~(60)CO-γ射线诱发的德国蜚蠊精母细胞中心体畸变

德国蜚蠊经不同剂量的~(60)Co-γ射线照射,以光镜和电镜观察精母细胞巨大中心体结构和数目的变化,发现:γ射线可诱发各种类型中心体畸变,如棒状、断裂、不分离、超数和微小中心体等;畸变率随剂量增加而升高;畸变类型和辐射剂量有密切关系,低剂量(500—1000r)诱发较多的棒状中心体和中心体断裂、中等剂量(2000r)诱发较多的超数中心体和中心体不分离、高剂量(5000r)诱发较多的微小中心体,看来低剂量γ射线主要影响中心体结构,高剂量则对中心体的生长发育有明显的阻滞作用。本文还讨论了中心体畸变的可能产生机制及在遗传毒理研究中应用的前景。

CENTRIOLE ABERRATION IN SPERMATOCYTES OF THE GERMAN COCKROACH INDUCED BY RADIATION

German cockroaches Blattella germanica] were irradiated by 60Co-? ray with different doses (500r, 1000r, 2000r, 5000r). Giant centrioles at pachytene stage of meiosis were observed under both light and electron microscope. The results show that: 1) Radiation can induce various abnormal centrioles such as rod-shaped, broken, undisjuncted, additional and microcentrioles. 2 ) The frequency of centriole aberration will increase as the dose of radiation is raised. 3 ) There is close relationship between the dose and types of the centriole aberration. Lower doses (500-1000r) induced more rod-shaped and broken centrioles. Intermediate dose (2000r) causes more additional and undisjuncted centrioles. Higher dose (5000r) induces more microcentrioles. It shows that lower doses of radiation affect mainly the structure of centrioles, higher doses arrest the development of centriole. The possible mechanism of centriole aberration and its application in the study of genetic toxiocology are discussed in this paper.