Potential Inversions And Local Adaptation Among Small Brook Trout (Salvelinus fontinalis) Populations

Abstract

Chromosomal inversions can play a role in local adaptation as advantageous alleles become linked by supressed recombination in heterokaryotypes. Understanding the role of inversions in adaptation among small, isolated populations is an important addition for robust conservation strategies. As such, we conducted low-coverage whole genome sequencing on N=192 brook trout (Salvelinus fontinalis) collected from nine small streams in Nova Scotia. Individuals were sequenced at ~3x depth using paired end sequencing on the Illumina NovaSeq and genotype likelihoods calculated with ANGSD. Four potential inversions were discovered only in individuals from western streams that have lower streamflow and higher maximum daily water temperatures. Population genomics methods of LD, admixture and heterozygosity were used to support the detection of potential inversions. Some genes found within these putative inversion regions play a role in biological processes that are linked to thermotolerance and suggest evidence for potential local adaptation.