Limb BudsExtremitiesCell ProliferationChick EmbryoLimb Deformities, CongenitalPolydactylyMesodermFibroblast Growth Factor 4Gene Expression Regulation, DevelopmentalHedgehog ProteinsEctodermMorphogenesisFibroblast Growth FactorsFibroblast Growth Factor 8In Situ HybridizationSignal TransductionCells, CulturedForelimbCell DifferentiationBody PatterningWingCell DivisionHomeodomain ProteinsCartilageBone Morphogenetic ProteinsApoptosisLimb SalvageEmbryonic InductionHindlimbTranscription FactorsTrans-ActivatorsMSX1 Transcription FactorGenes, HomeoboxQuailRNA, MessengerImmunohistochemistryCell MovementMolecular Sequence DataCell CycleCell Line, TumorRegenerationMice, TransgenicEmbryo, MammalianPhantom LimbTime FactorsMice, Inbred C57BLGene ExpressionProteinsAmbystoma mexicanumCell SurvivalBase SequenceMutationMice, KnockoutFibroblast Growth Factor 10BromodeoxyuridineBone Morphogenetic Protein 2ChondrogenesisCell LineDNA-Binding ProteinsStem CellsReverse Transcriptase Polymerase Chain ReactionTretinoinLymphocyte ActivationEmbryonic and Fetal DevelopmentBlotting, WesternProto-Oncogene ProteinsAmino Acid SequencePhenotypeModels, BiologicalBone Morphogenetic Protein 4Avian ProteinsKruppel-Like Transcription FactorsWnt ProteinsSomitesMice, Mutant StrainsEctromeliaGene Expression RegulationIntercellular Signaling Peptides and ProteinsToesKi-67 AntigenDown-RegulationGrowth SubstancesTransforming Growth Factor betaPhosphorylationFibroblast Growth Factor 2Proliferating Cell Nuclear AntigenPaired Box Transcription FactorsOrgan Culture TechniquesDNA PrimersT-LymphocytesSalamandridaeTeratogensFlow CytometryEpithelial CellsSyndactylyLegTransfectionTumor Cells, CulturedSOX9 Transcription FactorEpithelium