Mouse Models of Functional Insertion Polymorphisms

描述(申请人提供)：我们的基因组主要由重复的‘垃圾DNA’组成，这些重复的‘垃圾DNA’源自可移动元素的插入。我们的团队已经开发了一些方法来识别这些未被研究的序列的多态插入，证明它们是我们基因组结构变异的主要来源，并发现它们经常与GWAS发现的与性状相关的SNPs连锁不平衡。其他人的实验和对基因组中移动DNA非随机分布的表征表明，它们具有显著的影响基因功能的潜力。我们的主要假设是，Alu插入的子集-人类最普遍和多态的移动DNA-具有表型后果。我们的具体目标是在等位基因转基因小鼠模型中分离和表征两个多态Alu插入的效果。第一个要研究的插入多态是血管紧张素转换酶(ACE)基因座上的内含子Alu 287bp。血管紧张素转换酶编码肾素-血管紧张素-醛固酮血压控制系统的一个关键组成部分，也通过降解缓激肽参与血管内稳态；ALU是一个研究得很充分的ACE酶水平降低的标志物，被认为是有功能的，尽管这还没有直接测试。我们建议研究的第二个多态性是富含AT的交互式结构域包含蛋白5B(ARID5B)基因座上168bp的内含子Alu插入。我们最近将这种多态Alu与最常见的儿童癌症--前驱B细胞急性淋巴细胞性白血病(ALL)的发病风险联系起来。这项拟议的研究将首次分离和测量体内常见的、自然发生的TE插入多态效应，并建立模型来研究这些效应的机制。更广泛地说，这项工作将为GWAS后续的小鼠建模提供研究设计，并开始工作，使等位基因YAC资源可用于研究其他Alu插入的功能。

DESCRIPTION (provided by applicant): Our genomes are mostly made up of repetitive 'junk DNA' derived from insertions of mobile elements. Our group has developed methods to identify polymorphic insertions of these understudied sequences, demonstrated they are major sources of structural variation our genome, and found they occur frequently in linkage disequilibrium with trait associated SNPs identified by GWAS. Experiments by others and characterizations of the non-random distribution of mobile DNAs in genomes indicate they have significant potential to effect gene function. Our overarching hypothesis is that a subset of Alu insertions - the most prevalent and polymorphic mobile DNAs in humans - has phenotypic consequence. Our specific objectives are to isolate and characterize the effects of two polymorphic Alu insertions in allelogenic transgenic mouse models. The first insertion polymorphism to be studied is an intronic Alu 287bp in the angiotensin converting enzyme (ACE) gene locus. ACE encodes a key component of the renin-angiotensin-aldosterone blood pressure control system and is also involved in vascular homeostasis through degradation of bradykinin; the Alu is a well-studied marker of reduced ACE enzyme levels and presumed to be functional, although this has not been directly tested. The second polymorphism we propose to study is a 168bp intronic Alu insertion in the AT-rich interactive domain-containing protein 5B (ARID5B) locus. We recently associated this polymorphic Alu with risk for developing the most common childhood cancer, precursor B-cell acute lymphoblastic leukemia (ALL). The proposed studies will be the first to isolate and measure effects common, naturally-occurring TE insertion polymorphisms in vivo and to generate models to study mechanisms of these effects. More broadly, the work will provide a study design for mouse modeling in GWAS follow-up and begin work to make available an allelogenic YAC resource for studying functions of other Alu insertions.