Alexandra C. C. Wilson Proposal # IOS-1121847 Characterization of Aphid Nutrient Amino Acid Transporters with Focus on the Symbiotic Interface Symbioses such as those between humans and their gut flora and the insect vector of Chagas disease and its obligate bacterium are ubiquitous in nature impacting human health, biodiversity and agriculture. Insects feeding on mammalian blood or plant sap are united in their dependence on intimate symbioses with bacteria that nutritionally compensate their hosts. While the nutritional bases of these symbioses are well understood, the processes and structures that mediate the intimate interactions between symbiotic partners have been neglected and remain uncharacterized. This project aims to functionally characterize the processes and structures that mediate amino acid exchange between aphids and their bacterial symbiont, Buchnera aphidicola. Buchnera live within membrane-bound compartments inside aphid bacteriocyte cells. The membranes of the bacteriocytes and the specialized compartments present a challenge to amino acid exchange, a process vital to aphid survival. Specifically, this project focuses on studying the molecules that transport amino acids across membranes at the aphid/Buchnera interface. The investigators will experimentally determine the transport capability of amino acid transporters and use microscopy to determine where these transporters are found. Research and educational goals will merge in measurement of changes in expression of amino acid transporter genes in response to dietary amino acid supply providing inquiry-based research training for up to 96 undergraduates. Broadly this work benefits genomic studies in all insect systems and additionally provides mentoring and research training for one graduate student and one early-career researcher. This project will be the first to functionally characterize the processes and structures operating at the interface of an insect nutritional symbiosis. Importantly, understanding how insects interact with their symbionts has the potential to facilitate development of targeted environmentally safe control of insect vectors of human and plant disease.
