FIGURE 6.

Loss of C/EBPβ rescues differentiation in cells lacking Mdm2. A, Mdm2, C/EBPβ, and myogenic marker protein expression in primary myoblasts from C/EBPβ conditional null mice (β−/−) or control littermates (WT) transduced to express shMdm2 or shScr and induced to differentiate for 3 days. B, immunocytochemistry for MyHC expression in differentiated cultures as in A. C, differentiation index for cells transduced and differentiated as in A. Means indicated with different letters are significantly different from one another, meeting a minimum cut-off of p < 0.05, n = 3. D, average myotube size for cells transduced and differentiated as in A.