Development and characterization of 27 new microsatellite markers for the Indian bullfrog Hoplobatrachus tigerinus and its congeneric species

Abstract

The Indian bullfrog Hoplobatrachus tigerinus and its four congeneric species are common frog species and distributed throughout South Asia. Due to recent human activity, they are facing a changing environment and reduction in natural population size. For effective conservation and molecular ecological studies, we therefore isolated and characterized microsatellite loci for these frogs. We obtained genomic data using an Ion Torrent PGM sequencer and designed 54 primer sets for candidate loci. By screening for polymorphic loci in individuals of H. tigerinus and its congeneric species, we isolated 27 loci as highly polymorphic microsatellite loci. Eight of these loci were commonly applicable for all species except H. chinensis. Within two populations of H. tigerinus, the total number of alleles per locus and expected heterozygosity ranged from 2 to 18 and 0.271 to 0.938, respectively. No significant linkage disequilibrium was observed across all loci, and five showed a significant deviation from Hardy-Weinberg equilibrium in some populations after Bonferroni correction. Consequently, our findings suggest that these novel markers will be applicable for conservation genetic studies across varying scales from inter-population to inter-individual.