Activin Receptors, Type IIActivin ReceptorsActivinsActivin Receptors, Type IMyostatinInhibinsFollistatinInhibin-beta SubunitsReceptors, Growth FactorSmad2 ProteinReceptors, Transforming Growth Factor betaTransforming Growth Factor betaBone Morphogenetic ProteinsSignal TransductionFollicle Stimulating Hormone, beta SubunitRNA, MessengerNodal ProteinMesodermSmad ProteinsGrowth SubstancesGonadotrophsZona ReticularisGlycoproteinsGrowth Differentiation FactorsBone Morphogenetic Protein Receptors, Type IMolecular Sequence DataGene ExpressionBone Morphogenetic Protein Receptors, Type IIOvaryCell DifferentiationSmad3 ProteinProtein-Serine-Threonine KinasesSmad4 ProteinReverse Transcriptase Polymerase Chain ReactionAmino Acid SequenceIn Situ HybridizationEmbryonic InductionGene Expression Regulation, DevelopmentalXenopus ProteinsImmunohistochemistryCells, CulturedMyositis OssificansXenopusFollicle Stimulating Hormone