Transduction of Aedes aegypti mosquitoes with vectors derived from Aedes densovirus

Aedes densovirus (AeDNV)-based constructs that express green fluorescent pr otein (GFP) from either the P7 or the P61 promoter were made. The construct in which GFP protein was expressed as a fusion protein to the C-terminus o f NS1 (NS1-GFP) showed the highest level of GFP expression. This hybrid NS1 -GFP protein preserved the biological functions of the parental proteins: i t showed GFP fluorescence, it stimulated expression from the virus promoter s, and it facilitated rescue and replication of the cloned AeDNV genome. Si milar to NS1, the hybrid NS1-GFP localized in the nucleus predominantly in a punctate pattern. Transducing virus particles carrying the NS1-GFP gene i nfected mosquito larvae. Expression of GFP was detected as early as 48 h po stinfection and in larval and pupal stages. Midgut, hindgut, and Malpighian tubule cells expressed GFP soon after transduction. However, the anal papi llae were the most commonly infected organ system. The anal papillae are sy ncytia and regulate ion concentration in the hemolymph of mosquito larvae, and they might be a novel route of mosquito larvae infection with densoviru ses. (C) 1999 Academic Press.