The Wilms tumor gene, Wt1, is required for Sox9 expression and maintenance of tubular architecture in the developing testis.

Abstract

Mutation of the transcription factor and tumor suppressor gene WT1 results in a range of genitourinary anomalies in humans, including 46,XY gonadal dysgenesis, indicating that WT1 plays a critical role in sex determination. However, because knockout of Wt1 in mice results in apoptosis of the genital ridge, it is unknown whether WT1 is required for testis development after the initial steps of sex determination. To address this question, we generated a mouse strain carrying a Wt1 conditional knockout allele and ablated Wt1 function specifically in Sertoli cells by embryonic day 14.5, several days after testis determination. Wt1 knockout resulted in disruption of developing seminiferous tubules and subsequent progressive loss of Sertoli cells and germ cells such that postnatal mutant testes were almost completely devoid of these cell types and were severely hypoplastic. Thus, Wt1 is essential for the maintenance of Sertoli cells and seminiferous tubules in the developing testes. Of particular note, expression of the testis-determining gene Sox9 in mutant Sertoli cells was turned off at embryonic day 14.5 after Wt1 ablation, suggesting that WT1 regulates Sox9, either directly or indirectly, after Sry expression ceases. Our data, along with previous work demonstrating the role of Wt1 at early stages of gonadal development, thus indicate that Wt1 is essential at multiple steps in testicular development.

• Authors: Fei Gao, Sourindra Maiti, Nargis Alam, Zhen Zhang, Jian Min Deng, Richard R Behringer, Charlotte Lécureuil, Florian Guillou, Vicki Huff
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 103 Issue 32 Pg. 11987-92 (Aug 08 2006) ISSN: 0027-8424 [Print] United States
• PMID: 16877546 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• High Mobility Group Proteins
• SOX9 Transcription Factor
• SOX9 protein, human
• Sox9 protein, mouse
• Transcription Factors
• WT1 Proteins

Topics

• Alleles
• Animals
• Gene Expression Regulation, Developmental
• High Mobility Group Proteins (genetics, metabolism, physiology)
• Male
• Mice
• Mice, Knockout
• Mutation
• SOX9 Transcription Factor
• Sertoli Cells (metabolism)
• Testis (embryology)
• Transcription Factors (genetics, metabolism, physiology)
• WT1 Proteins (genetics, physiology)
• Wilms Tumor (genetics)