Figure 6

E47 fails to trigger Ascl1 to switch from proliferation to differentiation target genes. (A) Map2 mRNA expression was elevated when Ascl1 was overexpressed in isolated neurospheres in vitro (100 ± 19.1 vs. 299.4 ± 5.8). Concomitant knock-down of E2-2 or E2A using shRNA, respectively, reduced or abolished Ascl1-dependent Map2 expression (299.4 ± 5.8 vs. 222.2 ± 3.7 or 94.9 ± 9.8, respectively). More strikingly, Ascl1 silencing decreased Map2 expression level to control conditions, when E2-2 (100 ± 19.1 vs. 242.4 ± 34.2, 242.4 ± 34.2 vs. 100.3 ± 4.9) or E47 (100 ± 19.1 vs. 214.6 ± 7.1, 214.6 ± 7.1 vs. 125.7 ± 13.6) was overexpressed. (B) Although significant expression changes could be detected, E-protein gain-of-function did not systematically promote activation of Ascl1 target genes mediating cell cycle arrest. Inversely, E-protein silencing did not activate Ascl1 target genes mediating cell cycle progression. P values: *P <0.05; **P <0.01; ***P <0.001. All quantifications were normalized to control conditions.