DEVELOPMENT AND ANALYSIS OF MURINE MODELS FOR SICKLE CELL ANEMIA

这项建议的长远目标是加深我们对 镰状细胞性贫血的分子基础，特别强调 检查导致临床变量的遗传因素 疾病的表现。具体目标是：（1）表征 镰状细胞病和影响其严重程度的因素， 最近开发的镰状细胞贫血小鼠模型，其红细胞 仅包含人类HbS;以及（2）应用全基因组作图工具 和数量性状分析，以确定遗传位点不连锁的 改变镰状细胞病严重程度的珠蛋白簇。 我们的第一个目标涉及转基因/基因敲除小鼠模型， 镰状细胞性贫血，这是我们在上一个资助期产生的。 这些动物只具有人类血红蛋白HbS， 鼠血红蛋白，出生时具有广泛的红细胞镰状化， 相关的发病率。我们将利用这种独特的模式来执行 详细调查的病理生理学的疾病，不可用 用于人体研究。我们将检查预测的代理的有效性 以减轻疾病的严重程度。这些研究将分析导致 对γ-珠蛋白基因表达的影响（即，羟基脲）和血管 音调（即，一氧化二氮）。 第二个目标将采用全基因组扫描来识别基因座， 使用近交系改变镰状细胞病的严重程度和珠蛋白链转换 小鼠品系。这些研究分为两个部分。他们将 使用不同的小鼠遗传背景鉴定修饰的基因座，所述修饰的基因座： (1)影响小鼠镰状细胞病的严重程度， 表达相同的人镰状转基因;和（2）影响γ-to 相同人β-珠蛋白YAC转基因的β-珠蛋白转换。无论是 在这些研究中，我们试图找出与珠蛋白簇无关的基因， 可能影响镰状细胞病的严重程度 在人类身上。预计这些研究将有助于我们改善 了解负责变量的分子机制 镰状细胞病的临床表现。

The long range objective of this proposal is to further our understanding of the molecular basis for sickle cell anemia with particular emphasis on examining genetic factors that contribute to the variable clinical expression of the disease. The specific goals are: (1) to characterize sickle cell disease and the factors which impact on its severity in our recently developed mouse model of sickle cell anemia, whose red cells contain exclusively human HbS; and (2) to apply genome-wide mapping tools and quantitative trait analyses to identify genetic loci unlinked to the globin cluster that modify the severity of sickle cell disease. Our first goal relates to the transgenic/gene knockout mouse model of sickle cell anemia which we generated during the previous funding period. These animals, possessing exclusively human hemoglobin HbS and no adult murine hemoglobins, are born with extensive red cell sickling and associated morbidity. We will exploit this unique model to perform detailed investigations of the pathophysiology of the disease, unavailable for study in humans. We will examine the effectiveness of agents predicted to lessen disease severity. These studies will analyze factors which have an impact on gamma-globin gene expression (i.e., hydroxyurea) and vascular tone (i.e., nitrous oxide). The second goals will employ a genome-wide scan to identify loci that alter sickle cell disease severity and globin chain switching using inbred strains of mice. These studies are divided into two parts. They will identify modified loci, using different mouse genetic backgrounds, that: (1) affect the severity of murine sickle cell disease resulting from the expression of the same human sickle transgene; and (2) affect gamma-to beta-globin switching of the same human beta-globin YAC transgene. In both of these studies, we seek to identify genes unlinked to the globin cluster in mice which are likely to impact on the severity of sickle cell disease in humans. The studies are anticipated to contribute to our improved understanding of the molecular mechanisms responsible for variable clinical expression of sickle cell disease.