Fig. 4. Forebrain defects in GPC4-depleted embryos. (A-D) Embryos injected with CoMo. (E-H) Embryos injected with Gpc4Mo. (A,E) Frontal view of Sox2 distribution at stage 21. White arrowheads indicate the level of the transverse sections shown in panels B-D and F-H. (B-D,F-H) Histological sections are at the level of the forebrain in panels B and F, the midbrain in panels C and G, and the spinal cord in panels D and H. Arrowhead in panels F and G points to defects in dorsal neural tube closure. No, notochord; So, somites.