Fig. 4. Changes in ventral and dorsal neuronal precursor populations at E10.5 following disruption of LDA. (A-F) In situ hybridization detection of Sim1 expression in neural tube sections. Genotypes of the embryos as indicated in each panel. (G-X) Immunofluorescence of neural tube sections. Genotypes of the embryos and antibodies as indicated in each panel. Sections in A-R are aligned ventrally (bottom). Sections in S-X are aligned dorsally (top). (Y-e) Quantification of neuronal precursor populations. (^*wild type significantly different from mutant, P<0.08). (f) The numbers of different types of neuronal precursors in MtPtch1;Ptch1^-/-, MtPtch1;Ptch1^-/-;Hhip1^+/- or MtPtch1;Ptch1^-/-;Hhip1^-/- spinal cord compared with those in the wild type (^*wild type significantly different from mutant, P<0.08). Scale bar: 50 µm.