Muscle morphogenesis in axolotl limb regenerates after removal of stump musculature.

This research was designed to determine whether or not a normal stump musculature is required for normal morphogenesis of muscle within the regenerating amphibian limb. Limbs of adult axolotls were amputated proximal to the elbow, and approximately 99% of the skeletal muscle was removed from the limb stump. The early stages of regeneration and blastema formation followed a relatively normal morphological and temporal course. In all cases grossly normal limbs regenerated. These regenerated limbs all contained large amounts of muscle, which was usually arranged into anatomically recognizable muscles in both the forearm and hand. It is concluded that muscle morphogenesis in the regenerating amphibian limb is not dependent upon an anatomically normal stump musculature.