Fig. 4.

Notch signaling is activated when PC1 or PC2 expression is lowered. a Primary cells prepared from the neocortices of E13.5 mice were cultured in the presence of 20 ng/ml bFGF, co-transfected on DIV1, and analyzed 2 days later following fixation. The co-transfection was carried out with the indicated shRNA constructs (in the vector pCRLH driving RFP expression) and the CBFRE-EGFP construct which allowed us to report the CBF1 activity. A co-immunostaining for RFP (red) and GFP (CBFRE sensor; green) was performed to quantify the activity from the CBF1-responsive element (CBFRE) of transfected cells. Scale bar, 15 μm. b A strong increase of CBF1 activity reported from the CBFRE was detected in the case of PC1 knockdown (to ~ 167% for Pkd1–kd1 and ~ 222% for Pkd1–kd2) or PC2 knockdown (to ~ 247% for Pkd2–kd1 and ~ 209% for Pkd2–kd2) when compared to the control (kdcontrol). Data are presented in a histogram as mean ± SEM (***p < 0.005; Dunn’s multiple comparison post hoc test following Kruskal–Wallis) and in a scatter plot (one dot represents the green fluorescence intensity of one analyzed cell)