title: Neural crest determination by co-activation of Pax3 and Zic1 genes in Xenopus ectoderm.
abstract: A number of regulatory genes have been implicated in neural crest development. However, the molecular mechanism of how neural crest determination is initiated in the exact ectodermal location still remains elusive. Here, we show that the cooperative function of Pax3 and Zic1 determines the neural crest fate in the amphibian ectoderm. Pax3 and Zic1 are expressed in an overlapping manner in the presumptive neural crest area of the Xenopus gastrula, even prior to the onset of the expression of the early bona fide neural crest marker genes Foxd3 and Slug. Misexpression of both Pax3 and Zic1 together efficiently induces ectopic neural crest differentiation in the ventral ectoderm, whereas overexpression of either one of them only expands the expression of neural crest markers within the dorsolateral ectoderm. The induction of neural crest differentiation by Pax3 and Zic1 requires Wnt signaling. Loss-of-function studies in vivo and in the animal cap show that co-presence of Pax3 and Zic1 is essential for the initiation of neural crest differentiation. Thus, co-activation of Pax3 and Zic1, in concert with Wnt, plays a decisive role for early neural crest determination in the correct place of the Xenopus ectoderm.
authors.affiliation: Organogenesis and Neurogenesis Group, Center for Developmental Biology, RIKEN, Kobe 650-0047, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Sato
authors.forename: Noriaki
authors.initials: N
authors.lastname: Sasai
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Sasai
mesh_terms: D000818:Animals; D015153:Blotting, Western; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004475:Ectoderm / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D009432:Neural Crest / Q000196:embryology* / Q000378:metabolism; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051153:Wnt Proteins; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; C489411:Pax3 protein, Xenopus; D014157:Transcription Factors; D051153:Wnt Proteins; D029867:Xenopus Proteins; C116546:Zic1 protein, Xenopus