Limited access to embryos has hampered the study of human embryogenesis and disorders that occur during early pregnancy. Human pluripotent stem cells provide an alternative means to study human development in a dish^{1,2,3,4,5,6,7}. Recent advances in partial embryo models derived from human pluripotent stem cells have enabled human development to be examined at early post-implantation stages^{8,9,10,11,12,13,14}. However, models of the pre-implantation human blastocyst are lacking. Starting from naive human pluripotent stem cells, here we developed an effective three-dimensional culture strategy with successive lineage differentiation and self-organization to generate blastocyst-like structures in vitro. These structures—which we term ‘human blastoids’—resemble human blastocysts in terms of their morphology, size, cell number, and composition and allocation of different cell lineages. Single-cell RNA-sequencing analyses also reveal the transcriptomic similarity of blastoids to blastocysts. Human blastoids are amenable to embryonic and extra-embryonic stem cell derivation and can further develop into peri-implantation embryo-like structures in vitro. Using chemical perturbations, we show that specific isozymes of protein kinase C have a critical function in the formation of the blastoid cavity. Human blastoids provide a readily accessible, scalable, versatile and perturbable alternative to blastocysts for studying early human development, understanding early pregnancy loss and gaining insights into early developmental defects.

对胚胎的有限获取阻碍了对人类胚胎发生和妊娠早期疾病的研究。人类多能干细胞提供了一种替代方法来研究人类在培养皿中的发育^{1,2,3,4,5,6,7}。源自人类多能干细胞的部分胚胎模型的最新进展使人类发育能够在植入后早期阶段进行检查^{8,9,10,11,12,13,14}. 然而，缺乏植入前人类胚泡的模型。从幼稚的人类多能干细胞开始，我们在这里开发了一种有效的三维培养策略，具有连续的谱系分化和自组织，以在体外产生胚泡样结构。这些结构——我们称之为“人类胚泡”——在形态、大小、细胞数量以及不同细胞谱系的组成和分配方面与人类胚泡相似。单细胞 RNA 测序分析还揭示了胚泡与胚泡的转录组相似性。人类胚状体适合于胚胎和胚胎外干细胞衍生，并且可以在体外进一步发展为植入周围胚胎样结构。使用化学扰动，我们表明蛋白激酶 C 的特定同工酶在胚状体腔的形成中具有关键作用。人类胚泡为研究早期人类发育、了解早期流产和深入了解早期发育缺陷提供了一种易于获得、可扩展、多功能和可扰动的胚泡替代方案。