Regeneration is a complex biological process by which parts of the body plan are restored after injury or amputation.
This process requires the concerted action of mechanisms inducing and regulating dedifferentiation, pattern generation and, in certain instances, transdifferentiation events. Although embryos from most vertebrates show a remarkable capacity to regenerate damaged structures, this ability plummets as development proceeds, such that adults generally display very limited regenerative capacity. Notable exceptions to this rule are urodele amphibians such as the newt and axolotl, and teleost fishes such as the zebrafish, which can regenerate tissues and even entire organs during their lifetime.
The process of limb regeneration in urodeles, as well as that of fin regeneration in zebrafish, has been specially well studied, and can be divided into three main phases:
In addition to limbs/fins, some urodele species and zebrafish also regenerate large portions of the heart after amputation. Contrary to mammals such as humans, in which heart injury results in the formation of a non-functional scar, urodeles and zebrafish respond to heart injury by regenerating fully-functional and correctly-patterned heart tissues, including myocardium, epicardium, and endocardium. Our laboratory is interested in understanding the molecular bases that underlie this regenerative process. We also hope that a better knowledge of heart and limb/fin regeneration in fish and amphibians could provide the bases for improving organ regeneration in humans.