FIG. 2.

Levels of p21, cyclin D3, and Rb mRNAs in C2 cells expressing wt E1A and E1A mutant derivatives. Northern blotting was used to analyze the RNA isolated from C2 parental cells and C2-derived stable lines expressing either wt E1A or the E1A mutants described in Table 1. Identical filters were probed for myogenin, MyoD, p21, cyclin D3, Rb, and myosin heavy chain. Shown are results for growing cells (GM) and cells kept for 48 h in differentiation medium (DM). One of the filters was reprobed with a GAPDH probe to normalize the amounts of loaded RNA.