Fig. 10. Round cells express Pax7 at high levels. Myofibers from EDL muscle were cultured in pmGM for 6 days. (A,B) Round cells expressed Pax7 at high levels. (C,D) Undifferentiated thick cells expressed Pax7 at a reduced level. (E,F) Differentiating thick cells (asterisks) expressed myogenin (green in F) but not Pax7 (red in F). A round cell (arrow) expressed Pax7 but not myogenin. (A,C,E) Phase contrast microscopy images of the same fields as those shown in B, D and F. Scale bars: 20 µm.