GastrulaGastrulationEmbryo, NonmammalianXenopus ProteinsMesodermFetal ProteinsOrganizers, EmbryonicEmbryonic InductionXenopus laevisNotochordEctodermBody PatterningGene Expression Regulation, DevelopmentalXenopusEndodermMorphogenesisT-Box Domain ProteinsNervous SystemIn Situ HybridizationBlastulaGoosecoid ProteinMolecular Sequence DataAmino Acid SequenceMicroscopy, Electron, ScanningPleurodelesZebrafishSignal TransductionCell MovementZebrafish ProteinsBase SequenceSea UrchinsBone Morphogenetic ProteinsTriturusHomeodomain ProteinsOtx Transcription FactorsNodal ProteinBlastomeresGenes, HomeoboxActivinsUrochordataGerm LayersKillifishesBlastocystFibroblast Growth FactorsPrimitive StreakSOXF Transcription FactorsBlastodermTissue TransplantationTranscription FactorsChordataEmbryologySomitesTailMicroinjectionsBone Morphogenetic Protein 4Chordata, NonvertebrateCentral Nervous SystemCell LineageCloning, MolecularSalamandridaeSequence Homology, Amino AcidEmbryonic DevelopmentNeural PlateZygoteRhombencephalonNeural CrestRNA, MessengerLIM-Homeodomain ProteinsDNA, ComplementaryDNA-Binding ProteinsInhibinsCypriniformesProteinsLarvaBone Morphogenetic Protein ReceptorsEchinodermataIntercellular Signaling Peptides and ProteinsRepressor ProteinsTrans-ActivatorsCell DifferentiationRanidaeHead