FIGURE 3.

In vitro iPSCs and neural progenitor cells produced from adult mouse fibroblasts (see Materials and Methods). The panels show that control (absence of the 20866 vector) tail cells still retain their original shape on Day 47 after culturing (A). The presence of the mOrange marker suggests that the fibroblasts have successfully integrated the 20866 plasmid (B). The iPSCs were further characterized by an alkaline phosphatase live stain (C), as well as staining of the three cell-surface stage-specific embryonic antigens: SSEA-1 to -4 (D–F), TRA-1-60 (G), TRA-1-81 (H), and Oct-4 (I). By Day 18, iPSCs began displaying projections (J) and further differentiation was clearly evident by Days 20, 23, and 28 (K–M), respectively. By the later time point (M), the cells had morphology consistent with that of neural progenitor cells and displayed a robust induction of the immature neuronal marker, doublecortin (N).