title: Adaptation and acclimation of aerobic exercise physiology in Lake Whitefish ecotypes (Coregonus clupeaformis).
abstract: The physiological mechanisms underlying local adaptation in natural populations of animals, and whether the same mechanisms contribute to adaptation and acclimation, are largely unknown. Therefore, we tested for evolutionary divergence in aerobic exercise physiology in laboratory bred, size-matched crosses of ancestral, benthic, normal Lake Whitefish (Coregonus clupeaformis) and derived, limnetic, more actively swimming "dwarf" ecotypes. We acclimated fish to constant swimming (emulating limnetic foraging) and control conditions (emulating normal activity levels) to simultaneously study phenotypic plasticity. We found extensive divergence between ecotypes: dwarf fish generally had constitutively higher values of traits related to oxygen transport (ventricle size) and use by skeletal muscle (percent oxidative muscle, mitochondrial content), and also evolved differential plasticity of mitochondrial function (Complex I activity and flux through Complexes I-IV and IV). The effects of swim training were less pronounced than differences among ecotypes and the traits which had a significant training effect (ventricle protein content, ventricle malate dehydrogenase activity, and muscle Complex V activity) did not differ among ecotypes. Only one trait, ventricle mass, varied in a similar manner with acclimation and adaptation and followed a pattern consistent with genetic accommodation. Overall, the physiological and biochemical mechanisms underlying acclimation and adaptation to swimming activity in Lake Whitefish differ.
authors.affiliation: Departement de Biologie, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine Université Laval, Québec City, Québec, Canada, G1V 0A6. anne.dalziel@gmail.com.
authors.forename: Anne C
authors.initials: AC
authors.lastname: Dalziel
authors.affiliation: Departement de Biologie, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine Université Laval, Québec City, Québec, Canada, G1V 0A6.|School of Medicine, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Martin
authors.affiliation: Departement de Biologie, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine Université Laval, Québec City, Québec, Canada, G1V 0A6.
authors.forename: Martin
authors.initials: M
authors.lastname: Laporte
authors.affiliation: Departement de Biologie, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine Université Laval, Québec City, Québec, Canada, G1V 0A6.|Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street PO BOX 15000, Halifax, NS, Canada, B3H 4R2.
authors.forename: Helga
authors.initials: H
authors.lastname: Guderley
authors.affiliation: Departement de Biologie, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine Université Laval, Québec City, Québec, Canada, G1V 0A6.
authors.forename: Louis
authors.initials: L
authors.lastname: Bernatchez
mesh_terms: D000064:Acclimatization; D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D060146:Ecotype; D004734:Energy Metabolism; D010641:Phenotype; D012487:Salmonidae / Q000235:genetics / Q000502:physiology*; D013550:Swimming
keywords: Aerobic energy metabolism; adaptation; oxygen transport cascade; phenotypic plasticity; physiology