Identification of SF-1 and and Their Effect on Activating P450 Aromatase Transcription Specific Binding to the Promoter Motifs in Sex Reversing .

The giant wrasse is a protogynous socially hermaphroditic fish. However, the physiological basis of its sex reversal remains largely unknown. is a key gender-related gene encoding P450 aromatase, which converts androgens to estrogens. transcription regulation is currently unknown in socially sexually reversible fish. We identified by encoding SF-1, and from giant wrasse cDNA and and promoter regions were cloned from genomic DNA to determine the function of both genes in regulation. Structural analysis showed that SF-1 contained a conserved DNA-binding domain (DBD) and a C-terminal ligand-binding domain (LBD). FOXL2 was comprised of an evolutionarily conserved Forkhead domain. transfection assays showed that SF-1 could upregulate promoter activities, but FOXL2 could only enhance promoter transcriptional activity in the HEK293T cell line. Furthermore, HEK293T and COS-7 cell lines showed that co-transfecting the two transcription factors significantly increased promoter activity. The -120 to -112 bp (5'-CAAGGGCAC-3') and -890 to -872 bp (5'-AGAGGAGAACAAGGGGAG-3') regions of the promoter were the core regulatory elements for SF-1 and FOXL2, respectively, to regulate promoter transcriptional activity. Collectively, these results suggest that both FOXL2 and SF-1 are involved in giant wrasse sex reversal.