Assessment of Genetic Diversity of Freshwater Mud Eel (Monopterus cuchia) Using RAPD and RFLP Markers

Abstract

Background: Monopterus cuchia, an economically important eel of Bangladesh, is confronting the challenge of population reduction and germplasm degeneration since the vast majority of fingerlings are collected from natural habitats and artificial cultivation of the fish is yet to be established. Materials and Methods: 30 individuals of M. cuchia from a natural population of Northern-East part of Bangladesh were analyzed using 8 decamer primers and glutamine synthetase gene was digested with 2 restriction enzymes. Results: A total of 735 bands with 228 polymorphic loci were detected among the selected 30 individuals by using RAPD assay while 100% polymorphism was revealed by all the primers. The genetic distance among the individuals was calculated by using the data from pair-wise similarity index where 36 groups of genetic diversities were measured while the lowest and highest genetic distance were found 0.58 and 0.97 respectively with an average genetic diversity of 0.81. The Nei’s genetic similarity values were found from 0.06 to 0.6 where average value was recorded 0.301746 which was found significant regarding genetic distance. Phylogenetic relationships using UPGMA clustering revealed linkage distance ranged from 3.6 to 6.24 and generated 6 clusters by 11 clades with the involvement of 22 individuals while the rest of the samples were connected to those clades with specific linkage distances. Genetic diversity of glutamine synthetase gene was analyzed with two restriction enzymes, e.g. +CfrI and +Hpy178III while both the enzymes digested the gene fragment at a length of 541 bp and polymorphism was detected in terms of wild type homogygotes, polymorphic homozygote and heterozygosity. The genetic diversity was observed by using the RFLP band analysis and four different groups of individuals were identified with the p-values of 0, 0.033, 0.05 and 1 respectively whereas different distances were found among the groups indicating the polymorphism among experimental individuals of glutamine synthetase gene. Conclusion: Herein, RAPD and RFLP analysis indicating the rich genetic diversity of this fish in the experimental ecological habitat and this would come helpful for the conservation of germplasm diversity and to support the sustainable breeding program of M. cuchia.