Matsuda Y, Tobari I
Division of Genetics, National Institute of Radiological Sciences, Chiba, Japan.
Mutat Res. 1988 Mar;198(1):131-44. doi: 10.1016/0027-5107(88)90048-6.
Chromosome aberrations were analyzed at the first-cleavage metaphase of mouse eggs fertilized in vitro with sperm exposed to ultraviolet light (UV) as well as to methyl and ethyl methanesulfonate (MMS and EMS). The frequencies of chromosome aberrations markedly increased with dose of UV as well as with concentration of MMS and EMS. In the UV-irradiation group, the frequency of chromosome-type aberrations was much higher than that of chromatid-type aberrations. About 90% of chromosome aberrations observed in the eggs following MMS and EMS treatment to sperm were chromosome type in which the frequency of chromosome fragments was the highest. The effects of UV on the induction of chromosome aberrations were clearly potentiated by post-treatment incubation of fertilized eggs in the presence of Ara-C or caffeine, but the effects of MMS and EMS were not pronounced by post-treatment of Ara-C or caffeine. The results indicate a possibility that UV damage induced in mouse sperm DNA is reparable in the eggs during the period between the entry of sperm into the egg cytoplasm and the first-cleavage metaphase.
对用经紫外线（UV）以及甲基磺酸甲酯和乙基磺酸甲酯（MMS和EMS）处理过的精子进行体外受精的小鼠卵子，在第一次卵裂中期分析其染色体畸变情况。染色体畸变频率随紫外线剂量以及MMS和EMS浓度的增加而显著升高。在紫外线照射组中，染色体型畸变的频率远高于染色单体型畸变。在用MMS和EMS处理精子后的卵子中观察到的染色体畸变，约90%为染色体型，其中染色体片段的频率最高。在阿糖胞苷（Ara-C）或咖啡因存在的情况下，对受精卵进行处理后孵育，可明显增强紫外线对染色体畸变的诱导作用，但Ara-C或咖啡因对MMS和EMS的作用不明显。结果表明，在精子进入卵细胞质到第一次卵裂中期这段时间内，小鼠精子DNA中诱导的紫外线损伤在卵子中可能是可修复的。
