Limb BudsExtremitiesLimb Deformities, CongenitalChick EmbryoMesodermChondrogenesisCartilageGene Expression Regulation, DevelopmentalEmbryo, MammalianPolydactylyFibroblast Growth Factor 4Limb SalvageHedgehog ProteinsEctodermForelimbMorphogenesisPhantom LimbFibroblast Growth Factor 8Fibroblast Growth FactorsBody PatterningIn Situ HybridizationHindlimbWingEmbryonic InductionHomeodomain ProteinsBone Morphogenetic ProteinsLegMSX1 Transcription FactorGenes, HomeoboxAmbystoma mexicanumLower ExtremityQuailIschemiaAmputationRegenerationTrans-ActivatorsToesEctromeliaFibroblast Growth Factor 10Bone Morphogenetic Protein 2Transcription FactorsAvian ProteinsSalamandridaeSomitesEmbryonic and Fetal DevelopmentArmProteinsSyndactylyMuscle, SkeletalTretinoinMolecular Sequence DataLoop of HenleBone Morphogenetic Protein 4Upper ExtremityTeratogensNotophthalmus viridescensTime FactorsSignal TransductionCell DifferentiationKruppel-Like Transcription FactorsPaired Box Transcription FactorsAmbystomaCoturnixMutationWnt ProteinsSOX9 Transcription FactorFeathersBase SequenceMusclesFootMice, TransgenicMice, Mutant StrainsAmino Acid SequenceT-Box Domain ProteinsAmputeesGene ExpressionBone and BonesChimera