Organizers, EmbryonicNucleolus Organizer RegionEmbryonic DevelopmentGoosecoid ProteinBody PatterningGene Expression Regulation, DevelopmentalGastrulaEmbryonic InductionEmbryo, NonmammalianXenopus ProteinsSilver StainingZebrafish ProteinsEmbryologyHomeodomain ProteinsMesodermZebrafishIn Situ HybridizationOtx Transcription FactorsXenopusEmbryonic and Fetal DevelopmentMorphogenesisFibroblast Growth Factor 8Embryo, MammalianRhombencephalonNotochordWnt ProteinsNodal ProteinNervous SystemEctodermXenopus laevisBone Morphogenetic ProteinsBlastocystTranscription FactorsIntercellular Signaling Peptides and ProteinsMesencephalonHeadHydraNodal Signaling LigandsSignal TransductionChick EmbryoMolecular Sequence DataAxisGenes, HomeoboxTissue TransplantationLIM-Homeodomain ProteinsEndodermBlastulaCell NucleolusAmino Acid SequenceWnt1 ProteinSilverFetal ProteinsActivinsCell DifferentiationZygoteT-Box Domain ProteinsProteinsRNA, MessengerBase SequenceFibroblast Growth FactorsEmbryo LossBlastodermLeft-Right Determination FactorsHedgehog ProteinsRepressor Proteinsbeta CateninDNA-Binding ProteinsGlycoproteinsBone Morphogenetic Protein 4MetencephalonTrans-ActivatorsMutationOocytesCentral Nervous SystemTransforming Growth Factor betaPhenotypeDevelopmental BiologyDrosophila ProteinsDrosophilaSequence Homology, Amino AcidBlastomeresPregnancySomitesMicroinjectionsNerve Tissue ProteinsCell LineageNeural TubeTwins, ConjoinedAnimals, Genetically ModifiedGenes, DevelopmentalMice, KnockoutAmphibiansModels, BiologicalCloning, MolecularMatrix Attachment Region Binding ProteinsHepatocyte Nuclear Factor 3-betaNeural PlateOrganogenesisVertebratesCarrier Proteins