Lymphatic-specific expression of VEGFR-3 in embryonic day 17 (E17) embryos and adult dermis.

(A) Whole-mount staining of the mesentery of E17 embryos by AFL4. A fraction of vascular system is stained. (B) Higher magnification of the marked area in panel A demonstrates that lymphatic vessels with typical sac-like structure are stained (arrows). (C) PECAM-1 staining of the same region shows that blood vessels (arrow) and lymphatic vessels (arrowhead) are stained. (D) A section of the E17 mesentery illustrating stained endothelial vessel (arrow) and an unstained blood vessel (arrowhead) (×200). Note that all stained vessels do not contain hematopoietic cells. (E) A section of an adult skin illustrates VEGFR-3⁺ (arrows) and VEGFR-3⁻ vessels (×100). Higher magnification (inset, ×200) reveals that VEGFR-3⁺ vessels (arrows) do not contain hematopoietic cells, whereas unstained blood vessels do (arrowheads).