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Metaphase

About: Metaphase is a research topic. Over the lifetime, 6925 publications have been published within this topic receiving 291590 citations. The topic is also known as: GO:0007091 & mitotic metaphase/anaphase transition.


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Journal Article
TL;DR: The utility of FISH with composite probes for rapid detection of numerical aberrations in metaphase and interphase amniotic cells is suggested.
Abstract: Fluorescence in situ hybridization (FISH) with chromosome-specific probes has been applied to detection of numerical aberrations involving chromosomes 13, 18, and 21 in metaphase and interphase amniocytes. High-complexity, composite probes for chromosomes 13, 18, and 21 were used as hybridization probes for this study. These probes were constructed as chromosome-specific libraries in Bluescribe plasmids and are designated pBS-13, pBS-18, and pBS-21. Elements of these probes bind at numerous sites along the target chromosome and, when detected fluorescently, stain essentially the entire long arm of the target chromosome. The target chromosome number (i.e., the number of chromosomes of the type for which the probe was specific) was correctly determined in 20 of 20 samples in which metaphase spreads were analyzed and in 43 of 43 samples in which interphase nuclei were analyzed; all of these studies were conducted in blind fashion. These results suggest the utility of FISH with composite probes for rapid detection of numerical aberrations in metaphase and interphase amniotic cells.

123 citations

Journal ArticleDOI
25 Apr 2003-Science
TL;DR: The chromosomal events up through the end of prophase I are normal in both CKS2–/– males and females, suggesting that the phenotype is due directly to failure to enter anaphase and not a consequence of a checkpoint-mediated metaphase I arrest.
Abstract: We generated mice lacking Cks2, one of two mammalian homologs of the yeast Cdk1-binding proteins, Suc1 and Cks1, and found them to be viable but sterile in both sexes. Sterility is due to failure of both male and female germ cells to progress past the first meiotic metaphase. The chromosomal events up through the end of prophase I are normal in both CKS2–/– males and females, suggesting that the phenotype is due directly to failure to enter anaphase and not a consequence of a checkpoint-mediated metaphase I arrest.

123 citations

Journal Article
TL;DR: It is likely that previous studies, based on flow cytometry, indicating that bis(2,6-dioxypiperazine) derivatives cause an accumulation of cells with a 4N DNA content, reflect the incomplete segregation of chromosomes in mitosis rather than a block in G2 of the cell cycle as had been proposed.
Abstract: Certain bis(2,6-dioxopiperazine) derivatives, which include ICRF-187 [(+)-l,2-bis(3,5-dioxopiperazinyl-1-yl]propane; ADR-529) and its racemic compound ICRF 159 (Razoxane), have been investigated as antineoplastic agents. In addition, ICRF-187 is currently under intense study as an agent to ameliorate the cardiac toxicity of anthracycline therapy. These agents have recently been identified as inhibitors of topoisomerase II. We studied the effects of ICRF-187 and ICRF-159 on the progression of cultured epithelial cells through M phase. Beginning approximately 1.5 h after drug addition, chromosome condensation was significantly inhibited. Cells entered and progressed through M phase at near normal rates, but the lack of complete chromosome separation during anaphase resulted in catastrophic effects on normal chromosome distribution. Immunolabeling with Crest autoimmune sera, which recognizes centromere proteins, and with MPM-2 monoclonal antibody, which recognizes mitotic phosphopro-teins, indicated that the centromeres of the chromosomes assembled a normal metaphase array in the presence of ICRF-187 and ICRF-159. Centromere separation in anaphase was initiated normally but was not completed because the chromatid arms failed to disengage from each other. Massive chromosome bridges were formed, and the chromatin mass became trapped in the cleavage furrow leading to its unequal distribution to the daughter cells. In many cases, all the chromatin was pushed into one of the two dividing cells. It is likely that previous studies, based on flow cytometry, indicating that bis(2,6-dioxypiperazine) derivatives cause an accumulation of cells with a 4N DNA content, reflect the incomplete segregation of chromosomes in mitosis rather than a block in G 2 of the cell cycle as had been proposed. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

123 citations

Journal ArticleDOI
TL;DR: Every mitosis, replicated chromosomes must be accurately segregated into each daughter cell, so that sisters separate and are pulled to opposite poles during anaphase.
Abstract: Every mitosis, replicated chromosomes must be accurately segregated into each daughter cell. Pairs of sister chromatids attach to the bipolar mitotic spindle during prometaphase, they are aligned at metaphase, then sisters separate and are pulled to opposite poles during anaphase. Failure to attach

122 citations

Journal ArticleDOI
TL;DR: Microinjection of calcium solutions does not promote precocious chromatid separation in nocodazole-arrested metaphase cells, indicating that the increase in calcium concentration does not induce centromere separation directly.
Abstract: Calcium-containing solutions were microinjected into dividing PtK1 cells to assess the effect of calcium ion concentration on the morphology and physiology of the mitotic spindle. Solutions containing 50 μM or more CaCl2 are immediately and irreversibly toxic to PtK1 cells. Those containing 5–10 μM CaCl2 cause reversible reduction in spindle birefringence followed by normal anaphase and cytokinesis. Microinjection of 5 μM or less CaCl2 into anaphase PtK1 cells has no detectable effect on the rate or extent of chromosome movement. Metaphase cells tend to enter anaphase 4–5 min after injection with 1–10 μM CaCl2, compared with an average of 16 min after injection with calcium-free buffer. Reducing the intracellular calcium concentration by injection of EGTA-CaCl2 buffers increases the lag between injection and anaphase to 20 min or more. Microinjection of calcium solutions does not promote precocious chromatid separation in nocodazole-arrested metaphase cells, indicating that the increase in calcium concentration does not induce centromere separation directly. An increase in the concentration of free calcium ions during metaphase appears to stimulate the onset of anaphase. Such an increase, regulated by the cell itself, may contribute to the initiation of chromosome separation in mammalian cells.

122 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202373
2022116
202182
202087
2019113
201888