title: Differential regulation of transcription factor gene expression and phenotypic markers in developing sympathetic neurons.
abstract: We have examined the regulation of transcription factor gene expression and phenotypic markers in developing chick sympathetic neurons. Sympathetic progenitor cells first express the bHLH transcriptional regulator Cash-1 (a chicken achaete-scute homologue), followed by coordinate expression of Phox2, a paired homeodomain protein, and GATA-2, a zinc finger protein. SCG10, a pan-neuronal membrane protein, is first detected one stage later, followed by the catecholaminergic neurotransmitter enzyme tyrosine hydroxylase (TH). We have used these markers to ask two questions: (1) is their expression dependent upon inductive signals derived from the notochord or floor plate?; (2) does their sequential expression reflect a single linear pathway or multiple parallel pathways? Notochord ablation experiments indicate that the floor plate is essential for induction of GATA-2, Phox2 and TH, but not for that of Cash-1 and SCG10. Taken together these data suggest that the development of sympathetic neurons involves multiple transcriptional regulatory cascades: one, dependent upon notochord or floor plate-derived signals and involving Phox2 and GATA-2, is assigned to the expression of the neurotransmitter phenotype; the other, independent of such signals and involving Cash-1, is assigned to the expression of pan-neuronal properties. The parallel specification of different components of the terminal neuronal phenotype is likely to be a general feature of neuronal development.
authors.affiliation: Division of Biology 216-76, California Institute of Technology, Pasadena 91125.
authors.forename: A K
authors.initials: AK
authors.lastname: Groves
authors.forename: K M
authors.initials: KM
authors.lastname: George
authors.forename: J P
authors.initials: JP
authors.lastname: Tissier-Seta
authors.forename: J D
authors.initials: JD
authors.lastname: Engel
authors.forename: J F
authors.initials: JF
authors.lastname: Brunet
authors.forename: D J
authors.initials: DJ
authors.lastname: Anderson
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004627:Embryonic Induction / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D005819:Genetic Markers; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D009024:Morphogenesis / Q000235:genetics; D009474:Neurons / Q000502:physiology*; D009672:Notochord / Q000502:physiology; D010641:Phenotype; D013564:Sympathetic Nervous System / Q000166:cytology / Q000196:embryology*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D014157:Transcription Factors