A comprehensive transcriptional profiling of developing gonads reveals the role of TGFβ signaling in female gonadal asymmetry in chickens.

Asymmetrical gonadal development is an intriguing phenomenon observed in the majority of female birds. In chickens, the left gonad of female embryos develops into a functional ovary, while the right gonad undergoes degeneration during embryogenesis. This sexually dimorphic trait is primarily induced by the spatial differential expression of the paired like homeodomain 2 (PITX2) gene.