Development and characterization of microsatellite markers in the earthworm Drawida gisti Michaelsen, 1931 and cross-amplification in two other congeners.

The earthworm (Drawida gisti) is an ecologically important sentinel species for soils that is widely distributed throughout Eastern Asia; however, the molecular tools required for genetic diversity studies of this earthworm are still rare. The aim of the study was to develop and characterize microsatellite markers in D. gisti and to evaluate their transferability to other Drawida species. We employed a RAD-seq approach to develop 12 microsatellite markers for D. gisti. The characterization and analysis of loci was achieved using 24 individuals of D. gisti from a natural population. The number of alleles per locus ranged from four to eleven, with an average of 6.5. Observed and expected heterozygosities varied from 0.708 to 0.958, and from 0.568 to 0.883, respectively. No loci presented significant deviations from the Hardy-Weinberg equilibrium, while linkage disequilibrium was detected between three loci. Cross-species amplification tests suggested that the transferability of ten loci was positive for the two congeners D. japonica and D. ghilarovi. This set of microsatellite markers may be used to evaluate the genetic diversity and population structures of D. gisti and related species in the future.