Figure 3. Tonic Notch2 activity is required to maintain secretory cells by preventing their differentiation into ciliated cells.

a, Schematic representation of canonical Notch signaling inhibition in secretory cells. b, f, Immunostaining for YFP (green) and SCGB1A1 (left) or FOXJ1 (right) (red) in control (top) and experimental (bottom) mice (n=6 mice (b); n=7 mice (f)). White arrowheads, lineage labeled ciliated cells. c, g, Percentage of SCGB1A1⁺, SCGB3A2⁺, SSEA-1⁺, FOXJ1⁺, ACTUB⁺ and C-MYB⁺ cells per total YFP⁺ cells. n=3 mice (c); n=7 mice (g). d, h, Relative mRNA expression of Scgb1a1, Scgb3a2, FoxJ1 and c-Myb in control and experimental YFP⁺ cells (n=3 mice). e, Immunostaining for RBPJk (cyan), N2ICD (red) and FOXJ1 (green). White arrowheads, RBPJk⁻ N2ICD⁻ FOXJ1⁺ cells. i, Immunostaining for YFP (green), FOXJ1 (cyan) and N2ICD (red). White arrowheads, FOXJ1⁺ cells. Yellow arrows, N2ICD⁺ cells. White arrows, actual cilia in lineage labeled cells. Nuclei, DAPI (blue). n=biological replicates/condition repeated three times (three independent experiments). *** p<0.001; Error bars, means ± SEM. Scale bar, 20μm.