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Chromosome

Chromosome
This allows the very long DNA molecules to fit into the cell nucleus. The structure of chromosomes and chromatin varies through the cell cycle. Chromosomes are the essential unit for cellular division and must be replicated, divided, and passed successfully to their daughter cells so as to ensure the genetic diversity and survival of their progeny. Chromosomes may exist as either duplicated or unduplicated—unduplicated chromosomes are single linear strands, whereas duplicated chromosomes (copied during synthesis phase) contain two copies joined by a centromere. Compaction of the duplicated chromosomes during mitosis and meiosis results in the classic four-arm structure (pictured to the right). Chromosomal recombination plays a vital role in genetic diversity. If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe and die, or it may aberrantly evade apoptosis leading to the progression of cancer. However, in practice "chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. These small circular genomes are also found in mitochondria and chloroplasts, reflecting their bacterial origins. The simplest chromosomes are found in viruses: these DNA or RNA molecules are short linear or circular chromosomes that often lack any structural proteins.

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. (4) Long arm. A chromosome is an organized structure of DNA and protein that is found in cells. A chromosome is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions. The word chromosome comes from the Greek χρῶμα (chroma, color) and σῶμα (soma, body) due to their property of being very strongly stained by particular dyes. Chromosomes vary widely between different organisms. The DNA molecule may be circular or linear, and can be composed of 10,000 to 1,000,000,000[1] nucleotides in a long chain. Typically eukaryotic cells (cells with nuclei) have large linear chromosomes and prokaryotic cells (cells without defined nuclei) have smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example, mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosomes. In eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called chromatin.

History
Nucleus as the seat of heredity
The origin of this groundbreaking idea lies in a few sentences tucked away in Ernst Haeckel’s Generelle Morphologie of 1866.[2] The evidence for this insight gradually accumulated until, after twenty or so years, two of the greatest in a line of great German scientists spelled out the concept. August Weismann proposed that the germ line is separate from the soma, and that the cell nucleus is the repository of the hereditary material, which, he proposed, is arranged along the chromosomes in a linear manner. Further, he proposed that at fertilisation a new combination of chromosomes (and their hereditary material) would be formed. This was the explanation for the reduction division of meiosis (first described by van Beneden).

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Chromosome
different stages of the cell cycle, according to the requirements of the DNA.

Chromosomes as vectors of heredity
In a series of experiments, Theodor Boveri gave the definitive demonstration that chromosomes are the vectors of heredity. His two principles were based upon the continuity of chromosomes and the individuality of chromosomes. It is the second of these principles that was so original. Boveri was able to test the proposal put forward by Wilhelm Roux, that each chromosome carries a different genetic load, and showed that Roux was right. Upon the rediscovery of Mendel, Boveri was able to point out the connection between the rules of inheritance and the behaviour of the chromosomes. It is interesting to see that Boveri influenced two generations of American cytologists: Edmund Beecher Wilson, Walter Sutton and Theophilus Painter were all influenced by Boveri (Wilson and Painter actually worked with him). In his famous textbook The Cell, Wilson linked Boveri and Sutton together by the Boveri-Sutton theory. Mayr remarks that the theory was hotly contested by some famous geneticists: William Bateson, Wilhelm Johannsen, Richard Goldschmidt and T.H. Morgan, all of a rather dogmatic turn-of-mind. Eventually complete proof came from chromosome maps in Morgan’s own lab.[3]

Interphase chromatin
During interphase (the period of the cell cycle where the cell is not dividing), two types of chromatin can be distinguished: • Euchromatin, which consists of DNA that is active, e.g., being expressed as protein. • Heterochromatin, which consists of mostly inactive DNA. It seems to serve structural purposes during the chromosomal stages. Heterochromatin can be further distinguished into two types: • Constitutive heterochromatin, which is never expressed. It is located around the centromere and usually contains repetitive sequences. • Facultative heterochromatin, which is sometimes expressed. Individual chromosomes cannot be distinguished at this stage - they appear in the nucleus as a homogeneous tangled mix of DNA and protein.

