Testing Human Quantitative Genomic Variations in Mice

描述（由申请人提供）：我们研究的长期目标是确定人类基因组中的某些多态性变异是否在常见疾病（如原发性高血压、胰岛素抵抗、腹部肥胖和动脉粥样硬化）中起致病作用，这些疾病是心血管发病率和死亡率的重要危险因素。我们的工作假设是，人类基因组中影响基因产物表达水平的常见变异在决定风险方面发挥着重要作用。虽然个体差异的影响可能很小，但当它们普遍存在时，它们对总人口的影响可能是显著的。为了模拟这些形式的定量变异，我们建议开发一种新的系统程序，使小鼠的基因表达水平可以随意改变。该过程依赖于基因3'非翻译区（UTR）序列的靶向修饰，以产生在全身低（或高）表达基因的小鼠，同时具有在特定组织中增加（或减少）表达水平的能力。当小鼠与携带cre -重组酶基因的动物交配时，其表达将从“低”变为“高”，反之亦然。我们建议将这种新方法应用于编码血管紧张素II型1受体（Agtr1a）和细胞色素P450 3A11 （Cyp3a11）的基因，这两个基因分别是一个已经建立的和一个新的原发性高血压候选基因。我们将使用血压和体脂质量以及实验小鼠的分布作为两个主要的定量终点。我们期望我们的新方法将有助于测试人类基因组中的其他遗传数量变异是否对复杂疾病有致病作用，这是一个与人类福祉有关的非常重要的问题。我们生产的“低-高”小鼠品系应该有助于区分基因表达的局部和全身效应，并允许进一步解剖潜在的分子机制。

DESCRIPTION (provided by applicant): The long-term goal of our study is to determine whether certain polymorphic variations in the human genome play causative roles in the common conditions, such as essential hypertension, insulin resistance, abdominal obesity, and atherosclerosis, that are important risk factors for cardiovascular morbidity and mortality. Our working hypothesis is that common variations in the human genome that affect levels of expression of gene products play significant roles in determining risk. While the effect of individual variations may be small, when they are common their impact in the total population can be significant. To model these forms of quantitative variation, we propose to develop a new systematic procedure enabling the levels of gene expression to be altered at will in mice. The procedure depends upon targeted modification of 3'untranslated region (UTR) sequences of genes to generate mice with low (or high) expression of a gene in the whole body yet with the ability to increase (or decrease) the expression level in specific tissues. Expression will be altered from "low" to "high", or vice versa, in whole body or in tissue-specific fashion when mice are mated to an animal carrying a Cre-recombinase gene. We propose here to apply this new procedure to the genes coding for angiotensin II type 1 receptor (Agtr1a) and cytochrome P450 3A11 (Cyp3a11), which are respectively a well-established and a new candidate gene for essential hypertension. We will use blood pressure and body fat mass and distribution of resulting mice as the two primary quantitative endpoints. We expect that our new method will facilitate testing whether other inherited quantitative variants in the human genome have causative effects on complex diseases, a highly important problem in relation to human welfare. The "low-high" strains of mice that we produce should aid in distinguishing between local and systemic effects of gene expression and allow further dissection of the underlying molecular mechanisms.