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Cbx2, a polycomb group gene, is required for Sry gene expression in mice
Yuko Katoh-Fukui1, Kanako Miyabayashi, Tomoko Komatsu
1Department of Aging Intervention, National Institute for Longevity Sciences, Obu 474-8511, Japan. yfukui@ncgg.go.jp
Endocrinology
|December 22, 2011
Summary
Polycomb protein CBX2 (chromobox homolog 2) is crucial for male sex determination in mice. Its absence causes XY mice to develop ovaries instead of testes by affecting SRY gene expression.
Area of Science:
- Developmental biology
- Genetics
- Molecular biology
Background:
- Polycomb group proteins regulate gene expression and are essential for development.
- CBX2 (chromobox homolog 2) deficiency leads to developmental defects in multiple organs.
- The precise role of CBX2 in gonadal development is not well understood.
Purpose of the Study:
- To investigate the role of CBX2 in mammalian gonadal development.
- To identify the molecular mechanisms by which CBX2 influences sex determination.
- To explore the genetic network regulated by CBX2 in the developing gonad.
Main Methods:
- Gene expression analysis using microarray and RT-PCR.
- Immunohistochemical analysis of gonadal tissues.
- Genetic manipulation including knockout mice and transgenic rescue experiments.
Main Results:
- CBX2 knockout mice exhibit male-to-female sex reversal and gonadal hypoplasia.
- Expression of key gonadal development genes (Sry, Sox9, Lhx9, etc.) is altered in Cbx2 deficient gonads.
- Forced expression of Sry or Sox9 rescued sex reversal but not hypoplasia, suggesting distinct genetic control.
Conclusions:
- CBX2 is essential for testis determination, primarily by regulating Sry gene expression.
- Gonad size and sex determination are controlled by partially independent genetic pathways.
- CBX2 plays a critical role in the molecular circuitry of mammalian sex determination.
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