Integrated transcriptome provides resources and insights into the adaptive evolution of colonized brown trout (Salmo trutta fario) in the Tibetan Plateau

Abstract

AbstractThe Tibetan Plateau is the world's largest plateau that is characterized by low temperature, low oxygen, and strong ultraviolet radiation. Colonized species that invade the plateau must change their characteristics to adapt to the harsh environment. However, research on the adaptation of introduced species on plateaus is limited. In this study, brown trout (Salmo trutta fario) was studied as a colonized species of the Tibetan Plateau, and a de novo transcriptome assembly was conducted to explore the genetic basis of plateau adaptation. A total of 38,606 unigenes were assembled, with over 90% of the unigenes annotated. Using comparative transcriptomics analysis, we identified 129 positively selected genes and 126 species‐specific gene families in colonized brown trout that were associated with energy metabolism, angiogenesis, heart development, ammonium transport, and DNA damage and repair, which may play essential roles in the adaptation to high altitude of colonized brown trout compared to other inland Salmonidae species. Our results provide an integrated and comprehensive transcriptomic resource for brown trout colonized in Tibet. These results potentially contribute to future studies aiming to identify candidate genes and pathways underlying the genetic basis of adaptation in the Tibetan plateau and assist in the population protection and aquaculture of brown trout in Tibet.