Hemorrhages in embryos lacking endothelial survivin. Survivin^lox/lox (A,C,E,G) and tie1-cre/survivin^lox/lox (B,D,F,I) embryos were examined at E9.5 to E12.5. Embryos lacking endothelial cell survivin (B,D,F,I) exhibit evidence of vasodilatation and diffuse bleeding in the head, trunk, and intersomitic regions, and around the heart. Scale bars equal 1.0 mm. (H,J) High-power view (× 10) of the surface of the head of the embryos in panels G and I, respectively, reveals the extensive microvascular bleeding in the tie1-cre/survivin^lox/lox embryos.