Cristin-prosjekt-ID: 259396
Sist endret: 3. januar 2014, 11:52

Cristin-prosjekt-ID: 259396
Sist endret: 3. januar 2014, 11:52
Prosjekt

Sticklebacks (Gasterosteus aculeatus L.) on the Norwegian coast: fresh water colonisation, divergence rates and adaptive speciation

prosjektleder

Leif Asbjørn Vøllestad
ved Centre for Ecological and Evolutionary Synthesis ved Universitetet i Oslo

prosjekteier / koordinerende forskningsansvarlig enhet

  • Centre for Ecological and Evolutionary Synthesis ved Universitetet i Oslo

Tidsramme

Avsluttet
Start: 1. januar 2006 Slutt: 15. februar 2009

Beskrivelse Beskrivelse

Tittel

Sticklebacks (Gasterosteus aculeatus L.) on the Norwegian coast: fresh water colonisation, divergence rates and adaptive speciation

Vitenskapelig sammendrag

The threespine stickleback is a much used and well-suited model organism in evolutionary research, and has recently become a target species in functional genomics. This species complex display a bewildering diversity in morphology and life history in its natural environments covering the ocean, brackish water and freshwater. In some few lakes in western British Columbia, Canada, two distinct morphs of sticklebacks coexist, one occupying the benthic niche (bottom forager), and the other the pelagic niche (open water forager). The general lack of such distinct morphs (or species) in most system suggests that this pattern may not be a general feature. In our project we will search for early stages of population divergence in Norwegian lakes. By studying neutral genetic markers, QTL´s, physiology and behaviour, we will assess likely evolutionary scenarios. The combination of such analyses will result in an assessment of their adaptive evolution.This project will investigate how historical contingency and evolutionary mechanisms interact to prime ecological and physiological adaptation, which may ultimately result in speciation in the threespined stickleback. This primarily marine species has fou nded numerous anadromous- and stationary populations in fresh waters, living with- or without piscivorous predators, due to the glaciostatic uplift and its phylogeographic structure. By studying neutral genetic markers at both the regional- (mtDNA) and lo cal scales (micro-satellites), in comparison with datings of lake-isolation, we will assess the evolutionary history of a large number of stickleback populations. This will be achieved through a nested-cladistic analysis and historical demography. Adaptiv e specialisation associated with adoptation of new freshwater niches (studied using stable isotopes and feeding behaviour) will be contrasted with the marine ancestors by scoring a suite of armour and trophic traits, and life-history variables. The geneti c basis for variation in traits exposed to natural selection, will be assessed by markers associated with QTL´s as determined by previous mapping efforts. If physiological adaptations to freshwater niches increases with elapsed time in freshwater, then sa ltwater- and thermal-tolerance should be temporally associated with other traits also being exposed to natural selection. Common-garden experiments using half-sib designs will be conducted to estimate trait heritability, and to evaluate adaptive divergenc e (i.e. a Qst/Fst analysis) in wild populations. Saltwater- and thermal tolerance, and expression of candidate genes, including heat-shock proteins and prolactin genes, will be studied on offspring from experimental crosses. The joint effort to compare ma ny stickleback populations along the coast of both Norway and Canada, using the very same protecol, offers a unique possibility to study divergence rates and speciation in the threespine stickleback complex.

prosjektdeltakere

prosjektleder
Aktiv cristin-person

Leif Asbjørn Vøllestad

  • Tilknyttet:
    Prosjektleder
    ved Centre for Ecological and Evolutionary Synthesis ved Universitetet i Oslo
Aktiv cristin-person

Kjartan Østbye

  • Tilknyttet:
    Prosjektdeltaker
    ved Centre for Ecological and Evolutionary Synthesis ved Universitetet i Oslo

Tom Klepaker

  • Tilknyttet:
    Prosjektdeltaker
    ved Universitetet i Bergen

Louis Bernatchez

  • Tilknyttet:
    Prosjektdeltaker
    ved Université Laval

Paul Hart

  • Tilknyttet:
    Prosjektdeltaker
    ved University of Leicester
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