Embryo at 14.5 days shows developing blood vessels. (A) Whole-mount Nanog staining of an E14.5 embryo. The vasculature of the head and brain (solid line boxed area) and intersomitic vessels (dotted line boxed area) at indicated magnification. (B-D) Vasculature of the head and brain regions at higher magnifications. (E) Nanog is expressed at the intersomitic vessels as shown in higher magnification. Ca indicates, capillaries; iv, intersomitic vessels; asterisks, sprouting ECs; arrowheads, large-caliber neovessels. Scale bar, 20 μm. Results are representative of 3 experiments with similar results.