The mammalian body plan is established shortly after the embryo implants into the maternal uterus, and our understanding of post-implantation developmental processes remains limited. Although pre- and peri-implantation mouse embryos are routinely cultured in vitro^1,2, approaches for the robust culture of post-implantation embryos from egg cylinder stages until advanced organogenesis remain to be established. Here we present highly effective platforms for the ex utero culture of post-implantation mouse embryos, which enable the appropriate development of embryos from before gastrulation (embryonic day (E) 5.5) until the hindlimb formation stage (E11). Late gastrulating embryos (E7.5) are grown in three-dimensional rotating bottles, whereas extended culture from pre-gastrulation stages (E5.5 or E6.5) requires a combination of static and rotating bottle culture platforms. Histological, molecular and single-cell RNA sequencing analyses confirm that the ex utero cultured embryos recapitulate in utero development precisely. This culture system is amenable to the introduction of a variety of embryonic perturbations and micro-manipulations, the results of which can be followed ex utero for up to six days. The establishment of a system for robustly growing normal mouse embryos ex utero from pre-gastrulation to advanced organogenesis represents a valuable tool for investigating embryogenesis, as it eliminates the uterine barrier and allows researchers to mechanistically interrogate post-implantation morphogenesis and artificial embryogenesis in mammals.

哺乳动物的身体计划是在胚胎植入母体子宫后不久建立的，我们对植入后发育过程的理解仍然有限。虽然植入前和植入前的小鼠胚胎通常在体外培养^1,2，从卵圆柱阶段到高级器官发生的植入后胚胎的稳健培养方法仍有待建立。在这里，我们提出了用于植入后小鼠胚胎的宫外培养的高效平台，这使得胚胎能够从原肠胚形成前（胚胎日（E）5.5）到后肢形成阶段（E11）进行适当的发育。晚期原肠胚 (E7.5) 在三维旋转瓶中生长，而从原肠胚阶段 (E5.5 或 E6.5) 的扩展培养需要静态和旋转瓶培养平台的组合。组织学、分子和单细胞 RNA 测序分析证实，子宫外培养的胚胎在子宫内发育中精确地概括了。该培养系统适合引入各种胚胎扰动和显微操作，其结果可在子宫内追踪长达 6 天。建立一个系统，使正常小鼠胚胎从前原肠胚发育到晚期器官发生在子宫外稳健生长，这代表了研究胚胎发生的宝贵工具，因为它消除了子宫屏障，并允许研究人员机械地询问哺乳动物的植入后形态发生和人工胚胎发生。