Null alleles are ubiquitous at microsatellite loci in the Wedge Clam (Donax trunculus)

20 páginas, 1 figura, 3 tablas.
Recent studies have reported an unusually high frequency of nonamplifying alleles at microsatellite loci in bivalves. Null alleles have been associated with heterozygous deficits in many studies. While several studies have tested for its presence using different analytical tools, few have empirically tested for its consequences in estimating population structure and differentiation. We characterised 16 newly developed microsatellite loci and show that null alleles are ubiquitous in the wedge clam, Donax trunculus. We carried out several tests to demonstrate that the large heterozygous deficits observed in the newly characterised loci were most likely due to null alleles.Wetested the robustness of microsatellite genotyping for population assignment by showing that well-recognised biogeographic regions of the south Atlantic and south Mediterranean coast of Spain harbour genetically different populations.
CR was supported by the Spanish Ministry of Education (Grant no PR2010-0601) and the Spanish Scientific Research Council (CSIC). This research was financially supported by Organismo Autonomo de Parque Nacionales Grant OAPN122_2010 to CR, EM, JAC and PD. ADM was supported by the Strategic Research Themes of the University of the South Pacific.