Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
???displayArticle.abstract???
The border between the posterior ectoderm and the endoderm is a location where two germ layers meet and establish an enduring relationship that also later serves, in deuterostomes, as the anatomical site of the anus. In the sea urchin, a prototypic deuterostome, the ectoderm-endoderm boundary is established before gastrulation, and ectodermal cells at the boundary are thought to provide patterning inputs to the underlying mesenchyme. Here we show that a short-range Wnt5 signal from the endoderm actively patterns the adjacent boundary ectoderm. This signal activates a unique subcircuit of the ectoderm gene regulatory network, including the transcription factors IrxA, Nk1, Pax2/5/8 and Lim1, which are ultimately restricted to subregions of the border ectoderm (BE). Surprisingly, Nodal and BMP2/4, previously shown to be activators of ectodermal specification and the secondary embryonic axis, instead restrict the expression of these genes to subregions of the BE. A detailed examination showed that endodermal Wnt5 functions as a short-range signal that activates only a narrow band of ectodermal cells, even though all ectoderm is competent to receive the signal. Thus, cells in the BE integrate positive and negative signals from both the primary and secondary embryonic axes to correctly locate and specify the border ectoderm.
Angerer,
A BMP pathway regulates cell fate allocation along the sea urchin animal-vegetal embryonic axis.
2000, Pubmed,
Echinobase
Angerer,
A BMP pathway regulates cell fate allocation along the sea urchin animal-vegetal embryonic axis.
2000,
Pubmed
,
Echinobase Armstrong,
Cell-cell interactions regulate skeleton formation in the sea urchin embryo.
1993,
Pubmed
,
Echinobase Beddington,
Axis development and early asymmetry in mammals.
1999,
Pubmed Bhanot,
A new member of the frizzled family from Drosophila functions as a Wingless receptor.
1996,
Pubmed Bouwmeester,
Cerberus is a head-inducing secreted factor expressed in the anterior endoderm of Spemann's organizer.
1996,
Pubmed Bradham,
Chordin is required for neural but not axial development in sea urchin embryos.
2009,
Pubmed
,
Echinobase Bradham,
p38 MAPK is essential for secondary axis specification and patterning in sea urchin embryos.
2006,
Pubmed
,
Echinobase Briscoe,
Specification of neuronal fates in the ventral neural tube.
2001,
Pubmed Cameron,
LiCl perturbs ectodermal veg1 lineage allocations in Strongylocentrotus purpuratus embryos.
1997,
Pubmed
,
Echinobase Croce,
Frizzled5/8 is required in secondary mesenchyme cells to initiate archenteron invagination during sea urchin development.
2006,
Pubmed
,
Echinobase Croce,
A genome-wide survey of the evolutionarily conserved Wnt pathways in the sea urchin Strongylocentrotus purpuratus.
2006,
Pubmed
,
Echinobase Croce,
Dynamics of Delta/Notch signaling on endomesoderm segregation in the sea urchin embryo.
2010,
Pubmed
,
Echinobase Croce,
Wnt6 activates endoderm in the sea urchin gene regulatory network.
2011,
Pubmed
,
Echinobase Czerny,
The characterization of novel Pax genes of the sea urchin and Drosophila reveal an ancient evolutionary origin of the Pax2/5/8 subfamily.
1997,
Pubmed
,
Echinobase Dahmann,
Boundary formation and maintenance in tissue development.
2011,
Pubmed Davidson,
Specification of cell fate in the sea urchin embryo: summary and some proposed mechanisms.
1998,
Pubmed
,
Echinobase Davidson,
Lineage-specific gene expression and the regulative capacities of the sea urchin embryo: a proposed mechanism.
1989,
Pubmed
,
Echinobase Davidson,
A genomic regulatory network for development.
2002,
Pubmed
,
Echinobase Duboc,
Nodal and BMP2/4 signaling organizes the oral-aboral axis of the sea urchin embryo.
2004,
Pubmed
,
Echinobase Duboc,
Nodal and BMP2/4 pattern the mesoderm and endoderm during development of the sea urchin embryo.
2010,
Pubmed
,
Echinobase Duloquin,
Localized VEGF signaling from ectoderm to mesenchyme cells controls morphogenesis of the sea urchin embryo skeleton.
2007,
Pubmed
,
Echinobase Green,
Ror receptor tyrosine kinases: orphans no more.
2008,
Pubmed Guss,
Skeletal morphogenesis in the sea urchin embryo: regulation of primary mesenchyme gene expression and skeletal rod growth by ectoderm-derived cues.
1997,
Pubmed
,
Echinobase Hardin,
Commitment along the dorsoventral axis of the sea urchin embryo is altered in response to NiCl2.
1992,
Pubmed
,
Echinobase Hemmati-Brivanlou,
Inhibition of activin receptor signaling promotes neuralization in Xenopus.
1994,
Pubmed Ho,
Wnt5a-Ror-Dishevelled signaling constitutes a core developmental pathway that controls tissue morphogenesis.
