Cell cycle arrest by MadMyc chimera expression in RD cells. A. Cell lysates from polyclonal population of CMV, MadMyc chimera and c-Myc transiently and stably transfected RD cells were analysed by immunoblotting with c-Myc monoclonal antibody recognising both c-Myc and MadMyc chimera proteins. Same filters were re-probed with pospho-ERKs, ERKs and α-tubulin antibodies. B. Growth curve of polyclonal populations of RD cells stably transfected with MadMyc chimera (▼), c-Myc (○), and CMV (●). Polyclonal populations of stably transfected RD cells were plated and counted at indicated times. The data show the mean ± s.e.m. of triplicates of a representative experiment. Similar results were obtained in two experiments.