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

哺乳动物的大多数基因都是通过遗传自母亲和父亲的拷贝来表达的，但也有少数基因只通过这两个拷贝中的一个来表达；这些被称为印记基因。该项目旨在研究最终允许这些印迹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。了解这些基因的调控是很重要的，因为如果印迹基因的表达失调，就像两个或两个拷贝都不表达一样，哺乳动物的正常生长和发育模式就会受到干扰。这些研究将在布林莫尔学院进行，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，为她们提供使用当前方法推进科学探索的机会，最终使这些本科女性成为下一代研究科学家。印迹基因只从两个亲本遗传等位基因中的一个表达。印迹基因的单等位基因表达与母体和父本等位基因的差异DNA甲基化有关，这些甲基化在受精时传递给后代。目前尚不清楚的是，在受精后发育过程中如何进一步完善染色质结构，以维持印迹表达并建立组织特异性印迹。受精后在印迹基因座内的其他位置获得DNA甲基化已被提出用于此目的，但这种次级差异甲基化区域的DNA甲基化是高度可变的。本研究将检验所观察到的变异是由于半甲基化水平和/或5-羟甲基胞嘧啶水平增加的假设。此外，本研究将利用染色体构象捕获技术鉴定组织特异性印迹的顺式调控元件，以了解这些元件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的表达。总的来说，这项研究将有助于深入了解对印迹基因表达至关重要的染色质结构的建立和维持机制。

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.