Genetic diversity of Naja oxiana (Eichwald, 1831) populations in Iran using cytochrome b mitochondrial marker

Abstract

Introduction: The phylogenetic relationships of the Caspian cobra (Naja oxiana), the easternmost species of the subgenus Naja, have remained contentious for long. The present study aims at investigating the genetic diversity and structure, as well as phylogenetic relationships of the Caspian cobra populations from northeastern Iran, Afghanistan and Turkmenistan.
Materials & Methods: We sequenced 1107 base pairs of the mitochondrial gene cytochrome b for 54 samples to assess the genetic diversity, genetic structure and phylogenetic relationships of the Caspian cobra. Phylogenetic analyses were conducted under Bayesian and Maximum likelihood inferences using the best-fitting evolutionary model. Haplotype relationships were inferred using maximum parsimony.
Result: Reconstruction of the phylogenetic trees confirmed that the Caspian cobra is the sister taxon of Naja kaouthia. The estimated haplotype and nucleotide diversity were 0.42 and 0.00058, respectively, indicating low genetic variation among Caspian cobra populations.
Conclusion: Our findings suggest that populations of the species have experienced a recent radiation and sudden range expansion from the northeast toward Golestan province. The results, based on a single mitochondrial marker, revealed no significant genetic differentiation between the populations and recommend that all populations of the Caspian cobra be considered as a significant evolutionary unit in future conservation plans.