Function of Kdm4dl-mediated heterochromatin removal in the preimplantation mouse embryo

Kdm4dl 介导的植入前小鼠胚胎异染色质去除的功能

• 批准号: 10540694
• 负责人: Sean Shadle
• 金额: $ 7.18万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10540694
• 关键词: Ablation; Address; Affect; Animals; Area; Assisted Reproductive Technology; Auxins; Biological Assay; Cancer Biology; Cell Line; Cell Nucleus; Cells; Chimera organism; Chromatin; Chromatin Modeling; Code; Complement; Data; Deposition; Development; Developmental Process; Doxycycline; Embryo; Embryonic Development; Environment; Epigenetic Process; Excision; Fertility; Fertilization; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genetic Epistasis; Genetic Transcription; Genome; Goals; Health; Heterochromatin; Histones; Human; Immunofluorescence Immunologic; Knock-out; Knockout Mice; Lysine; Mediating; Methylation; Modeling; Mus; Orthologous Gene; Pathway interactions; Pattern; Phenotype; Placenta; Pre-implantation Embryo Development; Process; Productivity; Proteins; Research Personnel; Research Project Grants; Role; System; Testing; Time; Totipotency; Totipotent; Training; Transcript; Transcriptional Activation; Transgenes; Untranslated RNA; blastocyst; blastomere structure; chromatin remodeling; demethylation; egg; embryo cell; embryonic stem cell; histone demethylase; histone modification; in vivo; innovation; mouse model; novel; overexpression; placental mammal; preimplantation; programs; protein expression; transcription factor; transcriptome sequencing; zygote

PROJECT ABSTRACT This project will investigate the function of a currently unstudied histone demethylase, Kdm4dl, in the mouse preimplantation embryo. Many others have shown the developmental importance of activating genes and repeat sequences during a process known as Embryonic Genome Activation (EGA), the moment when the embryo switches on transcription for the first time. EGA involves activation of both protein coding genes as well as repeat sequences that are critical for remodeling the chromatin environment of the early embryo. Yet, even with its known developmental importance, the factors which facilitate EGA are still largely unknown. Here, for the first time, I will investigate the importance of Kdm4dl, which catalytically removes the repressive histone modification H3 Lysine 9 tri-methylation (H3K9me3), in early mouse embryogenesis. I hypothesize that Kdm4dl is required for reprogramming the nuclei of the preimplantation embryo by removing repressive H3K9me3, which facilitates strong activation of EGA-associated transcripts. In line with this hypothesis, my preliminary data demonstrate temporally coordinated Kdm4dl protein expression during the 2-cell stage, when EGA occurs. Moreover, Kdm4dl over-expression is sufficient to demethylate H3K9me3 in embryonic stem cells leading to strong activation of EGA-associate transcripts and repeats. Combined, these preliminary data provide further support for pursuing the project’s hypothesis further. The two outstanding questions I aim to address are: 1. Is Kdm4dl expression sufficient to reprogram cells to a state of expanded potential, consistent with a 2-cell-like totipotent state? and 2. Is Kdm4dl expression necessary for H3K9 demethylation and activation of EGA-associated genes and repeats in vivo? To aid in addressing these questions, I have developed both an innovative embryonic stem cell system which recapitulates the temporal dynamics of Kdm4dl expression in the preimplantation embryo, and I have also established a Kdm4dl knockout mouse model. This research project, combined with my detailed training plan, is consistent with my technical and professional goals of becoming an independent academic investigator studying chromatin dynamics in the early mammalian embryo, with relevance to human fertility.

项目摘要 本项目将研究一种目前尚未研究的组蛋白去甲基化酶Kdm4dl在细胞凋亡中的作用。 小鼠附植前胚胎许多其他人已经证明了激活基因在发育中的重要性 并在称为胚胎基因组激活（EGA）的过程中重复序列，此时 胚胎第一次开始转录EGA还涉及两种蛋白质编码基因的激活 作为对于重塑早期胚胎染色质环境至关重要的重复序列。但即使 尽管人们已经知道它对发展的重要性，但促进EGA的因素在很大程度上仍然是未知的。在这里 第一次，我将研究Kdm4dl的重要性，它可以催化去除抑制性组蛋白 修饰H3赖氨酸9三甲基化（H3K9me3），在早期小鼠胚胎发生中。我假设Kdm4dl 是通过去除抑制性H3K9me3对植入前胚胎的细胞核进行重编程所必需的， 其促进EGA相关转录物的强激活。根据这一假设，我的初步 数据表明，当EGA时，在2细胞阶段，时间协调的Kdm4dl蛋白表达 发生。此外，Kdm4dl过表达足以使胚胎干细胞中的H3K9me3去甲基化 导致EGA相关转录物和重复序列的强烈激活。综合起来，这些初步数据 为进一步研究项目假设提供进一步支持。我的目标是两个悬而未决的问题 地址是：1. Kdm4dl表达是否足以将细胞重编程至扩展潜能的状态， 有两个细胞的全能状态和2. Kdm4dl表达是H3K9去甲基化所必需的， EGA相关基因和重复序列在体内的激活？为了帮助解决这些问题，我有 开发了一种创新的胚胎干细胞系统， Kdm4dl在植入前胚胎中的表达，并且我还建立了Kdm4dl敲除小鼠 模型这个研究项目，结合我详细的培训计划，符合我的技术和 成为一名独立的学术研究者，研究染色质动力学， 早期哺乳动物胚胎，与人类生育能力有关。