Cell DifferentiationCells, CulturedStem CellsGene Expression Regulation, DevelopmentalTranscription FactorsSex DifferentiationSignal TransductionCell LineEmbryonic Stem CellsCell LineageCell DivisionRNA, MessengerGene Expression RegulationCell ProliferationTretinoinMolecular Sequence DataDNA-Binding ProteinsOsteogenesisOsteoblastsAntigens, DifferentiationReverse Transcriptase Polymerase Chain ReactionHomeodomain ProteinsBase SequenceMice, Inbred C57BLPhenotypeMesenchymal Stromal CellsImmunohistochemistryAdipogenesisMice, KnockoutGene Expression