Natural Selection and Genetic Drift: Neutral and adaptive genetic variability of hatchery versus wild populations in brown trout Salmo trutta

Abstract

Event Abstract Back to Event Natural Selection and Genetic Drift: Neutral and adaptive genetic variability of hatchery versus wild populations in brown trout Salmo trutta Tamara Schenekar1* and Steven J. Weiss1 1 University of Graz, Austria Genetic drift and natural selection are two of the major forces shaping the genetic makeup of a population. Genetic drift reduces genetic variability due to the random loss of alleles during the transition from one generation to the next one. The smaller the population, the stronger genetic drift is. Natural selection favors the spread of specific alleles within a population over time, namely those alleles that are beneficial in the specific environment of this population. Individuals that carry alleles that are less advantageous have a lower probability to survive and reproduce. For establishing a captive population, very often, only a small number of individuals are taken and the number breeding individuals used to maintain the population is limited, thus increasing the amount of genetic drift. On the other hand, the drastically different environment in captivity (artificial diet, higher individual density, altered pathogen pressure, etc.) may favor alleles that are maladaptive for individuals when they are released back in the wild, e.g. for stocking measures. We screened both, neutral and adaptive genetic markers, in order to assess the relative importance of genetic drift and selection pressure on wild and hatchery populations of Austrian brown trout. We confirm a strong positive selection pressure on an adaptive locus of the Major histocompatibility Complex (MHC), whereas the signal of this selection pressure was more pronounced in hatchery populations. This may either stem from stronger genetic drift in wild populations due to smaller effective population sizes or a stronger directional selection in these wild populations, whereby only particular genetic variants proved to be adaptive in each specific environment. Therefore, the alleles arising from the hatchery selection regime may be detrimental in the wild, which can lead to lower survival rates of stocked fish in wild environments. Keywords: Adaptation to captivity, Genetic Drift, Satr-DAB, microsatellites, dN/dS, captive population genetics, MHC class II Conference: XV European Congress of Ichthyology, Porto, Portugal, 7 Sep - 11 Sep, 2015. Presentation Type: Oral Presentation Topic: Phylogeny, Systematics and Genetics Citation: Schenekar T and Weiss SJ (2015). Natural Selection and Genetic Drift: Neutral and adaptive genetic variability of hatchery versus wild populations in brown trout Salmo trutta. Front. Mar. Sci. Conference Abstract: XV European Congress of Ichthyology. doi: 10.3389/conf.fmars.2015.03.00062 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Nov 2015; Published Online: 11 Nov 2015. * Correspondence: Ms. Tamara Schenekar, University of Graz, Graz, Austria, tamara.schenekar@uni-graz.at Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract Supplemental Data The Authors in Frontiers Tamara Schenekar Steven J Weiss Google Tamara Schenekar Steven J Weiss Google Scholar Tamara Schenekar Steven J Weiss PubMed Tamara Schenekar Steven J Weiss Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.