Eggs from Aedes mosquitoes exhibit desiccation resistance that helps them to survive and spread as human disease vectors throughout the world. Previous studies have suggested that eggshell/chorion melanization and/or serosal cuticle formation are important for desiccation resistance. In this study, using dsRNAs for target genes, we analyzed the functional importance of two ovary-specific yellow genes, AalY-g and AalY-g2, in the resistance to egg desiccation of the Asian tiger mosquito, Aedes albopictus, a species in which neither the timing of the melanization nor temporal development of the serosal cuticle is correlated with desiccation resistance. Injections of dsAalY-g, dsAalY-g2 or dsAalY-g/g2 (co-injection) into adult females have no effect on their fecundity. However, initial melanization is delayed by 1-2 h with the eggshells eventually becoming black similar to that observed in eggs from dsEGFP-injected control females. In addition, the shape of the eggs from dsAalY-g, -g2 and -g/g2-treated females is abnormally crescent-shaped and the outermost exochorion is more fragile and partially peeled off. dsEGFP control eggs, like those from the wild-type strain, acquire resistance to desiccation between 18 and 24 h after oviposition (HAO). In contrast, ~80% of the 24 HAO dsAalY-g and dsAalY-g2 eggs collapse when they are transferred to a low humidity environment. In addition, there is no electron-dense outer endochorion evident in either dsAalY-g or dsAalY-g2 eggs. These results support the hypothesis that AalY-g and AalY-g2 regulate the timing of eggshell darkening and are required for integrity of the exochorion as well as for rigidity, normal morphology and formation of the outer endochorion, a structure that apparently is critical for desiccation resistance of the Ae. albopictus egg.

中文翻译：

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Yellow-g和Yellow-g2蛋白是亚洲虎蚊伊蚊（Aedes albopictus）卵抗脱水和暂时色素沉着所必需的。

伊蚊的卵表现出抗干燥性，这有助于它们作为人类疾病的媒介在世界上生存和传播。先前的研究表明，蛋壳/绒毛膜黑色素化和/或浆膜角质层的形成对于抗干燥性很重要。在这项研究中，使用针对目标基因的dsRNA，我们分析了两个卵巢特异性黄色基因AalY-g和AalY-g2在抵抗亚洲虎蚊伊蚊白纹伊蚊的卵干方面的功能重要性。浆化角质层的黑色素化时机和暂时性发展均与抗干燥性无关。向成年女性注射dsAalY-g，dsAalY-g2或dsAalY-g / g2（共同注射）对其生育力没有影响。然而，最初的黑色素化延迟了1-2小时，蛋壳最终变黑，类似于从dsEGFP注射的对照雌性卵中观察到的变黑。此外，用dsAalY-g，-g2和-g / g2处理的雌性卵的形状异常新月形，最外层的外胚轴更脆弱，部分剥落。像野生型菌株一样，dsEGFP对照卵在产卵（HAO）后18到24 h之间获得了对干燥的抗性。相反，当将24个HAO dsAalY-g和dsAalY-g2蛋转移到低湿度环境中时，它们会崩溃约80％。此外，在dsAalY-g或dsAalY-g2卵中均没有明显的电子致密外内膜。这些结果支持以下假设：AalY-g和AalY-g2调节蛋壳变黑的时间，并且对于排卵的完整性以及刚度，正常形态和外部内膜的形成是必需的，该结构显然对干燥至关重要Ae的电阻。白蛋。