LCR AND ITS COMPONENTS IN DEVELOPMENTAL REGULATION AND RESPONSE TO ANEMIC STRESS

(改编自申请人摘要)Beta- 珠蛋白基因簇受LCR控制。在这个项目中， 研究人员将试图确定LCR在应激过程中的作用 红细胞生成和发育过程中。在目标1中，调查人员将 折痕鼠标线，其中的贝塔珠蛋白LCR将很容易修改。 这将在一项强大的新技术的帮助下实现， 研究人员将其称为重组酶介导的盒式磁带交换(RMCE)。 RMCE基于Cre/LOX重组酶，允许单拷贝 在预先确定的基因座整合转基因。在目标2中， 研究人员将利用这一小鼠品系来研究LCR在 β-珠蛋白基因的发育调控。调查人员将 用人类的LCR替换小鼠的LCR，反转小鼠的珠蛋白 LCR，并研究小鼠HS5的作用。在《目标3》中，调查人员将 LCR在β-氨基丁酸基因上调中的作用研究 氯化血红素的存在和贫血应激的存在作为一种 实验模型5小鼠染色，靶向删除所有 组成LCR的个别房协。这将通过诱导 实验性或遗传性溶血性或血液性贫血 地中海贫血小鼠。调查人员最近发现HS2 但HS3不能在MEL细胞中以单拷贝形式诱导；这导致了 研究人员认为HS2可能对人类免疫缺陷病毒 红系应激状态下珠蛋白基因的表达。在目标3C至3F中， 调查人员将对氯化血红素进行功能和物理特征表征 HS2中的响应元素。在目标4中，调查人员将描述 人β-珠蛋白基因簇多态在糖尿病发病机制中的作用 转基因小鼠中伽马珠蛋白基因的表达。浅谈RMCE的使用 技术将使调查人员能够比较完整的80kb片段 含有塞内加尔和贝宁的贝塔-珠蛋白基因簇 在转基因小鼠中，同一基因座上的单拷贝。了解角色 在应激性红细胞生成过程中LCR的变化可能有助于改善治疗 通过提高对镰状细胞性贫血病程的预测能力 在遗传标记的帮助下，通过改善 对靶向药物的了解，这些药物会导致药物浓度的增加 成人体内HbF的产生。更好地理解对 β-珠蛋白基因簇也应该有助于设计新的治疗策略。

(Adapted from Applicant's Abstract) Regulation of expression of the Beta- globin gene cluster is under the control of the LCR. In this project the investigators will attempt to determine the role of the LCR during stress erythropoiesis and during development. In Aim 1 the investigators will crease a mouse line in which the beta globin LCR will be easy to modify. This will be achieved with the help of a powerful new technology that the investigators have termed Recombinase-Mediated Cassette Exchange (RMCE). RMCE is based on the CRE/LOX recombinase and allows single-copy integration of transgenes at pre-determined loci. In aim 2, the investigators will use this mouse line to study the role of the LCR in the developmental regulation of the Beta-globin genes. The investigators will replace the mouse LCR by its human counterpart, invert the mouse globin LCR, and study the role of mouse HS5. In aim 3, the investigators will study the role of the LCR in the up-regulation of the Betamin gene in the presence of hemin and in the presence of anemic stress using as an experimental model 5 mouse stains with targeted deletion of all the individual HS making up the LCR. This will be performed by inducing hemolytic or hemorragic anemia experimentally or genetically by breeding with thalassemic mice. The investigators have recently found out that HS2 but not HS3 was hemin inducible in single-copy in MEL cells; this lead the investigators to the hypothesis that HS2 might be important for the expression of the globin gene during erythroid stress. In aim 3C to 3F, the investigators will functionally and physically characterized the hemin response element within HS2. In Aim 4 the investigators will characterize the role of the human Beta-globin gene cluster polymorphisms in the level of gamma-globin gene expression in transgenic mice. The use of RMCE technology will allow the investigators to compare intact 80 kb fragments containing the Senegal an Benin Beta-globin gene clusters with integrated in single-copy at the same locus in transgenic mice. Understand the role of the LCR during stress erythropoiesis might help improve the treatment of sickle cell anemia by improving the ability to predict the course of the disease with the help of genetic markers and by improving of the understanding of the target drugs that induce an increase in the production of HbF in adults. Better understanding of the regulation of the Beta-globin gene cluster should also help devise new therapy strategies.