Does natural selection explain the fine scale genetic structure at the nuclear exon Glu-5' in blue mussels from Kerguelen ?

Abstract : The Kerguelen archipelago, isolated in the Southern Ocean, shelters a blue mussel Mytilus metapopulation far from any influence of continental populations or any known hybrid zone. The finely carved coast leads to a highly heterogeneous habitat. We investigated the impact of the environment on the genetic structure in those Kerguelen blue mussels by relating allele frequencies to habitat descriptors. A total sample comprising up to 2248 individuals from 35 locations was characterized using two nuclear markers, mac-1 and Glu-5’, and a mitochondrial marker (COI). The frequency data from 9 allozyme loci in 9 of these locations were also reanalysed. Two other nuclear markers (EFbis and EFprem’s) were monomorphic. Compared to Northern-Hemisphere populations, polymorphism in Kerguelen blue mussels was lower for all markers except for the exon Glu-5’. At Glu-5’, genetic differences were observed between samples from distinct regions (FCT=0.077), as well as within two regions, including between samples separated by less than 500 meters. No significant differentiation was observed in the AMOVA analyses at the two other markers (mac-1 and COI). Like mac-1, all allozyme loci genotyped in a previous publication, displayed lower differentiation (Jost's D) and FST values than Glu-5'. Power simulations and confidence intervals support that Glu-5’ displays significantly higher differentiation than the other loci (except a single allozyme for which confidence intervals overlap). AMOVA analyses revealed significant effects of the giant kelp Macrocystis and wave exposure on this marker. We discuss the influence of hydrological conditions on the genetic differentiation among regions. In marine organisms with high fecundity and high dispersal potential, gene flow tends to erase differentiation, but this study showed significant differentiation at very small distance. This may be explained by the particular hydrology and the carved coastline of the Kerguelen archipelago, together with spatially variable selection at Glu-5’.
Type de document :
Article dans une revue
Ecology and Evolution, Wiley Open Access, 2015, 5, pp.1456-1473. 〈10.1002/ece3.1421 〉
Liste complète des métadonnées

Littérature citée [94 références]  Voir  Masquer  Télécharger

http://hal.ird.fr/ird-01366543
Contributeur : Philippe Borsa <>
Soumis le : mercredi 14 septembre 2016 - 17:44:02
Dernière modification le : lundi 23 avril 2018 - 08:56:03
Document(s) archivé(s) le : jeudi 15 décembre 2016 - 15:56:49

Fichier

MYTILUSGerard-et-al-2015-EcolE...
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

K Gerard, C Roby, N Bierne, Philippe Borsa, J.-P Féral, et al.. Does natural selection explain the fine scale genetic structure at the nuclear exon Glu-5' in blue mussels from Kerguelen ?. Ecology and Evolution, Wiley Open Access, 2015, 5, pp.1456-1473. 〈10.1002/ece3.1421 〉. 〈ird-01366543〉

Partager

Métriques

Consultations de la notice

172

Téléchargements de fichiers

117