TGF-β signaling plays an essential role in the lineage specification of mesenchymal stem/progenitor cells in fetal bone marrow

TGF-β regulates fetale bone marrow niche emergence. Abrogating TGF-β signaling in mesenchymal cells during development results in a marked expansion of adipocytes and CAR cells in the bone marrow, while osteoblasts are reduced. RNA expression data from Osx-Cre targeted mesenchymal stromal cells obtained from E16.5 mouse hindlimbs of transgenic mice lacking Tgfbr2 in mesenchymal stromal cells or littermate controls. TdTomato+ hematopoietic lineage- (CD45, B220, CDllb, and Gr1) cells were sorted from the hindlimbs of E16.5 Osx-Cre, Ai9 or Osx-Cre, Tgfbr2flfl Ai9 mice. RNA was isolated and expression profiling performed.