Mitochondrial genome of Pogona vitticepes (Reptilia; Agamidae): control region duplication and the origin of Australasian agamids.

The complete mitochondrial DNA sequence for an Australian agamid Pogona vitticepes was determined. Twenty-two tRNA genes, two rRNA genes, thirteen protein-coding genes, and two control regions were identified in this mitochondrial genome. The second control region was inserted between NADH dehydrogenase subunits 5 and 6 genes. The duplication of the control region was found in all Australasian agamids examined and was not found in other Asian or African taxa. The two control regions had nearly identical sequences within species but they were divergent among species, suggesting their concerted sequence evolution. Phylogenetic analyses including divergence time estimation without assuming the molecular clock suggested that the duplication of the control region occurred on a lineage leading to the Australasian agamids 25-45 million years ago after their divergence from a Southeast Asian Physignathus cocincinus. Our finding thus supports the recent dispersal origin of Australasian agamids in connection with plate tectonic movement of Australia to the proximity of Southeast Asia.