CD146 mediates netrin-1-induced angiogenesis in zebrafish. (A) CD146 expression in the zebrafish embryos at different stages was detected by whole mount in situ hybridization. (B) The control, CD146 or netrin-1a specific MO was injected with control or human netrin-1 mRNA into the transgenic zebrafish Tg(kdrl:GFP) embryos that expressed GFP to enable visualization of vasculature. The vascular patterns of the fish embryos at 36, 48 and 60 hpf were analyzed. Yellow arrowheads indicate PAV. Red arrowheads mark ectopic sprouts in netrin-1 mRNA-injected embryos. (C) Tg(Fli1:nGFP) × Tg(kdrl:mcherry) embryos were injected with the indicated MO and mRNA. The number of endothelial cells in the ISVs of the embryos at 36 hpf, 48 hpf and 60 hpf stages was quantified and analyzed. Data are presented as average number of endothelial cells per ISV (means ± SEM). *P < 0.05; **P < 0.01; ***P < 0.001 (one-way ANOVA with Turkey post hoc tests).