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.
Development
2011 Aug 01;13815:3297-306. doi: 10.1242/dev.058792.
Show Gene links
Show Anatomy links
Wnt6 activates endoderm in the sea urchin gene regulatory network.
Croce J
,
Range R
,
Wu SY
,
Miranda E
,
Lhomond G
,
Peng JC
,
Lepage T
,
McClay DR
.
???displayArticle.abstract???
In the sea urchin, entry of β-catenin into the nuclei of the vegetal cells at 4th and 5th cleavages is necessary for activation of the endomesoderm gene regulatory network. Beyond that, little is known about how the embryo uses maternal information to initiate specification. Here, experiments establish that of the three maternal Wnts in the egg, Wnt6 is necessary for activation of endodermal genes in the endomesoderm GRN. A small region of the vegetal cortex is shown to be necessary for activation of the endomesoderm GRN. If that cortical region of the egg is removed, addition of Wnt6 rescues endoderm. At a molecular level, the vegetal cortex region contains a localized concentration of Dishevelled (Dsh) protein, a transducer of the canonical Wnt pathway; however, Wnt6 mRNA is not similarly localized. Ectopic activation of the Wnt pathway, through the expression of an activated form of β-catenin, of a dominant-negative variant of GSK-3β or of Dsh itself, rescues endomesoderm specification in eggs depleted of the vegetal cortex. Knockdown experiments in whole embryos show that absence of Wnt6 produces embryos that lack endoderm, but those embryos continue to express a number of mesoderm markers. Thus, maternal Wnt6 plus a localized vegetal cortical molecule, possibly Dsh, is necessary for endoderm specification; this has been verified in two species of sea urchin. The data also show that Wnt6 is only one of what are likely to be multiple components that are necessary for activation of the entire endomesoderm gene regulatory network.
Cha,
Wnt11/5a complex formation caused by tyrosine sulfation increases canonical signaling activity.
2009,
Pubmed
Cha,
Wnt5a and Wnt11 interact in a maternal Dkk1-regulated fashion to activate both canonical and non-canonical signaling in Xenopus axis formation.
2008,
Pubmed
Chuang,
Transient appearance of Strongylocentrotus purpuratus Otx in micromere nuclei: cytoplasmic retention of SpOtx possibly mediated through an alpha-actinin interaction.
1996,
Pubmed
,
Echinobase
Croce,
Coquillette, a sea urchin T-box gene of the Tbx2 subfamily, is expressed asymmetrically along the oral-aboral axis of the embryo and is involved in skeletogenesis.
2003,
Pubmed
,
Echinobase
Croce,
Dynamics of Delta/Notch signaling on endomesoderm segregation in the sea urchin embryo.
2010,
Pubmed
,
Echinobase
Croce,
A genome-wide survey of the evolutionarily conserved Wnt pathways in the sea urchin Strongylocentrotus purpuratus.
2006,
Pubmed
,
Echinobase
Davidson,
A genomic regulatory network for development.
2002,
Pubmed
,
Echinobase
Davidson,
Lineage-specific gene expression and the regulative capacities of the sea urchin embryo: a proposed mechanism.
1989,
Pubmed
,
Echinobase
Emily-Fenouil,
GSK3beta/shaggy mediates patterning along the animal-vegetal axis of the sea urchin embryo.
1998,
Pubmed
,
Echinobase
Ghiglione,
Early gene expression along the animal-vegetal axis in sea urchin embryoids and grafted embryos.
1996,
Pubmed
,
Echinobase
Hardin,
Commitment along the dorsoventral axis of the sea urchin embryo is altered in response to NiCl2.
1992,
Pubmed
,
Echinobase
Hörstadius,
[Not Available].
1927,
Pubmed
Kenny,
Tight regulation of SpSoxB factors is required for patterning and morphogenesis in sea urchin embryos.
2003,
Pubmed
,
Echinobase
Kenny,
SpSoxB1, a maternally encoded transcription factor asymmetrically distributed among early sea urchin blastomeres.
1999,
Pubmed
,
Echinobase
Kiyomoto,
Reconstruction of Starfish Eggs by Electric Cell Fusion: A New Method of Detect the Cytoplasmic Determinant for Archenteron Formation: (starfish/cell fusion/archenteron differentiation/determinant/egg polarity).
1993,
Pubmed
,
Echinobase
Leonard,
Analysis of dishevelled localization and function in the early sea urchin embryo.
