Regulation of pre-otic brain development by the cephalic neural crest.
Emergence of the neural crest (NC) is considered an essential asset in the evolution of the chordate phylum, as specific vertebrate traits such as peripheral nervous system, cephalic skeletal tissues, and head development are linked to the NC and its derivatives. It has been proposed that the emergence of the NC was responsible for the formation of a "new head" characterized by the spectacular development of the forebrain and associated sense organs. It was previously shown that removal of the cephalic NC (CNC) prevents the formation of the facial structures but also results in anencephaly. This article reports on the molecular mechanisms whereby the CNC controls cephalic neurulation and brain morphogenesis. This study demonstrates that molecular variations of Gremlin and Noggin level in CNC account for morphological changes in brain size and development. CNC cells act in these processes through a multi-step control and exert cumulative effects counteracting bone morphogenetic protein signaling produced by the neighboring tissues (e.g., adjacent neuroepithelium, ventro-medial mesoderm, superficial ectoderm). These data provide an explanation for the fact that acquisition of the NC during the protochordate-to-vertebrate transition has coincided with a large increase of brain vesicles.
Creuzet
Sophie E
SE
Institut de Neurobiologie-Alfred Fessard, Laboratoire Développement, Evolution et Plasticité du Système Nerveux, Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France. sophie.creuzet@inaf.cnrs-gif.fr
D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics; D055419:Bone Morphogenetic Protein 7 / Q000235:genetics; D001921:Brain / Q000196:embryology* / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002642:Chick Embryo; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics; D051524:Fibroblast Growth Factor 8 / Q000037:antagonists & inhibitors / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008959:Models, Neurological; D009432:Neural Crest / Q000196:embryology* / Q000378:metabolism / Q000601:surgery; D011784:Quail; D034622:RNA Interference; D000099176:Noggin Protein
D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D002352:Carrier Proteins; D051524:Fibroblast Growth Factor 8; D036341:Intercellular Signaling Peptides and Proteins; D000099176:Noggin Protein