Abundance of GFP, tk, or gC mRNA in d109-infected MRC-5 cells after superinfection. Infections, RNA isolation, cDNA preparation, and RT-PCR were performed as described in Materials and Methods. Quiescent infection by d109 was established for 1 week. The graphs indicate the numbers of RNA molecules of GFP per μg RNA at the indicated time points after superinfection by d105 (A) or at 24 h after the indicated adenovirus infection (B).