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

Hall Andrew B, Christiansburg VA

Investigators

Abstract

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.