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Fig. 3 Jagged 1a and Jagged 1b regulate cell fates during notochord development. (A) Defects in Mib-Jag1-Notch but not DeltaA/D-Notch signalling led to increased vacuoles in the notochord. Enlarged views of the yellow-boxed areas are shown in each right panel. (B) Notch activation reduced the vacuolated cells in the notochord. Control siblings (control) or double transgenic Tg(UAS:myc-Notch1a-intra);Tg(hsp70:Gal4) embryos (NICD) were heat shocked at 3 ss. A and B are side views of the BODIPY TR methyl ester-stained notochord cells in embryos at around 34 hpf. (C,D) Vacuolated cells were increased at the expense of non-vacuolated cells in jag1a/1b knockdown embryos. Nuclei were visualized by nuclear-localized mCherry (red, upper panels in C,D) or by Ntl antibody (red, lower panels in C,D). Vacuolated cells were revealed by using a transgenic fish line (214A-GFP), in which the vacuolated cells are labelled with GFP (green). Red arrowheads indicate non-vacuolated cell nuclei. Green arrows indicate vacuolated cell nuclei. (E) Quantification of the mean number of vacuoles and nuclei. The vacuoles and nuclei were counted within the trunk region of the notochord (230 μm in width, as in the upper images of C,D). Control MO (C, n=20), jag1a/1b MOs (J, n=22). (F) Vacuolated cells and non-vacuolated epithelial cells are derived from notochord precursor cells. The GFP-positive cells at 15 ss were followed until 32 hpf in an embryo injected with Flh-GFP plasmid. (G) Quantification of the proportion of non-vacuolated cells. GFP-positive vacuolated and GFP-negative non-vacuolated cells were counted in embryos co-injected with Flh-GFP plasmid and the control MO (C, n=6) or jag1a/1b MOs (J, n=8). Asterisks in F and G indicate statistically significant differences relative to the control (P<0.005). Error bars indicate s.e.m. Scale bars: 20 μm in A-D,F.