Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2003-9-16
pubmed:abstractText
In Xenopus neuroectoderm, posterior cells start differentiating at the end of gastrulation, while anterior cells display an extended proliferative period and undergo neurogenesis only at tailbud stage. Recent studies have identified several important components of the molecular pathways controlling posterior neurogenesis, but little is known about those controlling the timing and positioning of anterior neurogenesis. We investigate the role of Xrx1, a homeobox gene required for eye and anterior brain development, in the control of proliferation and neurogenesis of the anterior neural plate. Xrx1 is expressed in the entire proliferative region of the anterior neural plate delimited by cells expressing the neuronal determination gene X-ngnr-1, the neurogenic gene X-Delta-1, and the cell cycle inhibitor p27Xic1. Positive and negative signals position Xrx1 expression to this region. Xrx1 is activated by chordin and Hedgehog gene signaling, which induce anterior and proliferative fate, and is repressed by the differentiation-promoting activity of neurogenin and retinoic acid. Xrx1 is required for anterior neural plate proliferation and, when overexpressed, induces proliferation, inhibits X-ngnr-1, X-Delta-1 and N-tubulin and counteracts X-ngnr-1- and retinoic acid-mediated differentiation. We find that Xrx1 does not act by increasing lateral inhibition but by inducing the antineurogenic transcriptional repressors Xhairy2 and Zic2, and by repressing p27Xic1. The effects of Xrx1 on proliferation, neurogenesis and gene expression are restricted to the most rostral region of the embryo, implicating this gene as an anterior regulator of neurogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Basic Helix-Loop-Helix..., http://linkedlifedata.com/resource/pubmed/chemical/Hedgehog Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Homeodomain Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nerve Tissue Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Trans-Activators, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/Tretinoin, http://linkedlifedata.com/resource/pubmed/chemical/Xenopus Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Xrx1 protein, Xenopus, http://linkedlifedata.com/resource/pubmed/chemical/Zic2 protein, Xenopus, http://linkedlifedata.com/resource/pubmed/chemical/neurogenin, Xenopus
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5143-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12975341-Animals, pubmed-meshheading:12975341-Basic Helix-Loop-Helix Transcription Factors, pubmed-meshheading:12975341-Cell Differentiation, pubmed-meshheading:12975341-Cell Division, pubmed-meshheading:12975341-Gene Expression Regulation, Developmental, pubmed-meshheading:12975341-Hedgehog Proteins, pubmed-meshheading:12975341-Homeodomain Proteins, pubmed-meshheading:12975341-In Situ Hybridization, pubmed-meshheading:12975341-Morphogenesis, pubmed-meshheading:12975341-Nerve Tissue Proteins, pubmed-meshheading:12975341-Nervous System, pubmed-meshheading:12975341-Neurons, pubmed-meshheading:12975341-Proteins, pubmed-meshheading:12975341-Signal Transduction, pubmed-meshheading:12975341-Trans-Activators, pubmed-meshheading:12975341-Transcription Factors, pubmed-meshheading:12975341-Tretinoin, pubmed-meshheading:12975341-Xenopus Proteins, pubmed-meshheading:12975341-Xenopus laevis
pubmed:year
2003
pubmed:articleTitle
Xrx1 controls proliferation and neurogenesis in Xenopus anterior neural plate.
pubmed:affiliation
Dipartimento di Fisiologia e Biochimica, Università degli Studi di Pisa, Via Carducci 13, 56010 Ghezzano (Pisa), Italy. andream@dfb.unipi.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't