Organizers, EmbryonicCellular StructuresNucleolus Organizer RegionGoosecoid ProteinGastrulaEmbryonic InductionXenopus ProteinsCellsBody PatterningEmbryologyElectron Microscope TomographyXenopusMicroscopyMesodermEmbryo, NonmammalianGene Expression Regulation, DevelopmentalMicroscopy, FluorescenceXenopus laevisZebrafish ProteinsProteinsHomeodomain ProteinsOrganellesMicroscopy, Fluorescence, MultiphotonCytoskeletonCell Physiological PhenomenaNodal ProteinMicroscopy, ConfocalIntercellular Signaling Peptides and ProteinsBone Morphogenetic ProteinsEctodermSilver StainingMolecular Sequence DataMicrotubulesImaging, Three-DimensionalStaining and LabelingActinsSignal TransductionWnt ProteinsIn Situ HybridizationMicroscopy, ElectronModels, BiologicalAmphibiansAmino Acid SequenceActivinsBone Morphogenetic Protein 4Nervous SystemMorphogenesisOtx Transcription FactorsNanotechnologyLuminescent ProteinsActin CytoskeletonGenes, HomeoboxMicroscopy, Electron, ScanningGreen Fluorescent ProteinsFluorescent DyesT-Box Domain ProteinsMicrofilament ProteinsMicrotubule-Associated ProteinsCell LineFibroblast Growth Factor 8InhibinsGlycoproteinsCell MembraneTransforming Growth Factor betaTubulinTranscription FactorsRhombencephalonMicroinjectionsNotochordCell NucleusCell CompartmentationCytoplasmHydraImage Processing, Computer-AssistedMesencephalonAxisNodal Signaling LigandsZebrafishBone Morphogenetic Protein 7HeadCells, CulturedMembrane ProteinsProtein TransportProtein BindingProteomicsRepressor ProteinsTissue TransplantationNuclear ProteinsLIM-Homeodomain ProteinsHeLa CellsMutationSilverFluorescent Antibody TechniqueRecombinant Fusion ProteinsCell NucleolusImmunohistochemistrySequence Homology, Amino AcidCytoskeletal ProteinsTime FactorsWnt1 Protein