Purpose: Evaluation of genetic risk in germ cells is still matter of research, mainly due to their role in the transmission of genetic information from one generation to another. Although numerous experiments have been carried out in Drosophila in order to study the effect of radiation on germ cells, the role of dose rate (DR) has not been fully explored. The purpose of this study was to evaluate the action of DR on the radioprotection induction on male germ cell of D. melanogaster.

Material and method: The productivity and the sex-linked recessive lethal (SLRL) tests were used to evaluate the radio-sensitivity of different states of the germ line of males. Two-day-old males of Canton-S wild type strain were pretreated with 0.2 Gy at 5.4 or 34.3 Gy/h of gamma rays from a ⁶⁰Co source, three hours later, they were irradiated with 20 Gy at 907.7 Gy/h. Thereafter, each single male was crossed with 3 five-day old Basc virgin females, that were replaced every other day by new females. This procedure was conducted three times, to test the whole germ cell stages.

Results: Females crossed with males irradiated with 0.2 Gy at both DR tested, laid a higher number of eggs than control, but egg-viability was reduced. On the other hand, in the group of 0.2 Gy + 20 Gy -combined treatments- the total number of eggs laid decreased only when 0.2 Gy were delivered at 34.3 Gy/h however, the egg-viability increased. The dose of 0.2 Gy at both DR did not modify the baseline frequency of SLRL. A tendency to decrease in the frequency of lethals in brood III was found in combined treatments at both DR.

Conclusion: The fact that 0.2 Gy at 5.4 or 34.3 Gy/h induced an increase in the egg-viability and a tendency to decrease the genetic damage in pre-meiotic cells provoked by 20 Gy, might indicate the induction of any mechanism that could be interpreted as radioprotection in male germ cells of D. melanogaster. Results emphasize the need to carry out more studies on the effect of the DR on the induction of genetic damage in germ cells.

目的：评估生殖细胞的遗传风险仍然是研究的问题，主要是由于它们在遗传信息从一代传给另一世代的过程中的作用。尽管在果蝇中进行了大量实验以研究辐射对生殖细胞的影响，但剂量率（DR）的作用尚未得到充分研究。本研究的目的是评估DR对黑腹male雄性生殖细胞辐射防护的作用。

材料和方法：生产力和性连锁隐性致死（SLRL）测试用于评估雄性生殖系不同状态的放射敏感性。用来自⁶⁰ Co的γ射线以5.4或34.3 Gy / h的0.2 Gy预处理Canton-S野生型菌株的两天大雄性，三小时后，以907.7 Gy / h的剂量用20 Gy辐照。此后，每个单身男性与3个五天大的Basc原始女性杂交，每隔一天被新的女性替换。该过程进行了三次，以测试整个生殖细胞阶段。

结果：在两次DR测试中，雌性与雄性杂交并接受0.2 Gy辐射，产卵量高于对照组，但卵活力降低。另一方面，在0.2 Gy + 20 Gy的联合处理组中，仅当以34.3 Gy / h的速度输送0.2 Gy时，产卵总数减少了，但是，卵的存活率提高了。两个DR的0.2 Gy剂量均未改变SLRL的基线频率。在两个DR的联合处理中，发现了III族中致死率降低的趋势。

结论： 0.2 Gy在5.4或34.3 Gy / h时诱导卵子活力增加，并趋向于降低20 Gy激发的减数分裂前细胞遗传损伤的趋势，这可能表明诱导了任何可能的机制。被认为是D. melanogaster雄性生殖细胞的放射防护。结果强调有必要对DR对诱导生殖细胞遗传损伤的作用进行更多研究。