Fig. 4

Macrophage ablation leads to the absence of DLAV plexus formation as well as hypoxia-induced vascular disconnections.

(a) Schematic representation of the experiment shown in b?d. (b,c) Maximal intensity projections of time-lapse confocal images of control Tg(kdrl:EGFP);Tg(mpeg:NTR-mCherry) and macrophage-ablated embryos in normoxia starting at 30 hpf. Arrowheads point to a macrophage co-localizing with EC sprouts. (d) Quantification of embryos showing normal (grey) or abnormal/absent (red) DLAV plexus formation in 54 hpf control and macrophage-ablated embryos. (e) Schematic representation of the experiment shown in f?m. (f?k) Maximal intensity projections of confocal z-stacks of 54 hpf control Tg(kdrl:EGFP);Tg(mpeg:NTR-mCherry) and macrophage-ablated embryos in normoxia, after hypoxia chamber or DMOG treatment for 6?h starting at 48 hpf. All images represent lateral views. Arrowheads point to macrophages in proximity to blood vessels, and arrows to vessel ruptures. (l) Quantification of blood vessel ruptures in a 10 somite-long trunk area in 54 hpf control and macrophage-ablated embryos in normoxia, after hypoxia chamber or DMOG treatment for 6?h starting at 48 hpf. (m) Quantification of macrophages in proximity to blood vessels in a 10 somite-long trunk area in 54 hpf control and macrophage-ablated embryos in normoxia, after hypoxia chamber or DMOG treatment for 6?h starting at 48 hpf. n=10 embryos for each condition. (n) Quantification of embryos showing normal (grey) or abnormal/absent (red) DLAV plexus formation in 54 hpf control and macrophage-ablated hif-1?^?/?embryos. (o) Quantification of blood vessel ruptures in a 10 somite-long trunk area in 54 hpf control and macrophage-ablated hif-1?^?/?embryos in normoxia, after hypoxia chamber or DMOG treatment for 6?h starting at 48 hpf. Bars represent mean±s.e.m., n=10 embryos from three different clutches, (***P<0.001; ****P<0.0001; NS, no significant changes observed; t-test). Scale bars, 50??m.