Mechanisms of epiblast and primitive endoderm segregation

外胚层和原始内胚层分离的机制

• 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
• 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

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.

摘要