Generation of Blastocyst-like Structures from Extended Pluripotent Stem Cells

A single mouse blastomere from until 8-cell embryo can generate an entire blastocyst. Whether blastomere-like extended pluripotent stem cells (EPS cells) retain a similar generative capacity remains unknown. Here, we established a 3D differentiation system that enabled the generation of blastocyst-like structures from EPS cells (EPS-blastoids) through lineage segregation and self-organization. EPS-blastoids resembled blastocysts in morphology and cell lineage allocation. EPS-blastoids formation recapitulated key morphogenetic events during preimplantation and early postimplantation development in vitro. Upon transfer, some EPS-blastoids underwent implantation, induced decidualization, and generated live, albeit disorganized, tissues in utero. Single cell and bulk RNA-sequencing analysis revealed that EPS-blastoids contained all three blastocyst cell lineages and shared transcriptional similarity with natural blastocysts. We also provide proof-of-concept that EPS-blastoids can be generated from somatic cells via cellular reprograming. EPS-blastoids provide a unique platform for studying early embryogenesis, and pave the way to generate viable synthetic embryos using cultured cells. Overall design: To exaimine the similarity and difference between EPS-blasotids and nature blastocysts (control)