Improvement in pluripotency of BGHPES-2 after treatment with ascorbic acid. (A) Procedure of ascorbic acid treatment. At passages 3, 5 and 10 after treatment with ascorbic acid, a portion of cells was collected for molecular testing and another portion injected into SCID mice to form teratomas. (B) Paternally expressed genes were up-regulated in BGHPES-2 at passages 5 and 10. (C) No differences were observed for maternally expressed genes in BGHPES-2 at passage 0, 3, 5 and 10. (D) Rate of teratoma formation was increased in BGHPES-2 at passage 5 and 10. No differences in methylation modifications of IG-DMR and MEG3-DMR in BGHPES-2 were detected at passages 0 (E), 3 (F), 5 (G) and 10 (H). Different letters indicate significant differences among data (P <0.05) while the same letters are used to signify no differences (P >0.05). IG-DMR intergenic differentially methylated region; SCID, severe combined immunodeficiency.