TRANSIENT EXPRESSION OF A PROMOTER-REPORTER CONSTRUCT IN DIFFERENTIATED ADULT SALIVARY-GLANDS AND EMBRYOS OF THE MOSQUITO AEDES-AEGYPTI

Vector-borne pathogens develop in close association with specific tiss ues in their insect hosts. Efforts are being made to characterize inse ct genes that are expressed in tissues that have important roles in pa thogen propagation. Successful transfection and expression of exogenou s genes in terminally differentiated tissues of insects has previously proven difficult. Here we report a method that should allow the analy sis of genes that are expressed in adult tissues and organs. Transient expression assays have been developed using the salivary glands of th e mosquito, Aedes aegypti, which can now be used to analyze salivary g land-specific promoter sequences, a liposome-based transfection reagen t was used to transfect cultured adult salivary glands with a DNA cons truct carrying the luciferase reporter gene under the control of the D rosophila melanogaster heat shock 70 promoter. Luciferase activity was detected in glands 18-20 hr post-transfection. This assay can now be used to determine the regulatory activity of other putative promoter s equences from salivary gland-specific genes. Alternatively, the assay may be used to study the effect of recombinant gene expression on para site invasion and development. In addition, transient expression of ge ne constructs in embryos is shown to be a powerful tool for analyzing genes that are expressed at this stage of the mosquito life cycle.