Rapid and cost-effective screening of newly identified microsatellite loci by high-resolution melting analysis

This study describes a new method for identifying microsatellite loci that will reliably amplify and show high degree of polymorphism in a given species. Microsatellites are the most powerful codominant markers available today, but the development of novel loci remains a labour-intensive and expensive process. In de novo isolation, approaches using next generation sequencing (NGS) are gradually replacing ones using Escherichia coli libraries, resulting in unparalleled numbers of candidate loci available. We present a systematic review of published microsatellite primer notes and show that, on average, about half of all candidate loci are lost due to insufficient PCR amplification, monomorphism or multicopy status in the genome, no matter what isolation strategy is used. Thus, the screening of candidate loci remains a major step in marker development. Re-assessing capillary-electrophoresis genotyped loci via high-resolution melting analysis (HRM), we evaluate the usefulness of HRM for this step. We demonstrate its applicability in a genotyping case study and introduce a fast, HRM-based workflow for the screening of microsatellite loci. This workflow may readily be applied to NGS-based marker development and has the potential to cut the costs of traditional testing by half to three quarters.