Journal of the Marine Biological Association of the United Kingdom

Table of Contents - 2007 - Volume 87, Issue 01  



GENETICS

Genetic variation and population structure of western Mediterranean and northern Atlantic Stenella coeruleoalba populations inferred from microsatellite data

Vincent J.R.  Bourret a1c1, Matthias R.J.M.  Macé a1 and Brigitte  Crouau-Roy a1 1
a1 UMR 5174 UPS/CNRS ‘Evolution et Diversité Biologique’ EDB, Bât 4R3b2 2e étage, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse cedex 9, France

Article author query
bourret vjr   [PubMed][Google Scholar] 
macé mrjm   [PubMed][Google Scholar] 
crouau-roy b   [PubMed][Google Scholar] 

Abstract

The patterns of genetic differentiation and levels of genetic diversity among striped dolphin (Stenella coeruleoalba) populations from the North Atlantic Ocean (N=45 individuals) and the central and western Mediterranean Sea (N=78) were investigated using five polymorphic microsatellite loci. A North Pacific sample (N=14) was added as an out-group. Two of the markers were tetranucleotide repeats tested for the first time in this species. The Mediterranean, Atlantic and Pacific samples displayed a mean number of alleles per locus of 11.2, 13.4, and 9.6 respectively, suggesting a high but variable polymorphism across loci. The Mediterranean sample displayed particular characteristics: (i) the lowest allelic richness and expected heterozygosity (HeMediterranean=0.76, while HeAtlantic=0.83 and HePacific=0.85); (ii) a significant departure from Hardy–Weinberg equilibrium (P<0.001; FIS=0.050); and (iii) a significant linkage disequilibrium between two pairs of loci. These last two features, present neither in the Atlantic sample nor in the Pacific one, suggest that the western Mediterranean population might possibly be further subdivided. Significant genetic differentiation was detected between the Mediterranean and Pacific populations, and between the Mediterranean and Atlantic populations. However, pairwise Wright's FST was not significantly different from zero between the two geographically isolated Atlantic and Pacific populations.

(Published Online February 26 2007)
(Received June 15 2006)
(Accepted October 17 2006)


Correspondence:
c1 Corresponding author, e-mail: vincent@um.es

Footnotes

1 E-mail: bcrouau@cict.fr