Application of mtDNA d-loop region for the study of Russian sturgeon population structure from Iranian coastline of the Caspian Sea

The population structure of the Russian sturgeon (Acipenser gueldenstaedtii) was investigated using PCR amplification of the mtDNA D-loop region. Seven composite haplotypes were detected and average nucleotide and haplotype diversity over all samples were found to be 0.05 ± 0.00 and 0.75 ± 0.00 (mean ± SE) respectively. Restriction digest of the mtDNA D-loop region detected two genotypes A and B with a relative high frequencies of 0.5 and 0.36 respectively. These two genotypes (A and B) can be considered as potential genetic markers for different biological groups, stocks or seasonal races of Russian sturgeon. A maximum of 10.8% nucleotide diversity was found between haplotypes AAAAB and BBBBF. 100% heteroplasmy was found in Russian sturgeon and restriction digest of the mtDNA D-loop region also exhibited site heteroplasmy.