Mechanisms of Genomic Imprinting

描述(由申请人提供)：DNA甲基化模式是如何在发育过程中形成的--甲基化和去甲基化如何在特定时间针对特定的基因座--尚不清楚。生殖细胞在消除了从上一代继承的男性和女性特有的标记后，根据性腺的性别建立甲基化印记。我们的主要假设是DNA胞嘧啶5-羟甲基化和染色质组成是印记周期的重要组成部分，参与生殖细胞的擦除和建立阶段以及胞体的维持阶段。为了证明这一点，我们将在全球范围内分析DNA甲基化、DNA胞嘧啶羟甲基化和染色质，以及生殖细胞和体细胞中特定的印迹基因。为了测试特定的表观遗传修饰物在印记周期中的作用，我们将在印记周期的擦除、建立和维护阶段对这些功能进行遗传干扰。这些结果将有助于理解DNA甲基化、DNA羟甲基化和染色质标记如何在生殖细胞的表观遗传重塑以及擦除、建立和维持基因组印记方面进行合作。在胚胎-胎儿生殖细胞发育过程中，正确的全球表观遗传重塑和印记重置对于下一代和子孙后代的健康至关重要。 公共卫生相关性：我们建议测试DNA胞嘧啶羟甲基化和染色质在基因组印记的擦除、建立和维护中的作用。使用全基因组作图方法、新型等位基因特异性分析和小鼠遗传工具的实验将共同帮助理解DNA甲基化、DNA羟甲基化和染色质标记如何在生殖细胞的全球表观遗传重塑以及在擦除、建立和维持基因组印记方面合作。在胚胎-胎儿生殖细胞发育过程中，正确的全球表观遗传重塑和印记重置对于下一代和子孙后代的健康至关重要。

DESCRIPTION (provided by applicant): How DNA methylation patterns are shaped during development - how methylation and demethylation are targeted to specific loci at specific times - is not known. Germ cells establish methylation imprints depending on the sex of the gonad after erasing the male and female -specific marks inherited from the previous generation. Our main hypothesis is that DNA cytosine 5-hydroxymethylation and chromatin composition are important components of the imprint cycle, being involved in the erasure and establishment phases in germ cells and in the maintenance phase in the soma. To demonstrate this, we will analyze DNA methylation, DNA cytosine hydroxymethylation and chromatin globally and at specific imprinted genes in germ cells and somatic cells. To test the role of specific epigenetic modifiers in the cycle of imprinting, we will genetically perturb these functions during the erasure, establishment and maintenance phases of the imprinting cycle. These results collectively will help understand how DNA methylation, DNA hydroxymethylation and chromatin marks collaborate in the epigenetic remodeling of germ cells and in erasing, establishing and maintaining genomic imprints. Correct global epigenetic remodeling and imprint reseting during embryonic-fetal germ cell development is essential for the health of the next generation and for future generations. PUBLIC HEALTH RELEVANCE: We propose to test the role of DNA cytosine hydroxymethylation and chromatin in the erasure, establishment and maintenance of genomic imprints. Experiments using genome-wide mapping methods, novel allele- specific assays and mouse genetic tools will collectively help understand how DNA methylation, DNA hydroxymethylation and chromatin marks collaborate in the global epigenetic remodeling of germ cells and in erasing, establishing and maintaining genomic imprints. Correct global epigenetic remodeling and imprint resetting during embryonic-fetal germ cell development is essential for the health of the next generation and for future generations.