Fig. 10. Removal of the ligation tool restores arterial marker expression. (A) Vessel integrity 4 hours after ligation demonstrated by Fitcdextran injection. Note retrograde perfusion of the ligated vitelline artery. Boxed region is shown in Movie 6 at http://dev.biologists.org/supplemental. (B,C,F) The ligation tool was removed after the indicated time points, and embryos were fixed 6 hours later. Whole-mount in situ hybridization with NRP1 antisense riboprobe shows re-expression after 30 minutes (A) and 4 hours (B), but not after 6 hours (F). (D,E) Photomicrographs of a live embryo treated as the embryo in B. Note decreased size of the vascular plexus on the ligated side. (E) Higher magnification of the boxed region in D. Arterial blood flow is shown in red, venous blood flow in blue. Arrows indicate ligation site. Scale bars: 760 µm in A; 725 µm in B,C,F; 1400 µm in D; 780 µm in E.