Regulation of specific developmental fates of larval- and adult-type muscles during metamorphosis of the frog Xenopus.

During anuran metamorphosis, larval-type myotubes in both trunk and tail are removed by apoptosis, and only trunk muscles are replaced by newly formed adult-type myotubes. In the present study, we clarified the regulatory mechanisms for specific developmental fates of adult and larval muscles. Two distinct (adult and larval) types of myoblasts were found to exist in the trunk, but no or very few adult myoblasts were found in the tail.