6533b7d6fe1ef96bd12671de
RESEARCH PRODUCT
Early asymmetric cues triggering the dorsal/ventral gene regulatory network of the sea urchin embryo
Giovanni SpinelliVincenzo Cavalierisubject
Embryo NonmammalianTranscription GeneticEctodermp38 Mitogen-Activated Protein Kinasessymmetry breakingdorsal ventral axis sea urchin embryo nodal homeodomain repressor p38 MAPKAnimals Genetically ModifiedCell polarityMorphogenesisGene Regulatory NetworksBiology (General)ZebrafishSea urchinsea urchin embryoGeneticsbiologyGeneral NeuroscienceQRdorsal/ventral polarityCell PolarityGene Expression Regulation DevelopmentalEmbryoGeneral MedicineCell biologymedicine.anatomical_structureGene Knockdown Techniquesembryonic structuresParacentrotusMedicineCuesResearch Articleanimal structuresQH301-705.5Nodal ProteinScienceEmbryonic DevelopmentSettore BIO/11 - Biologia Molecolarep38 MAPKModels BiologicalGeneral Biochemistry Genetics and Molecular Biologybiology.animalEctodermmedicineAnimalsBody PatterningHomeodomain ProteinsGeneral Immunology and MicrobiologyotherCell Biologybiology.organism_classificationEmbryonic stem cellhomeodomain repressorRepressor ProteinsDevelopmental Biology and Stem CellsnodalNODALDevelopmental biologydescription
Dorsal/ventral (DV) patterning of the sea urchin embryo relies on a ventrally-localized organizer expressing Nodal, a pivotal regulator of the DV gene regulatory network. However, the inceptive mechanisms imposing the symmetry-breaking are incompletely understood. In Paracentrotus lividus, the Hbox12 homeodomain-containing repressor is expressed by prospective dorsal cells, spatially facing and preceding the onset of nodal transcription. We report that Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent transcription. Reciprocally, impairing hbox12 function disrupts DV polarity by allowing ectopic expression of nodal. Clonal loss-of-function, inflicted by blastomere transplantation or gene-transfer assays, highlights that DV polarization requires Hbox12 action in dorsal cells. Remarkably, the localized knock-down of nodal restores DV polarity of embryos lacking hbox12 function. Finally, we show that hbox12 is a dorsal-specific negative modulator of the p38-MAPK activity, which is required for nodal expression. Altogether, our results suggest that Hbox12 function is essential for proper positioning of the DV organizer. DOI: http://dx.doi.org/10.7554/eLife.04664.001
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-09-09 | eLife |