Fig. 7. Expression of genes similar to undetermined progenitor cells in CNIC-transfected epithelium. Stage 28 PV were transfected with TP-1Venus reporter (control) or CNIC and cultured for 36 hours. Serial sections were made from the same sample used in Fig. 6. Activation of Notch signaling is monitored by co-transfection of Venus reporter construct in neighboring or next neighboring sections of each panel (insets in B,K; not shown). Sections made from stage 28 of PV and explants, which are hybridized with the same probe, were placed on the same slide glass to compare intensity of signals. Sections of stage 28 PV are also serial with those in Figs 1 and 6. No apparent change was seen in the intensity of gene expression in comparison with stage 28 PV. More than 12 explants were investigated in three experiments. More than 15 sections made from each explant were investigated for each probe. No obvious difference between explants was observed. Scale bar: 100 µm.