Fig. 7. Inhibitors of VEGF signaling block neural tube-derived vascular plexus formation. 8.5 dpc Flt1^+/–, eGFP^+/– mouse presomitic mesoderm grafts were placed beside stage HH 10-13 quail neural tubes in collagen gels and cultured for 72 hours. Panels on the right (B,D,F) show eGFP expression that identifies mouse tissue. Co-cultures were grown in basal medium alone (A,B) or with added 1 µg/ml Flt/Fc (C,D) or 10 µM SU5416 (E,F). n4 for all three conditions. Scale bar: 200 µm for all panels.