title: Three chromosomal rearrangements promote genomic divergence between migratory and stationary ecotypes of Atlantic cod.
abstract: Identification of genome-wide patterns of divergence provides insight on how genomes are influenced by selection and can reveal the potential for local adaptation in spatially structured populations. In Atlantic cod - historically a major marine resource - Northeast-Arctic- and Norwegian coastal cod are recognized by fundamental differences in migratory and non-migratory behavior, respectively. However, the genomic architecture underlying such behavioral ecotypes is unclear. Here, we have analyzed more than 8.000 polymorphic SNPs distributed throughout all 23 linkage groups and show that loci putatively under selection are localized within three distinct genomic regions, each of several megabases long, covering approximately 4% of the Atlantic cod genome. These regions likely represent genomic inversions. The frequency of these distinct regions differ markedly between the ecotypes, spawning in the vicinity of each other, which contrasts with the low level of divergence in the rest of the genome. The observed patterns strongly suggest that these chromosomal rearrangements are instrumental in local adaptation and separation of Atlantic cod populations, leaving footprints of large genomic regions under selection. Our findings demonstrate the power of using genomic information in further understanding the population dynamics and defining management units in one of the world's most economically important marine resources.
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Berg
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Star
authors.affiliation: Marine Research Institute, Skúlagata 4, 101 Reykjavik, Iceland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Pampoulie
authors.affiliation: Institute of Marine Research, Flødevigen, N-4817 His, Norway.|Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway.
authors.forename: Marte
authors.initials: M
authors.lastname: Sodeland
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.
authors.forename: Julia M I
authors.initials: JM
authors.lastname: Barth
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.|Institute of Marine Research, Flødevigen, N-4817 His, Norway.|Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway.
authors.forename: Halvor
authors.initials: H
authors.lastname: Knutsen
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.
authors.forename: Kjetill S
authors.initials: KS
authors.lastname: Jakobsen
authors.affiliation: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, N-0316 Oslo, Norway.|Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway.
authors.forename: Sissel
authors.initials: S
authors.lastname: Jentoft
mesh_terms: D025041:Animal Migration; D000818:Animals; D001499:Bayes Theorem; D060146:Ecotype; D048389:Gadus morhua / Q000235:genetics*; D015321:Gene Rearrangement / Q000502:physiology*; D014644:Genetic Variation; D016678:Genome; D005838:Genotype; D006579:Heterozygote; D015810:Linkage Disequilibrium; D020641:Polymorphism, Single Nucleotide