Organizers, EmbryonicNucleolus Organizer RegionLigandsGoosecoid ProteinBody PatterningEmbryonic InductionGastrulaXenopus ProteinsSilver StainingEmbryologyGene Expression Regulation, DevelopmentalOtx Transcription FactorsEmbryo, NonmammalianZebrafish ProteinsHomeodomain ProteinsCD40 LigandXenopusMesodermFibroblast Growth Factor 8Intercellular Signaling Peptides and ProteinsFas Ligand ProteinNodal ProteinSignal TransductionRhombencephalonNotochordNodal Signaling LigandsHydraIn Situ HybridizationZebrafishWnt ProteinsMolecular Sequence DataMesencephalonXenopus laevisAxisBone Morphogenetic ProteinsHeadEctodermProtein BindingAmino Acid SequenceTissue TransplantationNervous SystemMorphogenesisLIM-Homeodomain ProteinsSilverTranscription FactorsCell NucleolusBinding SitesProteinsWnt1 ProteinActivinsGenes, HomeoboxGlycoproteinsLeft-Right Determination FactorsEndodermRANK LigandMetencephalonFetal ProteinsBlastulaModels, MolecularT-Box Domain ProteinsFibroblast Growth FactorsCarrier ProteinsMembrane GlycoproteinsRNA, MessengerBase SequenceProtein Structure, TertiaryTwins, ConjoinedMembrane ProteinsChick EmbryoCell LineBlastodermTransforming Growth Factor betaBone Morphogenetic Protein 4Sequence Homology, Amino AcidMutationMatrix Attachment Region Binding ProteinsRepressor ProteinsCD30 Ligandbeta CateninTNF-Related Apoptosis-Inducing LigandCell DifferentiationModels, BiologicalSilver NitrateTrans-ActivatorsNerve Tissue ProteinsTectum MesencephaliDNA-Binding ProteinsCells, CulturedInhibinsAmphibiansHepatocyte Nuclear Factor 3-betaHedgehog ProteinsReceptors, Cell SurfaceNeural PlateOX40 LigandProsencephalonReceptors, NotchMicroinjectionsStaining and LabelingCentral Nervous System