Rapid and repeated evolution of myosin copy number in threespine stickleback.

ABSTRACT: Copy number variants at genomic loci evolve at a high rate, are linked to many different diseases, and play a role in adaptive evolution in humans and other organisms. Here we show that stickleback fish from freshwater environments have rapidly and repeatedly evolved an expanded number of copies of a gene family involved in muscle development, Myosin Heavy Chain 3 Cluster C (MYH3C), compared to marine populations. Differences in copy number between marine and freshwater fish are maintained even in the presence of gene flow, suggesting that MYH3C changes represent adaptive divergence between ecotypes. Copy number expansion occurs by tandem duplication of MYH3C coding and regulatory regions on the stickleback sex chromosome. We identify a muscle regulatory enhance

SUBMITTER: Yoxsimer AM 

PROVIDER: S-EPMC12776057 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature