title: Neural induction and early patterning in vertebrates.
abstract: In vertebrates, the development of the nervous system is triggered by signals from a powerful 'organizing' region of the early embryo during gastrulation. This phenomenon--neural induction--was originally discovered and given conceptual definition by experimental embryologists working with amphibian embryos. Work on the molecular circuitry underlying neural induction, also in the same model system, demonstrated that elimination of ongoing transforming growth factor-β (TGFβ) signaling in the ectoderm is the hallmark of anterior neural-fate acquisition. This observation is the basis of the 'default' model of neural induction. Endogenous neural inducers are secreted proteins that act to inhibit TGFβ ligands in the dorsal ectoderm. In the ventral ectoderm, where the signaling ligands escape the inhibitors, a non-neural fate is induced. Inhibition of the TGFβ pathway has now been demonstrated to be sufficient to directly induce neural fate in mammalian embryos as well as pluripotent mouse and human embryonic stem cells. Hence the molecular process that delineates neural from non-neural ectoderm is conserved across a broad range of organisms in the evolutionary tree. The availability of embryonic stem cells from mouse, primates, and humans will facilitate further understanding of the role of signaling pathways and their downstream mediators in neural induction in vertebrate embryos.
authors.affiliation: Laboratory of Molecular Vertebrate Embryology, The Rockefeller University, New York, NY, USA.
authors.forename: Mohammad Zeeshan
authors.initials: MZ
authors.lastname: Ozair
authors.forename: Chris
authors.initials: C
authors.lastname: Kintner
authors.forename: Ali H
authors.initials: AH
authors.lastname: Brivanlou
mesh_terms: D000818:Animals; D019521:Body Patterning; D004627:Embryonic Induction; D050437:Genes, Developmental; D006801:Humans; D054258:Neural Plate / Q000196:embryology / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism; D055495:Neurogenesis; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D014714:Vertebrates / Q000196:embryology
chemical_list: D016212:Transforming Growth Factor beta