Metaphase


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metaphase

[′med·ə‚fāz]
(cell and molecular biology)
The phase of mitosis during which centromeres are arranged on the equator of the spindle.
The phase of the first meiotic division when centromeric regions of homologous chromosomes come to lie equidistant on either side of the equator.

Metaphase

 

one of the stages of mitotic cellular division.

Two periods of metaphase are distinguished. The first is metakinesis, during which the chromosomes concentrate in the equatorial region of the spindle and form what is called the equatorial plate. There are a number of hypotheses regarding the mechanism of metakinesis; the trajectories of the chromosomes have been described, and maps have been drawn of the paths of the centromeres and arms of the chromosomes.

The second period of metaphase is metaphase proper, during which links are established between the chromosomal threads of the spindle and the centromeres, the chromosomes separating into chromatids. Metaphase lasts from 0.3 to 175 min in different cells. In meiosis the analogous stage of the first division is called metaphase I.

References in periodicals archive ?
In the patient presented here, conventional cytogenetics was performed at presentation and revealed tetrasomy 8 as a sole anomaly in all metaphases examined.
Metaphase-I###on the metaphase plate of the spindle bivalents arrangement
From fertilization to metaphase of the first meiosis, the actin layer was equally distributed over the cortex of zygotes.
(4) Method Description Cytogenetics Giemsa banding is performed on fetal cells analysis at metaphase stage on amniocytes (grown in vitro) or CVS Fluorescence FISH involves hybridization of selected in situ chromosome-specific DNA sequences that hybridization have been labeled with fluorescent dye to chromosome preparation.
Karyotypes were constructed by arranging chromosomes in pairs according to size using images of spermatogonial metaphases. Relative chromosome lengths (RCLs) of each chromosome pair were calculated from 10 metaphases.
For each probe, we used a 3-step verification process: (1) checking for known genomic variants, (12) (2) end sequencing to match the intended chromosomal location, (11) and (3) confirmation of the expected metaphase band location.
Metaphase offers expertise in hand-intensive products and packaging, and is involved in research and design of ergonomic products.
Unlike [gamma]H2AX analysis which is done on interphase chromosomes, the specific timing requirement of metaphase spread preparation for SCE analysis makes this method technically challenging, and the majority of published studies utilising SCE analysis have focused on peripheral blood lymphocytes, which have relatively predictable doubling time.
FISH analysis of metaphase cells using BAC probes from 7p21.1 (RP11-5G13) and 7p2.1 (RP11-425P5) confirmed the presence of a duplication in the 7p22.1p21.1 region.
Mitotic metaphase nuclei of Mesabolivar spinulosus possess 2n[male] = 17 and 2n[female] = 18 (Fig.
The maturational status of oocytes were scored as germinal vesicle (GV), metaphase I (MI), or metaphase II (MII) as described by Donahue (1968), using an optical microscope.