Fig. 1. Forced Smad7 expression inhibited ES cell propagation. (A) Luciferase reporter assay in MGZ5 cells transfected with reporter constructs (ARE-luc reporter or Id-1-luc reporter) and each expression plasmid. Each bar represents the mean ± s.e.m. (n=3). (B) Colony morphologies of supertransfectants. MGZ5 cells were transfected with Smad7-expressing plasmid (middle), Smad6 plasmid (right), or empty vector (left), seeded at 2000 cells/well in six-well plates, and cultured for 1 week in medium supplemented with puromycin. Numbers indicate numbers of colonies appearing (n=3). The lower panel shows AP staining. Bars, 5 mm (upper panels); 200 µm (lower panels). (C) Relative numbers of each transfectant present on Day 7 of culture compared with that at Day 0. Each bar represents the mean ± s.e.m. (n=3). (D) Relative proliferation intensity is shown as total cell number/number of colonies appearing, compared with that of empty vector transfectants (100%). Each bar represents the mean ± s.e.m. (n=3).