Data from: Mosquitoes rely on their gut microbiota for development

Field studies indicate adult mosquitoes (Culicidae) host low diversity communities of bacteria that vary greatly among individuals and species. In contrast, it remains unclear how adult mosquitoes acquire their microbiome, what influences community structure, and whether the microbiome is important for survival. Here we used pyrosequencing of 16S rRNA to characterize the bacterial communities of three mosquito species reared under identical conditions. Two of these species, Aedes aegypti and Anopheles gambiae, are anautogenous and must blood feed to produce eggs, while one, Georgecraigius atropalpus, is autogenous and produces eggs without blood feeding. Our results indicated each hosts a low diversity community comprised primarily of aerobic bacteria. However, the communities in Ae. aegypti and An. gambiae larvae were much more similar to one another than to Ge. atropalpus. Studies with Ae. aegypti indicated adults transstadially acquire many members of the larval bacterial community, whereas only four genera of bacteria in blood fed females were detected on eggs. Functional assays showed that axenic larvae of each species failed to develop beyond the first instar. Experiments with Ae. aegypti indicated several members of the microbial community and Escherichia coli successfully colonized axenic larvae and rescued development. Overall, our results provide new insights about the acquisition and structure of bacterial communities in mosquitoes. They also indicate three mosquito species spanning the breadth of the Culicidae depend on their gut microbiome for development, while suggesting the possibility the gut microbiome is an important factor in autogeny.

野外研究表明，成年蚊类（蚊科，Culicidae）携带着低多样性的细菌群落，且不同个体与物种间的群落组成差异显著。与之相对，目前仍不清楚成年蚊类如何获得其微生物组，哪些因素会影响其群落结构，以及微生物组是否对蚊类的生存至关重要。
本研究通过16S rRNA基因焦磷酸测序技术，对在相同条件下饲养的3种蚊类的细菌群落进行了表征分析。其中两种——埃及伊蚊（Aedes aegypti）与冈比亚按蚊（Anopheles gambiae）——为需血产卵型（anautogenous），必须通过吸血来获取产卵所需的营养；而另一种乔治克雷格蚊（Georgecraigius atropalpus）则为自产卵型（autogenous），无需吸血即可产卵。
研究结果显示，三种蚊类均携带着以需氧菌为主的低多样性细菌群落。不过，埃及伊蚊与冈比亚按蚊的幼虫细菌群落彼此之间的相似性，远高于其与乔治克雷格蚊幼虫群落的相似性。针对埃及伊蚊的研究表明，成虫会通过跨龄期传播获得幼虫细菌群落中的多数类群；而仅在蚊卵上检测到吸血雌蚊体内的四类细菌菌属。
功能实验结果表明，所有受试蚊种的无菌（axenic）幼虫均无法完成一龄幼虫阶段后的发育进程。针对埃及伊蚊的实验显示，微生物群落中的多个类群与大肠杆菌（Escherichia coli）均可成功定殖于无菌幼虫体内，并挽救其发育缺陷。
总体而言，本研究结果为蚊类细菌群落的获取途径与结构特征提供了全新的认识。本研究同时证实，涵盖蚊科多个类群的3种受试蚊类的发育均依赖于其肠道微生物组；同时提示肠道微生物组可能是影响自产卵特性的关键因素之一。