Colchicine-induced abnormal meiotic chromosomal segregation in primary oocytes of the Chinese hamster

Abstract

SummaryA single dose of 3/~g/g b.w. colchicine was intraperitoneally injected to female Chinese hamsters with a normal estrous cycle at the onset of the formation of the first meiotic spindle. Morphologically abnormal secondary oocytes having one or two extremely large first polar bodies occurred frequently, i.e., 47 (11.3~) out of 416 oocytes. In 30 of them, chromosome analysis was successful with both the oocytes and their giant polar body/bodies. In 25 cases, the abnormal chromosome segregation between the oocyte and its giant polar body/bodies could Ice ascertained. Three types of abnormal segregation were classified. One of them was of nondisjunction and the remaining two of anaphase lagging. ~[he fate of the lagging chromosomes was observed. They were included neither in the oocytes nor in their polar body, and eventually were degenerated within perivitelline space. The behavior and the fate of the lagging chromosomes and the mechanism of the giant polar body formation were discussed. INTROD UCTIONAccording to Hamerton (1971), the failure of inclusion of chromosomes in either daughter cell is defined as "anaphase lagging." As mentioned in Part I of our paper (Sugawara and Mikamo, 1980), the in vivo administration of colchicine to primary oocytes of the Chinese hamster induced frequently hypohaploids having a small number of dyads in the secondary oocytes. Their occurrence was apparrently related to the formation of a giant first polar body/bodies which were especially frequent in the treated oocytes. In many of them, the dyads lost from the oocytes were not included in their polar body. Therefore, the phenomenon was clearly different from the so-called nondisjunction, but very much like the anaphase lagging. This prompts us to present the observation on the process of loss of dyads

The Chinese or Striped-Back Hamster

“…Some early cell biology studies conducted in CHO cells involved mutagenesis and isolation of certain auxotrophs (Puck and Kao, 1967) that facilitate cell growth and viability in cell culture. Cell mutants with deficiencies in metabolic enzymes such as adenosine Chromosome activities during meiosis of female germ cells Mikamo and Sugawara (1980) Chromosome anomalies of oocytes Mikamo and Kamiguchi (1983) Chromosome activities during spermatogenesis Murkherjee and Ghosal (1969); Barcellona and Brinkley (1973) Chromosome banding patterns of sperm Utakoji (1966); Pathak et al (1976); Vistorin et al (1982) Cytochemistry and behavior of dense bodies in sperm Takanari et al (1982) Karyotyping of synaptonemal complex in sperm Dresser and Moses (1980) a From Diani and Gerritsen(1987); reprinted with permission of Elsevier. Diani and Gerritsen (1987); reprinted with permission of Elsevier.…”

Evaluation of the mutagenic effects of SV40 in mouse, hamster, and mouse-human hybrid cells

“…After the expression period, the cells are selected in 6TG at the permissive temperature or nonpermissive temperature for a period of approximately 10 days to two weeks and the frequency of colony-forming cells (CFC) is determined at the permissive temperature and nonpermissive temperature. Treatment controls consist of cells treated with medium, with a drug known to induce chromosome loss such as colchicine or colcemid (32)(33)(34), or with a mock lysate. Strong presumptive evidence for whole human X chromosome loss is that the frequency of CFC in 6TG permissivetemperature test cultures is greater than the frequency of CFC in 6TG permissivetemperature control cultures and that the frequency of 6TG-resistant cells that are heat sensitive in the test cultures is greater than the frequency of 6TG resistant cells that are heat sensitive in the control cultures.…”