Fig. 2

MYL2^Neo/w and MYL2^EGFP/w hESCs maintained pluripotency and the ability to differentiate into highly pure cardiomyocytes. a MYL2^Neo/w and MYL2^EGFP/w hESCs maintained pluripotent stem cell morphology (bright field (BF)), positive alkaline phosphatase (AP) staining, and expression of the pluripotency markers OCT4, SOX2, Nanog, and SSEA-4. Scale bars, 200 μm. b Quantitative PCR examining endogenous expression of the pluripotency factors relative to GAPDH in MYL2^Neo/w and MYL2^EGFP/w hESCs. Data obtained from three independent experiments. Wildtype hESCs (H7) used as controls. c Undifferentiated MYL2^Neo/w and MYL2^EGFP/w hESCs formed teratomas, which exhibited tissues of all three developmental germ layers: ectoderm (e.g., sebaceous gland cells), mesoderm (e.g., cartilage cells), and endoderm (e.g., gland cells). Scale bars, 200 μm. d Purity of MYL2^Neo/w and MYL2^EGFP/w hESC-derived cardiomyocytes detected by flow cytometry analysis of cardiac specific marker cTnT. e Immunostaining showing MYL2^Neo/w and MYL2^EGFP/w hESC-derived cardiomyocytes expressed cardiomyocyte specific proteins sarcomeric α-actinin, cTnT, MLC-2v, and MLC-2a. Scale bars, 50 μm. EGFP enhanced green fluorescent protein, MLC-2v cardiac ventricular isoform of myosin light chain-2, MYL2 myosin light chain 2