title: Role of the isthmus and FGFs in resolving the paradox of neural crest plasticity and prepatterning.
abstract: Cranial neural crest cells generate the distinctive bone and connective tissues in the vertebrate head. Classical models of craniofacial development argue that the neural crest is prepatterned or preprogrammed to make specific head structures before its migration from the neural tube. In contrast, recent studies in several vertebrates have provided evidence for plasticity in patterning neural crest populations. Using tissue transposition and molecular analyses in avian embryos, we reconcile these findings by demonstrating that classical manipulation experiments, which form the basis of the prepatterning model, involved transplantation of a local signaling center, the isthmic organizer. FGF8 signaling from the isthmus alters Hoxa2 expression and consequently branchial arch patterning, demonstrating that neural crest cells are patterned by environmental signals.
authors.affiliation: The Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Trainor
authors.forename: Linda
authors.initials: L
authors.lastname: Ariza-McNaughton
authors.forename: Robb
authors.initials: R
authors.lastname: Krumlauf
mesh_terms: D000818:Animals; D019521:Body Patterning; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D016380:Brain Tissue Transplantation; D001934:Branchial Region / Q000196:embryology* / Q000378:metabolism; D002356:Cartilage / Q000196:embryology; D002465:Cell Movement; D002490:Central Nervous System / Q000196:embryology; D002642:Chick Embryo; D046508:Culture Techniques; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000494:pharmacology / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008636:Mesencephalon / Q000196:embryology / Q000378:metabolism; D009024:Morphogenesis; D009432:Neural Crest / Q000166:cytology / Q000196:embryology* / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D012249:Rhombencephalon / Q000196:embryology / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D018398:Homeodomain Proteins; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors