Landscape Genomics of White-Footed Mice (Peromyscus leucopus) along an Urban-to-Rural Gradient in the New York City Metropolitan Area

Urbanization can change an area’s habitat in ways that pose novel selection pressures on native species, and previous work has shown evidence for divergent selection in white-footed mice populations in New York City (NYC) parks compared to nearby rural populations. This study aims to 1) identify potential candidate genes exhibiting signatures of selection with increasing levels of urbanization, and 2) compare these results with previous findings that NYC populations of P. leucopus experience directional selection for metabolic processes and immune function. I approached these aims using a SNP dataset derived from exomes of 95 P. leucopus specimens sampled from sites in and around NYC. Outlier detection consisted of methods which rely on measures of population genetics (such as FST) and genotype-environment analyses that incorporate environmental factors (such as degree of urbanization). I ran Gene Ontology enrichment tests on the resulting outliers to see what biological functions are overrepresented among the outliers. I found overrepresentation of genes related to metabolic function as well as ciliary function, particularly with regard to spermatogenesis, which corroborates previous findings in this system. I additionally found multiple unconventional myosins and other proteins that imply possible selection on genes related to hearing function.