In vivo, N-cadherin/VE-cadherin imbalance promotes vascular elongation, angiogenesis and pericyte coverage. (A) Whole-mount preparation of VE-cadherin +/+ and ± rostral trachea at P5 (PECAM-1, red) analyzed by confocal microscopy. Scale bar: 100 μm. Middle panel: quantification of the endothelial projections expressed per mm² of cartilage ring (*P < .05). Right panel: measurements of vessel elongation expressed as percentage of vessels longer that 150 μm (P < .05). (B) Pericyte coverage of tracheal vasculature of adult VE-cadherin +/+ and ± mice. Confocal micrographs of tracheal whole-mounts stained for PECAM-1 (red) and NG2 (green). Data are expressed as percentage of tracheal capillary length covered by pericytes (**P < .02). (C) FGF-2–induced in vivo angiogenesis in the Matrigel plug assay of adult VE-cadherin +/+ and ± mice and quantification of the vascularised area. FGF-2 (500 ng/mL) were injected and the gel plugs were evaluated 7 days later. FGF-2 caused a significant increase of the vascularization in VE-cadherin ± mice compared with VE-cadherin +/+ controls. Arrows indicate blood vessels. The mean ± SE are graphed (n = 4; *P < .05).