Limb BudsExtremitiesChick EmbryoMesodermGene Expression Regulation, DevelopmentalForelimbHedgehog ProteinsMorphogenesisIn Situ HybridizationFibroblast Growth FactorsBody PatterningLimb Deformities, CongenitalPolydactylyHomeodomain ProteinsFibroblast Growth Factor 4EctodermFibroblast Growth Factor 8WingCartilageLimb SalvageEmbryonic InductionHindlimbBone Morphogenetic ProteinsMSX1 Transcription FactorGenes, HomeoboxQuailPhantom Limb