RUI: Analysis of Chromatin-level Mechanisms Regulating Genomic Imprinting in Mouse

RUI：小鼠染色质水平调控基因组印记的机制分析

• 批准号: 1514600
• 负责人: Tamara Davis
• 金额: $ 31.95万
• 依托单位: Bryn Mawr College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1514600&HistoricalAwards=false
• 关键词: RUI; Analysis; Chromatin; level; Mechanisms

Most genes in mammals are expressed from copies inherited from both the mother and the father, but a small number of genes are only expressed from one of these two copies; these are called imprinted genes. This project aims to investigate the mechanisms that ultimately allow one copy of these imprinted genes to be expressed while the other copy remains silent, or non-functional. Understanding the regulation of these genes is important because normal patterns of mammalian growth and development are perturbed if the expression of imprinted genes is dysregulated, as when both or neither copy is expressed. These studies will be conducted at Bryn Mawr College, a women's undergraduate institution, and will provide a diverse cohort of undergraduate students with an enhanced educational environment by affording them the opportunity to use current methodologies to advance scientific exploration, ultimately preparing these undergraduate women to be the next generation of research scientists.Imprinted genes are only expressed from one of the two parentally inherited alleles. Monoallelic expression of imprinted genes is associated with differential DNA methylation on the maternal and paternal alleles that are passed to offspring at fertilization. What remains unknown is how further refinement of chromatin structure is achieved during post-fertilization development in order to maintain imprinted expression and establish tissue-specific imprinting. Post-fertilization acquisition of DNA methylation at additional sites within imprinted loci has been proposed to serve this purpose, but DNA methylation at such secondary differentially methylated regions is highly variable. This research will test the hypotheses that the observed variability is due to increased levels of hemi-methylation and/or increased levels of 5-hydroxymethylcytosine. In addition, this work will identify cis-regulatory elements responsible for tissue-specific imprinting using chromosome conformation capture to understand how these elements work in concert with epigenetic factors to achieve monoallelic vs. biallelic expression. Overall, this research will lend insight into the mechanisms governing the establishment and maintenance of chromatin structure critical for imprinted gene expression.

哺乳动物中的大多数基因都是从母亲和父亲遗传的拷贝中表达的，但少数基因只从这两个拷贝中的一个表达;这些基因被称为印记基因。该项目旨在研究最终允许这些印记基因的一个拷贝表达而另一个拷贝保持沉默或无功能的机制。了解这些基因的调节是很重要的，因为如果印记基因的表达失调，哺乳动物生长和发育的正常模式就会受到干扰，就像两个拷贝都表达或都不表达一样。这些研究将在布林莫尔学院（Bryn Mawr College）进行，这是一所女子本科院校，将为不同的本科生群体提供一个更好的教育环境，让他们有机会使用当前的方法来推进科学探索，最终使这些本科女生成为下一代的研究科学家。印记基因只表达于父母遗传的两个等位基因之一。印迹基因的单等位基因表达与在受精时传递给后代的母本和父本等位基因上的差异DNA甲基化相关。 目前尚不清楚的是，在受精后发育过程中如何进一步细化染色质结构，以保持印记表达并建立组织特异性印记。受精后在印记基因座内的额外位点获得DNA甲基化已被提出用于这一目的，但在这样的二级差异甲基化区域的DNA甲基化是高度可变的。本研究将检验观察到的变异性是由于半甲基化水平升高和/或5-羟甲基胞嘧啶水平升高所致的假设。此外，这项工作将确定顺式调节元件负责组织特异性印迹使用染色体构象捕获，以了解这些元素如何与表观遗传因素协同工作，以实现单等位基因与双等位基因表达。总的来说，这项研究将有助于深入了解的机制，建立和维护的染色质结构的关键印记基因的表达。

项目成果

Hemimethylation of CpG dyads is characteristic of secondary DMRs associated with imprinted loci and correlates with 5-hydroxymethylcytosine at paternally methylated sequences

CpG 二元体的半甲基化是与印记位点相关的次级 DMR 的特征，并与父系甲基化序列上的 5-羟甲基胞嘧啶相关

• DOI: 10.1186/s13072-019-0309-2
• 发表时间: 2019
• 期刊: Epigenetics & Chromatin
• 影响因子: 3.9
• 作者: Nechin, Julianna;Tunstall, Emma;Raymond, Naideline;Hamagami, Nicole;Pathmanabhan, Chris;Forestier, Samantha;Davis, Tamara L.
• 通讯作者: Davis, Tamara L.