Fig. 2: The generation and characterization of hESCs-QKI^del.

A Schematic diagram of the exon 3 targeting site for designing guide RNAs using the CRISPR/Cas9 strategy and a representative Western blot screening for positively targeted clones, which is confirmed by additional two repeats of western blottings and followed by sequencing confirmation. B Representative confocal images of immunofluorescence staining confirming the genetic ablation of QKI-5. No detectable positive QKI-5 expression was found in mutant H1-8 cells, whereas there was strong nuclear QKI-5 expression (green fluorescence signal) in control H1 cells. Three independent sets of cells are used in the analysis and the finding is consistently confirmed. C Representative heatmap of Maestro-MEA assay for contractile function comparing Day-30 cardiomyocytes derived from control hESCs (H1) and hESCs-QKI^del (H1-8). D Comparison of the relative contractility and the excitation–contraction delay between Day-30 cardiomyocytes derived from control hESCs (H1) and hESCs-QKI^del (H1-8). Significantly reduced contractility and prolonged E–C delay in cardiomyocytes derived from hESCs-QKI^del when compared to cardiomyocytes derive from control hESCs. Data are shown as the mean ± SEM and statistical significance was determined by a two-tailed Student’s t-test.