RFLP analysis of the mtDNA D-loop region in Hilsa shad (Tenualosa ilisha) population from Bangladesh

Abstract

The genetic structure of three populations Hilsa shad (Tenualosa ilisha), belonging to three different ecological zones such as freshwater (Chandpur), brackish (Kuwakata) and marine (Cox’s Bazar) were studied by Polymerase Chain
Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) of mitochondrial DNA. Fifteen composite haplotypes, representing information from 7 restriction enzymes were generated for samples of 7 fish from each site. All populations have polymorphic haplotype and the haplotype diversity (h) of the three populations were 0.979, 0.979 and 0.918 for Chandpur, Kuwakata and Cox’s Bazar respectively. The intra-population nucleotide diversity was 36.75%
in Chandpur and Kuwakata and 25.56% in Cox’s Bazar population. These indicate that the genetic variability of the present Hilsa shad population falls within the range of good condition and the genetic status of Hilsa shad does
not appear to be affected, though the catch has decreased due to overexploitation and indiscriminate killing. Genetic distance between Chandpur and Kuwakata populations, Chandpur and Cox’s Bazar, Kuwakata and Cox’s Bazar were 0.0213, 0.1823 and 0.1610 respectively. UPGMA dendrogram shows that the
Chandpur and Kuwakata populations are very close group and Cox’s Bazar population is a different group.