Figure 3.
The cbs mutant exhibits a pronounced disorganization of the dorsal telencephalon. A–D, H, Hematoxylin-stained coronal sections of E12.5 wild-type (A, C) and cbs/cbs (B, D, H–J) embryos. A, B, E-G, Rostral and (C, D, H–J) caudal telencephalon. E–G, Hematoxylin-stained coronal sections of a E11.5 Ift88ko/− embryo (E), a Ift88ko/cbs compound heterozygote littermate (F), and a cbs/cbs embryo (G). A, C, E, Inset (lower left) indicates the plane of section for (A, B), (C, D), and (E–G), respectively. H, Caudal-most telencephalon showing lateral heterotopias (left, boxed). Enlargement of the boxed region shows them to have a rosette-like morphology (right). B, D, G, H, Arrows indicate heterotopias. G, Arrowhead indicates VZ. I–L, Mitotic cells revealed with an anti-phosphorylated-histone H3 antibody (green, PH3) in subpial heterotopias (I, J) and VZ of the dorsolateral cortex (K) and the ganglionic eminences (L) in E12.5 wild-type and cbs/cbs embryos. Red = anti-nestin antibody. I–L, Arrows indicate nestin/PH3-double positive cells. Arrowheads indicate sub-VZ mitoses. Asterisks indicate blood cells. M, N, O, Quantitation of PH3 staining in the cortex (cortex) and ganglionic eminences (GE), expressed as the number of PH3-positive (M) and double nestin/PH3-positive (N) cells per 100 μm of VZ, and in the number of basally located (i.e., >30 μm from the ventricular zone) PH3-positive cells per 1 mm2 (O). ***p < 0.001, Student's t test. A–L, Dorsal is to the top. H–L, Lateral is to the left; V, ventricle; P, pial surface. Scale bars: A–G, H (left), 300 μm; H (right), I–L, 50 μm.