ABSTRACT. Vitellogenin (VTG), a biomarker for environmental estrogenic pollution, can be detected in the bloodstream of oviparous animals before morphological and functional abnormalities appear due to exposure to environmental estrogens. Reports observing VTG in turtles have been limited. We therefore cloned and sequenced a partial cDNA of VTG in Reeves' pond turtle, Chinemys reevesii. The cloned cDNA fragment possessed the start codon and 2,229 bp, encoding 743 amino acid residues. A sequence of deduced amino acid from the cDNA did not contain a high serine content, such as that which exists in phosvitin. Two N-glycosylation sites were found in the sequence. The sequence was compared to those of two birds (chicken and herring gull), one amphibian (Xenopus), and five fishes (carp, zebrafish, eel, haddock, and red seabream). The C. reevesii VTG was similar to that of herring gull (78%, value of positives), chicken (76%), Xenopus (69%), eel (63%), red seabream (62%), haddock (62%), carp (62%), and zebrafish (61%). The phylogenetic tree showed that C. reevesii VTG existed between the amphibian and birds, and it was present far from fish VTGs. A reverse transcription-polymerase chain reaction method was employed to detect the mRNA expression of the C. reevesii VTG through the use of primers designed from our sequence. The VTG mRNA expression (292 bp) was proven in the total RNA extraction from the liver of the juvenile turtles which were treated with estradiol-17β. The information herein would be useful for ecotoxicological studies using freshwater turtles and these findings are expected to contribute positively towards wildlife conservation.

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.