title: Rapid parallel evolution of standing variation in a single, complex, genomic region is associated with life history in steelhead/rainbow trout.
abstract: Rapid adaptation to novel environments may drive changes in genomic regions through natural selection. Such changes may be population-specific or, alternatively, may involve parallel evolution of the same genomic region in multiple populations, if that region contains genes or co-adapted gene complexes affecting the selected trait(s). Both quantitative and population genetic approaches have identified associations between specific genomic regions and the anadromous (steelhead) and resident (rainbow trout) life-history strategies of Oncorhynchus mykiss. Here, we use genotype data from 95 single nucleotide polymorphisms and show that the distribution of variation in a large region of one chromosome, Omy5, is strongly associated with life-history differentiation in multiple above-barrier populations of rainbow trout and their anadromous steelhead ancestors. The associated loci are in strong linkage disequilibrium, suggesting the presence of a chromosomal inversion or other rearrangement limiting recombination. These results provide the first evidence of a common genomic basis for life-history variation in O. mykiss in a geographically diverse set of populations and extend our knowledge of the heritable basis of rapid adaptation of complex traits in novel habitats.
authors.affiliation: Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, , 110 Shaffer Road, Santa Cruz, CA 95060, USA, Institute of Marine Sciences, University of California, , Santa Cruz, CA 95060, USA, Institute of Molecular Biology, University of Oregon, , Eugene, OR 97403, USA, Department of Animal Science, University of California, , One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Devon E
authors.initials: DE
authors.lastname: Pearse
authors.forename: Michael R
authors.initials: MR
authors.lastname: Miller
authors.forename: Alicia
authors.initials: A
authors.lastname: Abadía-Cardoso
authors.forename: John Carlos
authors.initials: JC
authors.lastname: Garza
mesh_terms: D025041:Animal Migration; D000818:Animals; D005075:Biological Evolution; D002140:California; D002875:Chromosomes; D017753:Ecosystem; D015870:Gene Expression; D016678:Genome; D017686:Oncorhynchus mykiss / Q000235:genetics*; D009922:Oregon; D012641:Selection, Genetic
keywords: adaptation; anadromy; phenotypic plasticity; polymorphism; salmonid