Molecular control of oocyte arrest, meiosis, and the transition to development

项目摘要/摘要 动物的繁殖需要产生精子和卵子，这些精子和卵子经过受精来构建一个新的 有机体通过胚胎发生。为了完成这一壮举，细胞分裂机械必须经历一个 为了适应这些发育转变，进行了一系列戏剧性的修改。人类卵母细胞出现 胚胎和停滞在减数分裂前期，在那里它们将保持长达数十年，直到激素 刺激会触发它们的生长和细胞周期重新进入。在经历了这种长期的停滞之后，卵母细胞必须 在减数分裂过程中准确分离染色体，受精，然后高保真分裂。它是好的- 认识到人类卵母细胞在减数分裂、受精和发育方面的能力随着时间的延长而丧失。 随着孕妇年龄的增加，导致非整倍体的发生率显著增加， 流产和发育障碍。因此，卵母细胞在早期停滞中坚持的能力是 对人类生命周期至关重要，但研究是一个具有挑战性的状态，我们知道相对 几乎没有关于它是如何受到分子调控的。 这项提案的目标是定义未来维持卵母细胞能力的分子程序。 延长停搏期间的分裂，这种状态如何受到卵巢环境的影响，以及细胞如何 在进入减数分裂并开始发育后，分裂装置重新布线。解决这一问题的挑战 问题是哺乳动物卵母细胞的可获得性有限，这是人体内最稀有的细胞之一。 为了应对这一挑战，我开发了扩展体外培养生化数量的策略 来自海星Patiria mini ata的卵母细胞，这是一种强大的模式生物，其卵母细胞具有共同特征 并与人类保持保守的分子机制。利用这一优势，我将执行一系列细胞 生物学和高通量分析，以询问转录、翻译和翻译后 卵母细胞执行并在延长的停滞过程中坚持的机制。这一方法将开启 了解人类生育的重要方面的新大门，并将使我能够过渡到 作为一名独立的调查员，致力于研究发育和生育。

Project Summary / Abstract Animal reproduction requires the production of sperm and eggs which undergo fertilization to construct a new organism through embryogenesis. To accomplish this feat, the cell division machinery must undergo a dramatic series of modifications to adapt to these developmental transitions. Human oocytes arise embryonically and arrest in meiotic prophase, where they will remain for as long as decades until a hormonal stimulus triggers their growth and cell cycle re-entry. After enduring this extended arrest, oocytes must accurately segregate chromosomes in meiosis, be fertilized, and then divide with high fidelity. It is well- appreciated that human oocytes lose their competency for meiosis, fertilization, and development as the length of this arrest and the maternal age increases, resulting in markedly increased incidence of aneuploidies, miscarriage and development disorders. The ability of an oocyte to persist through prophase arrest is therefore of paramount importance for the human life cycle, but is a challenging state to study, and we know relatively little about how it is molecularly regulated. The goal of this proposal is to define the molecular program that maintains oocyte competency for future division during extended arrest, how this state is influenced by the ovarian environment, and how the cell division apparatus is rewired after meiotic entry and initiation of development. A challenge for addressing this question has been the limited availability of mammalian oocytes, which are among the rarest cells in the body. To address this challenge, I have developed strategies for extended in vitro culture of biochemical quantities of oocytes from the sea star Patiria miniata, a powerful model organism whose oocytes share common features and conserved molecular mechanisms with humans. Leveraging this advantage, I will perform a series of cell biological and high-throughput analyses to interrogate the transcriptional, translational, and post-translational mechanisms that oocytes enact to enforce and persist through their extended arrest. This approach will open new doors for understanding important aspects of human fertility, and will enable my transition to independence as an investigator committed to the study of development and fertility.