Figure 3

Immunocytochemical analysis of proliferating human mononucleated myoblasts. (A) The strong homogeneous staining for desmin revealed the myogenic potential of virtually all mononucleated cells. (B) Only a small number of the myonuclei of proliferating cells expressed myogenin (arrows). (C) A subset of myoblasts showed immunoreactivity with antibody against titin. (D-E-F-G-H) Demonstrate positive staining of a few cells with antibodies against MyHC-embryonic, MyHC-neonatal, MyHC-slow/beta cardiac, MyHC-fast and MyHC-fast IIa+slow, respectively. Insets demonstrate considerable numbers of mononucleated myoblasts expressing various MyHC isoforms, as indicated. Homogeneous staining of proliferating mononucleated cells with antibodies against slow (I) and fast (J) MyBPC respectively. Uniform and strong staining of proliferating myoblasts with antibody against alpha-cardiac actin (K). The cells were weakly stained with antibody against alpha-skeletal actin (L). The bar represents 10 μm and 100 μm for the insets.