Level of genetic differentiation affects relative performances of EST- and genomic SSRs

Microsatellites, also called simple sequence repeats (SSRs) are markers of choice to estimate relevant parameters for conservation genetics, such as migration rates, effective population size and kinship. Cross-amplification of SSRs is the simplest way to obtain sets of markers and highly conserved SSRs have recently been developed from Expressed Sequence Tags (EST) to improve SRR cross-species utility. As EST-SSRs are located in coding regions, the higher stability of their flanking regions reduces the frequency of null alleles and improves cross-species amplification. However, EST-SSRs have generally less allelic variability than genomic SSRs, potentially leading to differences in estimates of population genetic parameters such as genetic differentiation. To assess the potential of EST-SSRs in studies of within-species genetic diversity, we compared the relative performance of EST- and genomic SSRs following a multi-species approach on passerine birds. We tested whether patterns and l...