Phylogenetic Relationships, Genetic Structure and Differentiation of the Caspian Cobra (Naja oxiana Eichwald 1831) snake in Iran Using D-Loop Mitochondrial DNA Marker

As the most easterly species of the subgenus Naja, the Caspian Cobra (Naja oxiana) has long remained a case of major controversy with regard to phylogenetic relationships. The aim of the present study is to analyze the evolutionary relationships, genetic diversity, structure and variations of the Caspian Cobra in north and northeastern populations of Iran. To this end, 5 to 10 abdominal scales were obtained from 19 collected individuals from natural habitats in the north (Golestan province) and northeast (Khorasan Razavi and South Khorasan provinces) of Iran. DNA extraction was done using Ammonium acetate. Forward and reverse primers were used to amplify a segment of the D-Loop gene with 589 base pairs in length. The genealogy analysis was conducted to determine the best evolutionary model using Bayesian and maximum likelihood analyses. Analysis of haplotype relationships was performed using maximum parsimony. The results identified seven unique haplotypes and one common haplotype among populations of the north (Golestan province) and northeast (Khorasan Razavi and South Khorasan province) of Iran. Genealogical analyses revealed that populations of the Caspian Cobra have bifurcated from the Chinese Cobra, supported with rather inadequate bootstrap and posterior probability values of 54.31 and 0.61, respectively. Eventually, Analysis of Molecular Variance (AMOVA) found no significant genetic variation (Fsc 0.05, p 0.05) between populations of the Caspian Cobra in the north and northeast of Iran, whereas significantly large genetic variations (Fsc 0.25, p 0.01) were detected between Caspian and Chinese Cobra populations. Our data set demonstrated that the Caspian Cobra lineage is genetically relatively homogenous, as we found no significant genetic variation between populations of the species in Iran, possibly suggesting their historically recent radiation in the most western part of the species range in Asia. It is demonstrated that an integrated conservation plan is needed to protect the Caspian Cobra in populations of the north and northeast of Iran.