Embryonic DevelopmentGene Expression Regulation, DevelopmentalEmbryonic and Fetal DevelopmentEmbryo, MammalianEmbryo, NonmammalianBlastocystZebrafishIn Situ HybridizationEmbryo LossMolecular Sequence DataPregnancyChick EmbryoZebrafish ProteinsOocytesZygoteCell DifferentiationMorphogenesisTranscription FactorsBody PatterningMesodermHomeodomain ProteinsAmino Acid SequenceSignal TransductionRNA, MessengerBase SequenceGenes, LethalMice, KnockoutPhenotypeGene TargetingOrganogenesisNervous SystemEmbryo Culture TechniquesDevelopmental BiologyMutationXenopus ProteinsEmbryonic Stem CellsGastrulaFertilizationFertilization in VitroTime FactorsDrosophila ProteinsMice, TransgenicOvumMice, Inbred C57BLDrosophilaOogenesisImmunohistochemistryDNA, ComplementarySequence Homology, Amino AcidDNA-Binding ProteinsStem CellsYolk SacXenopus laevisWnt ProteinsEctodermBlastulaCells, CulturedEmbryo ImplantationHedgehog ProteinsMorulaReverse Transcriptase Polymerase Chain ReactionCloning, MolecularGastrulationSomitesMice, Mutant StrainsEndodermAnimals, Genetically ModifiedDrosophila melanogasterGene ExpressionNeural TubeNeural CrestParthenogenesisGenes, HomeoboxCell MovementGene Expression ProfilingCentral Nervous SystemCell LineageTissue DistributionTranscription, GeneticLarvaEmbryologyModels, BiologicalGerm LayersXenopusBone Morphogenetic ProteinsHomozygoteDNA PrimersExtremitiesSpermatozoaGestational AgeOrgan SpecificityTrans-ActivatorsPlacentaMice, Inbred ICRHeartRepressor ProteinsBlastomeresSequence AlignmentNuclear ProteinsEye