Endodermal expression of GFP-Gpc4 rescues C&E defects in all germ layers of gpc4^−/− embryos. (A–D′) The expression of foxa3 as detected by WISH, showing the morphology of the gut, liver (L), and pancreas (P) in the indicated embryos. (A–D) Dorsal view. (A′–D′) Lateral view. White lines indicate the width of the gut tube, and lines in all embryos are equal in length; red dashed lines indicate posterior body length. (E–H) Bright-field images of the indicated embryos at 2 somite (s) stage. Red arrowheads point to the anterior and posterior points of the embryonic axis. Lateral view. (I–L′) Expression of hgg1 (red), dlx3, krox20, shh, and deltaC at 3 somite (s) stage, as detected by WISH. *, axial mesoderm (shh); np, neural plate (dlx3); red arrows indicate hgg1 expression; white lines with double arrows indicate the width of the neural plate, and white lines (deltaC) indicate the width of the first somite. All lines of each type are equal in length. (I–L) Dorsoanterior view. (I′–L′) Dorsal view. (M) Average posterior body length in embryos shown in A′–D′, from four independent experiments (represented by different color dots), with the number of embryos indicated. (N) Average width of the neural plate in embryos shown in I–L, from three independent experiments (represented by different color dots), with the number of embryos indicated. Data are mean ± SEM. #, P > 0.05; ***, P < 0.001; ****, P < 0.0001; unpaired Student's t test. Scale bars, 200 µm.