Genetic variation and differentiation in the Stinging catfish, Heteropneustes fossilis (Bloch), populations assessed by heterologous microsatellite DNA markers

Abstract

85-90Microsatellite DNA markers have been increasingly used in genetic diversity studies. The present study reports on the characterization of genetic variation and differentiation in four different natural populations of the stinging catfish, Heteropneustes fossilis (Bloch), in Bangladesh, viz., Mymensingh, Netrakona, Narsingdi and Rangpur, using cross-species microsatelllite DNA markers developed from the walking catfish, Clarias batrachus. Eighteen polymorphic alleles were found in the 128 diploid individuals (32 from each population), with nine alleles at each of the two loci analyzed. The Netrakona and Rangpur population deviated from the Hardy-Weinberg proportion at one locus. The population differentiation (FST) value between the Narsingdi and Netrakona population was found to be insignificant, while the values between all the other population pairs were found to be significant. The genetic distance values ranged between 0.165 and 0.626. The UPGMA dendrogram based on genetic distance resulted in two clusters: the Mymensingh population alone was in one cluster and the three other populations in the second cluster. This study revealed a fairly high level of genetic variation in the microsatellite loci within and between the four populations, and identified existence of distinct population groups of H. fossilis