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.

项目摘要 染色质的戏剧性重组是施肥前后的重要事件。这 发展的精子核经历极端压实，而这种绩效遗传物质迅速， 进入卵母细胞后不久，积极地重新包装到染色式状态。未能制定这些 变化会导致核混乱并产生不可或缺的胚胎。镀铬物很大，密集 在这些过渡过程中协调抑制性异染色质的重编程的核结构，并且 染色体的完整性对于生育力很重要。尽管它很重要，但一个主要的未解决问题是什么 信号或信号触发染色体拆卸在开发精子头并刺激 铬中心重新组装胚胎。该项目的总体目的是定义分子途径 在施肥事件发生之前和之后，控制着染色体的重组。中心假设是 同一染色质调节剂DOT1L在受精前控制两个染色体拆卸 通过刺激周围质粒大调的转录，在受精后重新组装染色体 卫星重复。该假设得到了初步数据的支持，表明DOT1L具有专业角色 在促进主要卫星重复元素的表达时，此功能对于形成很重要 中心者。初步研究还表明，男性生育需要DOT1L，这是 活跃于铬中心物，在精子的后期进行核重编程和冷凝所必需 发育，并且其活性是植入前胚胎发生所必需的。该假设将进行检验 在两个具体目标中：第一个目标将测试DOT1L对精子过程中铬中心拆卸的贡献 核凝结，第二个目标将决定DOT1L如何调节中心装配 早期胚胎。该项目具有创新的概念性提前，这意味着一个统一的监管因素 在受精前后，控制异染色质拆卸和重新组装，其对新颖的探索 将表观遗传信息传播的机制，建立了新的分子 和DOT1L的生物学功能，以及其在使用精度异染色质可视化技术中的使用 植入前胚胎。预计这项工作将揭示一个基本缺失的链接，管理着戏剧性 在受精之前和之后发生的异染色质重编程，促进对 配子和胚胎开发过程中的基因组调节，并揭示父亲之间的新关系 染色质和胚胎的表观遗传状态。