MOLECULAR STUDIES OF GENOMIC IMPRINTING IN HUMANS

描述：（改编自研究者摘要）这是一份经过修订的申请，申请竞争性更新资助，以研究印迹障碍的分子机制。Prader-Willi综合征（PWS）是一种毁灭性的、复杂的发育和神经行为障碍，由染色体15q11-q13上父本印迹基因表达缺失引起。研究者和其他人已经确定了一系列父系表达的印迹基因在这个染色体区域和染色体7C的同质小鼠区域。研究者最近开发了一种新的PWS和Angelman综合征（AS）小鼠模型，其中转基因插入删除了所有PWS/AS同源基因。严重的新生儿发育不良，人类PWS的典型，发生在父系遗传上，但转基因系是通过母系传播维持的。该PWS小鼠模型将用于确定哪些基因在PWS中发挥哪些作用，并确定该疾病的生化基础。主要假设是PWS是一种连续基因综合征，多个印迹基因参与了PWS表型，这些基因可以通过转基因拯救PWS小鼠模型来唯一鉴定。本提案的目标是通过以下三个特定目的的方法对PWS和PWS小鼠模型表型的每个组成部分的印迹基因进行遗传剖析：(1)在PWS小鼠模型中使用转基因拯救PWS相关表型，以便定义每个表型组成部分的特定基因。利用来自2 Mb PWS区域的不同基因含量的基因组克隆和cDNA克隆进行转基因技术，以挽救PWS相关表型；(2)研究与PWS表型相关的基因功能；(3)筛选无已知15q11-q13分子异常的PWS或PWS样患者，或具有PWS单一表型成分的患者，筛选小鼠模型鉴定的特定表型成分的每个候选基因突变。

DESCRIPTION: (Adapted from investigator's abstract) This is a revised application for a competitive renewal of a grant to study the molecular mechanisms of imprinting disorders. Prader-Willi syndrome (PWS) is a devastating, complex developmental and neurobehavioral disorder which results from loss of paternal imprinted gene expression at chromosome 15q11-q13. The investigator and others have defined a series of paternally expressed imprinted genes in this chromosome region and the syntenic mouse region in chromosome 7C. The investigator has recently developed a novel mouse model for PWS, and Angelman syndrome (AS), in which a transgene insertion has deleted all the PWS/AS homologous genes. A severe neonatal failure-to-thrive, typical of PWS in humans, occurs on paternal inheritance, but the transgenic line is maintained by maternal transmission. This PWS mouse model will be used to determine which genes play which roles in PWS, and to define the biochemical basis of the disorder. The main hypotheses are that PWS is a contiguous gene syndrome with multiple imprinted genes contributing to the PWS phenotype, and that these genes can be uniquely identified by transgenic rescue of the PWS mouse model. The goal of this proposal is to genetically dissect the imprinted gene(s) underlying each component of the PWS and PWS mouse model phenotypes by an approach consisting of three Specific Aims: (1) use of transgenic rescue of the PWS-associated phenotypes in the PWS mouse model, in order to define specific genes for each phenotypic component. Transgenic technology utilizing genomic clones of varying gene content from the 2 Mb PWS region, and cDNA clones, will be done to rescue the PWS-related phenotypes; (2) to characterize the function of genes shown to be responsible for phenotypic aspects of PWS; and (3) to screen PWS or PWS-like patients with no known 15q11-q13 molecular abnormality, or those patients with single phenotypic components of PWS, for mutations in each candidate gene for specific phenotypic components identified by mouse models.