FIG. 3.

Ras-expressing cells exhibit TSH-independent DNA synthesis. Ras-expressing cells were incubated in TSH-deficient medium for 48 h and then labeled with BrdU for 48 h. The results shown are for Ras^V12 (clone 3), Ras^S35 (pool 10b), Ras^G37 (pool 1), and vector-transfected cells (C). More than 200 cells were scored on each coverslip. Error bars indicate 95% confidence intervals based on the standard error of proportion. The absence of an error bar indicates a standard error of proportion of 1 or less. Three experiments performed in duplicate gave similar results. Three independent Ras^S35 isolates and two independent Ras^G37 isolates were analyzed with similar results.