Development of an orally infectious Sindbis virus transducing system that efficiently disseminates and expresses green fluorescent protein in Aedes aegypti.

We have constructed an orally infectious Sindbis virus, ME2/5'2J/GFP, that expresses green fluorescent protein (GFP) in the midgut of Aedes aegypti and in other tissues as the virus disseminates. This virus has two unique features that are improvements over the SIN-based expression systems currently used in mosquitoes. First, a subgenomic RNA promoter and GFP coding sequence is located 5'- to the second subgenomic promoter and structural genes of the virus. Second, the E2 glycoprotein gene of TE/5'2J/GFP is replaced with the E2 gene of MRE16 SIN virus. The first feature enhances virus genome stability during virus dissemination from the midgut to other tissues and the second allows efficient virus entry into the midgut epithelial cells and then spread of the virus throughout the mosquito.