Fig. 6. Defects in ventral body wall closure and eye development in Bmp4^lacZ/S2G mutants. (A) E17.5 Bmp4^lacZ/S2G embryo with complete failure of ventral body wall closure. (B) Coronal sections through E16 embryos. Arrowhead indicates umbilical artery, arrow denotes midgut, which has been enclosed by the ventral body wall in the Bmp4^S2G/+ embryo but remains externalized in the Bmp4^lacZ/S2G littermate. (C,D) E12.5 embryos showing loss of eye pigment in Bmp4^lacZ/S2G embryos. (E,F) Expression of Tbx5 in E10.5 embryos, analyzed by whole-mount in situ hybridization. e, eye; he, heart; lb, limb bud. Insets show staining of the eye at higher magnification.