Differentiation potential of subcultured cells from Sca-1+-enriched population into smooth muscle-like cells in vitro. A- C. All cell populations were stained for the smooth muscle specific marker SMA (green), smooth muscle MHC (green), calponin (green) and DAPI (blue) after induction. Scale bar = 200 μm. D. Expression of smooth muscle specific genes α-SMA and calponin was analyzed by RT-PCR. RNA extracted from whole postnatal mouse heart (mH) was used as a positive control.