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受精前后的重要事件。的 发育中的精子核经历了极度的致密化，这种超致密的遗传物质迅速地， 在进入卵母细胞后不久就被积极地重新包装成染色质化状态。未能颁布这些 变化导致核解体并产生不能存活的胚胎。色心大而密集 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生育力很重要。尽管其重要性，一个主要的未解决的问题是什么 一种或多种信号触发发育中精子头部中的染色中心解体，并刺激 胚胎中的染色体重组。这个项目的总体目标是确定分子途径 控制受精前后染色体中心重组的基因。核心假设是 同一个染色质调节因子DOT1L在受精前控制着两个染色中心的分解， 和受精后通过刺激大着丝粒周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具有特殊的作用， 在促进主要卫星重复元件的表达中，这种功能对于形成 染色中心。初步研究还表明，DOT1L是男性生育所必需的， 在染色中心有活性，在精子后期的核重编程和浓缩中需要 发育，并且其活性是植入前胚胎发生所需的。假设将被检验 在两个特定目的中：第一个目的将测试DOT1L在精子过程中对染色中心分解的贡献 核凝聚，第二个目的将确定如何DOT1L调节色心组装在 早期胚胎这个项目是创新的概念的进步，涉及一个统一的监管因素， 控制异染色质在受精前后的拆卸和重组，其探索一种新的 表观遗传信息跨代传递的机制，它建立了一个新的分子 DOT1L的生物学功能，以及其在 植入前胚胎这项工作有望揭示一个基本的缺失环节， 异染色质重编程发生在受精之前和之后， 配子和胚胎发育过程中的基因组调控，并揭示了父本之间的新关系 染色质和胚胎的表观遗传状态。