Figure 2. Effects of combinations of reprogramming factors and SOX9 on formation of G418-resistant colonies from 1.7 × 105 Col11a2-βgeo transgenic reporter cells.
(A) Effects of removal of 1 reprogramming factor from 4 factors plus SOX9 on the formation of G418-resistant colonies from Col11a2-βgeo transgenic reporter MDFs. For metachromatic toluidine blue staining, **P < 0.01 compared with 4R + SOX9. (B) Morphology of cells induced by removal of c-Myc, Klf4, or Oct3/4 from 4 reprogramming factors plus SOX9 from βgeo MDFs and morphology of MDFs. Scale bars: 100 μm. (C) Effects of c-Myc and/or Klf4 plus SOX9 on the formation of G418-resistant colonies from βgeo MDFs. For metachromatic toluidine blue staining, **P < 0.01 compared with c-Myc + Klf4 + SOX9. The number of colonies composed of polygon-shaped cells is indicated by gray bars. (D) Morphology of cells induced by c-Myc, Klf4, and SOX9, c-Myc and SOX9, and Klf4 and SOX9 from βgeo MDFs. Scale bars: 100 μm. (E) Effects of c-Myc, Klf4, and SOX9 on the formation of G418-resistant colonies from ADSCs prepared from Col11a2-βgeo transgenic mice. For metachromatic toluidine blue staining, *P < 0.05. (F) Effects of various combinations of reprogramming factors and SOX9 on the formation of G418-resistant colonies from Col11a2-βgeo transgenic MEFs. For metachromatic toluidine blue staining, *P < 0.05 and **P < 0.01 compared with c-Myc + Klf4 + SOX9. Black bars indicate the number of all colonies, and white bars indicate the number of colonies stained with toluidine blue. Error bars indicate mean ± SD (n = 3). MOI for each vector in A and F was: pMXs-EGFP, 41; pMXs-c-Myc, 5; pMXs-Klf4, 11; pMXs-Oct3/4, 24; pMXs-Sox2, 16; pMXs-SOX9, 7. MOI for each vector in C and D was: pMXs-EGFP, 61; pMXs-c-Myc, 7; pMXs-Klf4, 16; pMXs-SOX9, 11.