Figure 5

Inhibition of AKT signaling reduces β-catenin transcriptional activity in vivo . β-catenin mediated transcriptional activation was examined through expression of destabilized GFP controlled by the TOP promoter. E13.5 embryos were electroporated with pTOP-dGFP, pCAG-mCherry, and pcDNA in the control treatment, and with pTOP-dGFP, pCAG-mCherry, and dominant negative AKT (DN-AKT) in the experimental condition and analyzed 30 hours after electroporation. The dot image below shows the positions of the electroporated cells (green dots represent electroporated cells co-expressing dGFP and mCherry, and red dots represent dGFP- cells (expressing mCherry only)). Only electroporated cells in the ventricular zone (VZ) were included in the analysis, and the proportion of cells expressing dGFP was compared to the total number of electroporated cells (red, labeled by mCherry) in the VZ. Compared to pcDNA control, DN-AKT expression reduced the fraction of TOPdGFP-expressing cells from 73 to 53% (n = 3 brains each), **P = 0.0043 by unpaired t-test. Error bars represent 1 SEM. Scale bar = 100 µm. EP’d, electroporated.