NSF Postdoctoral Fellowship in Biology FY 2021: Oviposition-relevant gustatory receptor evolution as a missing link governing insect-host plant specialization

Godfrey, Rebekah Keating, Tucson AZ

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Identifying a cohesive theory of insect-host plant associations has proved one of the most challenging biological questions. While the ecological and evolutionary relationships between insects and their host plants often hinge on variation in a few key genes, we know relatively little about which genes drive host plant associations and how variation in these genes affects host plant selection or use. Where an insect lays her eggs has very real fitness consequences, making oviposition a strong candidate behavior to connect genetic variation and host plant use. This research will identify taste receptor genes involved specifically in oviposition and quantify variation in these genes within and across species of closely related hawkmoths that vary in host plant use. The Fellow will work within the McGuire Center for Lepidoptera Diversity to directly mentor scientists at the undergraduate and graduate level and to broaden knowledge of and interest in insect neuroscience both in students underrepresented in STEM and the general public. This project tests the hypothesis that selection on oviposition-related sensory receptors acts as a primary driver in host breadth in Lepidoptera. The project focuses on gustatory receptors (GRs) because they are the primary sensory receptors used to sense plant surface compounds and elicit or deter oviposition. The Fellow will (1) test whether variation in gustatory receptor genes is associated with host use in species that vary in host breadth, (2) identify gustatory receptor genes involved in host selection by comparing sex-specific gene expression, and (3) test whether variation in receptor gene sequences and gene expression across populations are associated with population-specific host use. This fellowship will provide the Fellow with training in collecting and analyzing molecular data from an evolutionary perspective. Furthermore, the project will provide functionally relevant targets for gene editing in future neuroethology experiments and will serve as a model for studying natural selection on the nervous system; the Fellow’s museum outreach activities and involvement of students in research ensures these ideas and training will reach a diverse, public audience. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.