2007,
Pubmed
,
Echinobase
Logan,
Nuclear beta-catenin is required to specify vegetal cell fates in the sea urchin embryo.
1999,
Pubmed
,
Echinobase
McClay,
A micromere induction signal is activated by beta-catenin and acts through notch to initiate specification of secondary mesenchyme cells in the sea urchin embryo.
2000,
Pubmed
,
Echinobase
McClay,
Regulative capacity of the archenteron during gastrulation in the sea urchin.
1996,
Pubmed
,
Echinobase
Minokawa,
cis-Regulatory inputs of the wnt8 gene in the sea urchin endomesoderm network.
2005,
Pubmed
,
Echinobase
Momose,
Two oppositely localised frizzled RNAs as axis determinants in a cnidarian embryo.
2007,
Pubmed
Nasevicius,
Evidence for a frizzled-mediated wnt pathway required for zebrafish dorsal mesoderm formation.
1998,
Pubmed
Oliveri,
A regulatory gene network that directs micromere specification in the sea urchin embryo.
2002,
Pubmed
,
Echinobase
Oliveri,
Repression of mesodermal fate by foxa, a key endoderm regulator of the sea urchin embryo.
2006,
Pubmed
,
Echinobase
Owraghi,
Roles of the Wnt effector POP-1/TCF in the C. elegans endomesoderm specification gene network.
2010,
Pubmed
Peter,
The endoderm gene regulatory network in sea urchin embryos up to mid-blastula stage.
2010,
Pubmed
,
Echinobase
Range,
LvGroucho and nuclear beta-catenin functionally compete for Tcf binding to influence activation of the endomesoderm gene regulatory network in the sea urchin embryo.
2005,
Pubmed
,
Echinobase
Rizzo,
Identification and developmental expression of the ets gene family in the sea urchin (Strongylocentrotus purpuratus).
2006,
Pubmed
,
Echinobase
Röttinger,
A Raf/MEK/ERK signaling pathway is required for development of the sea urchin embryo micromere lineage through phosphorylation of the transcription factor Ets.
2004,
Pubmed
,
Echinobase
Sandmann,
A core transcriptional network for early mesoderm development in Drosophila melanogaster.
2007,
Pubmed
Sardet,
A marker of animal-vegetal polarity in the egg of the sea urchin Paracentrotus lividus. The pigment band.
1985,
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,
A gene regulatory network subcircuit drives a dynamic pattern of gene expression.
2007,
Pubmed
,
Echinobase
Smith,
Regulative recovery in the sea urchin embryo and the stabilizing role of fail-safe gene network wiring.
2009,
Pubmed
,
Echinobase
Stamateris,
The expression and distribution of Wnt and Wnt receptor mRNAs during early sea urchin development.
2010,
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
Tao,
Maternal wnt11 activates the canonical wnt signaling pathway required for axis formation in Xenopus embryos.
2005,
Pubmed
Terasaki,
Large plasma membrane disruptions are rapidly resealed by Ca2+-dependent vesicle-vesicle fusion events.
1997,
Pubmed
,
Echinobase
Thorpe,
Wnt signaling polarizes an early C. elegans blastomere to distinguish endoderm from mesoderm.
1997,
Pubmed
Vonica,
TCF is the nuclear effector of the beta-catenin signal that patterns the sea urchin animal-vegetal axis.
2000,
Pubmed
,
Echinobase
Weitzel,
Differential stability of beta-catenin along the animal-vegetal axis of the sea urchin embryo mediated by dishevelled.
2004,
Pubmed
,
Echinobase
Wessel,
Sequential expression of germ-layer specific molecules in the sea urchin embryo.
1985,
Pubmed
,
Echinobase
Wikramanayake,
Nuclear beta-catenin-dependent Wnt8 signaling in vegetal cells of the early sea urchin embryo regulates gastrulation and differentiation of endoderm and mesodermal cell lineages.
2004,
Pubmed
,
Echinobase
Wikramanayake,
beta-Catenin is essential for patterning the maternally specified animal-vegetal axis in the sea urchin embryo.
1998,
Pubmed
,
Echinobase
Zeitlinger,
Whole-genome ChIP-chip analysis of Dorsal, Twist, and Snail suggests integration of diverse patterning processes in the Drosophila embryo.
2007,
Pubmed