Fig. 2. Derivation of naive hESCs under normoxia (21% O₂).

a Schematic diagram of the AIC-N medium by incorporating the key components for the maintenance of naive pluripotency³⁹ into the AIC medium.³⁵ b Representative phase contrast images showing the generation of naive hESCs (AIC-N hESCs) from blastocysts and by conversion of primed hPSCs under normoxia. Four AIC-N hESC lines were established from seven blastocysts. The conversion of primed hPSCs required addition of valproic acid (VPA) for 4–6 d. c Immunostaining of naive, primed and general pluripotency markers for AIC-N hESCs. d Principle componet analysis (PCA) of the gene expression profiles of hPSCs grown in various conditions. e Whole-genome CpG methylation levels of four AIC-N hESC lines and three primed hPSC (CC-hPSC) lines based on bisulfite sequencing (BS-seq) analysis. f CpG methylation levels at X-linked promoter CpG islands (CGIs) (left), non-CGI promoter regions (middle) and random 2 kb bins (right) in AIC-N hESCs and CC-hPSCs. The random 2 kb bins do not overlap any CGIs or non-CG promoters. Promoters are defined as +/−1 kb regions around transcription start sites. g Representative phase contrast and immunostaining images showing the generation of blastoids from AIC-N hESCs. h Quantification of the percentage of blastoids comprising three lineages (TE-, HB- and EPI-like cells), three independent experiments; more than 100 blastoids were quantified for each experiment. Data are presented as mean ± SD. Scale bars, 100 µm. See also Supplementary information, Fig. S2.