Detecting signatures of pathogen-mediated selection using population genomics

This study used RAD-sequencing of Arabidopsis lyrata individuals sampled from across the range of two subspecies, A.l. lyrata (N.American) and A.l .petraea (European), to determine genome-wide patterns of polymorphism and genetic structure in this species. Using these data we also investigated whether genomic smoothing approaches across RAD loci could detect genomic regions showing signatures of balancing selection, specifically significantly elevated diversity and either elevated differentiation among geographic regions or shifts towards intermediate allele frequencies within regions. We then identified annotated disease resistance loci within these genomic regions of interest. Together this project shows that genome scans based on a small number of individuals sampled from a wide range of populations confirmed the relative scarcity of signatures of balancing selection across the genome, but also identified new potential disease resistance candidates within genomic regions showing signatures of balancing selection that would be strong candidates for further sequencing efforts.