To date, only a limited number of promoter sequences have been described to drive transgene expression in the disease vector Aedes aegypti. We sought to increase this repertoire by characterizing the ability of upstream sequences derived from the Ae. aegypti UbL40 and polyubiquitin genes to drive the expression of marker proteins. Both genomic fragments were able to drive robust expression of luciferase in cultured mosquito cells. Following Mos1-transformation, the UbL40 promoter drove strong expression of a fluorescent marker in early larvae and in ovaries, while the polyubiquitin promoter drove robust EGFP expression in all stages of development including constitutive expression throughout the midgut. These promoter fragments provide two new expression profiles for future Ae. aegypti genetic experiments.

Heat shock genes are highly evolutionarily conserved and are expressed to varying degrees in all organisms in response to stress. Heat shock 70 (hsp70) genes have been well characterized in a number of organisms, most notably Drosophila melanogaster, but not as yet for any of the major arthropod-borne viral mosquito vectors. To identify hsp70 genes in the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae), basic local alignment searches of the Ae. aegypti genome were performed using D. melanogaster Hsp70 protein sequences as query. Two clusters of six previously unannotated AaHsp70 genes were identified and found to be organized into three pairs of nearly identical open reading frames, which mapped to two genomic scaffolds. Consistent with a designation as heat shock genes, no detectable level of expression of AaHsp70 genes was observed under normal rearing conditions (28°C), with robust expression observed with a heat shock of 37–39°C. Northern analysis showed heat-inducible expression of putative AaHsp70 genes at all life stages and in all tissues tested in a time- and temperature-dependent manner. Monitoring of AaHsp70 gene expression levels in field-caught Ae. aegypti may serve as a general marker for stress. In addition, promoter sequences from AaHsp70 genes may be used to control the expression of transgenes in an inducible manner.