title: Vive la résistance: genome-wide selection against introduced alleles in invasive hybrid zones.
abstract: Evolutionary and ecological consequences of hybridization between native and invasive species are notoriously complicated because patterns of selection acting on non-native alleles can vary throughout the genome and across environments. Rapid advances in genomics now make it feasible to assess locus-specific and genome-wide patterns of natural selection acting on invasive introgression within and among natural populations occupying diverse environments. We quantified genome-wide patterns of admixture across multiple independent hybrid zones of native westslope cutthroat trout and invasive rainbow trout, the world's most widely introduced fish, by genotyping 339 individuals from 21 populations using 9380 species-diagnostic loci. A significantly greater proportion of the genome appeared to be under selection favouring native cutthroat trout (rather than rainbow trout), and this pattern was pervasive across the genome (detected on most chromosomes). Furthermore, selection against invasive alleles was consistent across populations and environments, even in those where rainbow trout were predicted to have a selective advantage (warm environments). These data corroborate field studies showing that hybrids between these species have lower fitness than the native taxa, and show that these fitness differences are due to selection favouring many native genes distributed widely throughout the genome.
authors.affiliation: Northern Rocky Mountain Science Center, US Geological Survey, Missoula, MT 59802, USA rkovach@usgs.gov.
authors.forename: Ryan P
authors.identifier: 0000-0001-5402-2123
authors.initials: RP
authors.lastname: Kovach
authors.affiliation: Flathead Biological Station, University of Montana, Polson, MT 59860, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Hand
authors.affiliation: Institute for Bioinformatics and Evolutionary Studies, Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Hohenlohe
authors.affiliation: Flathead Biological Station, University of Montana, Polson, MT 59860, USA.|Fish and Wildlife Genomics Group, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
authors.forename: Ted F
authors.initials: TF
authors.lastname: Cosart
authors.affiliation: Montana Fish, Wildlife, and Parks, Kalispell, MT 59901, USA.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Boyer
authors.affiliation: Trout Unlimited, Boise, ID 83702, USA.
authors.forename: Helen H
authors.initials: HH
authors.lastname: Neville
authors.affiliation: Northern Rocky Mountain Science Center, US Geological Survey, Missoula, MT 59802, USA.|Flathead Biological Station, University of Montana, Polson, MT 59860, USA.
authors.forename: Clint C
authors.initials: CC
authors.lastname: Muhlfeld
authors.affiliation: Flathead Biological Station, University of Montana, Polson, MT 59860, USA.|Fish and Wildlife Genomics Group, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Amish
authors.affiliation: Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA.
authors.forename: Kellie
authors.initials: K
authors.lastname: Carim
authors.affiliation: Hagerman Genetics Laboratory, Columbia River Inter-Tribal Fish Commission, Hagerman, ID 83332, USA.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Narum
authors.affiliation: Fish and Wildlife Genomics Group, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
authors.forename: Winsor H
authors.initials: WH
authors.lastname: Lowe
authors.affiliation: Fish and Wildlife Genomics Group, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
authors.forename: Fred W
authors.initials: FW
authors.lastname: Allendorf
authors.affiliation: Flathead Biological Station, University of Montana, Polson, MT 59860, USA.|Fish and Wildlife Genomics Group, Division of Biological Sciences, University of Montana, Missoula, MT, USA.
authors.forename: Gordon
authors.initials: G
authors.lastname: Luikart
mesh_terms: D000483:Alleles; D000818:Animals; D005838:Genotype; D006824:Hybridization, Genetic; D058865:Introduced Species; D017683:Oncorhynchus / Q000145:classification / Q000235:genetics*; D012641:Selection, Genetic
keywords: genomics; hybridization; introgression; invasive species; natural selection; temperature