Wound Healing Vs. Regeneration

Why do some animals have the ability to regenerate body parts and others do not?  Experiments outlined here suggest it is how the wound signals are “decoded” – including by Wnt signaling – to stimulate either “wound healing” or “regeneration” pathways.  Can this be somehow manipulated to introduce regeneration to those animals (e.g., humans) that do not naturally have it?  Abstract:

Despite the identification of numerous regulators of regeneration in different animal models, a fundamental question remains: why do some wounds trigger the full regeneration of lost body parts, whereas others resolve by mere healing? By selectively inhibiting regeneration initiation, but not the formation of a wound epidermis, here we create headless planarians and finless zebrafish. Strikingly, in both missing-tissue contexts, injuries that normally do not trigger regeneration activate complete restoration of heads and fin rays. Our results demonstrate that generic wound signals have regeneration-inducing power. However, they are interpreted as regeneration triggers only in a permissive tissue context: when body parts are missing, or when tissue-resident polarity signals, such as Wnt activity in planarians, are modified. Hence, the ability to decode generic wound-induced signals as regeneration-initiating cues may be the crucial difference that distinguishes animals that regenerate from those that cannot.