PRFB FY 2021: Disentangling a Genetic Paradox: Leveraging European Green Crabs to Examine Genomic and Plastic Contributions to Thermal Tolerance

Venkataraman, Yaamini Ranjani, Woods Hole MA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, 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. European green crabs (Carcinus maenas) are one of the world’s most successful marine invasive species, due in part to their ability to thrive across a range of temperatures. On the North American West Coast, invasive green crabs negatively impact species important for commercial shellfish production and tribal food sovereignty through competition with native crabs, predation of juvenile shellfish, and destruction of nursery eelgrass beds. In order to accurately predict and prevent further spread and damages, it is important to understand the factors that help this species tolerate temperature changes. This work will uncover how genetic and environmental factors contribute to an individual crab’s temperature tolerance. The fellow will expand on previous justice, diversity, equity, and inclusion work by developing lessons about genetics and marine invasions for under-resourced schools in the Greater Boston area. West Coast C. maenas populations are characterized by substantially lower genetic diversity than in their native range. Recent discovery of a supergene (block of genes inherited together) with amino acid-changing mutations strongly associated with thermal tolerance suggests a genetic basis for C. maenas thermotolerance at a population level. While population-level differences in thermal performance are important, they can obscure the individual variation in phenotypically plastic traits that influences thermotolerance. The fellow will pair whole-animal thermal physiology, transcriptomics, and metabolomics in adult C. maenas to disentangle thermal response variation associated with acclimatory plasticity and adaptive evolution. By leveraging the mechanistic understanding provided by high-throughput sequencing technologies such as untargeted transcriptomics and metabolomics, the fellow will elucidate impacts of temperature on molecular physiology that may not be easily observed by whole-organism response metrics alone. Molecular reprogramming identified by these methods will demonstrate how individual-level thermotolerance contributes to population stress responses. This research will quantify individual thermal tolerance variation and create a framework for dissecting the mechanistic underpinnings of plasticity-adaptation interactions. The methods can be applied to other systems, and will expand the fellow’s research breadth. The fellow will providing paid research opportunities for undergraduate students from historically excluded groups in ocean sciences, thus training students in ecophysiology and molecular biology while also developing mentorship skills necessary for the fellow to be a successful professor. 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.