Germ line-restricted supernumerary (B) chromosomes inEptatretus okinoseanus
作者:
S. Kubota,
Y. Nakai,
M. Kuro-o,
S. Kohno,
期刊:
Cytogenetic and Genome Research
(Karger Available online 1992)
卷期:
Volume 60,
issue 3-4
页码: 224-228
ISSN:1424-8581
年代: 1992
DOI:10.1159/000133345
出版商: S. Karger AG
数据来源: Karger
摘要:
Cytogenetic studies were performed on two types of Japanese hagfish (Eptatretus okinoseanus) that eliminate about 45% (type A) and 55% (type B) of their DNA from presumptive somatic cells during the differentiation of somatic cells. The observations revealed inter- and intraindividual variations in the number of chromosomes in germ cells of both types of hagfishes. Although the modal number of chromosomes in the germ cells was 54 in both types, the percentage of cells with the modal number was rather low (38.6% [51/132] in five specimens of type A and 22.7% [25/110] in eight specimens of type B). In addition, one of seven type B specimens clearly had a modal number of 62 chromosomes. Another specimen of type B had a bimodal distribution of chromosome numbers, with peaks of 54 and 59 chromosomes. The observation of interindividual variations was supported by data on the amount of DNA in germ cells of type B specimens. However, these variations were rarely observed in somatic cells. These results suggest that supernumerary (B) chromosomes are maintained in germ cells and are eliminated together with some other chromosomes and/or chromatin from somatic cells.
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