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Mechanism of the Induction of Chromosomal Errors, Interchromosomal Effects in Chinese Hamsters Heterozygous for Inversions
Author(s) -
NARUKAWA Takashi
Publication year - 1994
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.1994.tb00792.x
Subject(s) - nondisjunction , meiosis , biology , genetics , chromosome , meiosis ii , andrology , aneuploidy , gene , medicine
Using Chinese hamsters heterozygous for inversions of chromosomes 1 or 4 [INV(1)37Idr and INV(4)Idr], as well as karyotypically normal animals, interchromosomal effects on meiotic disjunctions were investigated by chromosomal analysis of the meiotic cells and one‐cell conceptuses. The mean frequency of nondisjunction at the first meiosis in five normal +/+ males was calculated at 1.28%, by doubling the frequency (0.64%) of hyperhaploid second meiotic (MII) cells, and there was no significant difference in the frequency among individuals. Among males heterozygous for INV(1)37Idr or INV(4)25Idr inversion, the frequencies of hyperhaploid cells with an extra inversion‐unrelated chromosome were 0.52% and 0.43%, respectively, which were not significantly different from the frequency of hyperploid MII cells in +/+ males (0.52%). In one‐cell conceptuses obtained from crosses between karyotypically normal females and males heterozygous for INV(1)37Idr or INV(4)25Idr, 1.18% and 1.22% of conceptuses had an extra inversion‐unrelated chromosome, respectively. The frequency of nondisjunction during meiotic divison in males heterozygous for these inversions was not significantly different from that in controls. The results therefore suggest that the presence of inversions in meiotic cells exerts no influence on disjunctions of normal bivalents and MII chromosomes unrelated to the inversions.