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Chromosome

About: Chromosome is a research topic. Over the lifetime, 17538 publications have been published within this topic receiving 660077 citations. The topic is also known as: chromosomes & GO:0005694.


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Journal ArticleDOI
TL;DR: Modeling of 3D CT arrangements suggests that cell-type-specific differences in radial CT arrangements are not solely due to geometrical constraints that result from nuclear shape differences, and gene-density-correlated arrangements of higher-order chromatin shared by all human cell types studied so far are found.
Abstract: Studies of higher-order chromatin arrangements are an essential part of ongoing attempts to explore changes in epigenome structure and their functional implications during development and cell differentiation. However, the extent and cell-type-specificity of three-dimensional (3D) chromosome arrangements has remained controversial. In order to overcome technical limitations of previous studies, we have developed tools that allow the quantitative 3D positional mapping of all chromosomes simultaneously. We present unequivocal evidence for a probabilistic 3D order of prometaphase chromosomes, as well as of chromosome territories (CTs) in nuclei of quiescent (G0) and cycling (early S-phase) human diploid fibroblasts (46, XY). Radial distance measurements showed a probabilistic, highly nonrandom correlation with chromosome size: small chromosomes-independently of their gene density-were distributed significantly closer to the center of the nucleus or prometaphase rosette, while large chromosomes were located closer to the nuclear or rosette rim. This arrangement was independently confirmed in both human fibroblast and amniotic fluid cell nuclei. Notably, these cell types exhibit flat-ellipsoidal cell nuclei, in contrast to the spherical nuclei of lymphocytes and several other human cell types, for which we and others previously demonstrated gene-density-correlated radial 3D CT arrangements. Modeling of 3D CT arrangements suggests that cell-type-specific differences in radial CT arrangements are not solely due to geometrical constraints that result from nuclear shape differences. We also found gene-density-correlated arrangements of higher-order chromatin shared by all human cell types studied so far. Chromatin domains, which are gene-poor, form a layer beneath the nuclear envelope, while gene-dense chromatin is enriched in the nuclear interior. We discuss the possible functional implications of this finding.

801 citations

Journal ArticleDOI
01 Dec 1988-Genetics
TL;DR: Linkage maps based on a common set of restriction fragment length polymorphism markers provide a basis for uniting the previously separate disciplines of tomato and potato genetics and may now be possible to test theories about homologies or orthologies of other genes, including those coding for disease resistance and stress tolerances.
Abstract: Potato (Solanum tuberosum L.) and tomato (Lycopersicon esculentum) are members of the Solanaceae (nightshade family) and have the same basic chromosome number (x = 12). However, they cannot be cross-hybridized and, until now, it was unknown how conserved the gene order might be between these two species. We report herein the construction of a genetic linkage map of potato chromosomes based on genomic and cDNA clones from tomato. The potato map was drawn from segregation data derived from the interspecific cross S. phureja X (S. tuberosum X S. chacoense) (2n = 2x = 24), and consists of 135 markers defining 12 distinct linkage groups. Nearly all of the tomato probes tested hybridized to potato DNA, and in most cases, the copy number of the employed clones was the same in both species. Furthermore, all clones mapped to the same linkage group in both species. For nine chromosomes, the order of loci appears to be identical in the two species, while for the other three, intrachromosomal rearrangements are apparent, all of which appear to be paracentric inversions with one breakpoint at or near the centromere. These results are consistent with cytogenetic theory, previously untested in plants, which predicts that paracentric inversions will have the least negative effect on fitness and thus be the most likely form of chromosomal rearrangements to survive through evolutionary time. Linkage maps based on a common set of restriction fragment length polymorphism markers provide a basis for uniting the previously separate disciplines of tomato and potato genetics. Using these maps, it may now be possible to test theories about homologies or orthologies of other genes, including those coding for disease resistance and stress tolerances.

798 citations

Journal ArticleDOI
16 Dec 1999-Nature
TL;DR: The sequence of chromosome 2 from the Columbia ecotype is reported in two gap-free assemblies (contigs) of 3.6 and 16 megabases, which represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date.
Abstract: Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.

792 citations

Book
27 Apr 1989
TL;DR: This chapter discusses parents with achromosome abnormalities detected at prenatal diagnosis, as well as elements of medical cytogenetics, and discusses Gonadal chromosomal damage from exposure to extrinsic agents.
Abstract: BASIC CONCEPTS 1. Elements of medical cytogenetics 2. The origins and consequences of chromosome pathology 3. Deriving and using a risk figure PARENT WITH A CHROMOSOMAL ABNORMALITY 4. Autosomal reciprocal translocations 5. Sex chromosome translocations 6. Robertsonian translocations 7. Centromere fissions 8. Inversions 9. Insertions 10. Autosomal rings 11. Complex rearrangements 12. Parental sex chromosome aneuploidy 13. Parental autosomal aneuploidy 14. The fragile X syndrome 15. Variant chromosomes NORMAL PARENTS WITH A CHROMOSOMALLY ABNORMAL CHILD 16. Down syndrome and other full aneuploidy, and polyploidy 17. Structural rearrangements and uniparental disomy 18. The XY female, the XX male, and the true hermaphrodite 19. Chromosome instability syndromes REPRODUCTIVE FAILURE 20. Pregnancy loss and infertility PRENATAL DIAGNOSIS 21. Parental age counseling and screening for fetal trisomy 22. Prenatal diagnostic procedures 23. Chromosome abnormalities detected at prenatal diagnosis APPENDIXES A. Cytogenetic abbreviations and nomenclature B. Ideograms of human chromosomes and haploid autosomal lengths C. Determining 95 percent confidence limits, and the standard error References Index

789 citations

Journal ArticleDOI
06 Nov 2009-Science
TL;DR: The analysis reveals an evolutionarily new centromere on equine chromosome 11 that displays properties of an immature but fully functioning Centromere and is devoid of centromeric satellite sequence, suggesting thatCentromeric function may arise before satellite repeat accumulation.
Abstract: We report a high-quality draft sequence of the genome of the horse (Equus caballus). The genome is relatively repetitive but has little segmental duplication. Chromosomes appear to have undergone few historical rearrangements: 53% of equine chromosomes show conserved synteny to a single human chromosome. Equine chromosome 11 is shown to have an evolutionary new centromere devoid of centromeric satellite DNA, suggesting that centromeric function may arise before satellite repeat accumulation. Linkage disequilibrium, showing the influences of early domestication of large herds of female horses, is intermediate in length between dog and human, and there is long-range haplotype sharing among breeds.

745 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023862
20221,198
2021368
2020359
2019365