TY - JOUR AU - Jacques Labonne, Renaud Kaeuffer AU - ois Gué AU - raud, Mingsha Zhou AU - lie Manicki and Andrew P. Hendry PY - 2016// TI - From the bare minimum: genetics and selection in populations founded by only a few parents T2 - 1522-0613 JO - EVOLUTIONARY ECOLOGY RESEARCH SP - 21 EP - 34 IS - 17 N2 - Question: Genetic variation is expected to control the fate of populations colonizing newenvironments, because the amount and nature of this variation influences adaptation. Thus, it isgenerally expected that the ability of populations to colonize new environments is severelycompromised if the number of founding individuals is very few.Organisms: Brown trout (Salmo trutta) are native to the northern hemisphere, but have beenwidely introduced globally, including into the southern hemisphere.Times and places: We analysed two isolated populations of brown trout introduced in 1993 tothe remote Kerguelen Islands in the sub-Antarctic region, each population being founded withthe offspring of only a single mother, and with either only one or two fathers.Methods: Scale samples were collected in 2003 and 2010 and analysed using a set of 16microsatellite markers. These data were used to calculate individual homozygosity level andvariance in inbreeding. The association between age (estimated through scale reading) andhomozygosity level was used to assess the potential consequences of low genetic variation forindividual survival.Results: The two populations represented different outcomes. In one population, variance ininbreeding was high and a clear heterozygosity–fitness correlation (HFC) was evident: olderindividuals were less homozygous than younger individuals. Consistent with these results,homozygosity level in this population decreased from 2003 to 2010. In the other population,variance in inbreeding was low, no consistent HFC was detected, and no decline in homozygositylevel was evident from 2003 to 2010. Low genetic variation and severe initialbottlenecks through founding effects did not prevent the establishment and success of thesepopulations, one of which appears to be actively purging inbred individuals.Keywords: genetic variation, heterozygosity, inbreeding, invasion, small population.ACKNOWLEDGEMENTSThis study was funded by the French Polar Institute (IPEV) and Institut national de la rechercheagronomique (INRA). Full logistic support was provided by IPEV. We thank the many people thathelped us during field sampling in the Kerguelen Islands. SN - 1522-0613 N1 - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=6404), last updated on Sat, 29 Jun 2024 10:17:11 +0200 ID - JacquesLabonne_etal2016 ER -