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ABSTRACT. The complete mitochondrial DNA (mtDNA) control regions (CR), cytochrome b (Cyt b), NADH dehydrogenase subunit 4 (ND4) and cytochrome coxidase subunit I (CO I) genes of four Asian freshwater turtles, Mauremys japonica, Ocadia sinensis, M. mutica, and Annamemys annamensis, were sequenced using universal PCR and long-PCR techniques. Combined with CR sequences of Chinemys reevesii, the composition and structure of CR of the five species were compared and analyzed. Three functional domains (TAS, CD and CSB) in CR and their conserved sequences (TAS, CSB-F, CSB-1, CSB-2, and CSB-3) were identified based on sequence similarity to those of other turtles. At the 3' end of CSB, six type motifs of variable number of tandem repeats (VNTRs) of five species were recognized, in which the TTATATTA motif may be the VNTR motif of the ancestral species of these five turtles. Comparison of nucleotide divergences among Cyt b, ND4, CO I, and CR of 11 turtle species using transitions + transversions and transversions-only methods supported the conclusion that CR evolved 2.6-to 5.7-fold faster than the other mtDNA genes. After excluding VNTRs of CR, molecular phylogenetic trees were constructed with maximum parsimony, maximum likelihood and Bayesian inference methods. The results supported an expanded clade of Mauremys, which included species formerly in Ocadia, Chinemys, Mauremys, and Annamemys; this was also reflected in the results of VNTR analysis.

The Malabar trevally Carangoides malabaricus is a widely distributed inshore fish species and commercially important in some tropical regions. This study presented the complete mitochondrial genome of C. malabaricus as well as its phylogenetic position in Carangidae. The entire sequence was 16,561 bp in length, including the typical structure of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, 1 control regions and 1 L-strand replication origin. The arrangement of the genes was in line with other teleosts. The genome was composed of 29.6% C, 27.8% A, 26.2% T and 16.4% G, showing an obvious anti G bias. Phylogenetic analyses using the concatenated sequence of the protein-coding genes showed similar results in the Neighbour-Joining and Bayesian inference trees. Three clades were formed as Subfamilies Caranginae, Seriolinae and Trachinotinae in Carangidae based on the current dataset. C. malabaricus was most closely related to the species in the same genus.

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