FGF signaling is essential for ophthalmic trigeminal placode cell delamination and differentiation.
The ophthalmic trigeminal (opV) placode gives rise exclusively to sensory neurons of the peripheral nervous system, providing an advantageous model for understanding neurogenesis. The signaling pathways governing opV placode development have only recently begun to be elucidated. Here, we investigate the fibroblast growth factor receptor-4 (FGFR4), an opV expressed gene, to examine if and how FGF signaling regulates opV placode development. After inhibiting FGFR4, Pax3+ opV placode cells failed to delaminate from the ectoderm and did not contribute to the opV ganglion. Blocking FGF signaling also led to a loss of the early and late neuronal differentiation markers Ngn2, Islet-1, NeuN, and Neurofilament. In addition, without FGF signaling, cells that stalled in the ectoderm lost their opV placode-specific identity by down-regulating Pax3. We conclude that FGF signaling, through FGFR4, is necessary for delamination and differentiation of opV placode cells.
Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah 84602, USA.
Rhonda N T
RN
Lassiter
Stephanie B
SB
Reynolds
Kristopher D
KD
Marin
Tyler F
TF
Mayo
Michael R
MR
Stark
D000818:Animals; D002642:Chick Embryo; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016900:Neurofilament Proteins / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics; D009882:Ophthalmic Nerve / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D051761:Paired Box Transcription Factors / Q000378:metabolism; D051499:Receptor, Fibroblast Growth Factor, Type 4 / Q000235:genetics / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors
D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D016900:Neurofilament Proteins; D051761:Paired Box Transcription Factors; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; D005346:Fibroblast Growth Factors; D051499:Receptor, Fibroblast Growth Factor, Type 4