Murine models to identify CF lung disease modifiers

描述(由申请人提供)： 人类和老鼠是目前仅有的两种表现为囊性颤抖症的物种 而且两者都可以在受影响的个体之间表现出显著的差异。 似乎很明显，至少有一部分变异是遗传的， 促使使用遗传策略和最先进的分子 寻找相关基因的技术。卡介苗对小鼠和人的限制作用 限制了人们可以用来识别修饰基因的模型系统的选择 囊性纤维化。在两者中，人类显然是更相关的模型 研究，但进行基因研究有很大的局限性 在人类身上。因此，小鼠可以作为人体研究的辅助工具， 提供控制遗传和非遗传因素的能力不是 对人类来说是可能的。然而，缺点是，一个人可能会 牺牲相关性，因为在 两个彼此关系不大的物种。如果一个模型系统，如 小鼠，被用来识别与CF相关的基因，它会有最高的 如果所研究的表型也与CF相关，则成功的机会是否 无论是在临床、细胞还是生化水平。在此应用程序中，我们 建议利用鼠标系统的好处，通过识别 修改CF或与CF相关的表型。在相关应用程序中，我们将 确定这些基因的人类同源基因是否会影响人类的CF。至 要实现这个应用程序的目标，第一个具体目标是绘制基因座图 使小鼠在与CF相关的特征上产生变异，例如涉及的那些 对铜绿假单胞菌的反应和依赖CFs的生长迟缓。我们的 离子转运遗传学的初步发现表明，多个基因是 与观察到的变化有关。对于那些表现出多个 我们希望知道单个基因座的贡献以及如何 它们相互作用。因此，第二个目标是产生 AIM 1和相关项目中确定的基因座的同源小鼠 回交和杂交小鼠。基因将在以下时间生成 无论是在CF背景上还是在非CF背景上。改变cftr水平似乎有 患者有明显的表型效应，但CFTR的调节机制 人们对表达方式的理解很少。我们发现依赖于组织和应变 Cftr表达的差异，使cftr的潜在鉴定成为可能 转录调控因子。为此，第三个目标是确定 Cftr启动子的转录调控元件及其相应 转录因子。 总体目标是确定影响或可以被操纵的基因 影响，疾病严重程度的慢性纤维性心脏病患者。为了达到这个目标，体内的基因 问题必须被分离出来，并确定它们的人类对应对象以供研究。 为此，最终的目标是：在AIM I中识别控制表型的基因 并控制AIM 3的表达，以及它们的人类同源物。

DESCRIPTION (provided by applicant): Man and mouse are currently the only two species that display cystic tibrosis and both can demonstrate significant variation between affected individuals. It seems clear that at least some of the variation is genetic in nature, prompting the use of genetic strategies and state of the art molecular technology to find the genes involved. The restriction of CF to mouse and man limits the choice of model systems one can use to identify genes that modify cystic fibrosis. Of the two, human is obviously the more relevant model to study, but there are significant limitations to carrying out genetic studies in humans. Therefore, the mouse can be used as an adjunct to human studies, providing the ability to control both genetic and non-genetic factors not possible with humans. The drawback, however,.is that one may potentially sacrifice relevance, as there may be CF-associated characteristics between the two species that pertain little to each other. If a model system, such as the mouse, is used to identify genes relevant to CF, it would have the highest chance of success if the phenotypes studied are also relevant to CF, whether it be at the clinical, cellular or biochemical level. In this application we propose to exploit the benefits of the mouse systems by identifying loci that modify CF or CF-related phenotypes. In a related application, we will determine if the human homologues of those genes influence CF in humans. To achieve the goals of this application, the first specific aim is to map loci causing variation in mice for traits relevant to CF, such as those involved responses to Pseudomonas aeruginosa, and CFdependent growth retardation. Our preliminary findings on ion transport genetics indicate multiple genes are involved in the observed variation. For those traits showing multiple contributing loci, we wish to know the contribution of individual loci and how they interact with each other. Therefore, the second aim is to generate congenic mice for loci identified in Aim 1 and related projects by backcrossing and intercrossing consomic mice. Congenics will be generated on both on CF and non-CF backgrounds. Altering CFTR levels appears to have a significant phenotypic effect in patients, but regulatory mechanisms of CFTR expression are poorly understood. We have found tissue- and strain dependent differences in Cftr expression, allowing the potential identification of Cftr transcriptional regulators. Toward this end, the third aim is to identify transcriptional control elements of the Cftr promoter and corresponding transcription factors. The overall goal is to identify genes that affect, or can be manipulated to affect, disease severity in CF patients. To reach that goal, the genes in question must be isolated and their human counterparts identified for study. For this, the final aim is:to identify genes controlling phenotypes in Aim I and controlling expression in Aim 3, as well as their human homologues.