Expression of fibroblast growth factor receptors (FGFR1, FGFR2, FGFR3) in the developing head and face.

Fibroblast growth factors may play an important role in the differential growth of the skull, brain, and facial prominences. In order to understand the role of FGFs in vivo, we have analyzed the competency of head mesenchyme to respond to FGFs via expression of the high affinity receptors FGFR1, 2, and 3. Receptor transcripts, especially those of FGFR2 and FGFR3, were localized to specific regions of the head. We raise the possibilities of particular receptor-ligand combinations and the possible functions of these interactions in the morphogenesis of the head, face, and brain. Finally, we discuss the relationship between FGF receptor expression in the chicken and the phenotypes of FGF receptor mutations in humans.