RAD-QTL Mapping Reveals Both Genome-Level Parallelism and Different Genetic Architecture Underlying the Evolution of Body Shape in Lake Whitefish ( Coregonus clupeaformis ) Species Pairs

Martin Laporte (1) , Sean Rogers (2) , Anne-Marie Dion-Côté (1) , Eric Normandeau (1) , Pierre-Alexandre Gagnaire (3) , Anne Dalziel (1) , Jobran Chebib (2) , Louis Bernatchez (1)

1 IBIS - Institut de Biologie Intégrative et des Systèmes [Québec]
2 University of Calgary
3 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier

Parallel changes in body shape may evolve in response to similar environmental conditions, but whether such parallel phenotypic changes share a common genetic basis is still debated. The goal of this study was to assess whether parallel phenotypic changes could be explained by genetic parallelism, multiple genetic routes, or both. We first provide evidence for parallelism in fish shape by using geometric morphometrics among 300 fish representing five species pairs of Lake Whitefish. Using a genetic map comprising 3438 restriction site2associated DNA sequencing single-nucleotide polymorphisms, we then identified quantitative trait loci underlying body shape traits in a backcross family reared in the laboratory. A total of 138 body shape quantitative trait loci were identified in this cross, thus revealing a highly polygenic architecture of body shape in Lake Whitefish. Third, we tested for evidence of genetic parallelism among independent wild populations using both a single-locus method (outlier analysis) and a polygenic approach (analysis of covariation among markers). The single-locus approach provided limited evidence for genetic parallelism. However, the polygenic analysis revealed genetic parallelism for three of the five lakes, which differed from the two other lakes. These results provide evidence for both genetic parallelism and multiple genetic routes underlying parallel phenotypic evolution in fish shape among populations occupying similar ecological niches.

Mots clés: adaptive radiation; fish body shape; genotyping-by-sequencing; geometric morphometrics; parallel evolution.

Domaines: Biodiversité et Ecologie; Génétique des populations [q-bio.PE]

Martin Laporte, Sean Rogers, Anne-Marie Dion-Côté, Eric Normandeau, Pierre-Alexandre Gagnaire, et al.. RAD-QTL Mapping Reveals Both Genome-Level Parallelism and Different Genetic Architecture Underlying the Evolution of Body Shape in Lake Whitefish ( Coregonus clupeaformis ) Species Pairs. G3, 2015, 5 (7), pp.1481-1491. ⟨10.1534/g3.115.019067⟩. ⟨hal-02395342⟩