Document Detail

Anterior neurectoderm is progressively induced during gastrulation: the role of the Xenopus homeobox gene orthodenticle.
MedLine Citation:
PMID:  7743941     Owner:  NLM     Status:  MEDLINE    
In order to study the regional specification of neural tissue we isolated Xotx2, a Xenopus homolog of the Drosophila orthodenticle gene. Xotx2 is initially expressed in Spemann's organizer and its expression is absent in the ectoderm of early gastrulae. As gastrulation proceeds, Xotx2 expression is induced in the overlying ectoderm and this domain of expression moves anteriorly in register with underlying anterior mesoderm throughout the remainder of gastrulation. The expression pattern of Xotx2 suggests that a wave of Xotx2 expression (marking anterior neurectoderm) travels through the ectoderm of the gastrula with the movement of underlying anterior (prechordal plate) mesoderm. This expression of Xotx2 is reminiscent of the Eyal-Giladi model for neural induction. According to this model, anterior neural-inducing signals emanating from underlying anterior mesoderm transiently induce anterior neural tissues after vertical contact with the overlying ectoderm. Further patterning is achieved when the ectoderm receives caudalizing signals as it comes in contact with more posterior mesoderm during subsequent gastrulation movements. Functional characterization of the Xotx2 protein has revealed its involvement in differentiation of the anterior-most tissue, the cement gland. Ectopic expression of Xotx2 in embryos induces extra cement glands in the skin as well as inducing a cement gland marker (XAG1) in isolated animal cap ectoderm. Microinjection of RNA encoding the organizer-specific homeo-domain protein goosecoid into the ventral marginal zone results in induction of the Xotx2 gene. This result, taken in combination with the indistinguishable expression patterns of Xotx2 and goosecoid in the anterior mesoderm suggests that Xotx2 is a target of goosecoid regulation.
I L Blitz; K W Cho
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Development (Cambridge, England)     Volume:  121     ISSN:  0950-1991     ISO Abbreviation:  Development     Publication Date:  1995 Apr 
Date Detail:
Created Date:  1995-06-12     Completed Date:  1995-06-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8701744     Medline TA:  Development     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  993-1004     Citation Subset:  IM    
Department of Developmental and Cell Biology, University of California, Irvine 92717-2300, USA.
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MeSH Terms
Base Sequence
Blotting, Northern
Ectoderm / physiology
Embryonic Induction / genetics*
Gastrula / physiology*
Gene Expression
Gene Expression Regulation, Developmental*
Genes, Homeobox*
Homeodomain Proteins*
In Situ Hybridization
Molecular Sequence Data
Morphogenesis / genetics
Nerve Tissue Proteins / genetics*
Nervous System / embryology*
Oligonucleotide Probes / genetics
Otx Transcription Factors
Trans-Activators / genetics*
Xenopus / embryology*,  genetics
Xenopus Proteins
Grant Support
Reg. No./Substance:
0/Homeodomain Proteins; 0/Nerve Tissue Proteins; 0/Oligonucleotide Probes; 0/Otx Transcription Factors; 0/Otx2 protein, Xenopus; 0/Trans-Activators; 0/Xenopus Proteins

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