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

Abstract Our previous findings suggest the activity of cytochrome P -450 aromatase ( P -450arom), the enzyme which converts testosterone to estradiol-17β, in the ovarian follicle of medaka ( Oryzias latipes ) is regulated at the transcriptional level. In this study, we cloned a cDNA encoding a FTZ-F1-like protein ( mdFtz-F1 ) from ovarian follicles of medaka. In vitro translated mdFTZ-F1, and nuclear extract from medaka ovarian follicles, formed complexes with oligonucleotide probes containing putative orphan nuclear receptor binding motifs, which are present in the promoter region of the medaka P -450arom gene. The expression pattern of mdFtz-F1 transcripts during oogenesis coincides with that of P -450arom transcripts. Transfection assays further suggest a potential transcriptional regulatory activity of mdFTZ-F1 upon the medaka P -450arom promoter. Taken together, these results suggest a potential role of mdFTZ-F1 in the transcriptional regulation of P -450arom in the ovarian follicle of medaka.