Expression Profiles of in , and Their Relation to CpG Methylation of Its Promoter and Temperature.

To elucidate the role of in sex differentiation of a teleost fish , the full-length sequences of its cDNA and promoter were cloned by rapid amplification of cDNA ends (RACE) and genome walking. The relative mRNA expression levels were determined by quantitative real-time PCR (RT-PCR). The 1095-bp cDNA was predicted to encode a protein of 264 amino acids. It was expressed only in the gonads, and the expression was 17-times higher in the testis than in the ovary. The 1215-bp promoter sequence of was cloned and analyzed to detect sex-related differences in its methylation levels. A significant negative relationship between the expression and CpG methylation of its promoter were found in the testes and ovaries of . Significant differences in expression levels were also found between the larval and juvenile stages. No significant differences in expression were found during the entire larval stage, and in the individuals among three different temperature groups (10°C, 14°C, and 18°C). Considering that the sex of sampled larval fish cannot be distinguished, correlations between expression and effects of temperature on sex differentiation in need further study.