Embryonic StructuresGene Expression Regulation, DevelopmentalBody PatterningEmbryonic DevelopmentEmbryo, MammalianEmbryo, NonmammalianZebrafishIn Situ HybridizationMesodermEmbryonic and Fetal DevelopmentBlastocystEmbryo LossChick EmbryoMolecular Sequence DataZebrafish ProteinsPregnancyOocytesZygoteMorphogenesisCell DifferentiationTranscription FactorsHomeodomain ProteinsBase SequenceSignal TransductionAmino Acid SequenceRNA, MessengerGenes, LethalMice, KnockoutGene TargetingPhenotypeOrganogenesisNervous SystemEmbryo Culture TechniquesDevelopmental BiologyXenopus ProteinsEmbryonic Stem CellsGastrulaMutationFertilizationFertilization in VitroDrosophila ProteinsOvumMice, TransgenicDrosophilaOogenesisMice, Inbred C57BLDNA, ComplementaryYolk SacDNA-Binding ProteinsStem CellsSequence Homology, Amino AcidImmunohistochemistryXenopus laevisEctodermBlastulaWnt ProteinsMorulaHedgehog ProteinsEmbryo ImplantationGastrulationTime FactorsSomitesCloning, MolecularCells, CulturedReverse Transcriptase Polymerase Chain ReactionMice, Mutant StrainsEndodermAnimals, Genetically ModifiedNeural TubeNeural CrestDrosophila melanogasterParthenogenesisGenes, HomeoboxGene ExpressionCell MovementCentral Nervous SystemCell LineageEmbryologyModels, BiologicalTissue DistributionGene Expression ProfilingGerm LayersLarvaTranscription, GeneticXenopusBone Morphogenetic ProteinsHomozygoteExtremitiesDNA PrimersSpermatozoaOrgan SpecificityTrans-ActivatorsMice, Inbred ICRBlastomeresRepressor ProteinsPlacentaGestational AgeHeartEyeNuclear Proteins