Fig. 6

Reticulum of desmin in muscle fibers of human origin. Unfixed cross sections of the xenografts of groups 2 and 3 were labeled with antibodies to desmin (a, b). The reticular pattern of staining for desmin (red) in the myoplasm of human myofibers (white arrowheads), identified by the presence of human β-spectrin (green) at the sarcolemma, indicates that the larger myofibers in both groups 2 (a) and 3 (b) are fully differentiated. c A fiber from group 3 with desmin in striations, indicating that the reticulum of desmin is fully organized around myofibrils. Scale bars = 5 μm