Transcriptome reprogramming in the early embryo

早期胚胎中的转录组重编程

• 批准号: 10246506
• 负责人: Miler T. S. Lee
• 金额: $ 35.92万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-24 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10246506
• 关键词: Address; Binding; Biochemical Genetics; Cells; Development; Developmental Gene; Disease; Disease model; Embryo; Gene Activation; Gene Expression; Genes; Genetic Transcription; Genome; Goals; Hour; Human; Logic; Malignant Neoplasms; Maps; Maternal Messenger RNA; Measures; Modeling; Organism; Pattern; Pluripotent Stem Cells; Process; Property; Regulator Genes; Source; Specificity; System; Techniques; Vertebrates; Zebrafish; cell type; egg; genetic approach; genome-wide; genomic data; innovation; loss of function; negative affect; novel; pluripotency; pluripotency factor; transcriptional reprogramming; transcriptome; vertebrate embryos

Early in development, a highly coordinated maternal-to-zygotic transition “reprograms” the embryo to a pluripotent cellular identity, capable of giving rise to all subsequent cell types in the developing organism. How cells are induced to pluripotency is still poorly understood, and yet has enormous implications, not only for understanding fundamental developmental and gene regulatory processes, but also for disease modeling and therapies. The long-term goal is to decipher mechanisms and principles conserved across vertebrates that guide pluripotency induction. To begin to address this question, this proposal aims to elucidate how pluripotency factors provided to the egg activate the first genes from the embryonic genome in the model vertebrate zebrafish. Zebrafish produce large clutches of externally developing embryos and express many key regulators of pluripotency that are conserved with humans, making them an ideal experimental system to discover novel regulatory paradigms that induce vertebrate pluripotency. This proposal has three primary goals. First, the regulatory logic underlying the specificity of embryonic gene activation will be deciphered. Maternal pluripotency factors act on a transcriptionally quiescent embryonic genome to initially activate only a few hundred genes, prior to the activation of thousands of genes hours later. Cutting-edge techniques will be used to map pluripotency factor binding genome wide, at earlier developmental stages than have previously been profiled. Binding patterns will be compared in the vicinity of early- versus later activated genes, and distinguishing properties of their respective gene regulatory sequences will be extracted. Second, novel regulators of embryonic genome activation will be deduced by integrating multiple sources of genomics data. These factors will be evaluated using innovative loss-of-function strategies to measure their contributions to embryonic reprogramming and pluripotency. Third, this proposal will uncover post-transcriptional mechanisms that regulate the maternal pluripotency factors themselves. Biochemical and genetic approaches will be used to discover factors that bind maternal mRNA to positively or negatively affect their expression, and in turn exert precise temporal control over pluripotency induction. Together, these analyses will further elucidate the gene regulatory logic of the early vertebrate embryo and provide a deeper understanding of how pluripotent identities are induced.

在发育早期，高度协调的母体到合子的转变将胚胎“重新编程”为 多能细胞身份，能够在发育中的生物体中产生所有后续细胞类型。如何 细胞被诱导成多能性仍然知之甚少，但具有巨大的影响，不仅对于 了解基本的发育和基因调控过程，也用于疾病建模和 疗法。长期目标是破译脊椎动物中保守的机制和原则 指导多能性诱导。为了开始解决这个问题，本提案旨在阐明如何 提供给卵子的多能因子激活模型中胚胎基因组的第一个基因 脊椎动物斑马鱼。斑马鱼产生大量外部发育的胚胎并表达许多关键的 人类保守的多能性调节因子，使其成为理想的实验系统 发现诱导脊椎动物多能性的新调控范式。该提案有三个主要内容 目标。首先，将破译胚胎基因激活特异性的调控逻辑。 母体多能因子作用于转录静止的胚胎基因组，最初仅激活 数百个基因，数小时后数千个基因被激活。尖端技术将 用于在比以前更早的发育阶段绘制全基因组范围的多能因子结合图谱 已被分析。将比较早期激活基因与晚期激活基因附近的结合模式，并且 将提取它们各自基因调控序列的区别特性。二、新颖 通过整合多个来源的基因组数据来推断胚胎基因组激活的调节因子。 这些因素将使用创新的功能丧失策略进行评估，以衡量它们对 胚胎重编程和多能性。第三，该提案将揭示转录后机制 调节母体多能性因子本身。将使用生化和遗传学方法 发现与母体 mRNA 结合对其表达产生积极或消极影响的因素，进而发挥作用 对多能性诱导的精确时间控制。总之，这些分析将进一步阐明该基因 早期脊椎动物胚胎的调控逻辑，并提供对多能性如何产生更深入的理解 身份被诱导。