CCN-like gene promotes blastema formation in adult newt limb regeneration

A newly identified gene family, CCN-like factors, has been found to play a critical role in the initial stages of adult newt limb regeneration, with the protein nsCCN promoting proper blastema formation. This discovery clarifies the function of a factor previously thought to be unique to newts. The study shows nsCCN is not a canonical CCN member but belongs to a conserved amphibian sister group lost in amniotes. It is predominantly expressed by peripheral blood thrombocytes, which activate locally upon amputation and secrete nsCCN during blood coagulation. Injecting anti-nsCCN antibodies delayed blastema growth, indicating nsCCN facilitates blood influx and circulation into the interstitial space as the wound epidermis covers the amputation surface. This process likely ensures proper blastema formation by aiding thrombus fibrinolysis and regulating the extracellular environment.