EctodermClone CellsEmbryo, NonmammalianEmbryo, MammalianChick EmbryoGene Expression Regulation, DevelopmentalGastrulaEmbryonic InductionMesodermEmbryo ImplantationBody PatterningBlastocystEmbryonic DevelopmentMorphogenesisIn Situ HybridizationXenopus ProteinsEndodermNervous SystemMolecular Sequence DataEmbryonic and Fetal DevelopmentBase SequenceSea UrchinsHomeodomain ProteinsCloning, MolecularAmino Acid SequenceBone Morphogenetic ProteinsNeural CrestBlastomeresXenopusEmbryo LossGerm LayersXenopus laevisCleavage Stage, OvumBone Morphogenetic Protein 4Cell DifferentiationTranscription FactorsZebrafishZebrafish ProteinsPregnancyFertilization in VitroRNA, MessengerZygoteGastrulationExtremitiesFibroblast Growth FactorsEmbryonic StructuresNotochordSignal TransductionNeural PlateChimeraFibroblast Growth Factor 8QuailDNA, ComplementaryCulture TechniquesDrosophilaGenes, HomeoboxDrosophila ProteinsBlastulaWnt ProteinsCell LineageTissue TransplantationNodal ProteinEmbryo DispositionEctogenesisBlastodermPaired Box Transcription FactorsSequence Homology, Amino AcidMorulaSomitesMutationDNA-Binding ProteinsBranchial RegionCentral Nervous SystemOocytesOtx Transcription FactorsHedgehog ProteinsPhenotypeTrans-ActivatorsLimb BudsGene ExpressionLens, CrystallineDNACryopreservationCloning, OrganismHeadAnimals, Genetically ModifiedMicroinjectionsOrganizers, EmbryonicTime FactorsDNA PrimersProteinsModels, BiologicalStrongylocentrotus purpuratusCoturnixEmbryo ResearchRepressor ProteinsEpidermisTranscription, GeneticRhombencephalonSingle Embryo Transfer