Figure 9. Dll4 is involved in suppressing Ca2+ responses in ECs adjacent to tip cells.
(A) The number of Ca2+-oscillating ECs at each somite boundary of the embryo injected with control MO or dll4 MO was quantified as in Figure 4A. (B) 3D-rendered time-sequential images of Tg(fli1:Gal4FF);(UAS:GCaMP7a);(fli1:H2B-mC) embryos during tip cell budding injected with dll4 MO (24 ss). Green and blue arrowheads indicate two neighboring Ca2+-oscillating ECs, both of which are budding from the DA. (C) The fluorescence changes in GCaMP7a (ΔF/F0) of individual ECs from B indicated by arrowheads at the left panel are shown as a graph. (D) Ca2+ oscillation frequency (left) and mean ΔF/F0 (right) in budding ECs and other ECs within the DA in dll4 morphants during tip cell budding at 24–27 ss as illustrated at the left panel (n ≥ 13). Scale bar, 10 mm in B. ***p < 0.001. DA, dorsal aorta.
Figure 9—figure supplement 1. Ca2+ oscillations were maintained in two neighboring ECs in notch1b morphants during tip cell budding from the DA.
Figure 9—figure supplement 2. Vegfr is responsible for ectopic Ca2+ oscillations observed in dll4 morphants.
Figure 9—figure supplement 3. Vegfr3 is partially involved in increases in oscillating cells in dll4 morphants.
Figure 9—figure supplement 4. The expression of neither vegfr2 nor kdr is not altered in the trunk vessels of dll4 morphants.
