SomitesCellular StructuresOrganizers, EmbryonicNucleolus Organizer RegionCellsBody PatterningGoosecoid ProteinMesodermEmbryonic InductionElectron Microscope TomographyNotochordGene Expression Regulation, DevelopmentalMicroscopyGastrulaMicroscopy, FluorescenceXenopus ProteinsZebrafish ProteinsEmbryo, NonmammalianChick EmbryoOrganellesMicroscopy, Fluorescence, MultiphotonIn Situ HybridizationMicroscopy, ConfocalZebrafishCytoskeletonCell Physiological PhenomenaSilver StainingModels, BiologicalMicrotubulesQuailStaining and LabelingMorphogenesisImaging, Three-DimensionalHomeodomain ProteinsMicroscopy, ElectronActinsProteinsMolecular Sequence DataCoturnixOtx Transcription FactorsEmbryologyFibroblast Growth Factor 8Signal TransductionXenopusEctodermMicroscopy, Electron, ScanningAmino Acid SequenceNervous SystemRhombencephalonNanotechnologyTissue TransplantationLuminescent ProteinsGreen Fluorescent ProteinsWnt ProteinsActin CytoskeletonFluorescent DyesMyogenic Regulatory Factor 5Bone Morphogenetic ProteinsXenopus laevisMicrofilament ProteinsCell LineHeadMicrotubule-Associated ProteinsTranscription FactorsMembrane ProteinsNodal ProteinCell MembraneMesencephalonTubulinGenes, HomeoboxCell NucleusMutationIntercellular Signaling Peptides and ProteinsPaired Box Transcription FactorsImage Processing, Computer-AssistedCell CompartmentationCells, CulturedCytoplasmHydraNeural CrestMyoD ProteinImmunohistochemistryTime FactorsWnt1 ProteinHedgehog ProteinsFetal ProteinsAxisNodal Signaling LigandsEndodermT-Box Domain ProteinsNuclear ProteinsProtein BindingAvian ProteinsEmbryonic and Fetal DevelopmentLIM-Homeodomain ProteinsProtein TransportProteomicsFibroblast Growth FactorsTailEmbryonic Development