Comparison of Mitochondrial Control Region Sequences Between Chelydridae and Platysternidae

The sequences of mitochondrial control region (CR) of Macroclemys temminckii, Chelydra serpentina and Platysternon megacephalum were obtained using PCR and sequencing techniques, with gene-specific primers, based on the CR and its flanking sequences from other species. The CR lengths of the three species were 1089 bp, 1124 bp and 1119 bp respectively, and the base composition of A+T were 68.97%, 69.34% and 69.44% respectively. One fragment of (TA)20 microsatellite was found in M. temminckii; one fragment of (TATAT) 13 direct tandem repeats followed by (TA)15 microsatellites were found in C.serpentina; and one fragment of (AGTATGTTAT)4 direct tandem repeats followed by (GTTGTTATATAACATAT) 13 repeats were found in P. megacephalum. The distribution of mtDNA microsatellites in tortoises was discussed based on the CR sequences of the three species and other six tortoises published in GenBank. The result suggested that all the nine tortoises have microsatellites, and there are obvious differences both at the site and the sequences.