title: A homeodomain protein code specifies progenitor cell identity and neuronal fate in the ventral neural tube.
abstract: Distinct classes of neurons are generated at defined positions in the ventral neural tube in response to a gradient of Sonic Hedgehog (Shh) activity. A set of homeodomain transcription factors expressed by neural progenitors act as intermediaries in Shh-dependent neural patterning. These homeodomain factors fall into two classes: class I proteins are repressed by Shh and class II proteins require Shh signaling for their expression. The profile of class I and class II protein expression defines five progenitor domains, each of which generates a distinct class of postmitotic neurons. Cross-repressive interactions between class I and class II proteins appear to refine and maintain these progenitor domains. The combinatorial expression of three of these proteins--Nkx6.1, Nkx2.2, and Irx3--specifies the identity of three classes of neurons generated in the ventral third of the neural tube.
authors.affiliation: Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA.
authors.forename: J
authors.initials: J
authors.lastname: Briscoe
authors.forename: A
authors.initials: A
authors.lastname: Pierani
authors.forename: T M
authors.initials: TM
authors.lastname: Jessell
authors.forename: J
authors.initials: J
authors.lastname: Ericson
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D005314:Embryonic and Fetal Development; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D029961:Zebrafish Proteins
chemical_list: D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; C501599:Irx3 protein, mouse; C000715627:Nkx2-2 protein, mouse; C491328:Nkx6-1 protein, mouse; D014157:Transcription Factors; D029961:Zebrafish Proteins; C000715630:nkx2.2b protein, zebrafish