Title: "Vector physiology: from hormones to symbionts”

Abstract: Great advances have been made over the last decade in reducing the burden of insect vectored diseases. Vector control relies heavily on insecticide-based approaches. The widespread deployment of these strategies has led to increasing insecticide resistance in many important vector species, highlighting the need for the development of new control strategies. Disrupting reproduction of hosts through manipulating hormonal signals is one potential avenue for controlling vector populations. While a number of hormones have been identified in regulating mosquito reproduction, a large number of peptide hormones lack characterized membrane receptors. These represent potential regulators of reproduction that could be leveraged to control insect populations, but which require identification of their ligands. Using a combination of phylogenetic and molecular approaches we have identified the receptor of ovary ecdysteroidogenic hormone and are currently examining peptide hormones of unknown function which may play important roles in mosquito reproduction. 

Our lab is also exploring the role of the bacterial symbiont Rhodococcus rhodnii in the development of the kissing bug Rhodnius prolixus. As an obligate hematophagous insect, R. prolixus likely relies on bacterially-produced B vitamins to develop. Previous work suggests that R. rhodnii, a free-living bacterium residing in the gut, provisions the insect with B vitamins, but is also likely providing other services to the host. We are employing a high-throughput transposon mutagenesis screen of R. rhodnii to identify bacterial genes that are involved in symbiont colonization. Simultaneously, we are using transcriptomics and RNAi to identify and functionally characterize host genes that are likely involved in maintaining this symbiosis. These experiments will help to improve our understanding of insect-microbe symbiosis and continue to develop R. rhodnii as a vehicle for paratransgenesis to control Trypanosoma cruzi transmitted by kissing bugs.