Genes, HomeoboxHomeodomain ProteinsCell DifferentiationGene Expression Regulation, DevelopmentalTranscription FactorsMolecular Sequence DataIn Situ HybridizationBase SequenceAmino Acid SequenceLIM-Homeodomain ProteinsOtx Transcription FactorsAvian ProteinsGoosecoid ProteinBody PatterningRNA, MessengerDNA-Binding ProteinsStem CellsMSX1 Transcription FactorMorphogenesisCells, CulturedGene ExpressionMesodermTrans-ActivatorsCell LineageGene Expression RegulationRepressor ProteinsSequence Homology, Amino AcidSignal TransductionAntennapedia Homeodomain ProteinPhenotypeEmbryo, NonmammalianDrosophila ProteinsCell LineDrosophilaEndodermTretinoinCloning, MolecularNerve Tissue ProteinsEmbryo, MammalianMutationCell DivisionTranscription, GeneticReverse Transcriptase Polymerase Chain ReactionMice, TransgenicEye ProteinsPromoter Regions, GeneticDNA, ComplementaryEctodermEmbryonic Stem CellsChick EmbryoMultigene FamilyMice, KnockoutExtremitiesSex DifferentiationCell ProliferationZebrafish ProteinsEmbryonic and Fetal DevelopmentXenopus ProteinsDNA PrimersImmunohistochemistry