Ultrastructure of Developing Human Muscle

Abstract

The ultrastructure of developing human muscle and the structures intimately related to it were studied, the material being obtained from fetuses ranging from 9 weeks to 9 months of development. Muscle of a male fetus from a known carrier of muscular dystrophy was also investigated. The features of myoblasts, myotubes and muscle fibres and their interrelationships are described. While most of the myotubes in the fetus obtained from the known muscular dystrophy carrier are like those of the other fetuses, its muscle also contains myotubes which show obvious structural changes and such changes do not occur in the myotubes of any of the other fetuses.