Imprinting defects leading to Angelman and Prader Willi syndromes

导致天使威利综合征和普莱德威利综合征的印记缺陷

• 批准号: 8613914
• 负责人: JAMES L RESNICK
• 金额: $ 32.63万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8613914
• 关键词: Alleles; Angelman Syndrome; Animal Model; Assisted Reproductive Technology; Brain; Cognition Disorders; Control Locus; DNA; DNA Methylation; DNA Methyltransferase; DNA Modification Methylases; DNA Sequence; Data; Defect; Detection; Development; Elements; Epigenetic Process; Exons; Frequencies; Future; Gene Cluster; Gene Expression; Gene Expression Profile; Gene Silencing; Genes; Genetic; Genetic Processes; Genetic Transcription; Genomic Imprinting; Goals; Human; Incidence; Investigation; Methylation; Modeling; Molecular; Molecular Genetics; Mus; Mutation; Oocytes; Patients; Pattern; Prader-Willi Syndrome; Prevention; Proteins; RNA; Role; Somatic Cell; Staging; Syndrome; Techniques; Testing; Time; Tissues; Transcript; Transgenes; Work; base; cell type; gene correction; imprint; improved; maternal imprint; microdeletion; mouse model; neurobehavioral disorder; promoter; public health relevance; research study; response; transmission process

PROJECT SUMMARY This application seeks to understand genetic imprinting mechanisms underlying Angelman and Prader-Willi syndromes, two lifelong neurobehavioral disorders. The proposed studies will determine the mechanisms by which the locus is imprinted, test the molecular role of a DNA element implicated in AS imprinting defects, and create an AS imprinting defect animal model. Similar to other imprinted gene clusters, an imprinting center (IC) is responsible for monoallelic gene expression at the PWS-AS locus. The IC at the PWS-AS locus is bipartite, consisting of the PWS-IC and the AS-IC. The PWS-IC works in somatic cells to activate gene expression from the paternal allele. The AS-IC functions in oocytes to epigenetically inactivate the PWS-IC, and thereby silence paternally-expressed genes on the future maternal allele. The AS-IC thus initiates imprinting in the region. The murine AS-IC has evaded detection, precluding mechanistic investigations into AS-IC function. However we recently demonstrated that transcription transiting through the PWS-IC in oocytes is necessary and sufficient to correctly imprint transgenes derived from the locus. We also found that oocyte-active transcriptional promoters were necessary to observe faithful transgene imprinting. Together, these results indicate that transcription transiting across the PWS-IC comprises AS-IC activity. In the first specific aim we will modify the endogenous PWS-AS locus to test the hypothesis the entire endogenous PWS-AS locus is imprinted by a similar transcription-based mechanism. Aim 2 will determine the developmental window in which imprints are established. Aim 3 will provide the first functional characterization of the AS-IC in human oocytes, the tissue in which it functions. At the conclusion of these studies, we will have a mechanistic understanding of how imprints are established at the PWS-AS locus and will have characterized the developmental stage and cell type in which imprinting occurs. We will also understand whether a similar mechanism operates in humans, and the molecular role of DNA sequences that when deleted result in AS. These results will inform future studies of the causes of AS imprinting defects that arise spontaneously, as a result of a deletion of the AS-IC, or at increased frequency following assisted reproductive technologies.

项目摘要 这个应用程序旨在了解遗传印记机制的基础安格尔曼和普拉德-威利 综合征，两种终身神经行为障碍。拟议的研究将通过以下方式确定机制： 该基因座被印迹，测试与AS印迹缺陷有关的DNA元件的分子作用，和 建立AS印迹缺陷动物模型。 与其他印记基因簇相似，印记中心（IC）负责单等位基因的表达， 在PWS-AS位点的表达。PWS-AS基因座上的IC是两部分的，由PWS-IC和 AS-IC。PWS-IC在体细胞中起作用，以激活来自父本等位基因的基因表达。关于AS-IC 在卵母细胞中起作用，表观遗传地抑制PWS-IC，从而沉默父系表达的基因 未来的母系等位基因因此，AS-IC在该区域中启动压印。小鼠AS-IC已逃脱 检测，排除对AS-IC功能的机械研究。然而，我们最近证明， 在卵母细胞中，通过PWS-IC的转录是必要的，并且足以正确地印记 来自该基因座的转基因。我们还发现卵母细胞激活的转录启动子是必需的 以观察可靠的转基因印迹。总之，这些结果表明，转录跨越 PWS-IC包括AS-IC活性。在第一个具体目标中，我们将修饰内源性PWS-AS基因座以测试 假设整个内源性PWS-AS基因座由类似的基于转录的机制印记。 目标2将确定建立印记的发展窗口。目标3将提供第一个 人卵母细胞中AS-IC的功能表征，其在其中发挥功能的组织。 在这些研究的结论，我们将有一个机械的理解是如何建立印记， PWS-AS基因座，并将表征发育阶段和细胞类型，其中印记 发生。我们还将了解是否有类似的机制在人类中起作用，以及 当缺失时导致AS的DNA序列。这些结果将为未来AS病因的研究提供信息 由于AS-IC缺失或频率增加而自发出现的压印缺陷 辅助生殖技术。