Genomic signatures of selection along a climatic gradient in the northern range margin of the white-footed mouse (Peromyscus leucopus)

• Published in: The Journal of heredity 2019-10, Vol.110 (6), p.684-695
• Main Authors: Garcia-Elfring, A, Barrett, R D H, Millien, V
• Format: Article
• Language: English
• ISSN: 0022-1503; 1465-7333
• DOI: 10.1093/jhered/esz045

Identifying genetic variation involved in thermal adaptation is likely to yield insights into how species adapt to different climates. Physiological and behavioural responses associated with overwintering (e.g. torpor) are thought to serve important functions in climate adaptation. In this study, we use two isolated Peromyscus leucopus lineages on the northern margin of the species range to identify SNPs showing a strong environmental association and test for evidence of parallel evolution. We found signatures of clinal selection in each lineage, but evidence of parallelism was limited, with only two SNPs showing parallel allele frequencies across transects. These parallel SNPs map to a gene involved in protection against iron-dependent oxidative stress (Fxn) and to a gene with unknown function but containing a forkhead-associated domain (Fhad1). Furthermore, within transects, we find significant clinal patterns in genes enriched for functions associated with glycogen homeostasis, synaptic function, intracellular Ca2+ balance, H3 histone modification, as well as the G2/M transition of cell division. Our results are consistent with recent literature on the cellular and molecular basis of climate adaptation in small mammals and provide candidate genomic regions for further study.