{"id":25031,"date":"2023-09-05T20:00:00","date_gmt":"2023-09-06T00:00:00","guid":{"rendered":"https:\/\/platohealth.ai\/complete-human-day-14-post-implantation-embryo-models-from-naive-es-cells-nature\/"},"modified":"2023-09-05T20:00:00","modified_gmt":"2023-09-06T00:00:00","slug":"complete-human-day-14-post-implantation-embryo-models-from-naive-es-cells-nature","status":"publish","type":"post","link":"https:\/\/platohealth.ai\/complete-human-day-14-post-implantation-embryo-models-from-naive-es-cells-nature\/","title":{"rendered":"Complete human day 14 post-implantation embryo models from na\u00efve ES cells – Nature","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

The ability to study human post-implantation development remains limited due to ethical and technical challenges associated with intrauterine development after implantation1<\/sup>. Embryo-like models with spatially organized morphogenesis of all defining embryonic and extra-embryonic tissues of the post-implantation human conceptus (i.e., embryonic disk, bilaminar disk, yolk- and chorionic sacs, surrounding trophoblasts) remain lacking2<\/sup>. Mouse na\u00efve embryonic stem cells (ESCs) have recently been shown to give rise to embryonic and extra-embryonic stem cells capable of self-assembling into post-gastrulation mouse Structured Stem cell-based Embryo Models with spatially organized morphogenesis (SEMs)3<\/sup>. Here, we extend these findings to humans, while using only genetically unmodified human na\u00efve ESCs (in HENSM conditions)4<\/sup>. Such human fully integrated SEMs recapitulate the organization of nearly all known lineages and compartments of post-implantation human embryos including epiblast, hypoblast, extra-embryonic mesoderm, and trophoblast surrounding the latter layers. These human complete SEMs demonstrated developmental growth dynamics that resemble key hallmarks of post-implantation stage embryogenesis up to 13-14 days post-fertilization (dpf) (Carnegie stage 6a). This includes embryonic disk and bilaminar disk formation, epiblast lumenogenesis, polarized amniogenesis, anterior-posterior symmetry breaking, PGC specification, polarized yolk sac with visceral and parietal endoderm, extra-embryonic mesoderm expansion that defines a chorionic cavity and a connecting stalk, a trophoblast surrounding compartment demonstrating syncytium and lacunae formation. This SEM platform may enable the experimental interrogation of previously inaccessible windows of human early post-implantation up to peri-gastrulation development.<\/p>\n