Blastema formation

Blastema formation is initiated by a signaling cascade, which results in the dedifferentiation of the cells near the wound.

During the first step of the blastema formation in an amputated axolotl limb, the epidermis expands over the wound. The epidermis cells in contact with the mesenchymal cells below trigger the release of enzymes that break down the extracellular matrix.

The molecular mechanisms that lead to the dedifferentiation of the blastemal cells are still under investigation. This process may hold the secret to why axolotls can regenerate whole limbs and us humans cannot.