Fig. 7. Roof plate ablation causes loss of Wnt1 and c1 populations, and reduces cerebellar anlage proliferation at E10.5. (A) Schematic of the genetic strategy to ablate roof plate cells. (B-I) Whole-mount in situ staining of E10.5 embryos with markers and genotypes indicated. (B,C and H,I) Dorsal views with broken line in C demarking the dorsal edge of the open neural tube. (D-G) Side views. Arrows in B-E indicate position of r1 roof plate. Arrowheads `o' and `v' mark normal otic and ventral midbrain Lmx1a expression in panels B and C. Upper and lower insets in panel E show Wnt1 and Fgf8 isthmic expression. Arrows in panels F and G point to the cerebellar rhombic lip. Arrows in panel H show broad expression of cyclin D2 which is eliminated in roof plate-ablated embryos (I). Weak staining in I is ventral, visible because of the open neural tube. Dark lines on dorsal edges are artifact. (J,K) Schematic illustration of E10.5 wild-type and roof plate-ablated embryos demonstrating the consequences of ablation. (L) Hematoxylin and eosin-stained sections at the level of the horizontal line in panels J and K in time series. Arrows point to the most dorsal neuroepithelium of roof plate-ablated embryo (M-P) Immunostained transverse sections at E10.5 demonstrating that cell proliferation and cyclin D2 expression is reduced across the entire cerebellar anlage in ablated embryos. Arrowheads point to the developing cerebellar anlage.