Human iPSC-derived ovarian follicles as a model of female reproduction

项目摘要 雌性生殖的中心过程是在发育中的卵巢内形成卵母细胞， 卵子发生这一过程对于健康卵母细胞的形成和遗传和发育的正确传递至关重要。 表观遗传信息来开始胚胎发育。在卵巢发育和卵子发生中的作用 是女性不育和性发育障碍的主要原因，此外， 许多发育障碍的后代，如唐氏综合征和安格尔曼综合征。 然而，对人类卵巢发育的遗传调控知之甚少。这是 与其他生物如小鼠相反，转基因和敲除系， 生殖周期，允许在这方面进行大量研究。人卵巢癌体外类器官模型的建立 发展将有助于填补这一空白，并使人类卵巢癌的理解得到改善。 这可能导致治疗不孕症和预防发育障碍。 卵巢发育涉及原始生殖细胞（PGCs）和体细胞（颗粒细胞）之间的相互作用 细胞）。颗粒细胞将PGCs包裹在卵泡内，并支持它们分化为 卵原细胞、减数分裂的进程和卵母细胞的发育。因此，这两个血统将需要 在体外模拟这个过程。现有方法允许诱导多能干细胞（iPSC）的分化 转化为PGC样细胞，但这些细胞处于未成熟状态，保留了iPSC的表观遗传特征。为 卵子发生的体外模型要成功，必须开发改进的方法来产生成熟的卵子。 生殖系细胞和颗粒细胞来自iPSC。 通过转录因子（TF）的表达对细胞身份进行重编程是一种强大的技术， 允许体细胞重编程为iPSC，以及iPSC定向分化为特定细胞 类型Church实验室最近开发了计算工具来预测指定细胞身份的TF， 以及筛选组合TF表达的方法，以找到可以将iPSC分化为细胞的集合， 兴趣的类型。目前提出的研究将确定可以促进PGC成熟的TF， 类细胞并从iPSC产生颗粒细胞。结果将通过单细胞 转录组学和表观遗传学分析以及关键表型的功能验证。这项研究将 提供了一个更好的了解卵巢发育的遗传调控，导致在体外 人类卵子发生的模型

PROJECT SUMMARY The central process of female reproduction is the formation of oocytes within the developing ovary, known as oogenesis. This process is crucial for the formation of healthy oocytes and proper transmission of genetic and epigenetic information to begin embryonic development. Abnormalities in ovarian development and oogenesis are a leading cause of female infertility and disorders of sexual development, and furthermore are the cause of many developmental disorders in the subsequent generation, such as Down syndrome and Angelman syndrome. However, relatively little is known about the genetic regulation of human ovarian development. This is in contrast to other organisms such as the mouse, where transgenic and knockout lines, and a short reproductive cycle, have allowed much research in this area. An in vitro organoid model of human ovarian development would help fill this gap, and enable an improved understanding of human ovarian development that could lead to treatments for infertility and prevention of developmental disorders. Ovarian development involves interactions between primordial germ cells (PGCs) and somatic cells (granulosa cells). The granulosa cells enclose the PGCs within ovarian follicles, and support their differentiation into oogonia, progression through meiosis, and development as oocytes. Therefore, both lineages will be required to model this process in vitro. Existing methods allow differentiation of induced pluripotent stem cells (iPSCs) into PGC-like cells, but these cells are in an immature state, retaining epigenetic characteristics of iPSCs. For an in vitro model of oogenesis to be successful, improved methods must be developed to generate mature germline cells and granulosa cells from iPSCs. Reprogramming of cellular identity by expression of transcription factors (TFs) is a powerful technique that can allow both reprogramming of somatic cells into iPSCs, and directed differentiation of iPSCs to specific cell types. The Church lab has recently developed computational tools to predict TFs that specify cell identity, as well as screening methods for combinatorial TF expression to find sets that can differentiate iPSCs to a cell type of interest. The currently proposed research will identify TFs that can promote maturation of PGC- like cells and produce granulosa cells from iPSCs. Results will be evaluated by single-cell transcriptomic and epigenetic profiling, and by functional validation of key phenotypes. This research will provide an improved understanding of the genetic regulation of ovarian development, leading to an in vitro model of human oogenesis.