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???
Anterior signaling centers help specify and pattern the early anterior neuroectoderm (ANE) in many deuterostomes. In sea urchin the ANE is restricted to the anterior of the late blastula stage embryo, where it forms a simple neural territory comprising several types of neurons as well as the apical tuft. Here, we show that during early development, the sea urchin ANE territory separates into inner and outer regulatory domains that express the cardinal ANE transcriptional regulators FoxQ2 and Six3, respectively. FoxQ2 drives this patterning process, which is required to eliminate six3 expression from the inner domain and activate the expression of Dkk3 and sFRP1/5, two secreted Wnt modulators. Dkk3 and low expression levels of sFRP1/5 act additively to potentiate the Wnt/JNK signaling pathway governing the positioning of the ANE territory around the anterior pole, whereas high expression levels of sFRP1/5 antagonize Wnt/JNK signaling. sFRP1/5 and Dkk3 levels are rigidly maintained via autorepressive and cross-repressive interactions with Wnt signaling components and additional ANE transcription factors. Together, these data support a model in which FoxQ2 initiates an anterior patterning center that implements correct size and positions of ANE structures. Comparisons of functional and expression studies in sea urchin, hemichordate and chordate embryos reveal striking similarities among deuterostome ANE regulatory networks and the molecular mechanism that positions and defines ANE borders. These data strongly support the idea that the sea urchin embryo uses an ancient anterior patterning system that was present in the common ambulacrarian/chordate ancestor.
Bafico,
Interaction of frizzled related protein (FRP) with Wnt ligands and the frizzled receptor suggests alternative mechanisms for FRP inhibition of Wnt signaling.
1999, Pubmed
Bafico,
Interaction of frizzled related protein (FRP) with Wnt ligands and the frizzled receptor suggests alternative mechanisms for FRP inhibition of Wnt signaling.
1999,
Pubmed
Bafico,
Novel mechanism of Wnt signalling inhibition mediated by Dickkopf-1 interaction with LRP6/Arrow.
2001,
Pubmed
Bhat,
Structure-function analysis of secreted frizzled-related protein-1 for its Wnt antagonist function.
2007,
Pubmed
Bovolenta,
Beyond Wnt inhibition: new functions of secreted Frizzled-related proteins in development and disease.
2008,
Pubmed
Burke,
Sea urchin neural development and the metazoan paradigm of neurogenesis.
2014,
Pubmed
,
Echinobase
Castro,
Neuronal Organization of the Brain in the Adult Amphioxus (Branchiostoma lanceolatum): A Study With Acetylated Tubulin Immunohistochemistry.
2015,
Pubmed
Cavodeassi,
Brain regionalization: of signaling centers and boundaries.
2012,
Pubmed
Cavodeassi,
Integration of anterior neural plate patterning and morphogenesis by the Wnt signaling pathway.
2014,
Pubmed
Cruciat,
Secreted and transmembrane wnt inhibitors and activators.
2013,
Pubmed
Darras,
β-catenin specifies the endomesoderm and defines the posterior organizer of the hemichordate Saccoglossus kowalevskii.
2011,
Pubmed
,
Echinobase
Dufourcq,
Regulation of endothelial cell cytoskeletal reorganization by a secreted frizzled-related protein-1 and frizzled 4- and frizzled 7-dependent pathway: role in neovessel formation.
2008,
Pubmed
Echevarría,
Neuroepithelial secondary organizers and cell fate specification in the developing brain.
2003,
Pubmed
Esteve,
Secreted frizzled-related proteins are required for Wnt/β-catenin signalling activation in the vertebrate optic cup.
2011,
Pubmed
Fritzenwanker,
The Fox/Forkhead transcription factor family of the hemichordate Saccoglossus kowalevskii.
2014,
Pubmed
,
Echinobase
Garner,
Neurogenesis in sea urchin embryos and the diversity of deuterostome neurogenic mechanisms.
2016,
Pubmed
,
Echinobase
Holland,
Gene duplication, co-option and recruitment during the origin of the vertebrate brain from the invertebrate chordate brain.
2008,
Pubmed
Houart,
Establishment of the telencephalon during gastrulation by local antagonism of Wnt signaling.
2002,
Pubmed
Hsu,
Novel intronic microRNA represses zebrafish myf5 promoter activity through silencing dickkopf-3 gene.
2010,
Pubmed
Kiecker,
A morphogen gradient of Wnt/beta-catenin signalling regulates anteroposterior neural patterning in Xenopus.
2001,
Pubmed
Kong,
Characterization of sFRP2-like in amphioxus: insights into the evolutionary conservation of Wnt antagonizing function.
2012,
Pubmed
Kozmik,
Pax-Six-Eya-Dach network during amphioxus development: conservation in vitro but context specificity in vivo.
2007,
Pubmed
Lagutin,
Six3 repression of Wnt signaling in the anterior neuroectoderm is essential for vertebrate forebrain development.
