A-P patterning and gastrulation were unaffected in Foxh1mEH1/mEH1 embryos. Expression of multiple A-P patterning genes was examined by whole-mount in situ hybridization in control (ctrl represents wild-type or Foxh1F/F) or Foxh1mEH1/mEH1 (mut) E6.75-E7.25 embryos. The expression patterns of Nodal (A,B), Lefty2 (C,D), Brachyury/T (E,F), Otx2 (G,H), and Gsc (I,J) were similar between control and Foxh1mEH1/mEH1 embryos. Red and blue lines mark representative location of extraembryonic tissue and embryo proper, respectively, in (A) E6.75 and (C) E7.25 embryos. Hash marks denote definitive endoderm. (K,L) Foxa2 expression was unaffected in Foxh1mEH1/mEH1, confirming midline (arrowhead) integrity in mutant embryos. Black and red lines outline headfolds and foregut pocket, respectively. Embryo orientations: (A–J) Lateral views. (K–L) Anterior views. Scale bars: 200 μm. A, anterior; L, left; P, posterior; R, right.