Metaphase chromatin and division
See also: mitosis and meiosis

Chromosomes in eukaryotes
Eukaryotes (cells with nuclei such as plants, yeast, and animals) possess multiple large linear chromosomes contained in the cell’s nucleus. Each chromosome has one centromere, with one or two arms projecting from the centromere, although, under most circumstances, these arms are not visible as such. In addition, most eukaryotes have a small circular mitochondrial genome, and some eukaryotes may have additional small circular or linear cytoplasmic chromosomes. In the nuclear chromosomes of eukaryotes, the uncondensed DNA exists in a semi-ordered structure, where it is wrapped around histones (structural proteins), forming a composite material called chromatin.

Chromatin

Human chromosomes during metaphase. In the early stages of mitosis or meiosis (cell division), the chromatin strands become more and more condensed. They cease to function as accessible genetic material (transcription stops) and become a compact transportable form. This compact form makes the individual chromosomes visible, and they form the classic four arm structure, a pair of sister chromatids attached to each other at the centromere. The shorter arms are called p arms (from the French petit, small) and the longer arms are called q arms (q follows p in the Latin alphabet). This is the only natural context in which individual chromosomes are visible with an optical microscope.

Fig. 2: The major structures in DNA compaction; DNA, the nucleosome, the 10nm "beads-on-a-string" fibre, the 30nm fibre and the metaphase chromosome. Chromatin is the complex of DNA and protein found in the eukaryotic nucleus which packages chromosomes. The structure of chromatin varies significantly between

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Chromosome numbers in some plants Plant Species Arabidopsis thaliana (diploid)[13] Rye (diploid)[14] Maize (diploid)[15] Einkorn wheat (diploid)[16] Durum wheat (tetraploid)[16] Bread wheat (hexaploid)[16] Potato (tetraploid)[17] Cultivated tobacco (diploid)[18] Adder’s Tongue Fern (diploid)[19] During divisions, long microtubules attach to the centromere and the two opposite ends of the cell. The microtubules then pull the chromatids apart, so that each daughter cell inherits one set of chromatids. Once the cells have divided, the chromatids are uncoiled and can function again as chromatin. In spite of their appearance, chromosomes are structurally highly condensed, which enables these giant DNA structures to be contained within a cell nucleus (Fig. 2). The self-assembled microtubules form the spindle, which attaches to chromosomes at specialized structures called kinetochores, one of which is present on each sister chromatid. A special DNA base sequence in the region of the kinetochores provides, along with special proteins, longer-lasting attachment in this region. # 10 14 20 14 28 42 48 48 approx 1,440

Chromosome

DNA packaging
Prokaryotes do not possess nuclei. Instead, their DNA is organized into a structure called the nucleoid.[9] The nucleoid is a distinct structure and occupies a defined region of the bacterial cell. This structure is, however, dynamic and is maintained and remodeled by the actions of a range of histone-like proteins, which associate with the bacterial chromosome.[10] In archaea, the DNA in chromosomes is even more organized, with the DNA packaged within structures similar to eukaryotic nucleosomes.[11][12] Bacterial chromosomes tend to be tethered to the plasma membrane of the bacteria. In molecular biology application, this allows for its isolation from plasmid DNA by centrifugation of lysed bacteria and pelleting of the membranes (and the attached DNA). Prokaryotic chromosomes and plasmids are, like eukaryotic DNA, generally supercoiled. The DNA must first be released into its relaxed state for access for transcription, regulation, and replication.

