Genomic dynamics of brown trout populations released to a novel environment. Issue 7 (3rd July 2022)

• Record Type: Journal Article
• Authors: Kurland, Sara; Rafati, Nima; Ryman, Nils; Laikre, Linda
• Is Part Of: Ecology and evolution. Volume 12:Issue 7(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-03
• Subjects: conservation genetics -- genetic monitoring -- hybridization -- population translocations -- whole‐genome sequencing; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.9050
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Population translocations occur for a variety of reasons, from displacement due to climate change to human‐induced transfers. Such actions have adverse effects on genetic variation and understanding their microevolutionary consequences requires monitoring. Here, we return to an experimental release of brown trout ( Salmo trutta ) in order to monitor the genomic effects of population translocations. In 1979, fish from each of two genetically ( F ST = 0.16) and ecologically separate populations were simultaneously released, at one point in time, to a lake system previously void of brown trout. Here, whole‐genome sequencing of pooled DNA (Pool‐seq) is used to characterize diversity within and divergence between the introduced populations and fish inhabiting two lakes downstream of the release sites, sampled 30 years later (c. 5 generations). Present results suggest that while extensive hybridization has occurred, the two introduced populations are unequally represented in the lakes downstream of the release sites. One population, which is ecologically resident in its original habitat, mainly contributes to the lake closest to the release site. The other population, migratory in its natal habitat, is genetically more represented in the lake further downstream. Genomic regions putatively under directional selection in the new habitat are identified, where allele frequencies in both established populations are more similar to the introduced population stemming from a resident population than the migratory one. Results suggest that the microevolutionary consequences of population translocations, for example, hybridization and adaptation, can be rapid and that Pool‐seq can be used as an initial tool to monitor genome‐wide effects. Abstract : The consequence of human induced translocations on natural populations is monitored over c. 3 decades in wild brown trout (Salmo trutta). Two genetically distinct populations released to the same environment are unequally represented in descendant populations, with one introduced population mainly contributing to the lake closest to the release site and the other dominating waters further downstream.