NSF Postdoctoral Fellowship in Biology: Fitness effects of a chromosomal rearrangement in the Pacific pocket mouse (Perognathus longimembris pacificus)

Fellow's name: Erik Funk Proposal number: 2208925

Research title: Fitness effects of a chromosomal rearrangement in the Pacific pocket mouse (Perognathus longimembris pacificus) Sponsoring scientist(s) and host institution(s): Aryn Wilder, San Diego Zoo Wildlife Alliance

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. While different versions of a gene can produce differences in the way a trait looks, variation can also arise due to differences in the way a genome is structured.

For example, different populations within a species might possess different numbers of chromosomes. When individuals from different populations reproduce, this difference in genome structure might result in lower survival and lower reproduction of offspring. Over time these incompatibilities can lead to the accumulation of differences between populations and possibly lead to the formation of new species.

This project studies how aspects of the environment and the genome influence survival and reproduction when chromosome numbers differ. This research focuses on the endangered Pacific pocket mouse, and will help inform the adaptive management of this species. Overall, this work will broaden our understanding of how and when differences in genome structure lead to populations becoming distinct, and possibly different species.

Additionally, the DNA sequences generated by this project provide opportunities for students from diverse backgrounds to develop skills in DNA analysis through project based learning.

This project combines lab and field techniques to understand the influence of a chromosomal rearrangement on fitness using the Pacific pocket mouse (Perognathus longimembris pacificus) as a model. The Pacific pocket mouse occurs in three isolated populations that have each become fixed for one of two different chromosome numbers following a chromosomal fission or fusion event.

This research (1) assesses the frequency of the chromosomal rearrangement over time using historical and contemporary samples, (2) measures the fitness effects of outbreeding and identifies associated genomic regions, and (3) models and tests for associations between genotype and the environment. This project provides unique training opportunities to incorporate diverse datasets including fitness measures, genomic data, and habitat modeling.

The data generated by this work also provides ample data for smaller research questions, ideal for independent research projects.

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.