EAPSI: Evaluating the Functional Role of Nix in the Asian Tiger Mosquito

在疾病传播方面，雄蚊和雌蚊有很大的不同。雌蚊需要吸血来产卵，在吸血的过程中，每年将疾病传播给数百万人。与之形成鲜明对比的是，雄性蚊子是无害的，因为它们不吸血。因此，蚊子的性别决定是非常有趣的。最近，一种名为Nix的基因被确定为黄热病蚊子中主要的雄性决定因素。尼克斯被证明对男性发育既必要又充分。这就提出了一个问题，即是否有可能在媒介控制策略中使用Nix将致命的雌性蚊子转化为无害的雄性蚊子。在亚洲虎蚊中也发现了Nix，但其功能尚不清楚。亚洲虎蚊是中国南方登革热的主要传播媒介，最近已将其传播范围扩大到欧洲和北美。该项目将调查Nix是否在亚洲虎蚊中起雄性决定因素的作用。​与陈博士的合作将使Nix的功能在广州亚洲虎蚊株中得到测试，并可能为新的蚊子控制措施铺平道路。我们将通过CRISPR/Cas9系统敲除和原生Nix的异位表达来检测Nix在亚洲虎蚊中的功能。为了评估Nix是否在亚洲虎蚊中起雄性决定因素的作用，将在敲除和异位表达后记录性别二态天线和生殖器的形态。还将监测调节下游性别分化的两个关键基因的同种异构体，以评估Nix对性别决定的影响。该奖项由美国国家科学基金会EAPSI与中国科技部合作资助，支持一名美国研究生的研究。

In terms of disease transmission male and female mosquitoes could not be more different. Female mosquitoes require a blood-meal to develop eggs and in the process of feeding transmit disease to millions annually. In stark contrast, male mosquitoes are harmless because they do not blood feed. Thus, sex determination in mosquitoes is of great interest. Recently, a gene, Nix, was identified as the dominant male-determining factor in the Yellow fever mosquito. Nix was shown to be both necessary and sufficient for male development. This raises the question of whether it is possible to use Nix in vector control strategies to convert deadly female mosquitoes into harmless males. Nix has also been identified in the Asian tiger mosquito but its function remains unknown. The Asian tiger mosquito is the major vector of Dengue fever in southern China and has lately expanded its range to Europe and North America. This project will investigate whether Nix functions as the male-determining factor in the Asian tiger mosquito. This research will be conducted in collaboration with Dr. Xiao-guang Chen, a preeminent mosquito researcher in China, at the Southern Medical University in Guangzhou China. The collaboration with Dr. Chen will allow the function of Nix to be tested in the Guangzhou strain of the Asian tiger mosquito and may pave the way for novel mosquito control measures. The function of Nix in the Asian tiger mosquito will be tested through knock-out with the CRISPR/Cas9 system and ectopic expression of native Nix. To assess whether Nix functions as the male-determining factor in the Asian tiger mosquito, morphology of the sexually dimorphic antenna and genitals will be documented after knock-out and ectopic expression. The isoforms of two key genes that regulate downstream sexual differentiation will also be monitored to assess the effect of Nix on sex determination. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Chinese Ministry of Science and Technology.