60Co－γ射线诱发小鼠卵母细胞染色体畸变与剂量效应的相关性研究

STUDY ON THE EFFECTS OF CHROMOSOME DAMAGE IN-DUCED BY60 Co γ RAYS IN SECOMDARY OOCYTES OF MICE

本文采用超数排卵技术，观察不同剂量（０～３Ｇｙ）６０ＣＯ—γ射线全身一次性照射雌性ＩＣＲ小鼠后，ＭⅡ卵母细胞染色体的损伤效应。结果表明，各受照射组的畸变细胞率（％）和总染色体畸变率（％）均明显高于对照组，其最适剂量效应方程式分别为Ｙ＝２１．１０５７Ｄ０．７９５８和Ｙ＝１．６５０２＋１５．９９８６Ｄ＋３．８５３３Ｄ２，而非整倍体率仅在２Ｇｙ以上各组有统计学上的差异。进一步估算在２，２．５和３Ｇｙ组子代平衡易位携带者的再现率分别为０．２５％，０．４２％和０．４６％。

The chromosome damage induced by various doses of60Co-γray(0.5 3. 0Gy)were examined with secondary oocytes of ICR mice. The frequencies of aberrant cells andchromosome aberrations are significantly higher in γ-irradiated groups than that in the con-trols. The most fittable regression equations for aberrations were Y=21.1057D0.7958 and Y=1.6502+ 15.9986D+3.8533D2,respectively. While the frequency of aneuploidy was signifi-cant only in over 2Gy groups. Based upon the frequency of chromatid aberrations in M Ⅱoocytes,the risk of balanced translocations in the offspring were predicted to be 0.25%,0.4%and 0. 46%in the 2,2. 5 and 3Gy groups,respectively.