Fig. 8. Fgf2 can restore FEZ activity to stage 25 FNP ectoderm. (A) Schematic illustration of a stage 25 ectoderm graft combined with an Fgf2 bead (green circle). (B) Seven days later, the upper beak exhibited an abnormal shape. (C) Trichrome stained sections demonstrated the presence of a bifurcated prenasal process and premaxilla in the ectopic outgrowth, which indicated a DV polarity. (D) Schematic view illustrating the placement of a Shh-N bead (yellow circle) underneath the dorsal ectoderm of a stage 25 host. (E,F) Exogenous Shh-N resulted in an overall increase in size of the FNP skeletal elements, but no patterning alterations were observed. (G) Schematic illustrating placement of an Fgf2 bead beneath the dorsal ectoderm of a stage 25 FNP. (H,I) Exogenous Fgf2 had no discernible effect on FNP development.