Genetic structure and within-generation genome scan analysis of fisheries-induced evolution in a Lake Whitefish (Coregonus clupeaformis) population

Abstract

Size-selective harvest may lead to over-exploitation of commercial fisheries, but the population genetic and evolutionary consequences of such practices remain poorly understood. We investigated the role of within-generation selection in a historically over-exploited Lake Whitefish (Coregonus clupeaformis) population associated with fisheries-induced evolution in Lesser Slave Lake, Alberta, Canada. DNA from archived scales of Lake Whitefish collected between 1986 and 1999 were genotyped at 20 microsatellites and 51 gene-coding SNPs associated with growth and reproduction. We found that the Lake Whitefish in Lesser Slave Lake consisted of a single genetic stock, with microsatellites revealing more temporal than spatial variation in allele frequencies. A comparative genome scan among replicate cohorts from commercially harvested versus random survey samples identified one candidate SNP under divergent selection. This SNP localized within a gene encoding nucleoside diphosphate kinase A, a protein associated with differential growth. Collectively, the results highlight the utility of within-generation genome scans towards investigating the evolutionary consequences of harvest in the wild.

Keywords : Coregonus, Lake Whitefish, SNP, Archived DNA, Historical DNA, Fisheries-induced evolution, Within-generation selection