Figure 2

(A–F) XZ planes and three-dimensional (3D) projection along Y axis of Airyscan images revealed intraluminal endothelial pillars at 2 days post fertilization (dpf) (A–C), whereas Cas9-injected control embryos displayed a normal patent lumen in both a dorsal and ventral caudal vein (D–F). Endothelial cells were labeled by EGFP in Tg(fli1:EGFP) embryos. Arrow, arrowhead, and asterisk indicated the dorsal aorta, dorsal vein, and ventral vein, respectively. (G and H) Ventral view of 3D reconstruction show the irregular surface of the dramatically dilated caudal vein segment in ccm2 CRISPR embryo (G) and normal ventral vein (H). Arrows in G indicate small pits where the endothelial pillars originate. (I–K) Intraluminal view of 3D reconstruction of ccm2 CRISPR embryo reveals the intraluminal pillars honeycombing the lumen and the accumulated red blood cells (I). Erythrocytes were not imaged in J to reveal pillars and the area within the box in (J) was magnified in (K), and arrowhead indicates the intravascular pillar. Endothelial cells and red blood cells were labeled by EGFP or DsRed respectively in Tg(fli1:EGFP)y¹;Tg(gata1:DsRed)^sd2 embryos. Scale bar: 20 µm.