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

（改编自申请人的摘要）β-半乳糖苷酶的表达调控 珠蛋白基因簇受LCR控制。本工程 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，研究人员将 在一条容易修饰β球蛋白LCR的小鼠线上打折痕。 这将在一项强大的新技术的帮助下实现， 研究者称之为酶介导的盒交换（RMCE）。 RMCE基于CRE/LOX重组酶，允许单拷贝 转基因在预定基因座的整合。在目标2中， 研究人员将使用这种小鼠系来研究LCR在 β-珠蛋白基因的发育调控。调查人员将 将小鼠LCR替换为人类LCR， LCR，并研究小鼠HS 5的作用。在目标3中，调查人员将 研究LCR在Betamin基因上调中的作用， 存在氯化血红素和存在贫血应激时， 实验模型5小鼠染色，靶向缺失所有 组成LCR的各个HS。这将通过诱导 实验性或遗传性溶血性或出血性贫血 地中海贫血小鼠调查人员最近发现，HS 2 而HS 3在MEL细胞中是单拷贝的氯化血红素可诱导的，这导致了 研究人员的假设，HS 2可能是重要的， 在红细胞应激期间珠蛋白基因的表达。在aim 3C至3F中， 研究人员将对氯化血红素进行功能和物理表征， HS 2中的响应元件。在目标4中，研究人员将描述 人类β-珠蛋白基因簇多态性在 在转基因小鼠中的γ-珠蛋白基因表达。RMCE的使用 这项技术将使研究人员能够比较完整的80 kb片段， 含有塞内加尔和贝宁β-珠蛋白基因簇， 在转基因小鼠的同一基因座的单拷贝。理解角色 应激红细胞生成过程中LCR的变化可能有助于改善治疗 镰状细胞性贫血的治疗方法， 在遗传标记的帮助下， 了解诱导增加的靶向药物 在成人中产生HbF。更好地了解 β-珠蛋白基因簇也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.