Data for: Genomic variation across Chinook salmon populations reveals effects of a duplication on migration alleles and supports fine scale structure
Horn, Rebekah (2023), Data for: Genomic variation across Chinook salmon populations reveals effects of a duplication on migration alleles and supports fine scale structure, Dryad, Dataset, https://doi.org/10.5061/dryad.r4xgxd2ht
Distribution of ecotypic variation in natural populations is influenced by neutral and adaptive evolutionary forces that are challenging to disentangle without understanding of genomic architecture for phenotypic traits. This study provides a high-resolution portrait of genomic variation in Chinook salmon (Oncorhynchus tshawytscha) with emphasis on a region of major effect for ecotypic variation in migration timing. With a filtered dataset of ~13 million SNPs from low coverage whole genome resequencing of 53 populations (3,566 barcoded individuals), we contrasted patterns of genomic variation within and among major lineages and examined the extent of a selective sweep at a major effect region underlying migration timing (GREB1L/ROCK1). Allele frequency variation in GREB1L/ROCK1 was highly correlated with mean migration timing for early- and late-run populations within each of the lineages (r2 between 0.58–0.95; P < 0.001). However, the extent of selection within the genomic region controlling migration timing was much narrower in one lineage (interior stream-type) compared to the other two major lineages which corresponded to the breadth of phenotypic variation in migration timing observed among lineages. Evidence of a duplicated block within GREB1L/ROCK1 may be responsible for reduced recombination in this portion of the genome and contributes to phenotypic variation within and across lineages. Lastly, SNP positions across GREB1L/ROCK1 were assessed for their utility in discriminating migration timing among lineages, and we recommend multiple markers nearest the duplication to provide highest accuracy in conservation applications such as those that aim to protect early migrating Chinook salmon. These results highlight the need to investigate variation throughout the genome and the effects of structural variants on ecologically relevant phenotypic variation in natural species.
Bonneville Power Administration, Award: 200890700