Chromosomes in prokaryotes
The prokaryotes - bacteria and archaea - typically have a single circular chromosome, but many variations do exist.[4] Most bacteria have a single circular chromosome that can range in size from only 160,000 base pairs in the endosymbiotic bacteria Candidatus Carsonella ruddii,[5] to 12,200,000 base pairs in the soil-dwelling bacteria Sorangium cellulosum.[6] Spirochaetes of the genus Borrelia are a notable exception to this arrangement, with bacteria such as Borrelia burgdorferi, the cause of Lyme disease, containing a single linear chromosome.[7]

Number of chromosomes in various organisms
Eukaryotes
These tables give the total number of chromosomes (including sex chromosomes) in a cell nucleus. For example, human cells are diploid and have 22 different types of autosome, each present as two copies, and two sex chromosomes. This gives 46 chromosomes in total. Other organisms have more than two copies of their chromosomes, such as bread wheat, which is hexaploid and has six copies of seven different chromosomes – 42 chromosomes in total.

Structure in sequences
Prokaryotic chromosomes have less sequence-based structure than eukaryotes. Bacteria typically have a single point (the origin of replication) from which replication starts, whereas some archaea contain multiple replication origins.[8] The genes in prokaryotes are often organized in operons, and do not usually contain introns, unlike eukaryotes.

Normal members of a particular eukaryotic species all have the same n mosomes, i.e., mitochondrial and plasmid-like small chromosomes, are per cell. Asexually reproducing species have one set of chromosomes, whic

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Chromosome numbers (2n) in some animals Species Common fruit fly Dove Earthworm Octodrilus complanatus[22] Domestic cat[23] Laboratory mouse Rabbit Hare Gorillas, Chimpanzees[24] Elephants[25] Donkey Dog[26] Goldfish[28] # 8 78 36 38 40 44 46 48 56 62 78 100-104 Chromosome numbers in other organisms Species Trypanosoma brucei Chicken[30] Large Chromosomes 11 8 Intermediate Chromosomes 6 2 sex chromosomes Species Guinea Pig[20] Garden snail[21] Tibetan fox Domestic pig Laboratory rat Syrian hamster Human[24] Domestic sheep Cow Horse Kingfisher[27] Silkworm[29]

Chromosome

# 64 54 36 38 42 44 46 54 60 64 132 56

Small Chromosomes ~100 60

Sexually reproducing species have somatic cells (body cells), which and one from the father. Gametes, reproductive cells, are haploid [n]: a diploid germ line cell. During meiosis, the matching chromosomes of and thus create new chromosomes that are not inherited solely from e new diploid organism is formed. Some animal and plant species are polyploid [Xn]: They have more ture such as tobacco or wheat are often polyploid, compared to their a still seen in some cultivars as well as the wild progenitors. The more-c 42 (hexaploid) chromosomes, compared to the 14 (diploid) chromosom

Prokaryotes

Prokaryote species generally have one copy of each major chromosom Buchnera, a symbiont of aphids has multiple copies of its chromosome, such as Epulopiscium fishelsoni up to 100,000 copies of the chromosome in eukaryotes, very variable in copy number. The number of plasmids plasmid - fast division causes high copy number, and vice versa.

Karyotype

The 24 human chromosome territories during prometaphase in fibroblast cells.

In general, the karyotype is the characteristic chromosome compleme part of cytogenetics. Although the replication and transcription of DNA is highly standa often highly variable. There may be variation between species in chro nificant variation within species. Often there is 1. variation between th gametes and the rest of the body); 3. variation between members of a p ation between races; 5. mosaics or otherwise abnormal individuals. Als ised egg.

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Chromosome

Figure 3: Karyogram of a human male

The three major single chromosome mutations; deletion (1), duplication (2) and inversion (3).

The technique of determining the karyotype is usually called karyotyping. Cells can be locked part-way through division (in met vitro (in a reaction vial) with colchicine. These cells are then stained, photographed, and arranged into a karyogram, with the set of somes arranged, autosomes in order of length, and sex chromosomes (here X/Y) at the end: Fig. 3. Like many sexually reproducing species, humans have special gonosomes (sex chromosomes, in contrast to autosomes). These a males and XY in males.

