Molecular Phylogenetics and Evolution, Vol. 19, pp. 187-201

Link to Molecular Phylogenetics and Evolution home page.

Return to my home page .

Evolution of the Mitochondrial DNA Control Region and Cytochrome b Genes and the Inference of Phylogenetic Relationships in the Avian Genus Lophura (Galliformes)

Istituto Nazionale per la Fauna Selvatica, via Cà Fornacetta 9, 40064, Ozzano dell Emilia, (BO), Italy (V.L., E.R.); Museum National d'Histoire Naturelle, Parc Zoologique de Clères, 76690, Clères, France (A.H.); Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA (R.T.K., E.L.B., J.D.L); Departments of Evolution, Ecology and Organismal Biology (R.T.K.) and Plant Biology (E.L.B.), Ohio State University, Columbus, OH, 43210, USA;
E.L.B. and R.T.K. are currently in the Department of Zoology at the University of Florida.

The entire mitochondrial DNA control region (mtDNA CR) and cytochrome b (cyt b) genes were sequenced in 10 of the 11 extant species of gallopheasants (Lophura). The cyt b from L. diardi and L. ignita showed unusual leucine-coding codons at the expected terminal 3' end of the gene. Presence of conserved functional motifs in the inferred amino acid sequences, conserved secondary structures of the flanking tRNA^Pro and tRNA^Thr, and Southern hybridization concordantly suggest that these cyt b represent functional mitochondrial genes and not nuclear transpositions. Functional stop codons can be generated by RNA editing of the primary transcripts rom these sequences. Despite strong site and domain substitution rate heterogeneity, CR and cyt b diverged at similar rates, on average, and expressed congruent phylogenetic signals. Phylogenetic analyses of the concatenated sequences split Lophura into five clades including (1) L. bulweri, (2) L. diardi–L. ignita, (3) L. erythrophthalma–L. inornata, (4) L. leucomelanos–L. nycthemera, and (5) L. swinhoii–L. edwardsi–L. hatinhensis. Basal relationships among these clades, which include species distributed in continental South East Asia and the Sundaland archipelago, were weakly resolved, suggesting the occurrence of rapid cladogenic events in the early evolutionary history of Lophura. A conventional calibration of mtDNA sequence divergence indicates a mid to late Pliocene evolution of the main clades in Lophura, which could have diversified in allopatry in continental South East Asia. Sundaland could have been colonized lately and independently by the different clades. Consequently, cyclic changes in late Pleistocene climate and landscape might not have increased rates of speciation in genus Lophura in Sundaland.

^* Corresponding author