For the first time, scientists have pinpointed the mechanism used by the amphibian to regrow missing body parts, a development they say will offer clues to muscle regeneration in mammals.

A team of scientists from the University of Tsukuba, Japan, and the University of Dayton, Ohio, set out to investigate the role of two types of cells believed to play a key role in a newt's muscle regeneration: skeletal muscle fiber cells (SMFCs) and muscle stem/progenitor cells (MPCs). MPCs are dormant cells that live in the muscle fiber and can be recruited to multiply into specialized muscle cells. 

The researchers added a gene to Japanese fire bellied newt embryos that was linked to a red fluorescent protein and known to be active in SMFCs, allowing them to track its activity throughout the muscle regeneration process. MPC activity was assessed through tissue sample collection and cell-specific staining.