Figure 4.

Increased sensitivity to a suboptimal mitogenic stimulus in thymocytes from young double transgenic mice. [³H]thymidine incorporation in thymocytes from control nontransgenic mice (Ctr) and mice expressing Skp2 and N-Ras transgenic proteins. Thymocytes were treated with Con A (A) or with Con A and IL-2 (B) for 72 h. [³H]thymidine was added to the medium during the last 24 h. The results are shown as the mean of [³H]thymidine incorporation obtained in several independent experiments with seven nontransgenic mice, three CD4-SKP2 mice, five TMTV-Nras mice, and eight double transgenic mice.