Mechanisms of epiblast and primitive endoderm segregation

外胚层和原始内胚层分离的机制

基本信息

批准号：
10566100
负责人：
Eszter Posfai
金额：
$ 44.46万
依托单位：
PRINCETON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-07 至 2028-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10566100
关键词：
3-Dimensional ATAC-seq Address Automobile Driving Binding Biological Models Biosensor Caenorhabditis elegans Capsicum Cell Communication Cell Cycle Progression Cell Differentiation process Cells Characteristics Chromatin Color Complex Cues Data Data Set Development Developmental Process Drosophila genus Educational process of instructing Embryo Embryonic Development Endoderm Endoderm Cell Ensure Environment Epiblast Fetus Fibroblast Growth Factor Gene Expression Gene Expression Profile Genetic Genetic Transcription Genetic study Genome engineering Genomic approach Genomics Heterogeneity Human Image Image Analysis Implant Individual Inherited Inner Cell Mass Lead Mammals Modeling Molecular Morphology Mothers Mus Nature Neighborhoods Nucleic Acid Regulatory Sequences Organism Outcome Pattern Population Positioning Attribute Pregnancy loss Process Recording of previous events Reporter Reproducibility Resolution Shapes Signal Transduction Sodium Chloride Sorting Source Specific qualifier value Statistical Data Interpretation Stereotyping Structure Techniques Technology Testing Time Uterus Variant Visualization Work analysis pipeline blastocyst cell fate specification cell type developmental disease embryo cell fascinate flexibility genome-wide image processing imaging approach insight intercellular communication mathematical model model organism novel pharmacologic preimplantation programs segregation temporal measurement tool transcription factor

项目摘要

Abstract Embryonic development is a fascinating process during which different cells types are made and organized into complex and functional structures, ultimately building an entire organism. If we watch embryos develop, patterns emerge with remarkable reproducibility. However, if we zoom in to the level of individual cells, the scene, especially during mammalian development, often seems chaotic. Cells move around, change shape, contact different neighbors and show fluctuations in their gene expression patterns. Yet from this apparent chaos, robust and reproducible patterns emerge. How are the right cell types made at the right time and place in correct proportions? In this proposal we will use a crucial cell fate decision in the preimplantation mouse embryo, when the inner cell mass (ICM) lineage segregates into the epiblast (EPI) and the primitive endoderm (PE) lineages, the cell types that will give rise to most of the fetus and extraembryonic cell types, respectively, as a model system to reveal fundamental insights into the molecular and cellular mechanisms that ensure robust and reproducible lineage formation. While studies employing genetic and pharmacological approaches have established the necessary molecular players involved in EPI and PE cell fates, these are limited in providing temporal information on an inherently dynamic process. Additionally, ICM cells differentiate into EPI and PE cell types in a seemingly random pattern, which varies from one embryo to the next, complicating the interpretation of analysis performed only at fixed time points. Here we develop novel genetically encoded fluorescent reporter mouse lines for key factors involved in EPI and PE cell fates, which allow us to visualize and probe the mechanisms of cell fate acquisition with unprecedented spatial and temporal resolution, using a combination of cutting-edge live imaging, computational image processing, and genomics approaches. Using these powerful tools, we will investigate the mechanism driving initial symmetry-breaking in the ICM to initiate EPI/PE lineage differentiation and determine whether purely stochastic fluctuations or more predictable systematic variations present in the embryo are responsible for initiating this fate decision. Next, we will determine how cell fates are propagated over space and time to achieve reproducible cell-type proportions, by uniquely visualizing multiple nodes in cell-cell communication signaling. Finally, we will use recently developed genomics techniques to probe transcription factor occupancy and chromatin accessibility to observe how cell type-specific transcriptional programs are set up by key factors during EPI/PE lineage segregation. This work will uncover fundamental mechanisms by which variable developmental process can lead to robust and reproducible developmental patterning in the early mammalian embryo.

抽象的胚胎发育是一个令人着迷的过程，在此过程中不同的细胞类型被制造并组织成复杂而功能性的结构，最终构建出一个完整的有机体。如果我们观察胚胎发育，就会发现模式具有显着的再现性。然而，如果我们放大到单个细胞的水平，场景，尤其是在哺乳动物的发育过程中，常常显得混乱。细胞四处移动、改变形状、接触不同的邻居并显示出其基因表达模式的波动。然而，从这种明显的混乱中，稳健并出现可重复的模式。如何在正确的时间、正确的地点制造出正确的细胞类型比例？在本提案中，我们将在植入前小鼠胚胎中使用关键的细胞命运决定，当内细胞团（ICM）谱系分离为外胚层（EPI）谱系和原始内胚层（PE）谱系，将分别产生大多数胎儿和胚胎外细胞类型的细胞类型作为模型系统揭示分子和细胞机制的基本见解，确保稳健和可重复的谱系形成。虽然采用遗传和药理学方法的研究已经建立了参与 EPI 和 PE 细胞命运的必要分子参与者，这些在提供方面受到限制固有动态过程的时间信息。此外，ICM细胞分化为EPI和PE细胞以一种看似随机的模式进行类型，每个胚胎的类型各不相同，这使解释变得复杂仅在固定时间点进行的分析。我们在这里开发新型基因编码荧光报告基因小鼠品系中涉及 EPI 和 PE 细胞命运的关键因素，这使我们能够可视化和探测细胞命运获取机制具有前所未有的空间和时间分辨率，结合使用尖端的实时成像、计算图像处理和基因组学方法。利用这些强大的工具，我们将研究驱动 ICM 中初始对称性破缺以启动 EPI/PE 谱系的机制微分并确定是纯粹的随机波动还是更可预测的系统变化存在于胚胎中的细胞负责启动这一命运决定。接下来，我们将确定细胞命运如何通过独特地可视化多个细胞，在空间和时间上传播，以实现可重复的细胞类型比例细胞间通信信号传导的节点。最后，我们将使用最近开发的基因组学技术来探测转录因子占据和染色质可及性，以观察细胞类型特异性转录如何计划是根据 EPI/PE 谱系分离过程中的关键因素制定的。这项工作将揭示基本的可变的发育过程可以导致稳健且可重复的发育的机制早期哺乳动物胚胎的模式。