Genetic characterisation of wild catla (Catla catla Hamilton) populations using microsatellite DNA markers

The genetic characterisation of catla, Catla catla populations from three rivers, the Halda, the Jamuna, and the Padma was performed employing six microsatellite DNA markers Ccat A12, Ccat C3, Ccat C6, Ccat C8, Ccat G1, and Ccat G2. All the studied loci were detected as polymorphic (P95) in nature. The appearance of five rare alleles in Halda, at Ccat A12 (149 and 153 bp), Ccat C6 (180 bp), and Ccat C8 (98 and 104 bp) demonstrated the genetic richness of the Halda population. The average highest (6.33) and lowest (4.67) number of alleles were recorded in the Halda and the Padma populations, respectively. The Halda population exhibited the highest (0.5111) average heterozygosity (Ho) compared to the Jamuna (0.4889) and the Padma (0.4167). The population differentiation (FST) between the Halda and the Padma populations was the highest (0.0653) and the lowest (0.0366) between the Halda and the Jamuna populations. The highest gene flow (Nm) (6.5747) existed between the Halda, and the Jamuna populations and the lowest (3.5811) between the Halda and the Padma populations. These findings revealed a reduced genetic variability of wild stocks of C. catla in relation to allelic diversity and heterozygosity that provided a benchmark for future comprehensive management programme to conserve the genetic resources of wild populations of this species.