Centromere

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Related to centromeric: kinetochore, telocentric chromosome

centromere

[′sen·trə‚mir]
(cell and molecular biology)
A specialized chromomere to which the spindle fibers are attached during mitosis. Also known as kinetochore; kinomere; primary constriction.

Centromere

 

a part of a chromosome that plays a fundamental role in its movement during cell division (mitosis). In the metaphase stage of mitosis, the area of the centromere within the chromosome is less dense than the chromosome’s other areas and forms a primary constriction that divides the chromosome into two sections; the position of this constriction is a basis for the classification of chromosomes. The cytoplasmic filaments (microtubules) of the spindle of cell division are attached to the centromere by their ends.

Some organisms, such as members of the genus Luzula and the scorpion, have polycentromeric chromosomes with a diffuse centromere and with the spindle filaments attached to the chromosome along its entire length. With a light microscope a cluster of chromomeres may be seen near the centromere of a chromosome during metaphase. Examination of mammalian cells with an electron microscope reveals a three-layered structure near each of the two longitudinal chromosome filaments, or chromatids. This structure is a kinetochore plate, whose interaction with the spindle filaments results in the even distribution of chromosomes among the daughter cells during cell division. Chromosomal aberrations involving the chromomere hamper the distribution of chromosomal material during mitosis and meiosis and alter the organism’s karyotype. Chromosomes that lack a centromere cannot take part in mitosis.

I. I. KIKNADZE

References in periodicals archive ?
Although some of these techniques may have increased accuracy on the use of centromeric probes, they are time consuming, are costly, and require nonstandard laboratory equipment for their operation and experienced personnel for interpretation of the results, and therefore are not suitable for use in a busy clinical laboratory.
A submetacentric chromosome with an interstitial band midway between the telomeric band and the centromeric band; there were no interstitial bands located on the long arms, although occasionally a tertiary constriction can be found on the long arms of the chromosomes.
4,8,10) Centromeric probes for chromosomes 17 (CEN17) were visualized by using Spectrum Green and locus-specific HER2/neu gene (HER2) probes were detected by using Spectrum Orange fluorescence.
gov/BLAST/) of the human genome using GRHPR cDNA picked up only 1 hit at the expected location at the centromeric region of chromosome 9.
A repeat that accounts to 1% to 4% of the genome has been isolated and mapped to centromeric regions of several chromosomes in the Pacific oyster (Clabby et al.
A metacentric chromosome with an interstitial band closer to the centromeric band than the telomeric band on the short arm of the chromosome with very few polymorphisms.
Measurements of short and long arms of each chromosome, and mean relative length (RL) of chromosomes were estimated according to Thiriot-Quievreux (1984), and centromeric indices (CI) and long and short arms relative lengths (LA, SA) based on Levan et al.
Centromeric to the KLK1 gene lies a nonkallikrein gene, testicular acid phosphatase (RCPT) (8).
AFLP markers from EcoRI/MseI restriction enzymes were found to concentrate often in the vicinity of the centromere of chromosome due to centromeric suppression of recombination (Haanstra et al.
FISH studies revealed multiple signals with BCR probe (chromosome 22) and centromeric probes for chromosomes 2 and 18 suggesting polyploidy.