Figure 1. Endothelial YAP/TAZ is a crucial regulator of vascular sprouting and growth.

(A) Diagram for EC-specific depletion of YAP/TAZ in retinal vessels from P2 and their analyses at P5 using Yap/Taz^iΔEC mice. (B and C) Images of CD31⁺ retinal vessels and comparisons of indicated parameters in WT and Yap/Taz^iΔEC mice (n = 5, each group). Scale bars: 500 μm. (D and E) Magnified images and comparisons of retinal vessels in the vascular front region of WT and Yap/Taz^iΔEC mice at P5 (n = 5, each group). Tip ECs in Yap/Taz^iΔEC mice exhibit an aneurysm-like structure with less and dysmorphic filopodia (yellow arrowheads). Scale bars: 100 μm, top panels; 50 μm, bottom panels. (F) Images showing phalloidin⁺ actin filament (F-actin) bundle and ICAM2⁺/collagen IV⁺ (COL4⁺) lumen formation in tip ECs of WT and Yap/Taz^iΔEC mice. No organized F-actin bundle–containing protrusions and defective lumen formation (white arrowhead) are detected in tip ECs of Yap/Taz^iΔEC mice. Scale bars: 50 μm. (G and H) Images and comparisons of ERG⁺ ECs, pHH3⁺ proliferating ECs (white arrowheads), and cl-CASP3⁺ apoptotic ECs in WT and Yap/Taz^iΔEC mice (n = 5, each group). Scale bars: 100 μm. Error bars represent mean ± SD. *P < 0.05 vs. WT by Mann-Whitney U test.