Fig. 5

The vascular architecture of Tak1{Delta}/{Delta} embryos is abnormal. In all panels, the developing vasculature of embryos was visualized by whole mount immunohistochemistry using an α-PECAM antibody. (A) Tak1+/{Delta} at E9.5. (B,C) Tak1{Delta}/{Delta} at E9.5. Two different vascular abnormalities are seen in Tak1{Delta}/{Delta} embryos. The embryo in B has an extremely dilated anterior dorsal aorta (arrowheads) in comparison with the Tak1+/{Delta} dorsal aorta in A (arrowheads). The embryo in C has a collapsed anterior dorsal aorta (arrowheads) and a dilated posterior dorsal aorta (arrow) in comparison with the posterior dorsal aorta in A (arrow). (D-F) Cranial sections of the heads shown in A-C, respectively. Arrowheads and broken lines indicate examples of cranial vessels that are extremely dilated in Tak1{Delta}/{Delta} embryos (E,F) in comparison with heterozygous embryos (D). (G-I) Cranial sections through the dorsal aorta of the embryos in A-C, respectively. Arrowheads indicate the dilated dorsal aorta in H and collapsed dorsal aorta in I in comparison with the heterozygote (arrowhead in G). (J) E10.5 Tak1+/{Delta} embryo exhibiting extensive remodeling of the vessels, most visibly in the head. (K) Tak1{Delta}/{Delta} embryo at E10.5, which has much less remodeling in comparison with the embryo in J (compare the tree-like branching vasculature of the head in J with the more honeycomb-like vasculature in K). The embryo in K also has a collapsed anterior (arrowhead) and posterior (arrow) dorsal aorta.