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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: The data present the first broad proteomic analysis of human cells with abnormal karyotypes and suggest a uniform cellular response to the presence of an extra chromosome.
Abstract: Extra chromosome copies markedly alter the physiology of eukaryotic cells, but the underlying reasons are not well understood. We created human trisomic and tetrasomic cell lines and determined the quantitative changes in their transcriptome and proteome in comparison with their diploid counterparts. We found that whereas transcription levels reflect the chromosome copy number changes, the abundance of some proteins, such as subunits of protein complexes and protein kinases, is reduced toward diploid levels. Furthermore, using the quantitative data we investigated the changes of cellular pathways in response to aneuploidy. This analysis revealed specific and uniform alterations in pathway regulation in cells with extra chromosomes. For example, the DNA and RNA metabolism pathways were downregulated, whereas several pathways such as energy metabolism, membrane metabolism and lysosomal pathways were upregulated. In particular, we found that the p62-dependent selective autophagy is activated in the human trisomic and tetrasomic cells. Our data present the first broad proteomic analysis of human cells with abnormal karyotypes and suggest a uniform cellular response to the presence of an extra chromosome.

374 citations

Journal ArticleDOI
TL;DR: In this paper, the authors conducted a cytological investigation of 50 resynthesized Brassica napus allopolyploids across generations S0:1 to S5:6 and in the S10:11 generation.
Abstract: Polyploidy has contributed to the evolution of eukaryotes, particularly flowering plants. The genomic consequences of polyploidy have been extensively studied, but the mechanisms for chromosome stability and diploidization in polyploids remain largely unknown. By using new cytogenetic tools to identify all of the homoeologous chromosomes, we conducted a cytological investigation of 50 resynthesized Brassica napus allopolyploids across generations S0:1 to S5:6 and in the S10:11 generation. Changes in copy number of individual chromosomes were detected in the S0:1 generation and increased in subsequent generations, despite the fact that the mean chromosome number among lines was approximately 38. The chromosome complement of individual plants (segregants) ranged from 36 to 42, with a bias toward the accumulation of extra chromosomes. Karyotype analysis of the S10:11 generation detected aneuploidy and inter- and intragenomic rearrangements, chromosome breakage and fusion, rDNA changes, and loss of repeat sequences. Chromosome sets with extensive homoeology showed the greatest instability. Dosage balance requirements maintained chromosome numbers at or near the tetraploid level, and the loss and gain of chromosomes frequently involved homoeologous chromosome replacement and compensation. These data indicate that early generations of resynthesized B. napus involved aneuploidy and gross chromosomal rearrangements, and that dosage balance mechanisms enforced chromosome number stability. Seed yield and pollen viability were inversely correlated with increasing aneuploidy, and the greatest fertility was observed in two lines that were additive for parental chromosomes. These data on resynthesized B. napus and the correlation of fertility with additive karyotypes cast light on the origins and establishment of natural B. napus.

374 citations

Journal ArticleDOI
14 Jul 2016-Nature
TL;DR: This study elucidates a biomechanical role of the mitotic chromosome periphery in mammalian cells and suggests that natural proteins can function as surfactants in intracellular compartmentalization.
Abstract: Eukaryotic genomes are partitioned into chromosomes that form compact and spatially well-separated mechanical bodies during mitosis. This enables chromosomes to move independently of each other for segregation of precisely one copy of the genome to each of the nascent daughter cells. Despite insights into the spatial organization of mitotic chromosomes and the discovery of proteins at the chromosome surface, the molecular and biophysical bases of mitotic chromosome structural individuality have remained unclear. Here we report that the proliferation marker protein Ki-67 (encoded by the MKI67 gene), a component of the mitotic chromosome periphery, prevents chromosomes from collapsing into a single chromatin mass after nuclear envelope disassembly, thus enabling independent chromosome motility and efficient interactions with the mitotic spindle. The chromosome separation function of human Ki-67 is not confined within a specific protein domain, but correlates with size and net charge of truncation mutants that apparently lack secondary structure. This suggests that Ki-67 forms a steric and electrostatic charge barrier, similar to surface-active agents (surfactants) that disperse particles or phase-separated liquid droplets in solvents. Fluorescence correlation spectroscopy showed a high surface density of Ki-67 and dual-colour labelling of both protein termini revealed an extended molecular conformation, indicating brush-like arrangements that are characteristic of polymeric surfactants. Our study thus elucidates a biomechanical role of the mitotic chromosome periphery in mammalian cells and suggests that natural proteins can function as surfactants in intracellular compartmentalization.

371 citations

Journal ArticleDOI
TL;DR: A systematic analysis of the spatial positioning of a subset of mouse chromosomes in several tissues shows that chromosomes exhibit tissue-specific organization, and points to a role for tissue- specific spatial genome organization in the formation of recurrent chromosome arrangements among tissues.
Abstract: Background: Genomes are organized in vivo in the form of chromosomes. Each chromosome occupies a distinct nuclear subvolume in the form of a chromosome territory. The spatial positioning of chromosomes within the interphase nucleus is often nonrandom. It is unclear whether the nonrandom spatial arrangement of chromosomes is conserved among tissues or whether spatial genome organization is tissue-specific. Results: Using two-dimensional and three-dimensional fluorescence in situ hybridization we have carried out a systematic analysis of the spatial positioning of a subset of mouse chromosomes in several tissues. We show that chromosomes exhibit tissue-specific organization. Chromosomes are distributed tissue-specifically with respect to their position relative to the center of the nucleus and also relative to each other. Subsets of chromosomes form distinct types of spatial clusters in different tissues and the relative distance between chromosome pairs varies among tissues. Consistent with the notion that nonrandom spatial proximity is functionally relevant in determining the outcome of chromosome translocation events, we find a correlation between tissue-specific spatial proximity and tissue-specific translocation prevalence. Conclusions: Our results demonstrate that the spatial organization of genomes is tissue-specific and point to a role for tissue-specific spatial genome organization in the formation of recurrent chromosome arrangements among tissues.

370 citations

Journal ArticleDOI
TL;DR: A convenient, reliable method for chromosome delineation of animal cells grown as monolayers on glass has been applied to human, opossum, and Chinese hamster cells, finding that cells of malignant, aneuploid constitution have been maintained in active growth for 3 years and hundreds of generations, with stable chromosomal and metabolic characteristics.
Abstract: A convenient, reliable method for chromosome delineation of animal cells grown as monolayers on glass has been applied to human, opossum, and Chinese hamster cells. Tissue cultured cells from 5 different, normal organs of 7 different human subjects uniformly displayed the expected chromosome number of 46 and showed no variations in morphology or number other than the expected sex differences and a small incidence of polyploidy. The chromosomes of normal cells from the American opossum were as uniform as those of human cells. Cells of the inbred Chinese hamster demonstrated appreciable karyotype variability, the cause of which is under investigation. The chromosome number and morphology of cells from normal human tissues have remained constant after more than 5 months of continuous, rapid growth in tissue culture involving scores of vessel transfers and a number of generations equivalent to many billions of progeny. By the use of routine recloning, even cells of malignant, aneuploid constitution have been maintained in active growth for 3 years and hundreds of generations, with stable chromosomal and metabolic characteristics. The cells of the American opossum and Chinese hamster which possess only 22 chromosomes have been established in vitro and are especially suitable for genetic studies. The readily recognizeable Y and X chromosomes of the male opossum are particularly favorable as cytological markers. Photomicrographs of the chromosomes of the various cells employed are presented.

370 citations


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