title: Rhodopsin gene polymorphism associated with divergent light environments in Atlantic cod.
abstract: The spectral sensitivity of visual pigments in vertebrate eyes is optimized for specific light conditions. One of such pigments, rhodopsin (RH1), mediates dim-light vision. Amino acid replacements at tuning sites may alter spectral sensitivity, providing a mechanism to adapt to ambient light conditions and depth of habitat in fish. Here we present a first investigation of RH1 gene polymorphism among two ecotypes of Atlantic cod in Icelandic waters, which experience divergent light environments throughout the year due to alternative foraging behaviour. We identified one synonymous single nucleotide polymorphism (SNP) in the RH1 protein coding region and one in the 3' untranslated region (3'-UTR) that are strongly divergent between these two ecotypes. Moreover, these polymorphisms coincided with the well-known panthophysin (Pan I) polymorphism that differentiates coastal and frontal (migratory) populations of Atlantic cod. While the RH1 SNPs do not provide direct inference for a specific molecular mechanism, their association with this dim-sensitive pigment indicates the involvement of the visual system in local adaptation of Atlantic cod.
authors.affiliation: Marine Research Institute, Skúlagata 4, 101, Reykjavík, Iceland, chrisp@hafro.is.
authors.forename: Christophe
authors.initials: C
authors.lastname: Pampoulie
authors.forename: Sigurlaug
authors.initials: S
authors.lastname: Skirnisdottir
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Star
authors.forename: Sissel
authors.initials: S
authors.lastname: Jentoft
authors.forename: Ingibjörg G
authors.initials: IG
authors.lastname: Jónsdóttir
authors.forename: Einar
authors.initials: E
authors.lastname: Hjörleifsson
authors.forename: Vilhjálmur
authors.initials: V
authors.lastname: Thorsteinsson
authors.forename: Ólafur K
authors.initials: ÓK
authors.lastname: Pálsson
authors.forename: Paul R
authors.initials: PR
authors.lastname: Berg
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Andersen
authors.forename: Steinunn
authors.initials: S
authors.lastname: Magnusdottir
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Helyar
authors.forename: Anna K
authors.initials: AK
authors.lastname: Daníelsdóttir
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001522:Behavior, Animal; D019143:Evolution, Molecular; D048389:Gadus morhua / Q000235:genetics*; D005828:Genetics, Population; D005838:Genotype; D008027:Light; D018895:Microsatellite Repeats; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012243:Rhodopsin / Q000235:genetics*; D012641:Selection, Genetic; D016708:Synaptophysin / Q000235:genetics; D014785:Vision, Ocular
chemical_list: D020413:3' Untranslated Regions; D016708:Synaptophysin; D012243:Rhodopsin