Figure 9
From: Temporal and spatial requirements of Smoothened in ventral midbrain neuronal development
Loss and gain of function in Smoothened affects Wnt1 , but not fibroblast growth factor ( FGF )8, expression, in ventral midbrain (vMB). (A-D’) In situ hybridization showed no detectable change in FGF8 expression in MHB in either (A’,C’) Shh-Cre;Smofl/fl or (B’,D’) Shh-Cre;SmoM2 mutants compared with (A,C and B,D) controls. (E-F’) Wnt1 mRNA was increased in vMB of Shh-Cre;Smofl/fl at both embryonic day (E)10.5 and E12.5. (G) Wnt1 mRNA was slightly decreased in vMB of Shh-Cre;SmoM2 at E10.5, but (H’) resumed at E12.5. (I-I’) LacZ staining from BAT-GAL reporter indicate that (I’) the number of Wnt-responsive cells was decreased in vMB of Shh-Cre;SmoM2;BAT-GAL mutants at E10.5, but returned to the same level as controls at E12.5 (data not shown). (I) Quantification confirms the decrease of Wnt-responsive cells in vMB of Shh-Cre;SmoM2;BAT-GAL mutants at E10.5, which returns to the same level as controls at E12.5. Student’s t-test, n = 3 or 4. Scale bars: (B’) 500 μm, applied to A to B’; (G’), 100 μm, applied to C-E’ and G-H’; (F’) 200 μm, applied to F-F’; (H) 500 μm, applied to H-H’; (I’), 100 μm, applied to I-I’.