Fig. 2. NFAT5 expression and localization during myogenesis in vitro. (A) Lysates were prepared from primary myoblasts (Mb), nascent myotubes (nMt) and mature myotubes (mMt) as well as from murine kidney (+). Representative immunoblot analyses demonstrated NFAT5 protein was increased in myotubes compared with myoblasts. (B) NFAT5 localization during myogenesis was detected by immunostaining with an antibody against NFAT5. Nuclei were counterstained with the fluorescent dye DAPI. NFAT5 appeared predominantly nuclear in myoblasts, nascent myotubes (nMt) and mature myotubes (mMt). A subset of nuclei in mMT contained less NFAT5 (arrows) than others. No immunostaining was observed with an IgG control (data not shown).