Topic
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.
Papers published on a yearly basis
Papers
More filters
TL;DR: Random inactivation of one of the two female X chromosomes establishes dosage compensation between XY males and XX females in placental mammals and is implicated in the mechanism of random choice.
163 citations
TL;DR: It is determined that the major mitotic phosphoprotein in chromosomes recognized by the antiphosphoprotein antibody MPM-2 is the 170-kDa isoform of topoisomerase II (topo II), the isoform predominant in proliferating cells.
Abstract: We have determined that the major mitotic phosphoprotein in chromosomes recognized by the antiphosphoprotein antibody MPM-2 is the 170-kDa isoform of topoisomerase II (topo II), the isoform predominant in proliferating cells. As a prerequisite to making this discovery, it was necessary to develop protocols to protect chromosomal proteins from dephosphorylation during cell extraction and chromosome isolation procedures. Immunofluorescence analysis of the large chromosomes prepared from Indian Muntjac cells revealed colocalization of MPM-2 and anti-topo II antibodies to the chromosomal centromeres and to the axial regions of the chromosomal arms. For biochemical fractionation studies, large quantities of chromosomes from the P388D1 mouse lymphocyte cell line were isolated and treated to remove DNA and histone proteins. Immunoblot and immunoprecipitation experiments with this chromosome scaffold fraction identified the major MPM-2-reactive phosphoprotein to be DNA topo II. Using a panel of anti-peptide antibodies specific to the isoforms of topo II, we determined that the major phosphoprotein recognized by MPM-2 is the 170-kDa isoform of topo II, topo II alpha. The 180-kDa isoform, topo II beta, present in the isolated chromosomes in much smaller quantities, is also recognized by MPM-2. The mitotic phosphorylation of the topo II proteins may be critical for proper chromosome condensation and segregation.
163 citations
TL;DR: Two related phenomena are suggested: an intrachromosomal association that holds the halves of a single broken sister chromatid together in metaphase and an interchromosomal force that tethers broken sister Chromatids to each other and promotes their missegregation.
163 citations
TL;DR: The results of comparative cytogenetic mapping efforts and population genetics studies demonstrated that ZAL2m suppresses recombination in the heterokaryotype and is evolving as a rare nonrecombining autosomal segment of the genome, and suggested that the ZAL/ZAL 2m polymorphism is a heretofore unrecognized model for the early stages of sex chromosome evolution.
Abstract: Variation in social behavior and plumage in the white-throated sparrow (Zonotrichia albicollis) is linked to an inversion polymorphism on chromosome 2 Here we report the results of our comparative cytogenetic mapping efforts and population genetics studies focused on the genomic characterization of this balanced chromosomal polymorphism Comparative chromosome painting and cytogenetic mapping of 15 zebra finch BAC clones to the standard (ZAL2) and alternative (ZAL2m) arrangements revealed that this chromosome is orthologous to chicken chromosome 3, and that at a minimum, ZAL2 and ZAL2m differ by a pair of included pericentric inversions that we estimate span at least 98 Mb Population-based sequencing and genotyping of multiple loci demonstrated that ZAL2m suppresses recombination in the heterokaryotype and is evolving as a rare nonrecombining autosomal segment of the genome In addition, we estimate that the first inversion within the ZAL2m arrangement originated 22 ± 03 million years ago Finally, while previously recognized as a genetic model for the evolution of social behavior, we found that the ZAL2/ZAL2m polymorphism also shares genetic and phenotypic features with the mouse t complex and we further suggest that the ZAL2/ZAL2m polymorphism is a heretofore unrecognized model for the early stages of sex chromosome evolution
162 citations
TL;DR: Chromosomal structural changes-deletions and translocations-occurred in almost half the progeny of a monosomic addition line of common wheat, Triticum aestivum, which had a chromosome from Aegilops cylindrica, suggesting that when the A. cylindica chromosome was in the sporophytes, chromosome breakage was likely to occur in the gametophytes that lacked it, resulting in the production of offspring with chromosome structural changes.
Abstract: Chromosomal structural changes-deletions and translocations-occurred in almost half the progeny of a monosomic addition line of common wheat, Triticum aestivum (2n = 42, AABBDD), which had a chromosome from Aegilops cylindrica (2n = 28, CCDD). Most of the progeny with chromosomal structural changes lacked the A. cylindrica chromosome. Chromosome breaks were observed in various regions of all the wheat chromosomes and the A. cylindrica chromosome. Chromosome aberrations occurred far less frequently both in the self-progeny of the disomic addition plants and in the F1 monosomic addition plants derived from reciprocal crosses with normal common wheat. These findings suggest that when the A. cylindrica chromosome was in the sporophytes, chromosome breakage was likely to occur in the gametophytes that lacked it but that the gametophytes were still functional, resulting in the production of offspring with chromosomal structural changes.
162 citations