Gene expression profiles and proliferation abilities of Sca-1 high-expressing cell populations analyzed by RT-PCR and CCK-8. A. Expression of stem cell-related genes Nanog and TERT, cardiac precursor-related genes ISL-1 and TBX5, early cardiogenic genes GATA4, Nkx2.5, MEF2c, and mature cardiomyocyte specific gene α-MHC was analyzed by RT-PCR. RNA extracted from whole postnatal mouse heart (mH) was used as a positive control. (n = 3). B. Proliferation abilities were tested with CCK-8. Five successive time points were chosen: days 1 (24 hours after seeding), 3, 5, 7, and 9. Proliferation abilities of these cell populations were indirectly measured by the OD value at 450 nm. (n = 3). (*P < 0.01 vs P7, P28; #P < 0.01 vs d1).