PLoS One 3, e2064 (2008)

Credit: M. LANE/NHPA WRITEIMAGESPECS

Hans Rolf of the University of Göttingen in Germany and his colleagues report that they have found evidence of stem cells in the antler 'growth zones' of fallow deer (Dama dama; pictured). They hunted for stem-cell 'markers' such as STRO-1 in several tissues located inside regenerating antlers and in regions called pedicles at the antlers' bases, pinpointing their quarry in several tissues.

The annual regrowth of antlers has long been considered the only case of complete appendage regeneration in mammals, and so this finding may prove useful in regenerative medicine.