Parashar Vijay, Frankel Stewart, Lurie Alan G, Rogina Blanka
Department of Genetics and Developmental Biology, School of Medicine, University of Connecticut Health Center, Farmington CT 06030-3301, USA.
Radiat Res. 2008 Jun;169(6):707-11. doi: 10.1667/RR1225.1.
Drosophila melanogaster (fruit fly) is a well-established model organism for genetic studies of development and aging. We examined the effects of lethal ionizing radiation on male and female adult Drosophila of different ages, using doses of radiation from 200 to 1500 Gy. Fifty percent lethality 2 days postirradiation (LD(50/2)) in wild-type 1-day-old adult fruit flies was approximately 1238 Gy for males and 1339 Gy for females. We observed a significant age-dependent decline in the radiation resistance of both males and females. Radiation damage is postulated to occur by the generation of oxygen radicals. An age-related decline in the ability of flies to resist an agent that induces oxygen radicals, paraquat, was observed when comparing 10- and 20-day adults. Female flies are more resistant to paraquat than male flies. Oxidative stress mediated by paraquat was additive with sublethal exposures to radiation in young adults. Therefore, the ability to repair the damage caused by oxygen radicals seems to decline with the age of the flies. Because Drosophila adults are largely post-mitotic, our data suggest that adult Drosophila melanogaster can serve as an excellent model to study the factors responsible for radiation resistance in post-mitotic tissue and age-dependent changes in this resistance.
黑腹果蝇是一种成熟的用于发育和衰老遗传研究的模式生物。我们使用200至1500戈瑞的辐射剂量，研究了致死性电离辐射对不同年龄的成年雌雄果蝇的影响。对于1日龄野生型成年果蝇，辐射后2天的半数致死率（LD(50/2)），雄性约为1238戈瑞，雌性约为1339戈瑞。我们观察到雄性和雌性果蝇的辐射抗性均随年龄显著下降。据推测，辐射损伤是由氧自由基的产生所致。在比较10日龄和20日龄成虫时，观察到果蝇抵抗诱导氧自由基的百草枯的能力随年龄下降。雌性果蝇比雄性果蝇对百草枯更具抗性。在年轻成虫中，百草枯介导的氧化应激与亚致死剂量的辐射具有累加效应。因此，修复氧自由基造成损伤的能力似乎随果蝇年龄增长而下降。由于果蝇成虫大多处于有丝分裂后阶段，我们的数据表明，成年黑腹果蝇可作为研究有丝分裂后组织中辐射抗性相关因素以及该抗性随年龄变化的优秀模型。
