Molecular Cloning of Full-Length Dmrt1 cDNA of Reeves Turtle (Chinemys reevesii)

Abstract

We cloned and sequenced a full-length open reading frame turtle dmrt1 cDNA (Crdmrt1) that was 1,504 bp in length and encoded 371 amino acid residues. RT-PCR analysis in different tissues of adult male turtle showed that the Crdmrt1 cDNA fragment was only detected in the testis. The amino acid sequence derived from Crdmrt1 demonstrated high homology to sequences from dmrt1 of Pelodiscus sinensis (92% identities and 93% positives) and Elaphe quadrivirgata (75% identities and 83% positives). The deduced amino acid from Crdmrt1 contained a conserved DM domain, a male-specific motif, and a P/S-rich region. In DMRT1 from reptiles, birds, mammals, amphibians, and fish, the amino acid identities and positives for DM domains were 85-100% and 88-100%, respectively, those for male-specific motifs were 47-100% and 60-100%, and those for P/S-rich regions were 24-100% and 35-100%. The module consisted of intertwined CCHC and HCCC Zn(2+)-binding sites in the DM domain and was conserved in all 11 species analyzed in this study. Amino acid sequences of Crdmrt1 and previously reported DMRT1s, DMRT2s, and DMRT3s were subjected to phylogenetic analysis. The resulting tree showed that CrDMRT1 belongs to DMRT1, and turtles are a sister group to a cluster of birds and snakes. This is the first study of the cloning of full-length dmrt1 from a reptile.