferenced date December 2009 Chromosome jumping is a tool of molecular biology that is used in the physical genome project mapping of genome s. It is related to several other tools used for the same purpose, including chromosome walking . Chromosome jumping is used to bypass regions difficult to cloning clone , such as those containing repetitive DNA , that cannot be easily mapped by chromosome walking, and is useful in moving along a chromosome rapidly in search of a particular gene . In chromosome jumping, the DNA of interest is identified, cut into fragments with restriction enzyme s, and circularised the beginning and end of each fragment are joined together to form a circular loop . From a known DNA sequence sequence a primer molecular biology primer is designed to DNA sequencing sequence across the circularised junction. This primer is used to jump 100 base pair kb 300 kb intervals a sequence 100 kb away would have come near the known sequence on circularisation. Thus, sequences not reachable by chromosome walking can be sequenced. Chromosome walking can be used from the new jump position in either direction to look for gene like sequences, or additional jumps can be used to progress further along the chromosome. DEFAULTSORT Chromosome Jumping Category Laboratory techniques Category Molecular biology Category DNA Molecular cell biology stub ca Jumping es Salto cromos mico fr Saut sur le chromosome ... more details
Image Single Chromosome Mutations.png thumb right The three major single chromosome mutations deletion 1 , duplication 2 and inversion 3 . Image Two Chromosome Mutations.png thumb right The two major two chromosome mutations insertion 1 and Translocation 2 . A chromosome anomaly , abnormality or aberration reflects an atypical number of chromosome s or a structural abnormality in one or more chromosomes ... Karyotype for the species via genetic testing . A chromosome anomaly may be detected or confirmed in this manner. Chromosome anomalies usually occur when there is an error in cell division following meiosis or mitosis . There are many types of chromosome anomalies. They can be organized into two ... an abnormal number of chromosomes , and occurs when an individual is missing either a chromosome from ... an individual with Down Syndrome has three copies of chromosome 21, rather than two . Turner Syndrome is an example of a monosomy where the individual is born with only one sex chromosome, an X. Structural abnormalities When the chromosome s structure is altered, this can take several forms genetic deletion Deletions A portion of the chromosome is missing or deleted. Known disorders in humans include Wolf Hirschhorn syndrome , which is caused by partial deletion of the short arm of chromosome 4 ... A portion of the chromosome is duplicated, resulting in extra genetic material. Known human ... may be caused by duplication of the gene encoding peripheral myelin protein 22 PMP22 on chromosome 17. Chromosomal translocation Translocation s When a portion of one chromosome is transferred to another chromosome. There are two main types of translocations. In a reciprocal translocation, segments from two different chromosomes have been exchanged. In a Robertsonian translocation , an entire chromosome ..., 15, 21 and 22. Chromosomal inversion Inversions A portion of the chromosome has broken off, turned ... A portion of one chromosome has been removed from its normal place and inserted into another chromosome ... more details
Chromosome engineering is the controlled generation of chromosomal deletions, inversions, or translocations with defined endpoints. ref Reviews Glossary. nature.com. N.p., n.d. Web. 15 Oct. 2009. http www.nature.com nrg journal v6 n7 glossary nrg1638 glossary.html. ref By combining chromosomal translocation , chromosomal inversion ,and chromosomal deletion , chromosome engineering has been shown to identify the underlying genes that cause certain diseases in mice. In coming years, it is very likely that chromosomal engineering will be able to do the same identification for diseases in humans, as well as all other organisms. ref Ramirez Solis, R., P. Liu, and A. Bradley. Chromosome Engineering in Mice. Public Med. N.p., n.d. Web. 17 Oct. 2009. http www.ncbi.nlm.nih.gov pubmed 7501018 . ref The Three Types of Chromosome Engineering class wikitable chromosomal deletion chromosomal inversion chromosomal translocation Chromosomal deletion is a mutation a genetic aberration in which a part of a chromosome or a sequence of DNA is missing. Chromosomal inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. Chromosomal translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. Experiments of Chromosome Engineering In an experiment pertaining to chromosome engineering that was conducted in 2006, it was found that chromosome engineering can be effectively used as a method of identifying the causes of genetic disorders such as the continuous gene and aneuploidy syndromes. The experiment was conducted by infecting mice with the human disease, ES, to see the effectiveness of chromosomal engineering ... chromosomes, or chromosome engineering, is an excellent and efficient method of determining underlying genes in genetic orders and diseases. In the future, chromosome engineering will experiment .... See also Genetics Chromosome Chromosomal deletion Chromosomal inversion Chromosomal translocation ... more details
