The mitochondrial control region of Cervidae: evolutionary patterns and phylogenetic content

The mitochondrial control region (CR) sequence, also known as the D-loop, has been determined for six Cervidae (Artiodactyla, Ruminantia): the red and fallow deers (subfamily Cervinae), the brocket deer and two roe deers (subfamily Odocoileinae), and the Chinese water deer (Hydropotinae). These new sequences have been aligned with available cervid and bovid orthologues. Comparative analyses indicate that the 5'-peripheral domain exhibits a 75-bp length polymorphism near sequences associated with the termination of the H-strand replication. The New World Odocoileinae possess the longest cervid CR due to the presence of an additional 47-bp tandem repeat, located in the 3'-peripheral domain, downstream of the initiation site for H-strand replication (OH) and the first conserved sequence block (CSB-1). This insertion represents a duplication spanning the OH to CSB-1 region and constitutes an exclusive synapomorphy for New World Odocoileinae. Phylogenetic analyses of the complete CR support the paraphyly of antlered deers due to the nesting of the antlerless Hydropotes within Odocoileinae. Capreolus is the closest relative of Hydropotes, and the divergence of this Old World Odocoileinae clade may have occurred between 8.7 and 10.4 MYA. The conserved central domain of CR can be aligned across ungulates and indicates the Pecora monophyly, their close association with cetaceans, and the earlier emergence of suiformes.