Integrating cell identities and morphodynamics through extracellular cues

建议书摘要/摘要 在早期胚胎发育过程中建立适当的细胞特性和组织结构对于 成功怀孕。这些过程的协调对于形成哺乳动物胚胎的模式是不可或缺的，因为它们 增加植入阶段的复杂性。然而，这种紧密协调的监管方式仍然存在 人们对此知之甚少。受精后2-3周内人类胚胎的高死亡率是 早期妊娠丢失的主要原因，但基本的细胞、分子和机械变化仍然存在 几乎完全没有特征。 最近的研究表明，不仅仅是提供物理支持的结构组件， 细胞外基质(ECM)在调节细胞命运和形态发生方面发挥着重要作用。我的 最近的研究表明，胚胎基底膜(BM)是一种特殊的细胞外基质，在细胞外营养中起着重要的作用。 在构思植入后早期哺乳动物胚胎的过程中。我的初步结果为我的 确定BM如何协调集体细胞行为并促进模式形成的建议 哺乳动物早期胚胎发育的关键阶段。 我们将应用新技术，包括4D定量成像和单细胞空间基因组学， 结合体内、体外和硅胶方法来验证BM促进胚胎的假设 通过协调细胞命运规范和组织形态动力学进行图案化。在我的第一个目标中，我们将 利用3D技术对胚胎发育过程中的细胞行为和形态动力学进行综合研究 定量成像和时间流逝成像方法。我们将通过基因来定义BM的角色 干细胞衍生的类胚胎模型以及自然胚胎中的操作。在我的第二个目标中，我们 将绘制BM组织图并应用单细胞空间转录方法来产生原位命运 地图。我们将从功能上测试BM如何通过定量定义基因表达来调节细胞特性 模式和BM体系结构，并通过功能损失分析验证发现。接下来，我们将构建 将细胞特性和细胞动力学与BM力学相结合的数学模型，以揭示 花纹形成的机制。在我的第三个目标中，我们将应用在 前两个目的是探讨BM在原肠形成过程中形成胚层的作用。 总体而言，我提议的工作将增加我们对细胞外暗示如何促进成功 这可能会激发新的治疗方法，以防止早孕丢失。提供的培训 通过这一奖项，我将获得必要的技能，以发展我的独立研究计划，以适用 一种量化的系统级方法，以揭示塑造 妊娠早期关键阶段的胚胎。

PROPOSAL SUMMARY/ABSTRACT Establishing proper cell identities and tissue architecture during early embryogenesis is crucial for a successful pregnancy. Coordination of these processes is integral to patterning the mammalian embryos as they increase complexity from the implantation stages. However, how this tight coordination is regulated remains poorly understood. A high rate of mortality seen in human embryos during the first 2-3 weeks post-fertilization is a major cause of early pregnancy loss, yet the essential cellular, molecular, and mechanical changes remain almost entirely uncharacterized. Rather than merely a structural component that provides physical support, recent studies have shown that the extracellular matrix (ECM) has emerging roles in regulating cell fate specification and morphogenesis. My recent work reveals that the embryonic basement membrane (BM), a specialized ECM, plays an essential role in patterning the early post-implantation mammalian embryo. My preliminary results lay the foundation of my proposal to determine how the BM coordinates the collective cell behaviors and facilitates pattern formation at critical developmental stages of early mammalian embryogenesis. We will apply novel technologies, including 4D quantitative imaging and single-cell spatial genomics, combined with in vivo, in vitro, and in silico approaches to test the hypothesis that the BM facilitates embryo patterning through coordinating cell fate specification and tissue morphodynamics. In my first aim, we will comprehensively map the cell behaviors and the morphodynamics of the developing embryos with 3D quantitative imaging and timelapse imaging approaches. We will define the role of the BM through genetic manipulations in stem cell-derived embryo-like models as well as in the natural embryos. In my second aim, we will map the BM organization and apply single-cell spatial transcriptomics approaches to generate in situ fate maps. We will functionally test how the BM regulates cell identities by quantitatively defining gene expression patterns with BM architecture and validate the findings with loss-of-function analyses. Next, we will build mathematical models that integrate cell identities and cell dynamics with the BM mechanics to uncover mechanisms of pattern formation. In my third aim, we will apply the technologies and tools developed in the previous two aims to explore the roles of the BM in shaping the formation of germ layers during gastrulation. Overall, my proposed work will increase our understanding of how extracellular cues facilitate a successful pregnancy and could inspire novel therapeutic approaches to prevent early pregnancy loss. The training provided by this award will allow me to acquire the necessary skills to develop my independent research program to apply a quantitative systems-level approach to uncover the dynamics, functions, and regulations that shape the embryos at critical stages of early pregnancy.