Function of steroidogenic factor 1 during development and differentiation of the reproductive system

Intact reproductive development depends on steroids and other endocrine sig nals. Although recent discoveries have elucidated important steps of sexual differentiation, the intricate mechanisms that regulate the development of steroid-producing tissues remain elusive. In adults, complex feedback mech anisms determine the hypothalamic and pituitary regulation of steroid hormo ne biosynthesis. Steroidogenic factor 1 (SF-1), an orphan member of the nuc lear receptor superfamily of proteins, plays a critical role in development and differentiation of the endocrine and reproductive systems. This review provides an overview of the function of SF-1, its mechanism of action, and a perspective on the interaction of SF-1 with other determinants of sexual differentiation. Whereas SF-1 is essential for the expression of numerous steroidogenic enzymes, its presence may not correlate with steroidogenic fu nction. Moreover, diverse co-regulators modulate the influence of SF-1 on g ene transcription. The significance of these interactions is discussed in t he context of reproductive development and function. Other orphan or ligand -dependent nuclear proteins may share similar mechanisms.