title: The status of Wnt signalling regulates neural and epidermal fates in the chick embryo.
abstract: The acquisition of neural fate by embryonic ectodermal cells is a fundamental step in the formation of the vertebrate nervous system. Neural induction seems to involve signalling by fibroblast growth factors (FGFs) and attenuation of the activity of bone morphogenetic protein (BMP). But FGFs, either alone or in combination with BMP antagonists, are not sufficient to induce neural fate in prospective epidermal ectoderm of amniote embryos. These findings suggest that additional signals are involved in the specification of neural fate. Here we show that the state of Wnt signalling is a critical determinant of neural and epidermal fates in the chick embryo. Continual Wnt signalling blocks the response of epiblast cells to FGF signals, permitting the expression and signalling of BMP to direct an epidermal fate. Conversely, a lack of exposure of epiblast cells to Wnt signals permits FGFs to induce a neural fate.
authors.affiliation: Department of Microbiology, Umeå University, S-901 87 Umeå, Sweden.
authors.forename: S I
authors.initials: SI
authors.lastname: Wilson
authors.forename: A
authors.initials: A
authors.lastname: Rydström
authors.forename: T
authors.initials: T
authors.lastname: Trimborn
authors.forename: K
authors.initials: K
authors.lastname: Willert
authors.forename: R
authors.initials: R
authors.lastname: Nusse
authors.forename: T M
authors.initials: TM
authors.lastname: Jessell
authors.forename: T
authors.initials: T
authors.lastname: Edlund
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D004475:Ectoderm / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004627:Embryonic Induction / Q000187:drug effects; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D007150:Immunohistochemistry; D008954:Models, Biological; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051497:Receptor, Fibroblast Growth Factor, Type 2; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000032:analysis; D051153:Wnt Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D000099176:Noggin Protein
chemical_list: D015415:Biomarkers; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D005346:Fibroblast Growth Factors; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011758:Pyrroles; D012333:RNA, Messenger; D020794:Receptor Protein-Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D014157:Transcription Factors; D051153:Wnt Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D000099176:Noggin Protein; C113865:FZD8 protein, Xenopus; C105686:SU 5402; C525812:bmp4 protein, Xenopus; C525813:bmp4 protein, zebrafish