Fig. 5. Analysis of the mD2LIC phenotype at gastrula stages. (A,B) Expression of Fgf8 is unaffected by loss of mD2LIC function. (A) Lateral view of wild-type embryo; (B) Lateral view of mD2LIC^–/– embryo. (C-E) Shh expression is reduced in the node and axial mesoderm of mD2LIC-null mutants. (C) Wild-type embryo showing expression of Shh in the node and in axial structures. (D,E) Reduction of Shh expression (arrowheads) in mD2LIC^–/– embryos. (F-J) Reduction in Foxa2 expression in mD2LIC null mutant embryos. (F) Wild-type embryo showing expression of Foxa2 in the node and axial mesendoderm. (G,H) Expression of Foxa2 is severely reduced (G) or absent (H) in mD2LIC-null mutant embryos. (I,J) Foxa2 expression is later reduced in anterior definitive endoderm in mD2LIC^–/– embryos. (I) Wild-type embryo. (J) mD2LIC^–/– embryo. Arrowheads mark anterior definitive endoderm. (K-P) TUNEL analysis of mD2LIC^–/– embryos reveals no elevation of cell death in the node or its derivatives but apoptosis does occur in anterior definitive endoderm. (K-M) Little apoptosis is observed in the embryonic region of wild-type embryos at 7.5 dpc (K, lateral view; L, anterior view; M, distal view). In mD2LIC^–/– embryos, no apoptosis is observed in the node or its derivatives (P) but substantial cell death occurs in the anterior definitive endoderm (arrowheads, N, lateral; O, anterior).