Defining the role of DOT1L in chromocenter stabilization pre- and post-fertilization

定义 DOT1L 在受精前后染色中心稳定中的作用

• 批准号: 10739438
• 负责人: Bluma J Lesch
• 金额: $ 46.06万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10739438
• 关键词: Automobile Driving; Biological Process; Cell Nucleus; Chromatin; Couples; Data; Development; Diagnosis; Elements; Embryo; Embryonic Development; Ensure; Epigenetic Process; Event; Excision; Failure; Fertility; Fertilization; Foundations; Generations; Genetic; Genetic Materials; Genetic Transcription; Genome; Germ Cells; Germ Lines; Goals; Heterochromatin; Infertility; Invaded; Link; Meiosis; Molecular; Molecular Target; National Institute of Child Health and Human Development; Nuclear; Nuclear Structure; Nucleosomes; Oocytes; Pathway interactions; Physical condensation; Process; Production; Protamines; Proteins; Public Health; Regulation; Reproduction; Research; Role; Signal Transduction; Sperm Head; Spermatids; Structure; Techniques; Testing; Transcript; Visualization; Work; blastocyst; conditional knockout; defined contribution; embryonic stem cell; healthy pregnancy; infertility treatment; innovation; male fertility; novel; nuclear reprogramming; preimplantation; programs; reconstruction; recruit; screening; sperm cell; targeted treatment; transmission process; zygote

PROJECT SUMMARY Dramatic restructuring of chromatin is an essential event preceding and immediately following fertilization. The developing sperm nucleus undergoes extreme compaction, and this hypercompact genetic material is rapidly, aggressively repackaged into a chromatinized state soon after entering the oocyte. Failure to enact these changes leads to nuclear disorganization and produces inviable embryos. Chromocenters are large, dense nuclear structures that coordinate reprogramming of repressive heterochromatin during these transitions, and chromocenter integrity is important for fertility. Despite its importance, a major unsolved problem is what signal or signals trigger chromocenter disassembly in developing sperm heads and stimulate chromocenter reassembly in embryos. The overall objective of this project is to define the molecular pathways that govern chromocenter restructuring before and after the events of fertilization. The central hypothesis is that the same chromatin regulator, DOT1L, controls both chromocenter disassembly before fertilization and chromocenter reassembly after fertilization by stimulating transcription of pericentromeric major satellite repeats. This hypothesis is supported by preliminary data indicating that DOT1L has a specialized role in promoting expression of major satellite repeat elements and that this function is important for formation of chromocenters. Preliminary studies also demonstrated that DOT1L is required for male fertility, and that it is active in chromocenters and required for nuclear reprogramming and condensation in the late stages of sperm development, and that its activity is required for preimplantation embryogenesis. The hypothesis will be tested in two Specific Aims: the first Aim will test the contribution of DOT1L to chromocenter disassembly during sperm nuclear condensation, and the second Aim will determine how DOT1L regulates chromocenter assembly in early embryos. This project is innovative for its conceptual advance implicating a unifying regulatory factor in control of heterochromatin disassembly and reassembly before and after fertilization, its exploration of a novel mechanism for transmission of epigenetic information across generations, its establishment of a new molecular and biological function for DOT1L, and its use of precision heterochromatin visualization techniques in preimplantation embryos. This work is expected to reveal a fundamental missing link governing the dramatic heterochromatin reprogramming that occurs both before and after fertilization, advancing understanding of genome regulation during gamete and embryo development and revealing a new relationship between paternal chromatin and the epigenetic state of the embryo.

项目概要 染色质的急剧重组是受精之前和之后的一个重要事件。这 发育中的精子核经历极度压缩，这种超紧凑的遗传物质迅速， 进入卵母细胞后不久就被积极地重新包装成染色质状态。未能制定这些 变化导致核解体并产生无法存活的胚胎。染色中心大而致密 在这些转变过程中协调抑制性异染色质重编程的核结构，以及 染色体中心的完整性对于生育能力很重要。尽管它很重要，但一个尚未解决的主要问题是 一个或多个信号触发发育中的精子头中的染色中心分解并刺激 胚胎中的染色体中心重组。该项目的总体目标是定义分子途径 控制受精前后的染色中心重组。中心假设是 相同的染色质调节因子 DOT1L 在受精前控制两个染色质中心的分解 受精后通过刺激主要着丝粒周围的转录进行染色中心重组 卫星重复。这一假设得到了初步数据的支持，表明 DOT1L 具有专门的作用 促进主要卫星重复元件的表达，并且该功能对于形成 染色中心。初步研究还表明，DOT1L 是男性生育能力所必需的，并且它是 在染色中心活跃，是精子后期核重编程和浓缩所必需的 发育，并且其活性是植入前胚胎发生所必需的。假设将被检验 两个具体目标：第一个目标将测试 DOT1L 对精子过程中染色中心分解的贡献 核凝结，第二个目标将确定 DOT1L 如何调节染色中心组装 早期胚胎。该项目的创新之处在于其概念上的进步，暗示了统一的监管因素 受精前后异染色质分解和重组的控制，探索一种新的方法 表观遗传信息跨代传递的机制，其建立了一个新的分子 DOT1L 的生物学功能，及其使用精密异染色质可视化技术 植入前胚胎。这项工作有望揭示控制戏剧性的一个基本缺失环节 受精前后发生的异染色质重编程，促进了对 配子和胚胎发育过程中的基因组调控，揭示父系之间的新关系 染色质和胚胎的表观遗传状态。