This process is rarely found in mammalian cells and this has been suggested as the basis for their poor regenerative abilities. But clearly, unraveling the mechanisms underlying this reprogramming is central to understanding why certain vertebrates can regenerate their limbs while others can’t, and how to repeat this process in humans.

If we were able to crack this puzzle, it could lead to strategies to enhance the reprogramming of cells from patients, and to better understand their disease and design appropriate cures.

We recently found a critical component of the reprogramming mechanism. In our study, published in Stem Cell Reports, we demonstrated that the sustained activation of a molecular pathway (a group of molecules in a cell that work together to control a particular function or functions) – called the ERK pathway – plays a key role during the natural reprogramming of salamander muscle cells. Only when the ERK pathway is constantly switched “on” are the cells able to re-enter the cell cycle, which is key to their regenerative potential.