title: Establishment and maintenance of the border of the neural plate in the chick: involvement of FGF and BMP activity.
abstract: We have investigated the cell interactions and signalling molecules involved in setting up and maintaining the border between the neural plate and the adjacent non-neural ectoderm in the chick embryo at primitive streak stages. msx-1, a target of BMP signalling, is expressed in this border at a very early stage. It is induced by FGF and by signals from the organizer, Hensen's node. The node also induces a ring of BMP-4, some distance away. By the early neurula stage, the edge of the neural plate is the only major site of BMP-4 and msx-1 expression, and is also the only site that responds to BMP inhibition or overexpression. At this time, the neural plate appears to have a low level of BMP antagonist activity. Using in vivo grafts and in vitro assays, we show that the position of the border is further maintained by interactions between non-neural and neural ectoderm. We conclude that the border develops by integration of signals from the organizer, the developing neural plate, the paraxial mesoderm and the non-neural epiblast, involving FGFs, BMPs and their inhibitors. We suggest that BMPs act in an autocrine way to maintain the border state.
authors.affiliation: Department of Genetics and Development, Columbia University, 701 West 168th Street, New York, NY 10032, USA.
authors.forename: A
authors.initials: A
authors.lastname: Streit
authors.forename: C D
authors.initials: CD
authors.lastname: Stern
mesh_terms: D000818:Animals; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D002352:Carrier Proteins; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000502:physiology; D024002:HMGB Proteins; D006609:High Mobility Group Proteins / Q000235:genetics / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins; D051957:MSX1 Transcription Factor; D008648:Mesoderm / Q000502:physiology; D008959:Models, Neurological; D009420:Nervous System / Q000196:embryology*; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology; D011506:Proteins / Q000502:physiology; D055748:SOXB1 Transcription Factors; D015398:Signal Transduction; D014157:Transcription Factors; D000099176:Noggin Protein
chemical_list: D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors; D006023:Glycoproteins; D024002:HMGB Proteins; D006609:High Mobility Group Proteins; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D051957:MSX1 Transcription Factor; D009687:Nuclear Proteins; D011506:Proteins; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors; D000099176:Noggin Protein; C054234:chordin