Figure 2

Long-term culture of Rb-transduced cells selects for low Rb expression. A. Rb expression in Y79 cells 3 days after transduction with MSCV-GFP and Rb derivatives (lanes 1–3), or in puromycin resistant Y79 cells 26 days after transduction with MSCV-Puro and Rb derivatives (lanes 4–6). Lysates from infected cultures were combined with mock-infected cell lysates to normalize the proportion of GFP+ cells. B. Rb expression after transduction with the indicated MSCV-Puro viruses and puromycin selection, at 19 days (lanes 1, 3, and 5) and 26 days (lanes 2, 4, and 6) after infection. For A and B, actin expression is displayed as a loading control. C. RT-PCR analysis of RB1 and GAPDH mRNA in puromycin resistant cells after infection with the indicated viruses, with PCR for 22, 26, and 30 cycles. D. Prevalence of GFP+ cells at 12 days relative to that at 44 h after infection of Y79 cells, or after infection of puromycin-selected Y79 derivatives that were earlier infected with MSCV-Puro or MSCV-Puro-Rb.