Wnt signaling in ovarian development inhibits Sf1 activation of Sox9 via the Tesco enhancer

Janelle Ryan, Pascal Alexandre Bernard, Helena Sim, Daniel Peter Czech, Andrew Sinclair, Peter Anthony Koopman, Vincent Russel Harley

Research output: Contribution to journalArticleResearchpeer-review

44 Citations (Scopus)

Abstract

Genome analysis of patients with disorders of sex development, and gain- and loss-of-function studies in mice indicate that gonadal development is regulated by opposing signals. In females, the Wnt/beta-catenin canonical pathway blocks testicular differentiation by repressing the expression of the Sertoli cell-specific gene Sox9 by an unknown mechanism. Using cell and embryonic gonad culture models, we show that activation of the Wnt/beta-catenin pathway inhibits the expression of Sox9 and Amh, whereas mRNA and protein levels of Sry and steroidogenic factor 1 (Sf1), two key transcriptional regulators of Sox9, are not altered. Ectopic activation of Wnt/beta-catenin signaling in male gonads led to a loss of Sf1 binding to the Tesco enhancer and absent Sox9 expression that we also observed in wild-type ovaries. Moreover, ectopic Wnt/beta-catenin signaling induced the expression of the female somatic cell markers, Bmp2 and Rspo1, as a likely consequence of Sox9 loss. Wnt/beta-catenin signaling in XY gonads did not, however, affect gene expression of the steroidogenic Leydig cell Sf1 target gene, Cyp11a1, or Sf1 binding to the Cyp11a1 promoter. Our data support a model in ovary development whereby activation of beta-catenin prevents Sf1 binding to the Sox9 enhancer, thereby inhibiting Sox9 expression and Sertoli cell differentiation.
Original languageEnglish
Pages (from-to)901 - 912
Number of pages12
JournalEndocrinology
Volume153
Issue number2
DOIs
Publication statusPublished - 2012

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