Figure 3.

Oncogenic Ras fails to induce senescence in wild-type SF-MEFs. Wild-type MEFs and wild-type SF-MEFs at PD 3 were transduced with H-RasV12 or empty viral vector. Day 0 represents the point when infected cell populations were split for the first time onto three plates (∼48 h after initial exposure to the retroviruses). (A) Growth curves for the wild-type MEFs and wild-type SF-MEFs transduced with H-RasV12 or empty vector. Each time point represents the average from the triplicate plates, and each curve was performed three times. Error bars represent the standard error of the mean from the three independent experiments. (B) Representative photographs of the indicated cells stained for SA-β-gal (pH 5.5) activity at day 4. Photographs are at the same magnification.