Fig. 3.

Contribution of extra-embryonic tissues by hPSCs + BMI1. a−c Ten indicated DsRed⁺ cells were microinjected into 8C stage mouse embryos and analyzed after 48–60 h culture in vitro. a Representative images showing the integrated UH10-DsRed⁺ with BMI1 expression coexpress OCT4, ICM marker or CDX2, early trophoblast marker in cultured chimeric embryos. White arrow, DsRed⁺/OCT4⁺ cells; yellow arrow, DsRed⁺/CDX2⁺ cells; scale bars, 20 µm. b Images of blastocysts injected with ten indicated cells after 48–60 h culture in vitro; scale bars, 20 µm. c Summary of chimera assays with injection of ten indicated DsRed⁺ cells at the 8C stage embryo, and followed 48–60 h in vitro development into blastocyst stage. d−f Contribution of extra-embryonic tissues by the injected hPSCs in E10.5 mouse embryos. d Representative images of the E10.5 chemaric yolk sac with injection of the UH10-DsRed + BMI1 cells in later morulas or early blastocysts; scale bars, 1 mm. e Images of the E10.5 chimeric placentas with injection of the UH10-DsRed + BMI1 cells in later morulas or early blastocysts; scale bars, 1 mm. f Representative placenta confocal images showing DsRed⁺ human cells can contribute to trophoblastic lineages in chimeric E10.5 placentas. The placentas were stained with anti-CK7 and TPBPA. The bottom images are the zoom-in pictures of the areas of yellow box; scale bars, 50 µm (up), 25 µm (down). g Representive quantitative genomic PCR analysis of the human mitochondria DNA in E10.5 mouse yolk sacs and placentas after injection of the indicated cells; h Summary of positive yolk sacs and placentas. i Summary of contribution of both ExEm and Em in in vivo chimera experiments. Embryos were recovered at E10.5 stage. ExEm extra-embryonic tissues, Em embryos