Inhibition of luciferase expression in transgenic Aedes aegypti mosquitoesby Sindbis virus expression of antisense luciferase RNA

A rapid and reproducible method of inhibiting the expression of specific ge nes in mosquitoes should further our understanding of gene function and may lead to the identification of mosquito genes that determine vector compete nce or are involved in pathogen transmission. We hypothesized that the viru s expression system based on the mosquito-borne Alphavirus, Sindbis (Togavi ridae), may efficiently transcribe effector RNAs that inhibit expression of a targeted mosquito gene. To test this hypothesis, germ-line-transformed A edes aegypti that express luciferase (LUC) from the mosquito Apyrase promot er were intrathoracically inoculated with a double subgenomic Sindbis (dsSI N) virus TE/3'2J/anti-luc (Anti-luc) that transcribes RNA complementary to the 5' end of the LUC mRNA, LUC activity was monitored in mosquitoes infect ed with either Anti-luc or control dsSIN viruses expressing unrelated antis ense RNAs, Mosquitoes infected with Anti-luc virus exhibited 90% reduction in LUC compared with uninfected and control dsSIN-infected mosquitoes at 5 and 9 days postinoculation. We demonstrate that a gene expressed from the m osquito genome can be inhibited by using an antisense strategy. The dsSIN a ntisense RNA expression system is an important tool for studying gene funct ion in vivo.