Localization of VEGFR-2 and VEGFR-3.

(A) E9.5 embryos were stained with anti-CD31 antibody to visualize all endothelial cells. (B) Embryos stained with anti–VEGFR-2 antibody. The pattern of VEGFR-2 expression was similar to that seen in panel A. (C) LacZ staining in VEGFR-3^+/LacZ embryos at E9.5. VEGFR-3 expression was detected mainly in large vessels. (D) Flow cytometric analysis of VEGFR-2 and VEGFR-3 in PECAM-1/CD31⁺cells. After FACS-gal staining, these cells were stained with VEGFR-2 and CD31 antibodies (see “Materials and methods”). The numbers indicate the percentage of cells that appeared in each quadrant. The result shown is representative of 3 independent experiments.