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Tissue interactions in the developing chick diencephalon

BACKGROUND: The developing vertebrate brain is patterned first by global signalling gradients that define crude anteroposterior and dorsoventral coordinates, and subsequently by local signalling centres (organisers) that refine cell fate assignment within pre-patterned regions. The interface between...

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Autores principales: Guinazu, Maria Flavia, Chambers, David, Lumsden, Andrew, Kiecker, Clemens
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2007
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217525/
https://www.ncbi.nlm.nih.gov/pubmed/17999760
http://dx.doi.org/10.1186/1749-8104-2-25
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author Guinazu, Maria Flavia
Chambers, David
Lumsden, Andrew
Kiecker, Clemens
author_facet Guinazu, Maria Flavia
Chambers, David
Lumsden, Andrew
Kiecker, Clemens
author_sort Guinazu, Maria Flavia
collection PubMed
description BACKGROUND: The developing vertebrate brain is patterned first by global signalling gradients that define crude anteroposterior and dorsoventral coordinates, and subsequently by local signalling centres (organisers) that refine cell fate assignment within pre-patterned regions. The interface between the prethalamus and the thalamus, the zona limitans intrathalamica (ZLI), is one such local signalling centre that is essential for the establishment of these major diencephalic subdivisions by secreting the signalling factor Sonic hedgehog. Various models for ZLI formation have been proposed, but a thorough understanding of how this important local organiser is established is lacking. RESULTS: Here, we describe tissue explant experiments in chick embryos aimed at characterising the roles of different forebrain areas in ZLI formation. We found that: the ZLI becomes specified unexpectedly early; flanking regions are required for its characteristic morphogenesis; ZLI induction can occur independently from ventral tissues; interaction between any prechordal and epichordal neuroepithelial tissue anterior to the midbrain-hindbrain boundary is able to generate a ZLI; and signals from the dorsal diencephalon antagonise ZLI formation. We further show that a localised source of retinoic acid in the dorsal diencephalon is a likely candidate to mediate this inhibitory signal. CONCLUSION: Our results are consistent with a model where planar, rather than vertical, signals position the ZLI at early stages of neural development and they implicate retinoic acid as a novel molecular cue that determines its dorsoventral extent.
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spelling pubmed-22175252008-01-30 Tissue interactions in the developing chick diencephalon Guinazu, Maria Flavia Chambers, David Lumsden, Andrew Kiecker, Clemens Neural Develop Research Article BACKGROUND: The developing vertebrate brain is patterned first by global signalling gradients that define crude anteroposterior and dorsoventral coordinates, and subsequently by local signalling centres (organisers) that refine cell fate assignment within pre-patterned regions. The interface between the prethalamus and the thalamus, the zona limitans intrathalamica (ZLI), is one such local signalling centre that is essential for the establishment of these major diencephalic subdivisions by secreting the signalling factor Sonic hedgehog. Various models for ZLI formation have been proposed, but a thorough understanding of how this important local organiser is established is lacking. RESULTS: Here, we describe tissue explant experiments in chick embryos aimed at characterising the roles of different forebrain areas in ZLI formation. We found that: the ZLI becomes specified unexpectedly early; flanking regions are required for its characteristic morphogenesis; ZLI induction can occur independently from ventral tissues; interaction between any prechordal and epichordal neuroepithelial tissue anterior to the midbrain-hindbrain boundary is able to generate a ZLI; and signals from the dorsal diencephalon antagonise ZLI formation. We further show that a localised source of retinoic acid in the dorsal diencephalon is a likely candidate to mediate this inhibitory signal. CONCLUSION: Our results are consistent with a model where planar, rather than vertical, signals position the ZLI at early stages of neural development and they implicate retinoic acid as a novel molecular cue that determines its dorsoventral extent. BioMed Central 2007-11-13 /pmc/articles/PMC2217525/ /pubmed/17999760 http://dx.doi.org/10.1186/1749-8104-2-25 Text en Copyright © 2007 Guinazu et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an open access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Guinazu, Maria Flavia
Chambers, David
Lumsden, Andrew
Kiecker, Clemens
Tissue interactions in the developing chick diencephalon
title Tissue interactions in the developing chick diencephalon
title_full Tissue interactions in the developing chick diencephalon
title_fullStr Tissue interactions in the developing chick diencephalon
title_full_unstemmed Tissue interactions in the developing chick diencephalon
title_short Tissue interactions in the developing chick diencephalon
title_sort tissue interactions in the developing chick diencephalon
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217525/
https://www.ncbi.nlm.nih.gov/pubmed/17999760
http://dx.doi.org/10.1186/1749-8104-2-25
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