Fig. 1.

Morphological effects of GTP, GTPγS, and RB2 in differentiating C2C12 cells. C2C12 cells were induced to differentiate using DM and SM in the absence and presence of 500 μM GTP, 500 μM GTPγS, and with preincubation with 100 μM RB2 before 500 μM GTP (all as indicated). The images show: (a) timing of myogenesis in DM is more rapid than in SM at all time points; (b) cells stimulated with 500 μM GTP show more numerous, longer, and thicker myotubes than control cells; (c) myotubes obtained in medium plus 500 μM GTP and 500 μM GTPγS show very similar morphologies; and (d) pre-incubation with RB2 leads to thinner and fewer myotubes and a higher myoblast percentage. Magnification, ×400