Figure 4. Prdm1 and fast MyHC expression in cultures of E12 hindlimb cells.

Prdm1 immunostaining (Ab from Cell Signaling Technology) was found in the nuclei of both mononucleate cells (A, B) and myotubes (C, D). An additional Prdm1 antibody (Abcam) produced similar nuclear staining of E12 mononucleate cells and myotubes (not shown). As found in previous studies, myotubes formed from E12 myoblasts showed immunostaining with mAb F59 (E), which reacts with all fast MyHC isoforms, but did not stain with mAb S58 (F), which reacts with the slow MyHC2 and slow MyHC3 isoforms. Bar in Panel A = 10 µm for panels A–D and 30 µm for panels E and F.