Organizers, EmbryonicNucleolus Organizer RegionGoosecoid ProteinGastrulaBody PatterningEmbryonic InductionGene Expression Regulation, DevelopmentalXenopus ProteinsEmbryo, NonmammalianSilver StainingMesodermHomeodomain ProteinsIn Situ HybridizationEmbryologyZebrafish ProteinsXenopusMorphogenesisOtx Transcription FactorsEmbryo, MammalianChick EmbryoEctodermNotochordNervous SystemZebrafishXenopus laevisFibroblast Growth Factor 8EndodermNodal ProteinBone Morphogenetic ProteinsRhombencephalonEmbryonic DevelopmentHydraMolecular Sequence DataMesencephalonEmbryonic and Fetal DevelopmentYolk SacAxisNodal Signaling LigandsTranscription FactorsDevelopmental BiologyIntercellular Signaling Peptides and ProteinsWnt ProteinsGenes, HomeoboxHeadFetal ProteinsTissue TransplantationSignal TransductionLIM-Homeodomain ProteinsSilverAmino Acid SequenceBase SequenceCell NucleolusRNA, MessengerQuailCell DifferentiationProteinsWnt1 ProteinActivinsLeft-Right Determination FactorsBlastocystTissue DistributionCentral Nervous SystemNeural CrestMetencephalonHedgehog ProteinsCell AggregationRepressor ProteinsDNA-Binding ProteinsBlastulaT-Box Domain ProteinsTrans-ActivatorsExtremitiesGlycoproteinsCloning, MolecularSequence Homology, Amino AcidTwins, ConjoinedFibroblast Growth FactorsGestational AgeBlastodermPregnancyImmunohistochemistryCoturnixAminomethyltransferaseCell LineageMatrix Attachment Region Binding ProteinsModels, BiologicalDrosophilaBone Morphogenetic Protein 4Silver NitrateCarrier ProteinsDrosophila ProteinsDNA Primersbeta CateninHepatocyte Nuclear Factor 3-betaAmphibiansDNA, ComplementaryTransforming Growth Factor betaInhibinsMutationTectum Mesencephali