Satellite cells quantitated in the rat soleus and extensor digitorum longus (EDL) muscles following a complete regeneration returned to "normal" percentages of myofiber nuclei in both muscles 3 months after injury. Following cross-transplantation, the percentage of satellite cell nuclei in the EDL regenerated in the soleus bed was indistinguishable from the percentage in the soleus. Likewise, the soleus muscle regenerated in the EDL bed had a satellite cell percentage characteristic of the EDL. These results suggest that 1) the proportion of satellite cells is reestablished in a regenerated muscle and 2) the innervating nerve determines the proportion of satellite cell nuclei in a muscle.