Click on image to view larger version.

Fig. 2. Midline and rostral neural defects. (A-C) Neonate transverse sections. (A)
Wild type showing anterior commissure (ac) and bilateral cerebral hemispheres
(ch). (B) Midline mutant lacking anterior commissure (asterisk) and showing
cerebral hemispheres fused into a holosphere (hs). (C) Truncation mutant
lacking CNS rostral to hindbrain. (D,E) E13.5 transverse sections. (D) Wild
type showing medial falx cerebri (fc). (E) Midline mutant shows a single
rostral ventricle (asterisk). (F,G) E9.5 embryos. (F) Wild-type embryo shows
lamina terminalis (lt) marked by Vax1 expression. (G) Midline mutant
lacks lamina terminalis (asterisk). (H-J) Neonatal brains. (H) Wild type
showing olfactory bulbs (ob). (I,J) Mild truncation mutant showing
hypoplastic, fused olfactory bulbs (I) or lacking olfactory bulbs (J). (K,L)
E10.5 embryos. (K) Wild type showing telencephalic vesicles (tv). (L) Midline
mutant has single holospheric vesicle (hs). (M) Moderate truncation mutant
lacks telencephalon (asterisk). (N) Severe truncation mutant lacks both
forebrain and midbrain. mo, medulla oblongata; ov, optic vesicle; p, pons;
cbl, cerebellum; m/h, midbrain/hindbrain boundary. Scale bars: 2 mm in A-C;
0.5 mm in D,E; 0.2 mm in F,G; 1 mm in H-N.