Robust gut-specific gene expression in transgenic Aedes aegypti mosquitoes

Genetic modification of the vectorial capacity of mosquito vectors of human disease requires promoters capable of driving gene expression with appropr iate tissue and stage specificity. We report on the characterization in tra nsgenic Aedes aegypti of two mosquito gut-specific promoters. A 1.4-kb DNA fragment adjacent to the 5' end of the coding region of the Ae. aegypti car boxypeptidase (AeCP) gene and a corresponding 3.4-kb DNA fragment at the 5' end of the Anopheles gambiae carboxypeptidase (AgCP) gene were linked to a firefly luciferase reporter gene and introduced into the Ae. aegypti germ line by using Hermes and mariner (Mos1) transposons. Six independent transg enic lines were obtained with the AeCP construct and one with the AgCP cons truct. Luciferase mRNA and protein were abundantly expressed in the guts of transgenic mosquitoes in four of the six AeCP lines and in the AgCP line. Expression of the reporter gene was gut-specific and reached peak levels at about 24 h post-blood ingestion. The AeCP and AgCP promoters can be used t o drive the expression of genes that hinder parasite development in the mos quito gut.