Genomic Imprinting and Embryonic Development

基因组印记和胚胎发育

• 批准号: 7176450
• 负责人: LAURIE L JACKSON-GRUSBY
• 金额: $ 12.68万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7176450
• 关键词: DNA methylation; Prader Willi syndrome; RNA interference; developmental disease /disorder; developmental genetics; embryonic stem cell; fluorescent in situ hybridization; gene expression; gene expression profiling; gene therapy; genetic regulation; genetically modified animals; genomic imprinting; glucose tolerance test; happy puppet syndrome; laboratory mouse; microarray technology; morphometry; phenotype; polymerase chain reaction

DESCRIPTION (provided by applicant): Beckwith-Wiedeman Syndrome (BWS), and Prader-Willi/Angelman Syndromes (PWS/AS) are rare developmental disorders with parent-of-origin effects that occur in 1/15,000 live births in the US. The molecular basis for these diseases is deregulation of imprinted gene clusters on 11 p15 and 15q11 caused predominantly by either deletions within imprinting control centers (ICC) or by epigenetic DMA methylation changes in the ICC. Elevated risk for AS and BWS has been associated with assisted reproductive technologies, which are thought to induce epigenetic loss of imprinting during in vitro embryo culture. This proposal tests the overall hypothesis that epigenetic alterations alone can cause developmental pathologies that model these syndromes as a result of global loss of imprinting (LOI), and further tests a therapeutic approach for correcting LOI events. As a means to determine the cumulative developmental effects of global LOI, we have established a new mouse model for genome-wide epigenetic deregulation using sequential gene inactivation and reactivation for the essential DMA methyltransferase Dnmtl in embryonic stem cells. DMA methylation is the primary mechanism in mammals for stable propagation of epigenetic silencing at imprinted loci as well as across the entire genome. Using this LOI model we will: (1) identify all DMA methylation-dependent imprinted genes using transcriptional profiling and DNA methylation analyses, (2) determine developmental phenotypic effects of genome-wide loss of imprinting with particular emphasis on fetal growth and characteristic symptoms from BWS, PWS, and AS observed in critical organs including pancreas, kidney and heart, (3) selectively correct individual gene expression abnormalities to assess the contribution of single genes to the complex phenotype using a novel transgenic RNAi strategy. This project will define the set of genes responsive to changes in DNA methylation state during preimplantation development that cause subsequent developmental anomalies when epigenetically misregulated. This study will fill a current gap in knowledge by prospectively connecting epigenetic alterations to resultant developmental defects during organogenesis, and further establishing the subsequent pathologies that are observed in the adult.

描述（由申请方提供）：Beckwith-Wiedeman综合征（BWS）和Prader-Willi/Angelman综合征（PWS/AS）是一种罕见的发育障碍，在美国发生率为1/15，000例活产婴儿。这些疾病的分子基础是11 p15和15 q11上印迹基因簇的失调，主要由印迹控制中心（ICC）内的缺失或ICC中的表观遗传DNA甲基化变化引起。AS和BWS的风险升高与辅助生殖技术有关，这被认为是在体外胚胎培养过程中诱导印记的表观遗传丢失。该提案测试了表观遗传改变单独可以导致发育病理学的总体假设，该发育病理学模拟这些综合征作为整体印记丧失（LOI）的结果，并进一步测试了用于纠正LOI事件的治疗方法。作为一种手段，以确定全球LOI的累积发育影响，我们已经建立了一个新的小鼠模型的全基因组表观遗传失调，使用顺序基因失活和重新激活的胚胎干细胞中的必需的DMA甲基转移酶Dnmtl。DNA甲基化是哺乳动物中表观遗传沉默在印记基因座以及整个基因组中稳定传播的主要机制。使用这个LOI模型，我们将：（1）使用转录谱和DNA甲基化分析鉴定所有DMA甲基化依赖性印迹基因，（2）确定印迹的全基因组缺失的发育表型效应，特别强调胎儿生长和在关键器官（包括胰腺、肾脏和心脏）中观察到的来自BWS、PWS和AS的特征性症状，（3）使用新的转基因RNAi策略选择性地校正个体基因表达异常以评估单个基因对复杂表型的贡献。这个项目将定义一组基因，这些基因对胚胎植入前发育过程中DNA甲基化状态的变化有反应，当表观遗传学失调时，这些变化会导致随后的发育异常。这项研究将填补目前的知识空白，前瞻性地将表观遗传改变与器官发生过程中产生的发育缺陷联系起来，并进一步建立在成人中观察到的后续病理学。