Historical note

Investigation into the human karyotype took many years to settle the most basic question. How many chromosomes does a normal man cell contain? In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/ termination mechanism.[36] Painter in 1922 was not certain whether the diploid number of man is 46 or 48, at first favouring 46. [37] his opinion later from 46 to 48, and he correctly insisted on man’s having an XX/XY system.[38] New techniques were needed to definitively solve the problem: 1. Using cells in culture 2. Pretreating cells in a hypotonic solution, which swells them and spreads the chromosomes 3. Arresting mitosis in metaphase by a solution of colchicine 4. Squashing the preparation on the slide forcing the chromosomes into a single plane 5. Cutting up a photomicrograph and arranging the result into an indisputable karyogram.

It took until the mid-1950s until it became generally accepted that the human karyotype include only 46 chromosomes. Considerin niques of Winiwarter and Painter, their results were quite remarkable. [39][40] Chimpanzees (the closest living relatives to modern h have 48 chromosomes.

The two major two-chromosome mutations; insertion (1) and translocation (2). Chromosomal aberrations are disruptions in the normal chromosomal content of a cell, and are a major cause of genetic conditions such as Down syndrome. Some chromosome abnormalities do•not cause syndrome,carriers,is caused by an extra copy chromosoma Down’s disease in usually such as translocations, or of chromosom although they may lead to a higher chance of birthing a child with a chromosome disorder. Abnormal numbers of chromosomes or stockier build, asymmetrical skull, slanting eyes and mild to moder some sets, aneuploidy, may be lethal or give rise to genetic disorders. Genetic counseling is is the second-most-common trisomy;ch • Edwards syndrome, which offered for families that may carry a D rearrangement. Symptoms include mental and motor retardation and numerous co The gain or loss of DNA from chromosomes can lead to a variety of genetic disorders. Humanlive past their first birthday usually in infancy; however, those that examples include: • Cri du chat, which is caused by the deletion of part of the short arm of chromosome 5. "Cri du chat" means "cry of the cat" in Fr and overlapping fingers. the condition was so-named because affected babies make•high-pitched cries that sound like those of aor trisomy-13.individuals Patau Syndrome, also called D-Syndrome cat. Affected Symptoms set eyes, a small head and jaw, and are moderately to severely mentally retarded shape. short. characteristic hand and very • Wolf-Hirschhorn syndrome, which is caused by partial deletion of the short arm of chromosome 4. It is chromosome 15; also cal • Idic15, abbreviation for Isodicentric 15 on characterized by severe retardation and severe to profound mental retardation. same; IDIC(15), Inverted dupliction 15, extra Marker, Inv dup 15, pa

Chromosomal aberrations

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Chromosome

• Translocation - part of a chromosome breaks off and attaches to an Most mutations are neutral - have little or no effect A detailed graphical display of all human chromosomes and the dis

Human chromosomes

Human cells have 23 pairs of large linear nuclear chromosomes, giving dreds of copies of the mitochondrial genome. Sequencing of the huma chromosomes. Below is a table compiling statistics for the chromosom Vertebrate Genome Annotation (VEGA) database.[44] Number of genes some length is an estimate as well, based on the estimated size of unse

