FIG. 3.

Proliferation of cultured metazoan cells is unaffected by Cdk8 depletion. (A) Efficiency of the Cdk8 knockdown (Cdk8 dsRNA) compared to that of the control (GFP dsRNA) in Schneider S2 cells was assessed by anti-Cdk8 Western blot analysis. (B) The proliferation rate of parallel S2 cultures was determined and is presented as population doublings (PD) over 11 days. (C) Anti-Cdk8 Western blot analysis of shRNA-mediated knockdown in transiently transfected 293FT cells. (D) The effect on proliferation of expressing shRNA-targeting Cdk8 in 293FT cells is determined as the number of drug-resistant colonies at 13 days posttransfection. The values are the average number ± SD of colonies/10 microscopic fields (10× objective, approximately 3.1 cm²) of three independent transfections normalized to pCMV-β-gal activity.