Fig. 4. Nuclear deformation in myotubes with forced expression of vimentin. (A) Northern blots detecting vimentin expression in C2C12 cells and the vimentintransfected clones C2Vm1-10 (top). Ethidium bromide staining pattern of cytoplasmic RNAs in agarose gel electrophoresis showing the 28S and 18S rRNAs (bottom). (B) Nuclear shapes of C2Vm8 myoblasts (a-c) and myotubes (d-f). Phase-contrast images (a,d) and corresponding immunofluorescent staining of vimentin (b,e) and H33258 staining (c,f). Although C2Vm8 myotubes contain adequate vimentin filament networks, their nuclei have grooves and invaginations. Bar, 20 µm.