Fig. 1

vbg mutants exhibit abnormal circulation in the absence of vessel patterning abnormalities. (A) Wild-type zebrafish at 5 dpf. (B) vbg^y6 mutant at 5 dpf. Note edema in the head, pericardium, and yolk sac. This edema is associated with an abnormal circulation pattern in which most blood flows through a limited number of dilated cranial vessels, with little to no circulation through the trunk and tail (Movies 1,2; http://dev.biologists.org/supplemental/). (C,D) Schematic diagrams of the vasculature in the 2.25 dpf wild-type zebrafish head. See text for detailed explanation. (E) Dorsal anterior angiogram of a vbg⁺;TG(fli1:EGFP)^y1 wild-type embryo at 2.25 dpf. Note the prominent central arteries (CA) and the relatively small caliber of the basal communicating artery (BCA), posterior connecting segments (PCS), basilar artery (BA), and primordial hindbrain channels (PHBC). (F) Dorsal anterior angiogram of a vbg^y6;TG(fli1:EGFP)^y1 mutant at 2.25 dpf. Note the limited number of patent CAs, the enlarged vessels (BCA, PCS, BA, and PHBC), and the retention of a normally transient connection (*) between the BCA and the left PHBC. (I) fli1 promoter-driven EGFP expression in the same wild-type embryo shown in E. (J) fli1 promoter-driven EGFP expression in the same vbg^y6 mutant shown in F. (G) Tracing of wild-type vasculature from images shown in E,I. (H) Tracing of vbg^y6 mutant vasculature from images shown in (F,J). Patent vessels in G,H are black, blue, or red; solid cords are gray. While there is no difference in CA number or pattern, almost all CAs are patent in wild-type embryos, whereas most are not patent in vbg mutants (see also gray arrows, J). AA1, first arch artery; LDA, lateral dorsal aortae; ICA, internal carotid artery; CaDI, caudal division of ICA; (A,B,D-J) Dorsal view, anterior to the left. (C) Dorsolateral view, anterior to the left.