Genomic signatures of selection are enriched in differentially expressed genes in sticklebacks adapting to contrasting environments

Understanding how genetic variation translates into adaptive traits remains a central challenge in evolutionary biology. While whole-genome scans routinely identify candidate adaptive alleles, connecting these variants to functional phenotypes is complicated by epistasis, pleiotropy, and environmental effects. Here, we study gene expression patterns in threespine stickleback populations adapting to contrasting environments (marine vs freshwater) and investigate how signatures of selection interact with patterns of gene expression. We performed transcriptomic experiments of the brain and gill tissues of wild-caught sticklebacks sampled from one marine and two freshwater environments using TagSeq.