Specialized adult stem cells are make it possible for mammals to re-grow the tips of injured fingers or toes, rather than a “jack of all trades” cell type formed in response to serious injury, a new study shows. Researchers from Stanford University found the regenerating stem cells are tissue-specific, meaning each has a particular job regenerating bone, skin, tendon, vessels or nerves. The findings call into question a popular theory that damaged extremities are regenerated by a bump of cells considered “pluripotent,” meaning that they are able to grow into a variety of cell types. This versatile bump of repair cells is called a blastema, but it appears to have nothing to do with fingertip regeneration.
