Expression and subcellular localization of SF-1, SOX9, WT1, and AMH proteins during early human testicular development

Many transcription factors have been identified and implicated in male sex determination pathway. Specifically involved in Sertoli cell differentiatio n and subsequent anti-Mullerian hormone (AMH) secretion in eutherian mammal s, they include steroidogenic factor-1 (SF-l), SOX9 (SRY HMG box related ge ne 9), WT1 (Wilms' tumor 1), and GATA-4 (a zinc finger transcription factor ). These factors have been described to execute their function in the male sex determination pathway by controlling AMH transcriptional expression. To understand the hierarchies of these factors and their involvement in the d eveloping testis, for the first time we show the expression and subcellular localization of these factors by immunohistochemistry in the early human t estis during embryogenesis compared with AMH expression. If these studies d o not refute their possible synergistic interaction to control AMH expressi on in human embryo, they also reveal a new sexual dimorphism in SOX9 expres sion during the sex determination process. We show that SOX9 sex specifical ly shifts from the cytoplasmic to the nuclear compartment at the time of te stis differentiation and AMH expression. Putative models for this subcellul ar distribution are discussed. Dev Dyn 2000;217:293-298. (C) 2000 Wiley-Lis s, Inc.