See also

• Locus (explains gene location nomenclature) • Sex-determination system • XY sex-determination system • X chromosome • X-inactivation In Down syndrome, there are three copies of chromosome 21 • Y chromosome • Y-chromosomal Adam • Y-chromosomal disorder. Those affected have normal i • Jacobsen syndrome, also called the terminal 11q deletion disorder.[42] This is a very rare Aaron Genetic genealogy or mild mental retardation, with poor expressive language• skills. Most have a bleeding disorder called Paris-Trousseau syndrom Genealogical DNA test • Klinefelter’s syndrome (XXY). Men with Klinefelter syndrome•are usually sterile, and tend to have longer arms and legs and to b • Genetic deletion than their peers. Boys with the syndrome are often shy and quiet, and have a higher incidence of speech delay and dyslexia. Du • develop gynecomastia. puberty, without testosterone treatment, some of them may List of number of chromosomes of various organisms • For information characteristics are present but underdeveloped. P • Turner syndrome (X instead of XX or XY). In Turner syndrome, female sexualabout chromosomes in genetic algorithms, see chr Turner syndrome often have a short stature, low hairline, abnormal eye features and bone development and a "caved-in" appea the chest. • XYY syndrome. XYY boys are usually taller than their siblings. Like XXY boys and XXX girls, they are somewhat more likely to • Chromosome Abnormalities at AtlasGeneticsOncology learning difficulties. • What Can a higher incidence of dyslexia. • Triple-X syndrome (XXX). XXX girls tend to be tall and thin. They haveOur Chromosomes Tell Us?, from the University of Utah • Try making karyotype yourself, from the University on the origin • Small supernumerary marker chromosome. This means there is an extra,aabnormal chromosome. Features depend of Utah’s Ge Kimballs Chromosome pages extra genetic material. Cat-eye syndrome and isodicentric•chromosome 15 syndrome (or Idic15) are both caused by a supernum • Chromosome News from Genome News Network marker chromosome, as is Pallister-Killian syndrome. • Eurochromnet, European network for Rare chromosomes present Chromosomal mutations produce changes in whole chromosomes (more than one gene) or in the number ofChromosome Disorders • http://www.ensembl.org Ensembl project, presenting chromosom • Deletion - loss of part of a chromosome • Genographic Project • Duplication - extra copies of a part of a chromosome • • Inversion - reverse the direction of a part of a chromosome Home reference on Chromosomes from the U.S. National Library o

External links

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Chromosome 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 X (sex chromosome) Y (sex chromosome) Total Genes 4,220 1,491 1,550 446 609 2,281 2,135 1,106 1,920 1,793 379 1,430 924 1,347 921 909 1,672 519 1,555 1,008 578 1,092 1,846 454 32,185 Total bases 247,199,719 242,751,149 199,446,827 191,263,063 180,837,866 170,896,993 158,821,424 146,274,826 140,442,298 135,374,737 134,452,384 132,289,534 114,127,980 106,360,585 100,338,915 88,822,254 78,654,742 76,117,153 63,806,651 62,435,965 46,944,323 49,528,953 154,913,754 57,741,652 3,079,843,747 Sequenced bases[45] 224,999,719 237,712,649 194,704,827 187,297,063 177,702,766 167,273,993 154,952,424 142,612,826 120,312,298 131,624,737 131,130,853 130,303,534 95,559,980 88,290,585 81,341,915 78,884,754 77,800,220 74,656,155 55,785,651 59,505,254 34,171,998 34,893,953 151,058,754 25,121,652 2,857,698,560

Chromosome

References
[1] [2] [3] [4] [5] [6] [7] [8] [9]

