Besides mammals, however, the SF-1/Ad4BP cDNA has only been isolated to date in fish and birds.     ///    " SF-1/Ad4BP is a transcriptional factor that was originally found to be a mammalian homologue of the Drosophila Ftz-F1 (fushi tarazu factor 1) (), and transcribed from a gene designated the Ftz-F1 gene (). "    ///    "Here, we propose the use of SF-1/Ad4BP instead of Ftz-F1 for the gene that encodes SF-1/Ad4BP in vertebrates.. "    ///    "Molecular cloning and expression of the SF-1/Ad4BP gene in the frog, Rana rugosa.. "    ///    "SF-1/Ad4BP mRNA was expressed in the testes, brains, adrenals/kidneys and spleens, but not ovaries, of adult frogs. "    ///    "In addition, we also cloned the 5'-untranslated region (4.6kb) of the SF-1/Ad4BP gene with exons I and II. "    ///    "It encoded a protein of 468 amino acids, and its open reading frame (ORF) shared 70% similarity with that of chicken OR2.1 (a SF-1/Ad4BP homologue) and 62% with bovine SF-1/Ad4BP. "    ///    "Thus, the name of Ftz-F1 is not adequate for the gene coding SF-1/Ad4BP. "    ///    "In this study, we succeeded to isolate frog (Rana rugosa) SF-1/Ad4BP cDNA from a testis lambdagt10 cDNA library. "    ///    Genomic structure analysis revealed that frog SF-1/Ad4BP was also transcribed from the same gene as that of mammals. 