Pluripotent cells in the mammalian embryo undergo state transitions marked by changes in patterns of gene expression and developmental potential as they progress from pre-implantation through post-implantation stages of development. Recent studies of cultured mouse and human pluripotent stem cells (hPSCs) have identified cells representative of an intermediate stage (referred to as the formative state) between naive pluripotency (equivalent to pre-implantation epiblast) and primed pluripotency (equivalent to late post-implantation epiblast). We examine these recent findings in light of our knowledge of peri-implantation mouse and human development, and we consider the implications of this work for deriving human embryo models from pluripotent cells.

哺乳动物胚胎中的多能细胞经历状态转变，其特征是基因表达模式和发育潜力的变化，因为它们从植入前发育到植入后发育阶段。最近对培养的小鼠和人类多能干细胞 (hPSC) 的研究已经确定了代表幼稚多能性（相当于植入前外胚层）和启动多能性（相当于植入后晚期）之间的中间阶段（称为形成状态）的细胞外胚层）。我们根据我们对胚胎植入期小鼠和人类发育的了解来检查这些最近的发现，并考虑这项工作对从多能细胞中获得人类胚胎模型的意义。