Ccn2a acts downstream of <i>cx43</i> to influence joint formation during zebrafish fin regeneration

This study provides new insights into the molecular pathways dictating skeletal patterning during zebrafish fin regeneration. Connexin43 (Cx43) is known to influence skeletal patterning by inhibiting evx1 expression and thereby regulating the timing of joint formation. Here, we demonstrate that cellular communication network factor 2 (ccn2a) also contributes to this pathway. We find that Ccn2a appears to act downstream of Cx43 and similarly inhibits joint formation by inhibiting evx1 expression. Pharmacological inhibition of β-catenin demonstrates that ccn2a is likely regulated by β-catenin. Additionally, this paper provides evidence that Yap signaling contributes to joint formation through regulating ccn2a. These findings provide novel insights into the role of Ccn2a during skeletal patterning.