Mice regrow the tips of their foretoes.

Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are not the same. The regrowth reported here in mice is probably similar to the scattered clinical reports of fingertips regeneration in children, and presents a model system with which to explore the controls of wound healing and tissue reconstruction in mammals.