Figure 2.
OCT4 overexpression promotes ES cell self-renewal without LIF, GSK3i, or FBS (A) Alkaline phosphatase (AP) staining of wild-type ES cells (R1) cultured in ES cell media containing FBS, LIF and GSK3i. (B) Schematic of experimental design. iOCT4 ES cells were grown in LIF-independent ES cell media containing FBS and without doxycycline (−LIF/+GSK3i/+FBS/−dox) to induce OCT4 transgene overexpression for at least 30 days. iOCT4 and wild-type ES cells were then cultured in LIF-independent ES cell media without LIF, GSK3i, or doxycycline (−LIF/−GSK3i/+FBS/−dox) for 11 days, and subsequently stained for AP. (C) AP staining of wild-type ES cells cultured in FBS-containing media, and with GSK3i (top) or without GSK3i (bottom). (D,E) AP staining of LIF-independent iOCT4 ES cells cultured in LIF-independent ES cell media containing FBS with GSK3i (top) or without GSK3i (bottom). (F) ES cells were scored by AP staining. The percentage of AP positive colonies is represented as mean ± SEM. p values were calculated using a t test. (G) Schematic of experimental design. Wild-type and iOCT4 ES cells were transitioned to serum-free media over 8–10 days, and subsequently cultured and passaged in serum-free media for 1–2 weeks. (H) Bright-field microscopy (top) and AP staining (bottom) of wild-type ES cells cultured in LIF-independent serum-free ES cell media without GSK3i for 21 days. (I,J) Bright-field microscopy (top) and AP staining (bottom) of iOCT4 ES cells cultured in LIF-independent serum-free ES cell media without GSK3i or doxycycline for 21 days. (K) ES cells were scored by AP staining. The percentage of AP positive colonies is represented as mean ± SEM. p values were calculated using a t test. (L,N) AP staining of (L) wild-type ES cells and (M,N) LIF-independent ES cells cultured at low density (500 cells / 6-well) in serum-free media, and with JAKi (bottom) or without JAKi (top). (O) ES cells were scored by AP staining. The percentage of AP positive colonies is represented as mean ± SEM. p values were calculated using a t test.