Figure 6.

Shh and Patched1 expression is unaffected in the ventral forebrains lacking individual or both of Fgfr1 and Fgfr2. Coronal sections of E12.5 forebrain from single and double mutants of Fgfr1 and Fgfr2 and littermate controls taken from rostral (A) or caudal (B, C) regions of the forebrains were analyzed by in situ hybridization for the expression of Shh and its receptor Patched1 (as a readout of Shh signaling). Expression of Shh and Patched1 were not significantly affected in any of the mutants: Fgfr2^−/− (A–C), Fgfr1^−/− (B), Fgfr1^−/−;Fgfr2^+/− (C), or Fgfr1^−/−;Fgfr2^−/− (B). In situ hybridization for Foxg1 in adjacent sections of Fgfr1^−/− or Fgfr1^−/−; Fgfr2^−/− mutants show that Shh continues to be expressed in Foxg1+ region (brackets) in which floxed Fgfr1/2 genes should be deleted by Foxg1-cre. The same image of Foxg1 was used in Figure 5B. Scale bar, 200 μm.