Comparative analysis demonstrates cell type-specific conservation of SOX9 targets between mouse and chicken

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• SRY (sex-determining region Y)-box 9 (SOX9) is a key transcription factor involved in chondrogenesis and sex determination.
• While SOX9's role in chondrogenesis is conserved across vertebrates, its function in sex determination differs between species.

Purpose of the Study:

• To investigate the conserved regulatory functions of SOX9 in chondrogenesis and gonad development across different vertebrate species.
• To compare SOX9 binding patterns and target genes in mouse and chicken embryos.

Main Methods:

• Chromatin immunoprecipitation sequencing (ChIP-seq) was performed on developing limb buds and male gonads from mouse and chicken embryos.
• RNA sequencing (RNA-seq) was used to analyze gene expression in chondrocytes and Sertoli cells.
• Integration of ChIP-seq and RNA-seq data to identify SOX9 target genes.

Main Results:

• SOX9 binding patterns differed between limb buds and male gonads, with more intronic/distal binding in limb buds and proximal upstream binding in gonads.
• SOX9 binding regions showed higher conservation in limb bud genes compared to male gonad genes.
• SOX9 targets exhibited high similarity in chondrocytes but not in Sertoli cells between mouse and chicken.

Conclusions:

• SOX9's regulatory mechanisms in chondrogenesis are more conserved across vertebrates than those in sex determination.
• Comparative genomic analyses reveal species-specific SOX9 regulatory networks in gonad development.
• SOX9 plays a conserved role in chondrocyte development but exhibits divergent functions in Sertoli cell regulation.