Medaka (Oryzias latipes) FTZ-F1 potentially regulates the transcription ofP-450 aromatase in ovarian follicles: cDNA cloning and functional characterization

Our previous findings suggest the activity of cytochrome P-450 aromatase (P -450arom), the enzyme which converts testosterone to estradiol-17 beta, in the ovarian follicle of medaka (Oryzias latipes) is regulated at the transc riptional level. In this study, we cloned a cDNA encoding a FTZ-F1-like pro tein (mdFtz-F1) from ovarian follicles of medaka. In vitro translated mdFTZ -F1, and nuclear extract from medaka ovarian follicles, formed complexes wi th oligonucleotide probes containing putative orphan nuclear receptor bindi ng motifs, which are present in the promoter region of the medaka P-450arom gene. The expression pattern of mdFtz-F1 transcripts during oogenesis coin cides with that of P-450arom transcripts. Transfection assays further sugge st a potential transcriptional regulatory activity of mdFTZ-F1 upon the med aka P-450arom promoter. Taken together, these results suggest a potential r ole of mdFTZ-F1 in the transcriptional regulation of P-450arom in the ovari an follicle of medaka. (C) 1999 Elsevier Science Ireland Ltd. All rights re served.