Abstract

Appendage regeneration is not a simple task. The animal must harness all of its energy and resources to orchestrate perhaps one of the most complicated events since its development. Balancing the immune response, wound healing, proliferation, patterning and differentiation is an elegant job, and how some animals achieve that still leaves researchers enchanted today. In this work, we review some of the molecular aspects of regeneration, with a focus on the axolotl, the champion of tetrapod limb regeneration, and the mouse, an excellent mammalian model for digit tip regeneration. Advances in molecular and genomic tools have enabled the discovery of exciting fundamental features of limb regeneration. Integrating the data from different animal systems will be crucial to understanding the common requirements of successful appendage regeneration and places for flexibility. The combination of these efforts is paving the way to grasping how good regenerators respond to the loss of body parts, how these mechanisms might compare in modest regenerators, and, ultimately, in developing approaches for improving regenerative outcomes in humans.