Assessment of genetic structure of wild populations of mrigal carp,Cirrhinus cirrhosusby microsatellite DNA markers

Abstract

The genetic structure of mrigal carp, Cirrhinus cirrhosus was analysed using six microsatellite DNA markers (MFW1, MFW2, MFW17, Bgon22, Barb54, and Bgon17) to detect genetic variations among fish samples from the three rivers, the Halda, the Padma, and the Jamuna in Bangladesh. All the populations showed polymorphism at all loci except Bgon17. Genetic richness of the Halda and Padma populations was indicated by the presence of rare alleles, two in Halda at MFW2 (160 bp) and MFW17 (201 bp), and one in Padma at Bgon22 (96 bp). The highest average number of allele (2.8) was observed in the Halda followed by the Padma (2.6) and the Jamuna (2.4). The observed heterozygosity (Ho) was highest (0.400) in the Padma followed by the Halda (0.383) and the Jamuna (0.377). The highest (0.0257) population differentiation (FST) value was observed between the Halda and Padma populations and the lowest (0.0143) between the Padma and Jamuna populations. The highest gene flow (Nm) was recorded between the Padma and Jamuna populations (17.1756) and the lowest between the Halda and Padma populations (9.4832). The highest (0.037) genetic distance (D) was observed between the Halda and Padma populations and the lowest (0.0195) between the Jamuna and Padma populations. The results indicated a low level of genetic variation regarding allelic richness and heterozygosity among wild stocks of C. cirrhosus and indicated it might be advisable to take necessary measures for the conservation and enhancement of C. cirrhosus genetic resources.

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

“…The decline in river population is believed because of uncontrolled fishing practices such that indiscriminate harvesting of river spawn, insufficient and irregular river flow due to construction of dam and water pollution from anthropogenic activities (Alam et al 2009). Moreover, ongoing climatic changes and global warming are predicted to cause frequent rise of salinity level and habitat water temperature that may exhaust fish population adversely influencing their natural breeding and spawning activities (Nesa et al 2018). However, the highest Ho in the Halda population may be caused by genetic intermixing of individuals, inflow of alleles after mating is confirmed between local and migrating individuals that eventually contribute to overall genetic variation.…”

Exploiting the allelic polymorphism at microsatellite loci to underpin the genetic status of Cirrhinus mrigala in wild populations

“…By using microsatellite markers, Ahmed and Abbas (2018) found the same pattern of genetic differentiation in wild and hatchery stocks of Catla catla in Punjab province, Pakistan. In contrast, Chauhan et al (2007) and Nesa et al (2018) evaluated low level of genetic structuring in wild populations of Cirrhinus mrigala and Cirrhinus cirrhosus, respectively. The analysis for genetic bottleneck revealed a recent genetic bottleneck under various mutation models.…”