Figure 5. Activated Ras prevents normal vascular morphogenesis.

Uninduced and Ras expressing endothelial cells co-cultured with fibroblasts for 14 days and visualized by staining live endothelial cells with a FITC-tagged UEA-1 lectin. Ras expression was turned on in the uninduced cells by adding doxycycline and shut down in the induced cells by withdrawing doxycycline and the cells were again stained after an additional 14 days. The pictures (at 200X) are representative of data obtained from at least three independent experiments.