Abstract: Objective To investigate the effect of FGF on the migration of the neural crest cell in early chick embryos after blocking FGF signaling with Sprouty2 Methods The chick embryos were incubated EM>in vivo /EM>until HH9, Sprouty2 green fluorescent protein(GFP) plasmid was injected into the lumen of the neural tube using microinjection，and EM>in vivo/EM> electroporation was performed to transfect Sprouty2-GFP at a half-side of the neural tube while another half-side was used as the control side. We employed the immunofluorescence staining method to detect the HNK1-positive neural crest cell, specially labeled dorsal-ventrally, in order to determine whether Sprouty2 over-expression affects the delamination and migration of cranial and trunk neural crest cells. We studied if the FGF-related neural crest cell migration induced by Spourty2 transfection was controlled by regulating Ca+2-dependent N-Cadherin expression.Results The blocking FGF signaling via transfected Sprouty2-GFP resulted in more HNK1-positive neural crest cells in Sprouty2-GFP transfected side than in the control side in both cranial and trunk regions of the early chick embryos. The N-Cadherin expression did not significantly affected by Sprouty2-GFP transfection. BR>Conclusion The blocking FGF signaling using Sprouty2 promotes the neural crest cell delamination in the early chick embryos. However, N-Cadherin may not have the impact of FGF signaling on neural crest cell migration, on which

Key words: Sprouty2, Fibroblast growth factor, Neural crest cell, Cell migration, Electroporation, Immunofluorescence, Chick embryo