Figure 2.

Regulation by Sox9-partner complexes. A) Sox9 requires a binding partner to elicit either transcriptional activation or repression.22, 23 B) Sox9 can function to activate or repress transcription, depending on the partner factor and on the tissue in which it is expressed. During earlier chondrogenesis, Sox9-Gli2/3 complex represses Col10a1 while the “sox trio,” Sox9-Sox5/6 complex, activates Col2a1.24, 25 C) Sox-partner complexes form a feedforward, self-reinforcing pathway. During male gonad genesis, Sf1 and SRY cooperatively upregulate Sox9 and then, together with Sf1, Sox9 maintains its own expression.²⁶.