Understanding epigenetic remodeling in primordial germ cells

了解原始生殖细胞的表观遗传重塑

基本信息

批准号：
8898861
负责人：
Amander Clark
金额：
$ 31.16万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-02-05 至 2019-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8898861
关键词：
Address Alleles Binding Birth Cell Differentiation process Child Cytosine DNA DNA Methylation Data Development Dioxygenases Disease Environment Enzymes Epigenetic Process Excision Fertilization Fingers First Pregnancy Trimester Funding Future Future Generations Gametogenesis Generations Genes Genome Genome Mappings Germ Cells Germ Lines Goals Gonadal structure Grant Health Homologous Gene Human In Vitro Individual Inherited Knock-out Laboratories Lead Left Mammals Maps Methylation Mus Parents Phase Pregnancy Production Protein-Arginine N-Methyltransferase Proteins Regulation Repetitive Sequence Repression Research Resolution Retrotransposon Risk Role Science Second Pregnancy Trimester Site Sorting - Cell Movement Staging Structure of primordial sex cell Technology Tetanus Helper Peptide Time Transgenic Mice Ubiquitin Work base bisulfite sequencing cofactor demethylation disease transmission embryonic stem cell epigenome gene repression genome-wide imprint in utero in vitro Model in vivo insight next generation prevent progenitor

项目摘要

DESCRIPTION (provided by applicant): During pregnancy three generations of DNA co-exist. Mum's, baby's and the germ line of baby. During the first and second trimester the majority of methylated cytosines from the DNA of baby's progenitor germ line cells, called primordial germ cells (PGCs) are removed. This act is essential to remove errors in methylation acquired during gametogenesis in the parents, and/or during early development of baby after fertilization. If errors in cytosine methylation are not removed, the abnormally methylated alleles have a risk of being inherited as disease epialleles in the following generation. Given that the environment can stably influence the genome, including the genome of baby's PGCs in utero, there is a need to understand the mechanisms that regulate DNA demethylation in PGCs in order to develop strategies to guard against the transmission of disease epialleles in future generations. Recently my group discovered that DNA demethylation in human PGCs is regulated in two phases however the mechanisms underlying demethylation globally (phase 1) and locally (phase 2) are unclear. In this project we aim to uncover new details on the dynamics of DNA demethylation in human PGCs and use conditional deletions of mouse PGCs in vivo as well as differentiation of mouse PGCs from embryonic stem cells in vitro to address hypotheses regarding the specific mechanisms responsible for demethylation in the mammalian germ line. In aim 1 we will identify the dynamic removal of cytosine methylation at base resolution for the very first time in human PGCs and address the hypothesis that Ubiquitin- like, containing PHD and RING finger domains, 1 (Uhrf1) repression by protein arginine methyltransferase 5 (Prmt5) is responsible for the phase 1 DNA demethylation in mammals. In aim 2 using a conditional deletion in mouse PGCs we will address the hypothesis that Dnmt1 maintains cytosine methylation at discreet loci in PGCs in the absence of its major cofactor Uhrf1. In aim 3, we turn to phase 2 demethylation to directly address the hypothesis that conversion of 5-methylcytosine to 5-hydroxymethylcytosine by Tet methylcytosine dioxygenases has a functional role in the demethylation of imprinting control centers in PGCs. Taken together, results from this grant will lead to new insights into the mechanisms that regulate germ line epigenetic inheritance, and in future work our goal will be to prevent epialleles from being acquired and transmitted.

描述（由申请人提供）：在怀孕三代DNA共存期间。妈妈的，婴儿和婴儿的细菌系。在第一和第二个三个月中，除去了婴儿祖细胞细胞DNA的大多数甲基化细胞，称为原始生殖细胞（PGC）。该法案对于消除父母配子发生过程中获得的甲基化的错误和/或受精后早期发育期间至关重要的。如果未去除胞嘧啶甲基化中的错误，则异常甲基化等位基因在接下来的一代中具有遗传为疾病的风险。鉴于环境可以稳定影响基因组，包括婴儿在子宫内的PGC的基因组，因此有必要了解调节PGC中DNA脱甲基化的机制，以制定策略以防止未来后代的疾病传播。最近，我的小组发现，人类PGC中的DNA脱甲基化在两个阶段中受到调节，但是全球甲基化基础化的机制（第1阶段）和局部（第2阶段）尚不清楚。在该项目中，我们旨在发现有关人PGC中DNA脱甲基化动力学的新细节，并在体内使用小鼠PGC的条件缺失，以及在体外使用小鼠PGC与体外胚胎干细胞的分化，以解决有关负责哺乳动物胚系脱甲基的特定机制的假设。在AIM 1中，我们将首次在人类PGC中确定碱甲基化的动态去除，并解决以下假设：泛素（含有Phd和Ring Finger域）1（UHRF1）蛋白质精氨酸甲基转移酶5（PRMT5）对蛋白质精氨酸（PRMT5）的抑制作用。在使用小鼠PGC中有条件缺失的AIM 2中，我们将解决以下假设：DNMT1在没有主要辅助因子UHRF1的情况下在PGC中维持谨慎基因座的胞嘧啶甲基化。在AIM 3中，我们转向第2阶段的脱甲基化，直接解决了以下假设：通过TET甲基二加氧酶将5-甲基胞嘧啶转化为5-羟基甲基胞嘧啶，在PGCS中在压印控制中心的脱甲基化中具有功能性作用。综上所述，这笔赠款的结果将导致对调节细菌表观遗传遗传的机制的新见解，在将来的工作中，我们的目标是防止epialles被获取和传播。