Unreferenced auto yes date December 2009 The part of chromosome beyond the nuclear organiser is very short and appears like sphere satellite .The Satellite Chromosome is the chromosome which has a bulge on the telomeric end and SAT stands for Sine Acid thymonucleinico without thymonucliec acid or DNA since the chromosome on staining show relative deficiency of DNA in the nuclear organiser region.There are at least 2 SAT chromosomes in each diploid nucleus.It plays a vital role in the formation of the nucleolous after division is completed. It shows repetitive sequences of genes. Besides centromere , secondary constriction can also be observed in some chromosomes, which if present in the distal region of the arm, would pinch off a small fragment called Satellite . The satellite remains attached to the rest of the body of chromosome s by a thread of chromatin . The secondary constrictions are always constant in their positions and hence can be used as markers . The chromosomes having a satellite are marker chromosomes and are also called SAT chromosomes .these SAT chromosomes are helpful in transferring details to mRNA. DEFAULTSORT Satellite Chromosome Category Genetics Category Chromosomes Genetics stub pl Trabant biologia ... more details
unreferenced date September 2009 Image with unknown copyright status removed Image Centromere.png right Image Chromosome upright.png frame Diagram of a duplicated and condensed metaphase eukaryotic chromosome. 1 Chromatid one of the two identical parts of the chromosome after S phase . 2 Centromere the point where the two chromatids touch, and where the microtubules attach. 3 Short arm p . 4 Long arm q . Several chromosome regions have been defined by convenience in order to talk about gene locations. Most important is the distinction between chromosome region p and chromosome region q . These are Virtuality virtual regions that exist in all chromosome s. During cell division , the molecules that compose chromosomes DNA and protein s suffer a condensation process called the chromatin condensation , and forms a compact and small complex called a chromatid. In diploid organisms, sister chromatids are attached to each other by the centromere . The centromere divides each chromosome into two regions the smaller one, which is the p region, and the bigger one, the q region. Usually, as a convention, the p region is represented in the upper part of an image while the q region is in the bottom part. At either end of a chromosome is a telomere , a cap of DNA that protects the rest of the chromosome from damage. The areas of the p and q regions close to the telomeres are the subtelomere s, or subtelomeric regions. The areas closer to the centromere are the pericentronomic regions. Finally, the interstitial regions are the parts of the p and q regions that are close to neither the centromere nor the telomeres, but are roughly in the middle of p or q . Image subtelomere copy.jpg left DEFAULTSORT Chromosome Regions Category Chromosomes ... more details
Unreferenced stub auto yes date December 2009 Dicentric chromosome is an aberrant chromosome having two centromere s. Dicentric chromosomes form when two chromosome segments from different chromosomes or from the two chromatids of a single one , each with a centromere, fuse end to end, with loss of their acentric fragments. Dicentrics, despite their two centromeres, may be mitotically stable if one of the two centromeres is inactivated, or if the two centromeres always coordinate their movement to one or the other pole during anaphase. Such chromosomes are formally called pseudodicentric. The most common pseudodicentrics involve the sex chromosomes or the acrocentric chromosomes Robertsonian translocation . Evaluation of centromere function by Fluorescent in situ hybridization FISH combined with immunofluorescence analysis of centromere and kinetochore proteins is a specialized procedure in some clinical cytogenetics laboratories. DEFAULTSORT Dicentric Chromosome Category Chromosomes Genetics stub ... more details
Chromosome segregation is a step in cell reproduction or division, where chromosomes pair off with their similar homologous chromosome. In mitosis , a complete copy of each one is made. In meiosis , one chromosome from each pair migrates to opposite ends of the cell and the genes are split to make a gamete. ref cite book last Deppe first Carol title Breed your own Vegetable Varieties publisher Little, Brown & Company date 1993 pages 96 97 isbn 0 316 18104 8 ref For more information see Cell Cycle the Cell Cycle . References div class references small style moz column count 2 column count 2 references div Category Chromosomes ... more details
band of interest, and, using a very fine needle, tears that band away from the rest of the chromosome ... region of the chromosome in question. References Scalenghe F, Turco E, Edstrom JE, Pirrotta V, Melli ... more details
