Project description:: Sex determination triggers the differentiation of the bi-potential gonad into either an ovary or testis. In non-mammalian vertebrates, the presence or absence of oestrogen dictates gonad differ-entiation, while in mammals, this mechanism has been supplanted by the testis determining SRY gene. Exogenous oestrogen can override this genetic trigger to shift somatic cell fate in the gonad towards ovarian developmental pathways by limiting the bioavailability of the key testis factor SOX9 within somatic cells. Our previous work has implicated the MAPK pathway in mediating the rapid cellular response to oestrogen. We performed proteomic and phosphoproteomic anal-yses to investigate the precise mechanism through which oestrogen impacts these pathways to ac-tivate -catenin—a factor essential for ovarian development. We show that oestrogen can activate -catenin within 30 minutes, concomitant with the cytoplasmic retention of SOX9. This occurs through changes to the MAP3K1 cascade, suggesting this pathway is a mechanism through which oestrogen influences gonad somatic cell fate. We demonstrate that oestrogen can promote the shift from SOX9 pro-testis activity to -catenin pro-ovary activity through activation of MAP3K1. Our findings define a previously unknown mechanism through which oestrogen can promote a switch in gonad somatic cell fate and provided novel insights into the impacts of exogenous oestrogen exposure on the testis.
Project description:Morphogenesis of the gonad requires cell-cell adhesion changes between diverse cell types. In the Drosophila gonad, the gene traffic jam regulates cell adhesion changes required for gonad formation and germ cell development (Li et al., 2003. Nature Cell Biol). To determine if the mammalian homologs of traffic jam in mammals, c-Maf and Mafb, also play a role in the transcription regulation of cell adhesion molecules in the mouse gonad, we performed a microarray analysis of FACS-purified Mafb-GFP-positive cells in E12.5 male control and c-Maf/Mafb mutant gonads. We used microarrays to determine genes affected by c-Maf mutation in E12.5 mouse gonad/mesonephros interstitial cells and macrophages
Project description:Morphogenesis of the gonad requires cell-cell adhesion changes between diverse cell types. In the Drosophila gonad, the gene traffic jam regulates cell adhesion changes required for gonad formation and germ cell development (Li et al., 2003. Nature Cell Biol). To determine if the mammalian homologs of traffic jam in mammals, c-Maf and Mafb, also play a role in the transcription regulation of cell adhesion molecules in the mouse gonad, we performed a microarray analysis of FACS-purified Mafb-GFP-positive cells in E12.5 male control and c-Maf/Mafb mutant gonads. We used microarrays to determine genes affected by c-Maf mutation in E12.5 mouse gonad/mesonephros interstitial cells and macrophages E12.5 XY control (c-Maf+/-;Mafb-GFP+/-) and c-mutant (c-Maf-/-;Mafb-GFP+/-) gonad/interstitial interstitial cells and macrophages were obtained by FACS sorting of Mafb-GFP-positive cells. RNA was extracted for subsequent hybridization on Affymetrix microarrays.