Fig. 1

MABs do not synthesize laminin α2 neither in vitro nor in vivo. a Western blot analysis of mouse wild type (C57Bl6) muscle, differentiated and undifferentiated MABs, and medium from differentiated and undifferentiated MABs. Anti-laminin α2 chain antibody detects a specific band only in wild type muscle homogenate, whereas a polyclonal antibody recognizing laminin chain β1 and γ1 detects specific bands in all the homogenates, including medium from differentiated and undifferentiated MABs. Calnexin is shown as loading control (accordingly, it is absent when only medium is loaded). Each lane is loaded with 40 μg of protein. b Cultures of MABs differentiated in myotubes, as depicted by positive staining with anti myosin heavy chain (MyHC) antibody, show positive staining for laminin chains γ1. DAPI staining identifies nuclei. Scale bar = 30 μm. c Cultures of MABs differentiated in myotubes (MyHC positive) do not show staining with anti-laminin α2 chain antibody. DAPI staining identifies nuclei. Scale bar = 30 μm