2012,
Pubmed Inman,
SB-431542 is a potent and specific inhibitor of transforming growth factor-beta superfamily type I activin receptor-like kinase (ALK) receptors ALK4, ALK5, and ALK7.
2002,
Pubmed Katanaev,
Reggie-1/flotillin-2 promotes secretion of the long-range signalling forms of Wingless and Hedgehog in Drosophila.
2008,
Pubmed Lhomond,
Frizzled1/2/7 signaling directs β-catenin nuclearisation and initiates endoderm specification in macromeres during sea urchin embryogenesis.
2012,
Pubmed
,
Echinobase Li,
Direct and indirect control of oral ectoderm regulatory gene expression by Nodal signaling in the sea urchin embryo.
2012,
Pubmed
,
Echinobase Liem,
Dorsal differentiation of neural plate cells induced by BMP-mediated signals from epidermal ectoderm.
1995,
Pubmed Logan,
Nuclear beta-catenin is required to specify vegetal cell fates in the sea urchin embryo.
1999,
Pubmed
,
Echinobase MacDonald,
Wnt/beta-catenin signaling: components, mechanisms, and diseases.
2009,
Pubmed McClay,
Evolutionary crossroads in developmental biology: sea urchins.
2011,
Pubmed
,
Echinobase Mellitzer,
Eph receptors and ephrins restrict cell intermingling and communication.
1999,
Pubmed Mikels,
Purified Wnt5a protein activates or inhibits beta-catenin-TCF signaling depending on receptor context.
2006,
Pubmed Muñoz-Sanjuán,
Neural induction, the default model and embryonic stem cells.
2002,
Pubmed Nishita,
Cell/tissue-tropic functions of Wnt5a signaling in normal and cancer cells.
2010,
Pubmed Peter,
The endoderm gene regulatory network in sea urchin embryos up to mid-blastula stage.
2010,
Pubmed
,
Echinobase Rafiq,
The genomic regulatory control of skeletal morphogenesis in the sea urchin.
2012,
Pubmed
,
Echinobase Range,
Integration of canonical and noncanonical Wnt signaling pathways patterns the neuroectoderm along the anterior-posterior axis of sea urchin embryos.
2013,
Pubmed
,
Echinobase Revilla-i-Domingo,
A missing link in the sea urchin embryo gene regulatory network: hesC and the double-negative specification of micromeres.
2007,
Pubmed
,
Echinobase Roelink,
Floor plate and motor neuron induction by vhh-1, a vertebrate homolog of hedgehog expressed by the notochord.
1994,
Pubmed Röttinger,
FGF signals guide migration of mesenchymal cells, control skeletal morphogenesis [corrected] and regulate gastrulation during sea urchin development.
2008,
Pubmed
,
Echinobase Sasai,
Xenopus chordin: a novel dorsalizing factor activated by organizer-specific homeobox genes.
1994,
Pubmed Sato,
Morphological boundary forms by a novel inductive event mediated by Lunatic fringe and Notch during somitic segmentation.
2002,
Pubmed Saudemont,
Ancestral regulatory circuits governing ectoderm patterning downstream of Nodal and BMP2/4 revealed by gene regulatory network analysis in an echinoderm.
2010,
Pubmed
,
Echinobase Sethi,
Gene regulatory network interactions in sea urchin endomesoderm induction.
2009,
Pubmed
,
Echinobase Sherwood,
LvNotch signaling mediates secondary mesenchyme specification in the sea urchin embryo.
1999,
Pubmed
,
Echinobase Sherwood,
Identification and localization of a sea urchin Notch homologue: insights into vegetal plate regionalization and Notch receptor regulation.
1997,
Pubmed
,
Echinobase Smith,
Secreted noggin protein mimics the Spemann organizer in dorsalizing Xenopus mesoderm.
1993,
Pubmed Song,
Planar cell polarity breaks bilateral symmetry by controlling ciliary positioning.
2010,
Pubmed Su,
A perturbation model of the gene regulatory network for oral and aboral ectoderm specification in the sea urchin embryo.
2009,
Pubmed
,
Echinobase Sweet,
LvDelta is a mesoderm-inducing signal in the sea urchin embryo and can endow blastomeres with organizer-like properties.
2002,
Pubmed
,
Echinobase Watanabe,
EphrinB2 coordinates the formation of a morphological boundary and cell epithelialization during somite segmentation.
2009,
Pubmed Watanabe,
Tet-on inducible system combined with in ovo electroporation dissects multiple roles of genes in somitogenesis of chicken embryos.
2007,
Pubmed Xu,
In vivo cell sorting in complementary segmental domains mediated by Eph receptors and ephrins.
1999,
Pubmed Yaguchi,
Specification of ectoderm restricts the size of the animal plate and patterns neurogenesis in sea urchin embryos.
2006,
Pubmed
,
Echinobase Yaguchi,
TGFβ signaling positions the ciliary band and patterns neurons in the sea urchin embryo.
2010,
Pubmed
,
Echinobase
