Fig. 6. Cell cycle genes Mycn and cyclin D1 (Ccnd1) are downregulated in Smo-Nes cko and Gli2-En1 cko cerebella. RNA in situ hybridization shows downregulation of the transcriptional target of Shh, Gli1, in Smo-Nes cko mutants at E18.5 (A), although expression of Math1 (B) indicates the presence of GCPs. Another transcriptional target of Shh, Mycn, is downregulated in Smo-Nes cko at E18.5 and Gli2-En1 cko mutants at P0, respectively (E,G), compared with wild types (C). Ccnd1, which is downstream of Mycn, is also downregulated but still present in mutants (F,H) compared with wild types (D).