NSF Postdoctoral Fellowship in Biology FY 2021: Elucidating genomic, transcriptomic, and phenotypic consequences of genetic rescue in wild populations

Mittan, Cinnamon S, Ithaca NY

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. This project leverages genetic information to improve the conservation of endangered species. A common strategy to support endangered species is moving individuals from large populations to small, inbred populations, known as “human-assisted migration”. This exchange reduces inbreeding, and often improves the health of recipient populations. However, the exact causes of improvement are poorly understood. Mitchell’s Satyr Butterfly (MSB) is a critically endangered butterfly, and one of many species for which human-assisted migration is being considered. Mitchell’s Satyr once had a large range in the US, but is now restricted to a few small populations Michigan and larger, but disconnected populations in Mississippi. This project will identify the underlying genetic processes that improve offspring health in recipient populations (Michigan) to inform decisions about the choice of populations for assisted-migration. This novel approach will be broadly applicable to conserving other endangered species with disconnected populations that might otherwise face extinction. The fellow will also lead a two-day workshop for undergraduates to increase involvement and inclusion of groups historically underrepresented in field biology. The workshop includes finding and applying to research opportunities, hands-on training in field techniques, and professional network building to increase the students’ confidence in pursuing research. Research in model systems suggests that inbred individuals are more sensitive to stress, and that genes with reduced genetic variation due to inbreeding are more likely to be expressed mal-adaptively in stressful environments, leading to decreased fitness. This project investigates the mechanism and extent by which assisted migration (gene flow) mitigates this inbreeding-stress relationship in wild populations by (1) Quantifying genomic variation and inbreeding across the range of MSB through whole-genome sequencing of all extant populations; (2) Assessing critical-thermal maxima in Michigan, Mississippi, and outcrossed individuals, thus linking heat-tolerance phenotype to genomic variation (1), and transcriptional response; and (3) Quantifying gene expression during heat stress in Michigan, Mississippi and outcrossed individuals to identify the genes and molecular pathways most impacted by the inbreeding-stress relationship, and those potentially rescued by outcrossing. The fellow will receive training in whole-genome bioinformatics, receive mentorship in manuscript preparation, and will build collaborative relationships with conservation managers. 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.