Development and characterization of novel microsatellite loci in the native tree frog species, Polypedates braueri and cross-species amplification in the alien species, P. megacephalus, in Taiwan

<i>Polypedates megacephalus</i> is an alien species first recorded in 2006 in Taiwan. The expanding population of <i>P. megacephalus</i> poses potential threats to the native frog species, especially to the closely-related species <i>P. braueri</i>. To detect genetic diversity and analyse population structures of both native and alien <i>Polypedates</i> species in Taiwan, this study aimed to isolate microsatellite markers in <i>P. braueri</i> and test their cross-species amplification in the alien species <i>P. megacephalus</i>. We successfully amplified and characterised 10 polymorphic microsatellite loci in <i>P. braueri</i>. The number of alleles per locus ranged from 2 to 19 and no locus showed evidence of a null allele. The observed and expected heterozygosity ranged from 0.200 to 1.000 and 0.180 to 0.916, respectively and each locus was detected in Hardy-Weinberg equilibrium. Cross-amplification in <i>P. megacephalus</i> was successfully performed in seven out of 10 loci. Amongst these seven loci, five exhibited polymorphism and two showed no variation. These microsatellite markers will be helpful for further population genetics research on <i>Polypedates</i> species in Taiwan.