Mechanisms of sex determination in Anopheles and their implementation to control mosquito vectors

决定动物性别的分子发育过程是非常多变的。由于控制这些过程的基因经常发生快速变化，在一个物种中收集的性别决定途径的组成部分的信息可能提供很少或根本没有线索，以促进在其他更远的相关物种中识别性别决定基因。在昆虫中，该途径已在果蝇（Drosophila melanogaster）中详细描述;然而，尽管努力，它在其他昆虫群体（包括蚊子）中仍然未被探索或知之甚少。最近，我们已经确定了一个基因（命名为Yob），在疟疾蚊子，冈比亚按蚊，位于男性特异性Y染色体上，并控制个体发育为男性。令人惊讶的是，如果在女性发育的早期阶段表达（激活），Yob会杀死女性胚胎。Yob调节雄性发育和杀死雌性的机制仍然未知。为了填补这些知识空白，我们建议探索一个广泛的，高通量的基因序列数据的发展过程中的A。冈比亚。这些数据已经由我们的团队生成，并在从早期胚胎到成年的多个时间点分别收集男性和女性的数据，将被过滤以识别可能参与上述过程的性别特异性表达基因。在一个平行的方法中，我们将进行转基因蚊子株的分子研究，Yob在雄性中失活，或在雌性中激活，以检测基因与扰动的表达，指示它们与Yob的直接或间接相互作用。这种转基因菌株是我们小组最近产生的，可用于本研究。已鉴定的基因在按蚊性发育中的作用将通过一些实验方法进行测试。我们还将鉴定A.冈比亚的基因组，以激活早期胚胎中的基因表达，并评估其在转基因蚊子中的功能。我们提出的研究将大大有助于了解昆虫性别决定途径，并有望对新的蚊子控制策略产生重大影响。当在转基因技术中操纵性别决定基因时，可以通过导致雌性死亡或潜在地将遗传雌性逆转为雄性来用于消除雌性并产生仅雄性的世代。在更广泛的背景下，这项研究的结果将有助于确定其他昆虫害虫物种，包括蚊子媒介虫媒病毒的性别决定基因，并将刺激这些昆虫群体的遗传控制研究的新途径。

The molecular developmental processes that determine gender in animals are astonishingly variable. Because genes governing these processes often undergo rapid changes, information on the components of the sex determination pathway gathered in one species may provide little or no clue to facilitate identification of the sex determination genes in other, more distantly related, species. In insects, the pathway has been characterised in detail in the fruit fly Drosophila melanogaster; however, despite efforts, it remains unexplored or poorly understood in other insect groups, including mosquitoes. Recently, we have identified a gene (named Yob), which in the malaria mosquito, Anopheles gambiae, is located on the male-specific Y chromosome and controls the development of an individual into a male. Surprisingly, Yob kills female embryos, if expressed (activated) during early steps of female development. The mechanisms through which Yob regulates male development and kills females remain unknown. To fill these knowledge gaps, we propose exploration of an extensive, high-throughput sequence data of genes active during the development of A. gambiae. The data, already generated by our group and collected separately for males and females at a number of time points, starting from early embryos to adults, will be filtered to identify sex-specifically expressed genes that may be involved in the mentioned above processes. In a parallel approach, we will perform a molecular study of genetically modified mosquito strains, with Yob either inactivated in males, or activated in females, to detect genes with perturbed expression, indicative of their direct or indirect interaction with Yob. Such transgenic strains were recently generated by our group and are available for this study. The role of the identified genes in sexual development of Anopheles will be tested by a number of experimental approaches. We will also identify DNA regulatory regions in the A. gambiae genome necessary to activate gene expression in early embryos, and evaluate their function in transgenic mosquitoes. Our proposed research will significantly contribute to the understanding of insect sex determination pathways, and is expected to have a great impact on novel strategies of mosquito control. The sex determination genes, when manipulated in transgenic technology, could be used to eliminate females and produce male-only generations by causing female lethality or, potentially, sex reversal of genetic females into males. In a broader context, the outputs of this study will facilitate identification of sex determination genes in other insect pest species, including mosquito vectors of arboviruses, and will stimulate new avenues of research on genetic control of these insect groups.