<p>A: Schematic representation of the colony formation unit assay protocol. Cells seeded at P2 were allowed to form single-cell-derived colonies with or without 10<sup>-7</sup> M dexamethasone for 7 days before osteogenic induction. ND-ND indicates normal growth medium at P0, P1, and P2. ND-D indicates normal growth medium at P0 and P1 and dexamethasone-containing medium at P2. D-ND indicates dexamethasone-containing medium at P0 and P1 and normal growth medium at P2. D-D indicates dexamethasone-containing medium at P0, P1, and P2. Gross images of BMSCs (B) and MuSCs (D) in each dish stained by ALP and crystal violet. Quantification of the total colony number and fraction of ALP-positive colonies (%) among total colonies in BMSCs (C) and MuSCs (E). *** denotes P < 0.001 as determined by Student’s t-test.</p