[10] Sandman K, Pereira SL, Reeve JN (1998). "Diversity of prokaryotic chrom 1350–64. doi:10.1007/s000180050259. PMID 9893710. [11] Sandman K, Reeve JN (2000). "Structure and functional relationships of a Paux E, Sourdille P, Salse J, et al (2008). "A Physical Map of the 1-Gigabase Bread Wheat Chromosome10763747. 322 (5898): 101–104. doi:10 doi:10.1007/s002039900122. PMID 3B". Science science.1161847. PMID 18832645. [12] Pereira SL, Grayling RA, Lurz R, Reeve JN (1997). "Archaeal nucleosomes Haeckel E. 1866. Generelle Morphologie der Organismen: Allgemeine Gründzuge der organischen Formen-Wissenschaft. 2 vols, Reimer, B 9356501. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=93565 Mayr E. 1982. The growth of biological thought. Harvard. p749 Armstrong SJ, Jones GH (January 2003). "Meiotic cytology and chromoso [13] Thanbichler M, Shapiro L (2006). "Chromosome organization and segregation in bacteria". J. PMID 12456750. http://jexbot.oxfordjournals.or doi:10.1093/jxb/54.380.1. Struct. Biol. 156 (2): 292–303. doi:10.1016/j.jsb.20 PMID 16860572. [14] Gill BS, Kimber G (April 1974). "The Giemsa C-banded karyotype of rye". Nakabachi A, Yamashita A, Toh H, Ishikawa H, Dunbar H, Moran N,4133848. M (2006). "The 160-kilobase genome of the bacterial endosymbio Hattori Carsonella". Science 314 (5797): 267. doi:10.1126/science.1134196. PMID 17038615. JC, Birchler JA (September 2004). "Chromosome painting u [15] Kato A, Lamb Pradella S, Hans A, Spröer C, Reichenbach H, Gerth K, Beyer S (2002). "Characterisation, genomeSci. U.S.A.genetic manipulation of the myxob in maize". Proc. Natl. Acad. size and 101 (37): 13554–9. doi:10.1073/pnas Sorangium cellulosum So ce56". Arch Microbiol 178 (6): 484–92. doi:10.1007/s00203-002-0479-2. PMID 12420170. pmidlookup?view=long&pmid=15342909. Hinnebusch J, Tilly K (1993). "Linear plasmids and chromosomes in bacteria". Mol MicrobiolZhong GY, et aldoi:10.1111/j.1365-2958.1993.tb009 [16] ^ Dubcovsky J, Luo MC, 10 (5): 917–22. (1996). "Genetic map of diploid w 7934868. vulgare L". Genetics 143 (2): 983–99. PMID 8725244. Kelman LM, Kelman Z (2004). "Multiple origins of replication in archaea". Trends Microbiol. 12 of the chromosome numbers and morphology [17] Ellison, W. (1935). "A study (9): 399–401. doi:10.1016/j.tim.2004.07.001. PM Thanbichler M, Wang SC, Shapiro L (2005). "The bacterial nucleoid: buberosum L.)" (PDF). Genetica 17 (1): 1–26. doi:10.1007/BF01984179.506– a highly organized and dynamic structure". J. Cell. Biochem. 96 (3): http doi:10.1002/jcb.20519. PMID 15988757. 2008-05-11.

