Generation of human blastocyst-like structures from pluripotent stem cells

Abstract

Abstract Human blastocysts are comprised of the first three cell lineages of the embryo: trophectoderm, epiblast, and primitive endoderm, all of which are essential for early development and organ formation 1,2 . However, due to ethical concerns and restricted access to human blastocysts, we lack a comprehensive understanding of early human embryogenesis. To bridge this knowledge gap, we need a reliable model system that recapitulates early stages of human embryogenesis. Here we report a ∼three-dimensional (3D), two-step induction protocol for generating blastocyst-like structures (EPS-blastoids) from human extended pluripotent stem (EPS) cells. Morphological and single-cell transcriptomic analyses revealed that EPS-blastoids contain key cell lineages and are transcriptionally similar to human blastocysts. Furthermore, EPS-blastoids also exhibited the developmental potential to undergo post-implantation morphogenesis in vitro to form structures with a cellular composition and transcriptome signature similar to human embryos that had been cultured in vitro for 8 or 10 days. In conclusion, human EPS-blastoids provide a new experimental platform for studying early developmental stages of the human embryo. Highlights A method for generating human blastoids from EPS cells. Human blastoids resemble blastocysts in terms of morphology and cell lineage composition. Single-cell transcriptomic analyses reveal EPI, PE, and TE cell lineages in human blastoids. Human blastoids mimic in vitro the morphogenetic events of pre- and early post-implantation stages.