FIG. 1.

Blockade of the VEGF system inhibits VEGFR-positive cell migration. (A to F) Whole embryos were cultured with DMSO (B and E) or SU5416 (C and F), and VEGFR-positive cells in transverse sections at the levels schematized in panels A and D were identified by lacZ staining. Fewer LacZ-positive cells were found in the dorsal aorta (arrowheads) and head region (arrows) in embryos that were cultured with SU5416 (C and F). The open arrow indicates mismigrated cells surrounding the gut (F). (G) Numbers of endothelial cells lining the dorsal aorta in the anterior, middle, and posterior portions of cultured embryos with DMSO or SU5416 (each single dot is the average cell number for five sections per embryo).