Figure 2

Human induced pluripotent stem cells and human embryonic stem cells follow the same temporal course of neural differentiation. (a) Phase contrast images show that embryonic stem (ES) cells and induced pluripotent stem (iPS) cells grew as individual colonies, differentiated to columnar epithelial cells at days 8 to 10, and formed neural tube-like rosettes at day 15. (b) Both iPS cells and ES cells were positive for OCT4 at day 0, for PAX6 but not SOX1 at days 8 to 10, and for both PAX6 and SOX1 at day 15. (c) Fluorescence activated cell sorting analysis indicates that differentiating cells from H9 human embryonic stem cells (hESCs), iPS(IMR90)-1 and -4, iPS-M4-10, iPS-DF6-9-12, and iPS109 began to generate PAX6-expressing cells at days 6 to 8, and reached a plateau at day 14 but with different efficiency. (d,e) By 12 weeks in culture, many MAP2+ neurons also expressed synapsin (SYN); (e) higher magnification indicates a punctuate staining pattern on the cell bodies and neurites. (f) Glial fibrillary acidic protein (GFAP)-positive astrocytes were present in differentiated cultures at 12 weeks. (g) O4-positive oligodendrocytes were observed in cultures after 16 weeks. O4, oligodendrocyte marker referring to oligodendrocyte clone number 4. Scale bars: 50 μm. Reprinted from [86] with permission from the National Academy of Sciences.