A marker chromosome mar is a structurally abnormal chromosome in which no part can be identified. The significance of a marker is very variable as it depends on what material is contained within the marker. It is essentially a partial trisomy . However sometimes the marker is composed of inactive genetic material and has little or no effect. There are some markers that are passed down through a family with little effect. There are some markers that arise as new events. Often, markers are not passed down as they can be lost during cell division due to their small size. There are some individuals who have multiple markers. When special studies are performed to identify the material more conclusions can be drawn about the effects of the marker. There is a more common marker called inverted duplication of chromosome 15. This is a specific syndrome that has developmental delays and physical variations and often seizures as its features. A difficult situation arises when a marker chromosome is found on a prenatal study such as amniocentesis. If the marker is not one of the more common markers and neither parent has the marker, it can be very difficult to predict the effects of the marker. Usually, if a parent carries the same marker, the effect is much less. References http www.chromodisorder.org sytrix card list.php3?dbid 63&id 365 An International System for Human Cytogenetic Nomenclature, Shaffer, L.G., Tommerup N. eds S. Karger, Basel 2005 dead link Category Chromosomes ca Cromosoma marcador de Markerchromosom it Cromosoma marcatore pl Chromosom markerowy fi Marker kromosomi ... more details
The genetics genetic technique of chromosome landing is a method of molecular cloning cloning of a gene of interest from a clone library . It is based on the principle that the expected average between genetic marker marker genetic distance distance s can be smaller than the average insert length of a clone library containing the gene of interest. From the abstract of PMID 7716809 The strategy of chromosome walking is based on the assumption that it is difficult and time consuming to find DNA markers that are physically close to a gene of interest. Recent technological developments invalidate this assumption for many species. As a result, the mapping paradigm has now changed such that one first isolates one or more DNA marker s at a physical distance from the targeted gene that is less than the average insert size of the genomic library being used for clone isolation. The DNA marker is then used to Genetic screen screen the library and isolate or land on the clone containing the gene, without any need for chromosome walking and its associated problems. Chromosome landing, together with the technology that has made it possible, is likely to become the main strategy by which map based cloning is applied to isolate both major genes and genes underlying quantitative traits in plant species. See also Primer walking Category Molecular biology Category Genetic engineering ar ... more details
crossing over genetic recombination between homologous chromosome s during meiosis . Balancers ... chromosome journal Nature Genetics year 1998 volume 22 pages 375 378 url http www.nature.com ng ... PMC1212546 pdf 235.pdf Analysis of Chromosome 4 in Drosophila Melanogaster11 Ethyl Methanesulfonate Induced Lethals . ref cite journal last HOCHMAN first BENJAMIN title ANALYSIS OF CHROMOSOME 4 IN DROSOPHILA ... journal last Herman first Robert coauthors Donna, Albertson, Sydney, Brenner title Chromosome Rearrangements ..., Allan Bradley & Monica J. Justice title Functional genetic analysis of mouse chromosome 11 journal ... a balancer chromosome and the balancer s homolog does occur during meiosis each chromatid ends ... that make pigments allow researchers to easily recognize flies that carry the balancer chromosome ... reproductive fitness when carried homozygously a balancer chromosome ensures that the population it is carried in does not become fixed for the balancer chromosome. Balancer chromosomes always contain ... chromosome, one from the mother and one from the father, then the organism will not live. So any organism that is homozygous for that chromosome will not live to pass on its genes. However, offspring that only get one copy of one balancer chromosome and one copy of a wild type or mutant chromosome will live ... in the chromosome such as the Green Florescent Protein that fluoresces in ultraviolet light, or it can ... chromosomes are named for the chromosome they serve to stabilize and for the phenotypic or genetic ... letter of the chromosome s name represents the number of the chromosome it stabilizes. F stands for the first chromosome, S stands for second, and T stands for third. The small fourth chromosome ... chromosome. Additionally, the genetic marker or markers of the balancer are listed after the name and separated ... are heterozygous. For example, the commonly used TM3, Sb balancer is a balancer chromosome that stabilizes the third chromosome and carries a mutant Sb Stubble gene as a marker. All flies containing ... more details
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