Isolation and characterization of microsatellite DNA markers in endangered Mekong giant catfish Pangasianodon gigas

ABSTRACT:   The Mekong giant catfish is one of the largest freshwater fish in the world, and is endemic to the Mekong basin. Recently, the number of Mekong giant catfish has drastically decreased. In this study, seven microsatellite DNA markers of the Mekong giant catfish were developed for evaluation of the species' genetic diversity. Mendelian inheritance of four of seven markers was confirmed using offspring (F1) produced from one pair. Number of alleles per locus in the founder population ranged 1–4 with a mean of 2.8, and that in F1 ranged 1–2 with a mean of 1.6. The expected heterozygosity in the founder population ranged 0–0.66 with a mean of 0.38, and that in F1 ranged 0–0.5 with a mean of 0.28. The mean expected heterozygosity in the founder population is apparently lower than that in Pangasius bocourti and other freshwater species, but higher than that in endangered species. In the future, the microsatellite data in this study will be used in minimal kinship approaches, because these individuals constitute the basic seed for release into wild in an effort to conserve the native population of Mekong giant catfish.