Fig. 3

EC-specific Piezo1 mediates the blood flow effect on pericyte proliferation (A) Representative images of the pericytes and blood vessels in the midbrain of WT, piezo1f/f, and piezo1ΔEC larvae with Ki(pdgfrb:GAL4-VP16);Tg(4×nrUAS:GFP);Tg(fli1a:DsRedEx) background at 4.5 DPF. The images of pericytes in the midbrain are highlighted in (A′)–(A‴). EC is in red and pericyte in green. (B) Brain vessel segment numbers in WT, piezo1−/−, and piezo1ΔE larvae. The data of Figure S4A are replotted here for piezo1−/− group. (C) Effect of EC-specific piezo1 knockout on brain pericyte number. (D) Effect of EC-specific piezo1 knockout on pericyte coverage of brain vessels. (E) Effect of EC-specific piezo1 knockout on brain pericyte proliferation, compared with the sibling piezo1f/f larvae. (F and G) Effects of Yoda1 and NB treatment on brain pericyte number (F) and pericyte coverage of brain vessels (G) in Ki(pdgfrb:GAL4-VP16);Tg(4×nrUAS:GFP);Tg(fli1a:DsRedEx);piezo1ΔEC larvae. Images are shown from a top view and partially z-projected. Scale bar, 50 μm for (A) and (A′–A‴). Images of 4.5-DPF larvae are used for counting the brain pericyte number and the pericyte coverage of brain vessels, and time-lapse images during 3.0–3.5 DPF are used for counting the mean proliferation frequency of brain pericytes. Data are represented as mean ± SEM. The N values are shown above the aligned plots. Stars represent the results of unpaired two-tailed Student’s t test between groups (∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001). See also Figure S5.