A–F, CFP-negative Ptch1-deficient GNPs from Math1-Cre/Ptch1fl/fl/Nestin-CFP mice at P7 were immunostained with Nestin after treatment with PBS control (A and B), 1µg/mL Shh (C and D), or Shh plus 1% 5E1 (E and F) for 48 hours. G, Expression of Gli1 and Nestin mRNA in CFP-negative Ptch1-deficient GNPs treated with 1% 5E1, 1µg/mL Shh or Shh plus 5E1 for 48 hours, were examined by q-PCR. H–M, CFP-negative Ptch1-deficient GNPs were cultured alone (H and I) or co-cultured with TAA (GFP+, J–M) in the absence and presence of 5E1. N, The percentage of Nestin-CFP + cells among Ptch1-deficient GNPs was quantified. Data in figure G and N represent means ± SEM from three independent experiments. Scale bar, 10 µm.