Synergic coordination of stem cells is required to induce a regenerative response in anthozoan cnidarians

Little is known about the origin of the inductive signal that translates the amputation stress into a cooperative cellular response. By studying the process underlying the reformation of lost body parts in the anthozoan cnidarian Nematostella vectensis , we identified a regeneration-inducing structure that, via a tissue crosstalk, is responsible for the initiation of the repair program. We further revealed for the first time in anthozoan cnidarians, that fast and slow-cycling/quiescent stem cells respond to the amputation stress and actively participate in the reformation of lost body parts. Importantly, a synergic interaction of both stem cell populations is required to complete the regeneration process. Our findings suggest that the emergence/loss of structure complexity/compartmentalization influences the proprieties of tissue plasticity, changes the competence of a tissue to reprogram and, in the context of regeneration, the capacity of the tissue to emit or respond to a regeneration-inducing signal.