X射线诱发雄性小鼠生殖细胞多价体的遗传危险度评价

本文对不同剂量X射线照射雄性小鼠后诱发的多价体的遗传危险度作了评价。低刺量率0.05Gy/min小于1.00Gy X射线照射减数分裂前期精母细胞、精原细胞及精原干细胞后,多价体发生率均随剂量升高而增加,预期平衡易位配子发生率平均分别为1.22×10~(-5)、1.68×10~(-5)、4.02×10~(-5)/配子·10mGy,其倍加剂量分别约为0.05、0.036、0.015Gy。较大剂量率(0.28Gy/min)较大剂量(1.00～4.00Gy)X射线照射精原干细胞后,多价体也随剂量增加而增多,预期平衡易位配子发生率为1.65×10~(-5)/配子·10mGy,倍加剂量约为0.036Gy。预期自发平衡易位配子发生率为6.0×10~(-5)/配子。

EVALUATION OF GENETIC RISK OF MULTIVALENTS INDUCED BY X-RAYS IN GERM CELLS OF MALE MICE

The genetic risks resulting from multivalents induced by different doses of X-rays in germ cells of Swiss randomly bred and C57BL male mice were estimated. The frequencies of multivalents induced by small doses of X-lays (0.05 Gy/min, less than 1.0Gy) , when irradiation was given in the premeiotic phase, thedifferentiated spermatogonia and spermatogonial stem cells, were all increased with the increasing doses.The rates of expected balanced translocation heterozy-gotes after irradiation on average were 1.22 × 10-5, 1.68 × 10-5 and 4.02 × 10-5/ gamete · 10 mGy in 3 phases respectively. Their doubling-doses were about 5.0, 3.6 and 1.5 cGy respectively. The frequencies of multivalents induced by large doses of X-rays (1.0-4.0Gy) , irradiating at the spermatogonial stem cells, were also increasing dependant on doses.The rate of expected balanced translocation of heterozygotes was 1.65 × 10-5/gamete·10mGy, and its doubling-dose was about 0.036 Gy.The rate of spobtaneous balanced translocation heterozygotes was predicted to be 6.0 × 10-6/gamete in background radiation.