Figure 5. Klf4 and Oct4 Are Sufficient to Induce NS Cell Conversion to a Pre-iPS Cell State That Can Be Further Converted by 2i/LIF.
(A) Pre-iPS cell colonies 3 wk after infection of aNS cells with Oct4 and Klf4.
(B) Appearance of clusters of cells expressing Oct4-GFP within established pre-iPS colonies, after switch into 2i/LIF.
(C) Established 2i-iPS cell line generated by two-factor infection.
(D) RT-PCR analysis for pluripotency markers in two-factor 2i-iPS cells.
(E) Genomic PCR confirms retroviral integration of Oct4 and Klf4 only.
(F and G) Immunofluorescence staining for Oct4 and me3K27 (F) or Nanog (G) in 2i-iPS cells generated without exogenous Sox2 and cMyc.
(H) Adult chimera generated from injection of adult NS cell–derived two-factor 2i-iPS cells into C57BL/6 host blastocyst.
(I) Schematic comparison of the reprogramming dynamics of NS cells infected with either four, three (–Sox2), or two (–Sox2 and –cMyc) factors.