metacentric chromosome

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Related to metacentric chromosome: holocentric chromosome, submetacentric chromosome
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Noun1.metacentric chromosome - a chromosome having two equal arms because the centromere is in median positionmetacentric chromosome - a chromosome having two equal arms because the centromere is in median position
chromosome - a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order; "humans have 22 chromosome pairs plus two sex chromosomes"
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2003) used four Astyanax scabripinnis populations to analyze B chromosome characteristics and identified three forms of Bs, a metacentric macrochromosome, a submetacentric, and a metacentric chromosome.
amana is small and spherical whereas, the satellites in three metacentric chromosome pairs of F.
B Population showed 2n=50 chromosomes, with 12m + 16sm + 6st + 16a, and with also a macro supernumerary chromosome, similar in size to the first pair of metacentric chromosome found in 100% of the cells of about 80% of the females analized (Figure 1c).
The female with 2n = 41 had one extra small metacentric chromosome, and lacked two telocentric chromosomes of the autosomal complement.
The X chromosome was the second longest telocentric chromosome, while Y chromosome was the shortest and only metacentric chromosome.
Loureiro (1999) obtained the same pattern (NORs in only one chromosome pair) for two Crenicichla species, with NORs located on the short arm of the first metacentric chromosome pair, and for Geophagus brasiliensis, on the short arm of the larger pair of the ST-A group.
The location of the major ribosomal rDNA (ITS1) displayed the presence of 2 signals: in the telomeric regions of the short arms of the largest metacentric chromosome and in a submetacentric chromosome.
The differences observed in the cytotype C2 in relation to the cytotype C1 (loss of one element of the metacentric pair No 1, loss of one of the chromosomes of the subtelocentric pair No 4, and appearance of a large metacentric element) could be explained by: a) a fusion of one of the subtelocentrics of the pair No 4 with one of the acrocentric elements of pair No 5 (the largest of the acrocentric series), which would maintain the size relation between those elements and the new large metacentric chromosome (Figure 3); or b) a pericentric inversion of one of the chromosomes of the metacentric pair No 1 causing the displacement of the centromere from a medium to a terminal location, and maintaining the segment that possesses rDNA cluster at the same position (Figure 4).
This nonMendelian transmission would result from a basic asymmetry of the female meiotic spindle; thus when heterozygous Rb configurations are present, the partner bearing fewer centromeres will attach more frequently to the spindle pole that is less efficient in capturing centromeres, favoring metacentric chromosome transmission.
occur in the Nearctic region (Cokendolpher 1989) and show a great karyotypic uniformity in relation to diploid number (2n = 15), metacentric chromosome morphology, and X/XX sex determination chromosome system type.
The karyotype of this species is identical to that reported here for the Caucasian snow vole, including the possession of a metacentric chromosome 26.