Mauremys sensu lato was divided into Mauremys, Chinemys, Ocadia, and Annamemys based on earlier research on morphology. Phylogenetic research on this group has been controversial because of disagreements regarding taxonomy, and the historical speciation is still poorly understood. In this study, 32 individuals of eight species that are widely distributed in Eurasia were collected. The complete mitochondrial (mt) sequences of 14 individuals of eight species were sequenced. Phylogenetic relationships, interspecific divergence times, and ancestral area reconstructions were explored using mt genome data (10,854 bp). Subsequent interspecific gene flow level assessment was performed using five unlinked polymorphic microsatellite loci. The Bayesian and maximum likelihood analyses revealed a paraphyletic relationship among four old genera (Mauremys, Annamemys, Chinemys, and Ocadia) and suggested the four old genera should be merged into the genus (Mauremys). Ancestral area reconstruction and divergence time estimation suggested Southeast Asia may be the area of origin for the common ancestral species of this genus and genetic drift may have played a decisive role in species divergence due to the isolated event of a glacial age. However, M. japonica may have been speciated due to the creation of the island of Japan. The detection of extensive gene flow suggested no vicariance occurred between Asia and Southeast Asia. Inconsistent results between gene flow assessment and phylogenetic analysis revealed the hybrid origin of M. mutica (Southeast Asian). Here ancestral area reconstruction and interspecific gene flow level assessment were first used to explore species origins and evolution of Mauremys sensu lato, which provided new insights on this genus.

The Sox family of genes shares a high sequence similarity with the HMG box region of the human Y chromosomal gene, SRY. We used highly degenerate primers to clone and sequence seven Eremias breuchleyi Sox genes (EbSox2, EbSox3, EbSox4, EbSox11, EbSox12, EbSox14 and EbSox21). A database search for the cloned sequences revealed the following percentage identity with the homologous human SOX genes: EbSox2 = 96%, EbSox3 = 88%, EbSox4 = 94%, EbSox11 = 99%, EbSox12 = 96%, EbSox14 = 98%, EbSox21 = 97%. Cluster analysis indicates that they seem to belong to group B and group C of Sox gene family, respectively. The Sox (SRY related HMG-box gene, Sox) genes form a large family which is characterized by a highly conserved DNA-binding and share a high sequence similarity with the HMG (high mobility group, HMG) box region of the human Y chromosomal gene, SRY (Sex-determining region of Y chromosome, SRY) (Hawkins JR, 1994;Pevny LH, 1997). More than 30 Sox genes have been identified in mammals and their orthologues have been found in a wide range of other metazoans (Hagiuda et al., 2003). The Sox genes are highly conserved and are known to play important roles in embryonic development including roles in gonad, central nervous system, neural crest and skeletal development (Nagai, 2001). For instance, mutation in the SOX9 gene has been associated with sex reversal in men (Foster et al., 1994;Wagner et al., 1994), while targeted mutagenesis in mice has shown that Sox4 is essential for heart and lymphocyte development (Schilham et al., 1996). In addition, tissue culture experiments have shown that mouse Sox1, Sox2 and Sox3 genes are expressed mainly in nervous system development and are involved in determining the fate of neuronal cells (Collignon et al., 1996;Pevny et al., 1998;Li et al., 1998). However, the role of these genes in the development and differentiation of reptiles has yet to be explored.The lacertid lizard, Eremias breuchleyi, lacks identifiable sex chromosomes but it appears that the sex determination in this species might be genetic because incubation temperature does not influence sex development. As a prelude to understanding the involvement of SRY-like genes in the development and differentiation of reptiles, we attempted to clone the Sox genes family of E. breuchleyi using the polymerase chain reaction (PCR). In the present paper we report the cloning and nucleotide sequence of seven E. breuchleyi Sox genes which show extensive homology with the Sox genes of various other vertebrate taxa. The phylogenetic evolution of Sox genes is also discussed.Two male and two female E. breuchleyi were captured from Qianshan, Suzhou, Anhui province, China and the genomic DNA isolated from muscle tissues using routine protocols (Sambrook et al., 1989). A pair of PCR primers was designed using a multiple alignment of a HMG-box sequence representative of SRY/Sox gene family, primer 1 being: 5'-AGCGACCCATGAA(CT)GC(AGCT)TT(CT) AT(AGCT)G-3' and primer 2 being: 5'-ACGAGGTCG ATA(CT)TT(AG)TA(AG)T(CT)(AGCT)GG-3'. The amplifica...