Analysis of Fgf8 expression.

(A) Control and Shh null embryos were analyzed for Fgf8 expression at 8.5 and 9.0 dpc. (B) Control, cdKO and Gli3^+/r;cdKO embryos were analyzed for Fgf8 expression at 9.5 dpc, and in (C) for Foxg1 expression at 9.5 and 10.0 dpc. Embryos are representative of at least three of each genotype at each stage and 5 each for panel B. Arrows indicate the eye field expression of Foxg1, and show the partial rescue of eye field separation in the Gli3^+/r;cdKO embryo (arrowheads). Scale bar: 180 µm at 8.5 dpc and 250 µm at 9.0 dpc in A; 250 µm in B, C and D.