Isolation and characterization of microsatellite loci of Clarias macrocephalus and their application to genetic diversity study

Four microsatellite loci were identified for Clarias macrocephalus and the forward and reverse primers for each locus were designed according to their unique flanking regions. One locus, Cma-1*, was monomorphic, three loci, C ma-2*, Cma-3* and Cma-4*, were polymorphic having 5, 14 and 30 alleles per locus respectively. The polymorphic microsatellite loci were studied in fou r natural populations of C. macrocephalus collected from different location s in Thailand. Mean number of alleles per locus were 8.0, 8.7, 6.0 and 10.0 , respective to populations from Pattani, Pattalung, Chiangrai and Prachinb uri. Mean heterozygosities were 0.744, 0.765, 0.718 and 0.810 respectively. Nei's genetic distance showed the closest relationship between Pattalung a nd Prachinburi (0.230) and the largest genetic distance between Pattalung a nd Chiangrai (0.535). However, the genetic distances obtained in this study were not accorded with geographic distance.