Figure 1.

Msx2 mediated the beneficial functions of BMP4. A–C, different concentrations of BMP4 and LDN-193189 were used for different periods during reprogramming. The ability of BMP4 to up-regulate Msx2 were determined by qPCR on day 4 in both in MEFs and during reprogramming. D and E, Msx1/2/3 were overexpressed during reprogramming without BMP4 or suppressed during reprogramming with 2.5 ng/ml BMP4. GFP⁺ colonies were counted on day 15. F, the expression of Msx2 was modulated for different periods during reprogramming. GFP⁺ colonies were counted on day 15. G and H, mutations of MSX2 with deletion of different domains were constructed. Their functions during reprogramming were determined. All experiments were repeated at least five times. One-way ANOVA with Dunnett's post hoc test was used. *, p < 0.05; **, p < 0.01; ***, p < 0.001; ns, not significant.