Fig. 4: Characterization of embryonic and extraembryonic developmental potentials of xeno-free hEPS cells in vitro and in vivo.

a Representative images showing histological analysis of teratomas generated from xeno-free hEPS cells. Scale bars, 100 µm. Similar images were obtained in at least 3 independent experiments. b Phase contrast images of primed and XF-EPS cells. To derive hTSC-like cells, primed hPSCs and XF-EPS cells were cultured in hTSC medium. Primed H1 and XF H1-EPS cells were used. Scale bars, 100 µm. Similar images were obtained in at least three independent experiments. c Representative immune-staining images showing the marker expression of XF-EPS cells and hTSC-like cells. XF H1-EPS cells were used. Scale bars, 100 µm. Similar images were obtained in at least three independent experiments. d Representative images showing chimerism of xeno-free hEPS cells in E4.5 mouse blastocysts. GFP, anti-GFP antibody. White and yellow arrows indicate GFP + cells with OCT4 and CDX2 expression respectively. Scale bar, 100 µm. Similar images were obtained in at least 5 independent experiments. e Chimerism of XF-EPS cells, naive hPSCs and primed hPSCs in E6.5 mouse conceptuses. Representative images of chimerism were shown. A summary of the chimeric experiment was also shown. Scale bar, 500 µm. f Immunofluorescent staining of E6.5 chimeric embryos showing lineage contributions of xeno-free hEPS derivatives to epiblast or trophoblast lineages. mclover+ ES1-EPS cells were used. Embryos were stained for OCT4 (epiblast), CK18 (trophoblast compartment) and mclover (GFP). White and yellow arrows indicate GFP + cells with OCT4 and CK18 expression respectively. Scale bars, 50 µm. Similar images were obtained in at least 5 independent experiments. Experiments in a–f were all independently repeated at least three times with similar results.