Normal expression of neurogenins in Rbpj -deficient DRG. (A-L) Transverse sections through the upper neural tube (nt) and surrounding tissue of wild-type (WT) and Rbpj CKO with Ngn1 (A-F) and Ngn2 (G-L) mRNA probes at the indicated stages. Loss of Rbpj does not appear to affect the expression of neurogenins either in migrating NCCs at E9.5 and E10.0, or in post-migratory NCCs in the DRG at E10.0 and E10.5. Arrows in (A,B,G,H) point to a cluster of migrating NCCs, and those in (C-F,I-L) point to post-migratory NCCs condensed in the DRG located laterally to the neural tube. High magnification views of the areas delineated by black rectangles in panels (C-F,I,J) are shown at the bottom of each panel. Note that the signal of in situ hybridization is present in the cytoplasm, whereas the nuclei contain no signals. (M) Comparison of the number of Ngn1+and Ngn2+cells in the DRG between wild-type and Rbpj CKO mice at E10.0 and E10.5. Error bars represent standard error of the mean. (N) Black line on representative E10.5 embryo indicates the level at which embryos was cut transversely. Upper part of embryos were placed vertically (relative to the spinal cord) on the frozen pedestal for sectioning. Cell counting from E10.0 to E11.5 embryos was performed in the thoracic DRGs between black and dashed black lines. H, heart; L, liver; nt, neural tube. Scale bars: 100 μm.