Investigation of population genetic structure of common carp (Cyprinus carpio) in the south Caspian Sea using mtDNA Method (PCR-RFLP)

Abstract

The population genetic structure of common carp (Cyprinus carpio) was examined on 260 specimens from Tajan and Gorgan Rivers, Gorgan Gulf, Anzali Lagoon and other regions in east, middle and west of south Caspian Sea. DNA was extracted from fin tissue by phenol-chlorophorm method with a concentration of 50-100 nanograms. PCR was performed using ND-3/4 and ND-5/6 genes. The PCR products of samples were digested by 15 restriction endonuclease enzymes. The digested products accompanied with standard marker (50 pb). To measure fragment size, samples were run on a 6% vertical poyacrylamide gel. The fragments were visualized by silver staining of the polyacrylamide gel. Statistical analysis of data was performed by Reap software. We detected 14 and 12 different haplotypes in ND-3/4 and ND-5/6 genes of common carp. The mean values of haplotype diversity among populations were 0.59 and 0.48 and the average nucleotide diversity was 0.06 and 0.03 for ND3/4 and ND5/6 genes. Also, the mean values of nucleotide divergence among populations were 0.05% and 0.02%, respectively. The haplotype distribution was not significantly different between Mazandaran and Guilan coasts, Mazandaran and Golestan coasts, Golestan coast and Gorgan Gulf and Gorgan River (P less than or equal to 0.05), but this divergence was significantly different between Guilan region and Anzali Lagoon, Guilan and Golestan coasts, Tajan and Gorgan Rivers (P less than or equal to 0.05). We found a significant genetic divergence between some of the samples such that three genetic groups of common carp were identified in the southern part of the Caspian Sea.