FIGURE 2.

A gradual conversion process into iNSCs. A, heat map representing the global gene expression profile of MEFs, e-iNSCs (passages 5 and 20), r-iNSCs (passage 10), and control NSCs. Genes that are more than 4-fold differentially expressed between MEFs and control NSCs are represented. The color bar at the top of the heat map indicates gene expression in log₂ scale. Red and green colors represent higher and lower expression levels, respectively. B, pairwise scatter plot analysis of the global gene expression profiles of MEFs, e-iNSCs (passages 5 and 20), r-iNSCs (passage 10), and control NSCs. The black lines delineate the boundaries of 2-fold difference in gene expression levels. C, FACS analysis of early (p5) and late passage (p20) of both e-iNSCs and r-iNSCs using antibody against SSEA1. D, immunofluorescence microscopy images of early (p5) and late (p20) passage of both e-iNSCs and r-iNSCs using antibody against Olig2. The Olig2-negative cells are indicated by arrowheads. E, DNA methylation status of second intron of Nestin and promoter region of Col1a1 in MEFs, e-iNSCs (passage 5 and 20), r-iNSCs (passage 10), and control NSCs was assessed by bisulfite sequencing PCR. Open and filled circles represent unmethylated and methylated CpGs, respectively.