Reciprocal relationships between Fgf8 and neural crest cells in facial and forebrain development.
Fgf8 exerts a strong effect on the mesenchymal cells of neural crest (NC) origin that are fated to form the facial skeleton. Surgical extirpation of facial skeletogenic NC domain (including mid-diencephalon down through rhombomere 2), which does not express Hox genes, results in the failure of facial skeleton development and inhibition of the closure of the forebrain neural tube, while Fgf8 expression in the telencephalon and in the branchial arch (BA) ectoderm is abolished. We demonstrate here that (i) exogenous FGF8 is able to rescue facial skeleton development by promoting the proliferation of NC cells from a single rhombomere, r3, which in normal development contributes only marginally to mesenchyme of BA1, and (ii) expression of Fgf8 in forebrain and in BA ectoderm is subjected to signal(s) arising from NC cells, thus showing that the development of cephalic NC-derived structures depends on FGF8 signaling, which is itself triggered by the NC cells.
Creuzet
Sophie
S
Institut d'Embryologie Cellulaire et Moléculaire du Centre National de la Recherche Scientifique et du Collège de France, 49 Bis, Avenue de la Belle Gabrielle, 94736 Nogent-sur-Marne, France. sophie.creuzet@college-de-france.fr
Schuler
Bernadette
B
Couly
Gérard
G
Le Douarin
Nicole M
NM
D000818:Animals; D002642:Chick Embryo; D005145:Face / Q000196:embryology*; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000235:genetics*; D017403:In Situ Hybridization; D009420:Nervous System / Q000196:embryology*; D016548:Prosencephalon / Q000196:embryology*; D011784:Quail / Q000196:embryology
D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors