Figure 7: Rac1 is required for the formation of a single apical lumen.

(a) Schematic representation showing timing of 12 h treatment with Rac1 inhibitor. (b–e) MDCK cells were embedded in 3D Matrigel and allowed to grow for 4 days in the absence (c) or presence (d,e) of Rac1 inhibitor. The timing of inhibitor addition is shown in (a). Cells were then fixed and stained with phalloidin-Alexa594 (red) and anti-CGN (green) antibodies. Consecutive images without an individual letter label show the same cell. (b) shows quantification of cells with single or multiple lumens. Data shown are the means and s.d. derived from three independent experiments.