GastrulationGastrulaMovementEmbryo, NonmammalianMesodermGene Expression Regulation, DevelopmentalBody PatterningXenopus ProteinsEndodermZebrafishEctodermEye MovementsZebrafish ProteinsMorphogenesisIn Situ HybridizationEmbryonic InductionCell MovementXenopus laevisFetal ProteinsXenopusBlastulaNotochordNodal ProteinGerm LayersBlastodermPrimitive StreakEmbryonic DevelopmentWnt ProteinsOrganizers, EmbryonicT-Box Domain ProteinsBone Morphogenetic ProteinsPleurodelesHead MovementsNervous SystemSignal TransductionGoosecoid ProteinMovement DisordersMolecular Sequence DataHomeodomain ProteinsSea UrchinsEmbryonic and Fetal DevelopmentPlant Viral Movement ProteinsAmino Acid SequenceActivinsTranscription FactorsNodal Signaling LigandsHeadModels, BiologicalCell PolarityDrosophila ProteinsBlastomeresChick EmbryoFetal MovementDrosophilaPsychomotor PerformanceFibroblast Growth FactorsLeft-Right Determination FactorsCell LineageGenes, HomeoboxZygoteBone Morphogenetic Protein 4SomitesPhenotypeSequence Homology, Amino AcidBase SequenceTime FactorsMutationBlastocystCell DifferentiationTailOtx Transcription FactorsMicroinjectionsSaccadesNeural PlateArmEmbryo, MammalianElectromyographyUrochordataBiomechanical PhenomenaAnimals, Genetically ModifiedFrizzled ReceptorsOligonucleotides, AntisenseRNA, MessengerCadherinsIntercellular Signaling Peptides and ProteinsTolloid-Like MetalloproteinasesProteinsMorpholinosLytechinusHandTransforming Growth Factor betaAmphibiansDNA-Binding ProteinsAvian ProteinsCentral Nervous SystemCell AdhesionFixation, OcularNeurulationChimeraMicroscopy, Electron, Scanning