Gene Expression Regulation, DevelopmentalIn Situ HybridizationEmbryo, NonmammalianZebrafishEmbryonic DevelopmentEmbryo, MammalianMolecular Sequence DataEmbryonic StructuresBody PatterningAmino Acid SequenceMesodermDNA, ComplementaryBase SequenceEmbryonic and Fetal DevelopmentBlastocystEmbryo LossZygoteOocytesTranscription FactorsNervous SystemHomeodomain ProteinsZebrafish ProteinsXenopus ProteinsRNA, MessengerSequence Homology, Amino AcidGastrulaGene Expression ProfilingMorphogenesisGenes, HomeoboxCloning, MolecularDNA-Binding ProteinsGene ExpressionCell DifferentiationDrosophila ProteinsDrosophilaFertilizationPregnancyChick EmbryoXenopus laevisEctodermTissue DistributionPhenotypeGene TargetingReverse Transcriptase Polymerase Chain ReactionOogenesisDrosophila melanogasterXenopusEmbryo Culture TechniquesMutationSequence AlignmentPhylogenyGastrulationTranscription, GeneticEmbryologyMice, TransgenicSignal TransductionEmbryonic Stem CellsFibroblast Growth Factor 9ImmunohistochemistryMice, KnockoutGerm LayersTime FactorsFertilization in VitroGene Expression RegulationBlastulaTrans-ActivatorsMorulaDNA PrimersSomitesNuclear ProteinsCentral Nervous SystemBlastomeresOligonucleotide Array Sequence AnalysisOvumGenes, LethalGenes, InsectExtremitiesEndodermEmbryo ImplantationChordata, NonvertebrateMultigene FamilyPromoter Regions, GeneticOrgan SpecificityCleavage Stage, OvumMice, Inbred C57BLBlotting, NorthernLac OperonNerve Tissue ProteinsMice, Inbred StrainsCells, CulturedMembrane ProteinsStem CellsSpermatozoaChromosome MappingEmbryonic InductionMice, Mutant StrainsCell LineagePolymerase Chain ReactionParthenogenesisCattle