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Chromosome

[18] Kenton A, Parokonny AS, Gleba YY, Bennett MD (August 1993). "CharacterizationDW (1998). "Parameters of L. genome by molecular cytogen [30] Smith J, Burt of the Nicotiana tabacum the chicken genome (Gallus gall Gen. Genet. 240 (2): 159–69. doi:10.1007/BF00277053. PMID 8355650. 9745667. [19] Leitch IJ, Soltis DE, Soltis PS, Bennett MD (2005). "Evolution of [31] amounts across(1918), Kurze Mitteilung uber die Chromosomenzahlen u DNA Sakamura, T. land plants (embryophyta)". Ann. Bot. 95 (1): 207–17. doi mci014. PMID 15596468. http://aob.oxfordjournals.org/cgi/content/full/95/1/207. 151-154. [20] Umeko Semba, Yasuko Umeda, Yoko Shibuya, Hiroaki Okabe, [32] Charlebois R.L. (ed) Yamamoto (2004). "Primary structures of guinea p Sumio Tanase and Tetsuro 1999. Organization of the prokaryote genome. AS [33] Komaki K, Ishikawa H (March 2000). "Genomic copy number low-molecular-weight kininogens". International Immunopharmacology 4 (10-11): 1391–1400. doi:10.1016/j.intimp.2004.06.003. of intracellu morph of their host". Insect Biochem. http://www.sciencedirect.com/science/article/B6W7N-4CX6PRC-1/2/97487fdf611a04e3c88690da9e6d853b.Mol. Biol. 30 (3): 253–8. doi:10.1016/ [21] Vitturi R, Libertini A, Sineo L, et al (2005). "Cytogenetics of the[34] Mendell JE, Clements KD, ChoatC. mazzullii ER (May 2008). "Extreme poly land snails Cantareus aspersus and JH, Angert (Mollusca: Gastropoda: Pulm doi:10.1073/pnas.0707522105. PMID 18445653. http://www.pnas.org/cgi/p Micron 36 (4): 351–7. doi:10.1016/j.micron.2004.12.010. PMID 15857774. [35] White, M. J. colocalization and linkage (6th ed.). London: genes and (T [22] Vitturi R, Colomba MS, Pirrone AM, Mandrioli M (2002). "rDNA (18S-28S and 5S)D. (1973). The chromosomesbetween ribosomalChapman and [36] von Winiwarter H Lumbricidae), sur la spermatogenese double-color F telomeric sequence in the earthworm, Octodrilus complanatus (Annelida: Oligochaeta:(1912). "Études revealed by single- andhumaine". Arch [37] Painter TS (1922). "The spermatogenesis of man". Anat. Res. Hered. 93 (4): 279–82. doi:10.1093/jhered/93.4.279. PMID 12407215. http://jhered.oxfordjournals.org/cgi/content/full/93/4/279. 23: 129. [38] Painter cat, red panda and five mustelid species revealed by comparativ [23] Nie W, Wang J, O’Brien PC, et al (2002). "The genome phylogeny of domestic TS (1923). "Studies in mammalian spermatogenesis II. The sperm [39] Tjio JH, Levan A (1956). "The chromosome number chromosome painting and G-banding". Chromosome Res. 10 (3): 209–22. doi:10.1023/A:1015292005631. PMID 12067210. of man". Hereditas 42 [40] Hsu Old World monkeys". Genetica 73 (1-2): 37–52. PMID 3333352. [24] ^ De Grouchy J (1987). "Chromosome phylogenies of man, great apes, andT.C. Human and mammalian cytogenetics: a historical perspective close!" [25] Houck ML, Kumamoto AT, Gallagher DS, Benirschke K (2001). "Comparative cytogenetics of the African elephant (Loxodonta africana) and A [41] Miller, Kenneth R. (2000). "9-3". Biology elephant (Elephas maximus)". Cytogenet. Cell Genet. 93 (3-4): 249–52. doi:10.1159/000056992. PMID 11528120. (5th ed.). Upper Saddle River, Ne [42] European Chromosome 11 Network [26] Wayne RK, Ostrander EA (1999). "Origin, genetic diversity, and genome structure of the domestic dog". Bioessays 21 (3): 247–57. doi:10.1002/ [43] (SICI)1521-1878(199903)21:3 (inactive 2009-03-11). PMID 10333734. Exploring Genes & Genetic Disorders [44] http://vega.sanger.ac.uk/Homo_sapiens/index.html All data in t [27] Burt DW (2002). "Origin and evolution of avian microchromosomes". Cytogenet. Genome Res. 96 (1-4): 97–112. doi:10.1159/000063018. PMID 12 [45] Sequenced percentages are based on fraction of euchromatin por [28] Ciudad J, Cid E, Velasco A, Lara JM, Aijón J, Orfao A (2002). "Flow cytometry measurement of the DNA contents of G0/G1 diploid cells from th only the euchromatic portion of the genome. Telomeres, centrom teleost fish species". Cytometry 48 (1): 20–5. doi:10.1002/cyto.10100. PMID 12116377. as have a small number of unclonable gaps. See reveals synteny an [29] Yasukochi Y, Ashakumary LA, Baba K, Yoshido A, Sahara K (2006). "A second-generation integrated map of the silkwormhttp://www.ncbi gene order between lepidopteran insects". Genetics 173 (3): 1319–28. Genome Project. doi:10.1534/genetics.106.055541. PMID 16547103.

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