Creuzet Sophie, Schuler Bernadette, Couly Gérard, Le Douarin Nicole M
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.
Proc Natl Acad Sci U S A. 2004 Apr 6;101(14):4843-7. doi: 10.1073/pnas.0400869101. Epub 2004 Mar 23.
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.
Fgf8 对注定形成面部骨骼的神经嵴（NC）来源的间充质细胞具有强烈影响。手术切除不表达 Hox 基因的面部骨骼发生 NC 区域（包括中脑间脑直至菱脑节 2），会导致面部骨骼发育失败并抑制前脑神经管闭合，而端脑和鳃弓（BA）外胚层中的 Fgf8 表达则被消除。我们在此证明：（i）外源性 FGF8 能够通过促进来自单个菱脑节 r3 的 NC 细胞增殖来挽救面部骨骼发育，在正常发育中，r3 对 BA1 的间充质贡献极小；（ii）前脑和 BA 外胚层中 Fgf8 的表达受到来自 NC 细胞的信号影响，从而表明头部 NC 衍生结构的发育依赖于 FGF8 信号传导，而该信号传导本身由 NC 细胞触发。