2003,
Pubmed
Li,
Encoding regulatory state boundaries in the pregastrular oral ectoderm of the sea urchin embryo.
2014,
Pubmed
,
Echinobase
Lin,
The cysteine-rich frizzled domain of Frzb-1 is required and sufficient for modulation of Wnt signaling.
1997,
Pubmed
Mao,
Kremen proteins are Dickkopf receptors that regulate Wnt/beta-catenin signalling.
2002,
Pubmed
Mao,
LDL-receptor-related protein 6 is a receptor for Dickkopf proteins.
2001,
Pubmed
Marlow,
Larval body patterning and apical organs are conserved in animal evolution.
2014,
Pubmed
Marlow,
Ectopic activation of the canonical wnt signaling pathway affects ectodermal patterning along the primary axis during larval development in the anthozoan Nematostella vectensis.
2013,
Pubmed
Mii,
Secreted Frizzled-related proteins enhance the diffusion of Wnt ligands and expand their signalling range.
2009,
Pubmed
Mii,
Secreted Wnt "inhibitors" are not just inhibitors: regulation of extracellular Wnt by secreted Frizzled-related proteins.
2011,
Pubmed
Momose,
Two oppositely localised frizzled RNAs as axis determinants in a cnidarian embryo.
2007,
Pubmed
Nakajima,
Divergent patterns of neural development in larval echinoids and asteroids.
2004,
Pubmed
,
Echinobase
Nakamura,
Analysis of Dickkopf3 interactions with Wnt signaling receptors.
2010,
Pubmed
Nordström,
Progressive induction of caudal neural character by graded Wnt signaling.
2002,
Pubmed
Onai,
Essential role of Dkk3 for head formation by inhibiting Wnt/β-catenin and Nodal/Vg1 signaling pathways in the basal chordate amphioxus.
2012,
Pubmed
Pani,
Ancient deuterostome origins of vertebrate brain signalling centres.
2012,
Pubmed
Posnien,
Candidate gene screen in the red flour beetle Tribolium reveals six3 as ancient regulator of anterior median head and central complex development.
2011,
Pubmed
Range,
Specification and positioning of the anterior neuroectoderm in deuterostome embryos.
2014,
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
Rentzsch,
FGF signalling controls formation of the apical sensory organ in the cnidarian Nematostella vectensis.
2008,
Pubmed
Rodriguez,
SFRP1 regulates the growth of retinal ganglion cell axons through the Fz2 receptor.
2005,
Pubmed
Röttinger,
A framework for the establishment of a cnidarian gene regulatory network for "endomesoderm" specification: the inputs of ß-catenin/TCF signaling.
2012,
Pubmed
Semënov,
Head inducer Dickkopf-1 is a ligand for Wnt coreceptor LRP6.
2001,
Pubmed
Seo,
Expression of two zebrafish homologues of the murine Six3 gene demarcates the initial eye primordia.
1998,
Pubmed
Sethi,
Multicolor labeling in developmental gene regulatory network analysis.
2014,
Pubmed
,
Echinobase
Sinigaglia,
The bilaterian head patterning gene six3/6 controls aboral domain development in a cnidarian.
2013,
Pubmed
Steinmetz,
Six3 demarcates the anterior-most developing brain region in bilaterian animals.
2010,
Pubmed
Tendeng,
Cloning and embryonic expression of five distinct sfrp genes in the zebrafish Danio rerio.
2006,
Pubmed
Uren,
Secreted frizzled-related protein-1 binds directly to Wingless and is a biphasic modulator of Wnt signaling.
2000,
Pubmed
Veeck,
Targeting the Wnt pathway in cancer: the emerging role of Dickkopf-3.
2012,
Pubmed
Wei,
A database of mRNA expression patterns for the sea urchin embryo.
2006,
Pubmed
,
Echinobase
Wei,
The sea urchin animal pole domain is a Six3-dependent neurogenic patterning center.
2009,
Pubmed
,
Echinobase
Wikramanayake,
An ancient role for nuclear beta-catenin in the evolution of axial polarity and germ layer segregation.
2003,
Pubmed
Wilson,
Early steps in the development of the forebrain.
2004,
Pubmed
Yaguchi,
Fez function is required to maintain the size of the animal plate in the sea urchin embryo.
2011,
Pubmed
,
Echinobase
Yaguchi,
ankAT-1 is a novel gene mediating the apical tuft formation in the sea urchin embryo.
2010,
Pubmed
,
Echinobase
Yaguchi,
A Wnt-FoxQ2-nodal pathway links primary and secondary axis specification in sea urchin embryos.
2008,
Pubmed
,
Echinobase
Yaguchi,
Zinc finger homeobox is required for the differentiation of serotonergic neurons in the sea urchin embryo.
2012,
Pubmed
,
Echinobase
Yu,
AmphiFoxQ2, a novel winged helix/forkhead gene, exclusively marks the anterior end of the amphioxus embryo.
2003,
Pubmed
