Animals regulate the quality and quantity of their food intake to maintain nutrient homeostasis. Although studies on regulation of feeding behavior have focused on central feedback mechanisms that control appetite, some evidence suggests that peripheral sensory activity is modulated under certain conditions. That such modulation can be specific - carbohydrate deprivation causes increased sensitivity to sugars and protein deprivation causes increased sensitivity to amino acids - argues for the existence of mechanisms that target the activity of receptors or cells that recognize specific categories of taste chemicals. In insects, the levels of macronutrients in the hemolymph are known to sway the responsiveness of taste neurons, however the molecular mechanisms by which this occurs are poorly understood. This project investigates the hypothesis that members of a large, divergent family of Gustatory receptor (Gr) genes are regulatory targets of pathways that operate to sense internal nutritional needs. In addition, genome-wide approaches will be applied to identify novel genes that are differentially regulated by changes in nutrient demand. These studies will determine the importance of Gr regulation under different physiological conditions and establish a foundation for inquiry into the molecular underpinnings of compensatory food selection and intake.
The proposed studies will generate broader impact through an educational plan that provides hands-on research experience to several early-career undergraduate students from under-represented groups through a summer research program. The project will also provide training for a graduate student and a postdoctoral scientist. Each year two undergraduate students will be selected to participate in a follow-up research training program during which time they will engage in genetic screens to identify loci involved in regulating feeding behaviors. All participants will engage in near-peer mentoring and annual assessment will be used to develop effective ways with which to integrate research training with science education and career guidance. The data generated from this project will be made available through scientific publications and deposition in public databases.
