Using PGCLCs as a model system for early germ cell development to characterize the roles of histone marks and their readers in DNA methylation homeostasis and transcriptional regulation

使用 PGCLC 作为早期生殖细胞发育的模型系统来表征组蛋白标记及其读取器在 DNA 甲基化稳态和转录调控中的作用

• 批准号: RGPIN-2021-02808
• 负责人: Lorincz, Matthew
• 金额: $ 5.03万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742228
• 关键词: Using; PGCLCs; model; system; early

At a fundamental level, the field of epigenetics involves the study of chemical marks on DNA and the proteins associated with DNA that either promote or inhibit the turning on or off of genes encoded in DNA. One of these marks, which is widely studied in the field, is called "methylation". Our interest is in studying the interplay between the methylation on DNA and the methylation on proteins that interact with DNA, specifically in the cells that give rise to sperm and egg, using the mouse as a model system. So-called "primordial germ cells", the precursors to sperm and egg, emerge in the early embryo, when these epigenetic marks are quite dynamic. Using embryonic stem cells as a starting point and a novel cell culture system that mimics this essential developmental time window, we will specifically study whether disrupting the methylation on DNA-associated proteins via genetic engineering of the enzymes that deposit this mark, or a related set of proteins that recognize such marks in the cell, leads to the aberrant "turning on" of target germ cell genes, and/or parasitic elements, that are normally enriched for these marks in the genome and "turned off". These experiments will shed light on the fundamental role of epigenetic marks in primordial germ cell development as well as the molecular basis of "transgenerational inheritance", a phenomenon whereby changes in the marks on DNA or the proteins associated with DNA unrelated to changes in the sequence of the DNA itself in one generation lead to heritable alterations in the next generation. While the molecular basis of such heritable changes remain largely uncharacterized, they likely are dependent on epigenetic marks, established in the gametes, such as those under study here. As mechanistic studies of such epigenetic phenomena are difficult to study in living animals, given that these cells are present in only small numbers, development and application of a tissue culture model of germ cell development is an essential step in this line of basic research.

从根本上讲，表观遗传学领域涉及 DNA 上的化学标记以及与 DNA 相关的蛋白质的研究，这些标记可以促进或抑制 DNA 编码基因的开启或关闭。其中一个标记在该领域被广泛研究，称为“甲基化”。我们的兴趣是使用小鼠作为模型系统，研究 DNA 甲基化和与 DNA 相互作用的蛋白质甲基化之间的相互作用，特别是在产生精子和卵子的细胞中。所谓的“原始生殖细胞”，即精子和卵子的前体，出现在早期胚胎中，此时这些表观遗传标记非常活跃。使用胚胎干细胞作为起点和模拟这一重要发育时间窗口的新型细胞培养系统，我们将专门研究通过沉积此标记的酶的基因工程或识别细胞中此类标记的一组相关蛋白质的基因工程来破坏DNA相关蛋白质的甲基化，是否会导致通常富集的目标生殖细胞基因和/或寄生元件的异常“开启” 对于基因组中的这些标记并“关闭”。这些实验将揭示表观遗传标记在原始生殖细胞发育中的基本作用以及“跨代遗传”的分子基础，“跨代遗传”是一种现象，即DNA或与DNA相关的蛋白质的标记变化与一代人DNA本身序列的变化无关，导致下一代发生可遗传的改变。虽然这种遗传变化的分子基础在很大程度上仍然未知，但它们可能依赖于配子中建立的表观遗传标记，例如本文正在研究的那些。由于此类表观遗传现象的机制研究很难在活体动物中进行研究，因为这些细胞的数量很少，因此生殖细胞发育的组织培养模型的开发和应用是这一基础研究领域的重要一步。