Post-transcriptional gene regulation during early Drosophila development

果蝇早期发育过程中的转录后基因调控

• 批准号: 9192436
• 负责人: Jamie Kwasnieski
• 金额: $ 5.61万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9192436
• 关键词: 3' Untranslated Regions; Animals; Binding; Cells; Characteristics; Communities; Data; Deposition; Development; Developmental Biology; Distal; Drosophila genus; Drosophila melanogaster; Elements; Embryo; Embryonic Development; Event; Family; Fertilization; Foundations; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Goals; Half-Life; Hour; Human; Human Development; Individual; Label; Length; Mass Spectrum Analysis; Maternal Messenger RNA; Measurement; Measures; Messenger RNA; Metabolic; Methods; MicroRNAs; Modeling; Molecular; Output; Poly A; Poly(A) Tail; Positioning Attribute; Post-Transcriptional Regulation; Process; Production; Protein Isoforms; Proteins; RNA; RNA Sequences; RNA-Binding Proteins; Resources; Role; Shapes; Site; Specific qualifier value; System; Time; Transcript; cis acting element; egg; experience; fitness; fly; gene product; genetic manipulation; mRNA Expression; mRNA Stability; mRNA Transcript Degradation; mutant; novel; prevent; research study; temporal measurement; transcription termination; transcriptome sequencing

PROJECT SUMMARY/ABSTRACT Transcriptional and post-transcriptional mechanisms of gene regulation collaborate to shape the expression of every gene. During early development in all animals, post-transcriptional control of gene expression is uniquely important as no transcription occurs, instead, maternally deposited gene products control the earliest events of embryonic development after egg fertilization. Maternal gene products control development until the maternal- to-zygotic transition (MZT), when maternally deposited mRNAs are degraded and the zygotic genome is activated. In Drosophila melanogaster, nearly 60% of maternally deposited mRNAs are destabilized in a widespread, gene-specific wave of mRNA degradation that is controlled by maternally encoded and zygotically transcribed regulators. Successful handoff from maternal to zygotic control requires this wave of maternal mRNA destabilization, but there is a major gap in our understanding of this fundamental process because the molecular regulators underlying the destabilization are largely unknown. The goal of my proposal is to better understand the post-transcriptional control that operates in the early Drosophila embryo. A major barrier to understanding how maternally deposited mRNAs are destabilized is the fact that nearly two-thirds of maternally deposited mRNAs that are destabilized become transcribed once the zygotic genome is active. This prevents accurate identification of destabilized mRNAs, as the zygotically expressed transcript cannot be distinguished from the maternally deposited form of the same gene. First, I aim to determine the dynamics of maternally deposited and zygotically transcribed mRNAs during the maternal-to-zygotic transition using a method that can accurately distinguish between maternally deposited and zygotically transcribed transcripts. These quantitative measurements will be a valuable resource for the developmental biology and fly communities because they offer a perspective on mRNA dynamics with temporal resolution that is unparalleled by other studies. Second, I aim to identify proteins that regulate the stability of maternally deposited mRNAs. In a preliminary analysis, I annotated the 3′ ends of genes expressed during Drosophila embryogenesis and I found that most genes express multiple alternative 3′ tandem isoforms. I propose to leverage the naturally occurring differences between the sequence of tandem isoforms to identify RNA sequences that modulate mRNA stability and RBPs that recognize these sequences. These data will fundamentally contribute to our models of mRNA degradation during MZT and through exploring novel regulators of this process I will be in a position to determine why maternal mRNA degradation is essential for embryonic development. Any regulators identified as acting during MZT are also likely to influence mRNA stability in non-developmental contexts, providing information on determinants of mRNA half-life in other cellular contexts.

项目概要/摘要 基因调控的转录和转录后机制共同塑造基因的表达 在所有动物的早期发育过程中，每个基因的基因表达的转录后控制都是独特的。 重要的是，没有转录发生，相反，母体沉积的基因产物控制着最早的事件 卵子受精后的胚胎发育由母体基因产物控制，直至母体发育。 向合子转变 (MZT)，当母体沉积的 mRNA 被降解并且合子基因组被降解时 在果蝇中，近 60% 的母体沉积 mRNA 处于不稳定状态。 广泛的、基因特异性的 mRNA 降解波，由母源编码和合子控制 从母体控制到合子控制的成功切换需要母体的这一波。 mRNA 不稳定，但我们对这一基本过程的理解存在重大差距，因为 造成不稳定的分子调节剂在很大程度上是未知的，我的建议的目标是更好地进行。 了解早期果蝇胚胎中的转录后控制是实现这一目标的主要障碍。 了解母体沉积的 mRNA 是如何不稳定的事实是，近三分之二的母体沉积的 mRNA 是如何不稳定的。 一旦合子基因组活跃，沉积的不稳定的 mRNA 就会被转录。 准确识别不稳定的 mRNA，因为无法区分合子表达的转录本 首先，我的目标是确定母性的动态。 在母体到合子的转变过程中，使用一种方法可以沉积和合子转录 mRNA 准确区分母体沉积的转录本和合子转录的转录本。 测量结果将成为发育生物学和果蝇界的宝贵资源，因为它们 提供了其他研究无法比拟的具有时间分辨率的 mRNA 动态视角。 目的是鉴定调节母体沉积 mRNA 稳定性的蛋白质。 注释了果蝇胚胎发生过程中表达的基因的 3' 末端，我发现大多数基因 表达多种替代的 3' 串联亚型我建议利用自然发生的差异。 串联异构体序列之间的序列，以鉴定调节 mRNA 稳定性和 RBP 的 RNA 序列 这些数据将从根本上有助于我们的 mRNA 降解模型。 在 MZT 期间并通过探索该过程的新监管机构，我将能够确定原因 母体 mRNA 降解对于胚胎发育至关重要。 MZT 也可能影响非发育环境中的 mRNA 稳定性，提供以下信息： 其他细胞环境中 mRNA 半衰期的决定因素。