Isolation and characterization of 50 microsatellite loci for two shearwater species, Ardenna pacifica and Puffinus bailloni

Shearwaters (order Procellariiformes) are an excellent study system to investigate the genetic consequences of the co-called "seabird paradox", as they are able to disperse long distances but many species exhibit natal and breeding philopatry. However, few microsatellite markers are currently available for these taxa, hampering genetic inferences.

In this study, 25 novel microsatellite loci were isolated and characterized for each of two distantly related shearwater species: the wedge-tailed shearwater (Ardenna pacifica) and the tropical shearwater (Puffinus bailloni). Polymorphism tests were performed for a total of 91 A. pacifica individuals sampled at Reunion and Round Island, and 48 P. bailloni individuals from Reunion and Europa Island, in the western Indian Ocean. The analyses revealed 23 polymorphic loci for A. pacifica, with the number of alleles per locus (Na) ranging from 2 to 8 (mean = 3.957 ± 0.364). Nineteen polymorphic loci were found for P. bailloni, with Na varying from two to five (mean = 3.053 ± 0.247). The observed heterozygosity (H_o) was relatively low for the two species, with H_o ranging from 0.022 to 0.725 (mean = 0.326 ± 0.044) for A. pacifica and from 0.021 to 0.688 (mean = 0.271 ± 0.051) for P. bailloni, but comparable to the estimates available for other Puffinus species.

The new microsatellite loci provide a valuable tool for further population genetic studies, and will allow for design of effective conservation and management plans for A. pacifica, P. bailloni and other closely-related species.