LAC REPRESSOR MOUSE

描述（改编自申请人的摘要）：研究的目标 在本申请中提出的是通过以下方法控制内源小鼠基因组 来自E.杆菌 这是一个直接的延伸， 申请人最初提案的目标是控制 使用这些相同的元件的鼠转基因。 即使他们完成了这个目标， 申请人意识到他们努力的最终目标必须是 基因在自然环境中，所有调节和 存在对活动影响。 虽然申请人的个人原因， 开发这个系统是为了了解基因调控在 发展和可塑性，该系统将是一个强大的工具， 了解广泛的生物学和 生物医学现象 最初拨款的重点是开发一种小鼠， lac阻遏物的功能水平，lac阻遏物的关键调节蛋白， 鼠紫胶系统 这一延续的重点是第二部分 在该系统中，由阻遏物识别的独特启动子元件， lac操作符。 这一26 bp序列的两个拷贝相距约200 bp 可赋予调节哺乳动物基因（p53）启动子的能力，或 当作为转基因引入时驱动cDNA（酪氨酸酶）的哺乳动物启动子 小鼠基因组中。 下一个明显的步骤是引入这些紫胶 通过同源重组将操纵子插入内源基因的启动子 （具体目标#1）。目标等位基因可以通过杂交在全球范围内控制， 在乳糖阻遏物普遍表达的背景下， 申请人已经开发的，或在细胞中-或 使用具有限制性表达的lac阻遏物的组织特异性方式 具体目标#2（Specific Aim #2） 到项目第二阶段结束时， 目标是将转基因小鼠的lac系统转移到 内源性基因组，并开发了一种相对简单的方法， 甚至可以模拟复杂的表型（具体目标#3）。

DESCRIPTION (Adapted from the applicant's abstract): The goal of the research proposed in this application is control of the endogenous mouse genome by elements derived from the lac operon of E. coli. It is a direct extension of the goal of the applicants' original proposal, which was to gain control of murine transgenes using these same elements. Even as they complete this goal, the applicants are aware that the ultimate target of their efforts must be genes in their natural environment, where all the factors that regulate and impinge on activity are present. Although the appicants' personal reason for developing this system is to understand the role of gene regulation in development and plasticity, the system will be a powerful tool for understanding the molecular underpinning of a wide range of biological and biomedical phenomena. The focus of the original grant was the development of a mouse that expresses functional levels of the lac repressor, the key regulatory protein of the murine lac system. The focus of this continuation is on the second component of the system, the unique promoter element recognized by the repressor, the lac operator. Two copies of this 26 bp sequence approximately 200 bp apart can confer the ability to regulate promoters of mammalian genes (p53) or mammalian promoters driving cDNA (tyrosinase) when introduced as transgenes into the murine genome. The next obvious step is to introduce these lac operators into the promoter of an endogenous gene by homologous recombination (Specific Aim #1). Targeted alleles could be controlled globally, by crossing onto a background in which the lac repressor is ubiquitously expressed, such as the one that the applicants have already developed, or in a cell- or tissue-specific manner using lac repressors with restricted expression patterns (Specific Aim #2). By the end of the second phase of the project, the goal is to have transferred the lac system from the transgenic mouse to the endogenous genome and to have developed a relatively simply methodology by which even complex phenotypes can be modeled (Specific Aim #3).