LAUSR

Natural-origin steelhead trout in the Pacific Northwest USA are threatened by a number of factors including habitat destruction, disease, decline in marine survival and a potential erosion of genetic viability due to introgression from hatchery strains. Our major goal was to use a recently developed SNP array containing ~57,000 SNPs to identify a subset of SNPs that differentiate hatchery- and natural-origin populations. We analyzed 35,765 polymorphic SNPs in nine populations of steelhead trout sampled from Puget Sound, Washington State, USA. We then conducted two outlier tests and found 360 loci that were candidates for divergent selection between hatchery and natural-origin populations (average FCT = 0.29, max = 0.65) and 595 SNPs that were candidates for selection among natural-origin populations (average FST = 0.25, max = 0.51). Comparisons with a linkage map revealed that two chromosomes (Omy05, Omy25) contained significantly more outliers than other chromosomes, suggesting that regions on Omy05 and ...