Disruption of redox homeostasis leads to oxidative DNA damage in spermatocytes of Wolbachia-infected Drosophila simulans
Disruption of redox homeostasis leads to oxidative DNA damage in spermatocytes of Wolbachia-infected Drosophila simulans
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DOI：
10.1111/j.1365-2583.2012.01155.x
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发表时间：
2012-10-01
影响因子：
2.6
通讯作者：
Harris, H. L.
中科院分区：
文献类型：
--
作者：
Brennan, L. J.;Haukedal, J. A.;Harris, H. L.
共生细菌和它们的动物宿主之间的分子相互作用，至今知之甚少。最广泛的细菌内共生体，Wolbachia pipientis，发生在高密度的感染果蝇的睾丸，并导致细胞质不相容性（CI），一种形式的男性衍生的合子致死。沃尔巴克氏体在宿主液泡内生长和分裂，产生活性氧（ROS），进而刺激抗氧化酶的上调。这些酶似乎可以保护宿主免受ROS介导的损伤，因为携带沃尔巴克氏体感染的果蝇没有明显的健康成本。我们现在已经确定，来自Wolbachia感染的白纹伊蚊（Aa 23）细胞的DNA显示出比来自未感染细胞的DNA更高量的碱基8-氧代-脱氧鸟苷（氧化DNA损伤的标记），并且Wolbachia感染在D. simulans与减数分裂精母细胞中DNA链断裂的增加有关。雄性和雌性D. simulans显著增加Wolbachia数量，对宿主适合度没有明显影响。这些结果表明，ROS诱导的精子核中的DNA损伤可能有助于在沃尔巴克氏体感染的男性和沃尔巴克氏体的密度是敏感的氧化还原平衡在这些苍蝇的CI表达的修改特性。
Molecular interactions between symbiotic bacteria and their animal hosts are, as yet, poorly understood. The most widespread bacterial endosymbiont, Wolbachia pipientis, occurs in high density in testes of infected Drosophila simulans and causes cytoplasmic incompatibility (CI), a form of male-derived zygotic lethality. Wolbachia grow and divide within host vacuoles that generate reactive oxygen species (ROS), which in turn stimulate the up-regulation of antioxidant enzymes. These enzymes appear to protect the host from ROS-mediated damage, as there is no obvious fitness cost to Drosophila carrying Wolbachia infections. We have now determined that DNA from Wolbachia-infected mosquito Aedes albopictus (Aa23) cells shows a higher amount of the base 8-oxo-deoxyguanosine, a marker of oxidative DNA damage, than DNA from uninfected cells, and that Wolbachia infection in D. simulans is associated with an increase in DNA strand breaks in meiotic spermatocytes. Feeding exogenous antioxidants to male and female D. simulans dramatically increased Wolbachia numbers with no obvious effects on host fitness. These results suggest that ROS-induced DNA damage in sperm nuclei may contribute to the modification characteristic of CI expression in Wolbachia-infected males and that Wolbachia density is sensitive to redox balance in these flies.