Gastrulation is a phase in early mammalian development when the three germ layers are generated and body plan is formed. Although well studied in mice, much less is known about gastrulation in humans. Owing to the lack of access to primary human tissue for study and experimental manipulation, as well as legal and ethical constraints surrounding the use of human embryos, a dissection of the molecular and cellular mechanisms that underlie this process in humans has proven elusive. Nonhuman primates, owing to their relatedness to human species, comprise a tantalizing alternative model system for understanding human biology. Two recent studies have established novel systems to study monkey embryos for 20 days, demonstrating landmark events of early primate embryogenesis with possible relevance to human development. Most strikingly, cells grown in the dish closely resembled cells in in vivo embryos, suggesting that embryo development in a dish might actually be equivalent to that which occurs in vivo. In this piece, the author discusses the tremendous potential of these new methods to unveil insights into mechanisms that mediate primate embryo development. Moreover, repurposing the extended monkey embryo culture methods to create human–monkey embryonic chimeras would aid the development of strategies to create human organs inside livestock species. Finally, the ethical and regulatory issues that emerge from reconsideration of extending time limits for human embryo culture beyond 14 days or primitive streak formation are also briefly considered.

中文翻译：

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猴子胚胎培养至20天。

当三个胚芽层生成并形成人体计划时，放牧是哺乳动物早期发育的一个阶段。尽管已经在小鼠中进行了深入研究，但对人类胃排毒的了解却很少。由于缺乏进入人类主要组织进行研究和实验操作的途径，以及围绕使用人类胚胎的法律和道德约束，人们已经剖析了构成人类这一过程基础的分子和细胞机制。由于非人类灵长类动物与人类物种的相关性，它们构成了一个诱人的替代模型系统，用于理解人类生物学。最近的两项研究建立了新颖的系统来研究猴子的胚胎20天，证明了早期灵长类动物胚胎发生的标志性事件与人类发展可能相关。最惊人的是 在培养皿中生长的细胞与体内胚胎中的细胞非常相似，这表明培养皿中的胚胎发育实际上可能与体内发生的胚胎相等。在本文中，作者讨论了这些新方法的巨大潜力，以揭示对介导灵长类胚胎发育的机制的见解。此外，重新利用扩展的猴子胚胎培养方法来创建人猴杂交嵌合体将有助于制定在牲畜体内创建人体器官的策略。最后，还简要考虑了重新考虑将人类胚胎培养的时限延长到14天以上或形成原始条纹的伦理和法规问题。这表明培养皿中的胚胎发育实际上可能等同于体内发生的胚胎发育。在本文中，作者讨论了这些新方法的巨大潜力，以揭示对介导灵长类胚胎发育的机制的见解。此外，重新利用扩展的猴子胚胎培养方法来创建人猴杂交嵌合体将有助于制定在牲畜体内创建人体器官的策略。最后，还简要考虑了重新考虑将人类胚胎培养的时限延长到14天以上或形成原始条纹的伦理和法规问题。这表明培养皿中的胚胎发育实际上可能等同于体内发生的胚胎发育。在本文中，作者讨论了这些新方法的巨大潜力，以揭示对介导灵长类胚胎发育的机制的见解。此外，重新利用扩展的猴子胚胎培养方法来创建人猴杂交嵌合体将有助于制定在牲畜体内创建人体器官的策略。最后，还简要考虑了重新考虑将人类胚胎培养的时限延长到14天以上或形成原始条纹的伦理和法规问题。重新利用扩展的猴子胚胎培养方法来创建人猴杂交嵌合体将有助于制定在牲畜体内创建人体器官的策略。最后，还简要考虑了重新考虑将人类胚胎培养的时限延长到14天以上或形成原始条纹的伦理和法规问题。重新利用扩展的猴子胚胎培养方法来创建人猴杂交嵌合体将有助于制定在牲畜体内创建人体器官的策略。最后，还简要考虑了重新考虑将人类胚胎培养的时限延长到14天以上或形成原始条纹的伦理和法规问题。