Fig. 7

Ca²⁺ oscillations in tip and stalk cells that completely come out from the DA.

(A) 3D-rendered time-sequential images of Tg(fli1:Gal4FF);(UAS:GCaMP7a);(fli1:H2B-mC) embryos after stalk cells migrate out of the DA (29 ss). Green and orange arrowheads indicate tip and stalk cells, respectively. (B) The fluorescence changes in GCaMP7a (ΔF/F₀) of individual ECs from A indicated by arrowheads (green, orange, light gray, dark gray, and black) at the left panel are shown as a graph. (C) Quantification of Ca²⁺ oscillatory activity in untreated and ki8751-treated embryos after stalk cells migrate out of the DA as in A and Figure 7—figure supplement 1A, respectively. Graphs show Ca²⁺ oscillation frequency (left) and mean ΔF/F₀ (right) in tip cells, stalk cells and other ECs within the DA in untreated and ki8751-treated embryos. (Untreated, n ≥ 8; ki8751-treated, n ≥ 11). (D) Quantification of the number of synchronous and asynchronous Ca²⁺ rise between tip and stalk cells. We here define the case, in which a Ca²⁺ rise in one cell occurs within 10 s late behind a Ca²⁺ rise in the other cell, as synchronous. The number of synchronous and asynchronous Ca²⁺ rise were quantified in tip and stalk cells. Percentages of synchronous and asynchronous Ca²⁺ increase to total Ca²⁺ increase are shown. The total number of Ca²⁺ rise analyzed in tip cells and stalk cells is indicated at the top. (E) Schematic illustration of Ca²⁺-oscillatory activity in stalk cells. Frequency of Ca²⁺ oscillations found in stalk cells are comparable to that in tip cells after stalk cells have completely come out from the DA. Scale bar, 10 mm in A. ***p < 0.001; NS, not significant. DA, dorsal aorta.