Sadiq M F, Mathew C
Mutat Res. 1977 Oct;45(1):31-9. doi: 10.1016/0027-5107(77)90040-9.
The delayed effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in Drosophila melanogaster by the proportion of mosaic progeny produced after this treatment. Following injection of the chemical into wild type males, complete and mosaic sex-linked recessive lethals were scored by the Muller-5 method, in five successive broods representing the different stages of spermatogenesis. All broods showed significant increase over the control in the frequencies of complete lethals with gradual decrease in mutation rate from the post-meiotic stages to the pre-meiotic ones. In the case of mosaic lethals, too, the post-meiotic stages were generally more sensitive; but the increase over the control was significant only for the mature spermatozoa. The extension of the experiment to F4 generation showed that a mosaic F1 female may produce further mosaic progeny. The production of lethal mutations in successive generations after treatment with MNNG supports the view that chemically induced instabilities can be transmitted as such over several generations.
通过处理后产生的嵌合后代比例，研究了N-甲基-N'-硝基-N-亚硝基胍（MNNG）对黑腹果蝇的延迟效应。将该化学物质注射到野生型雄性果蝇体内后，采用Muller-5方法对完整和嵌合的性连锁隐性致死突变进行评分，在代表精子发生不同阶段的连续五窝后代中进行统计。与对照组相比，所有窝的完整致死率均显著增加，从减数分裂后阶段到减数分裂前阶段，突变率逐渐降低。在嵌合致死的情况下，减数分裂后阶段通常也更敏感；但与对照组相比，仅成熟精子的增加具有显著性。将实验扩展到F4代表明，嵌合的F1雌性果蝇可能会产生更多的嵌合后代。用MNNG处理后连续几代产生致死突变，支持了化学诱导的不稳定性可以原样传递几代的观点。
