Deficiency of Maged1 results in impaired myogenic differentiation. (A) Primary myoblasts derived from wild-type or Maged1 knockout mice were cultivated on collagen-coated plates and induced to differentiate by serum starvation. Cells were stained with anti-MHC antibody. Images were photographed under a light microscope. Scale bar, 100 μm. (B) The fusion index was calculated by dividing the number of nuclei in MHC-positive cells containing at least 2 nuclei by the total number of nuclei in MHC-positive cells. (C) eMHC and MCK RNA levels during differentiation were analyzed using qRT-PCR. Data are presented as the relative folds of induction with respect to wild-type myoblasts at the time of serum starvation (t = 0 h). GAPDH RNA was used for the normalization. (D) Representative sections analyzed by H&E staining of TA muscles of Maged1tm1Urfm/HSA-Cre mice after CTX injection. Arrows indicate newly formed myotubes. Scale bar, 50 μm. (E) Laminin expression (red) analyzed by immunostaining of TA muscles of Maged1tm1Urfm/HSA-Cre mice after CTX injection. Nuclei were visualized by Hoechst 33342. Scale bar, 50 μm.