Differentiation of satellite cells in vitro from wild-type (+/+) and M-cadherin mutant (−/−) mice. Panel A shows satellite cells that were isolated according to a standard procedure, placed in culture, and shifted to differentiation medium. Immunostaining was performed at the indicated times after medium shift. Note that cultured satellite cells are initially positive for desmin (Desm.) and cMet receptor, indicated by brown staining. Under differentiation conditions, cells from wild-type and homozygous mutant mice rapidly form myotubes without apparent distinction and express myosin heavy chain, identified with the MF 20 monoclonal antibody. Panel B demonstrates a Western blot illustrating similar transient upregulation of protein components of adhesive contacts in M-cadherin-containing and -deficient satellite cells.