MOLECULAR GENETICS OF THE DROSPHILA ZESTE LOCUS

果蝇Zust基因产物在果蝇中的作用研究 突触依赖的基因表达(转导)被提出。这个 所描述的实验将扩展先前的发现，即这种蛋白质结合 结合特定的DNA序列，并在体外作为转录因子 共转染法。首先概述的方法需要详细研究 ZEST蛋白功能结构域的组织。这 然后，信息将用于设计模型系统以进行测试 关于其在转运中的活动的具体假说。 利用ZEST序列的缺失，ITS所需的ZEST结构域 核本地化，可能的多聚化或与其他 蛋白质、协同DNA结合和转录激活 将确定属性。这项工作将由一个 已知基因突变所编码的ZEST蛋白突变的分析 属性。以这种方式生成的信息应添加到 对显性关系的分子基础的理解 ZEST等位基因及其对靶基因剂量的不同要求 他们突变表型的表现。 ZEST蛋白相关区域的鉴定 它的功能方面将被利用来创造嵌合蛋白 有助于建立横断面模型体系。在中国进行试验 酵母和果蝇都将被用来测试详细的假设 Zust基因产物在这一现象中的作用。未来的可能性 研究包括：(A)ZEST介导DNA的环化和配对 序列；(B)ZEST功能需要与其他 转录因子，(C)ZEST的功能类似于其他 转录因子，但它的结构需要独特的元素 (D)ZEST亚基的协同结合是核心 它在横切过程中的作用。

An investigation of the role of the Drosophila zeste gene product in synapsis-dependent gene expression (transvection) is proposed. The experiments described will extend previous findings that this protein binds to specific DNA sequences and acts as a transcription factor in vitro and cotransfection assays. The approach outlined first requires detailed study of the organization of functional domains of the zeste protein. This information will then be used in the design of model systems to test specific hypotheses of its activities in transvection. Using deletions of zeste sequences, domains of zeste required for its nuclear localization, possible multimerization or contacts with other proteins, cooperative DNA binding, and transcriptional activation properties will be identified. This work will be supplemented by an analysis of altered zeste proteins encoded by mutations with known genetic properties. Information generated in this manner should add to understanding of the molecular basis of dominance relationships between zeste alleles and the differing requirements for target gene dosage in the manifestation of their mutant phenotypes. Identification of regions of the zeste protein involved in particular aspects of its function will be exploited to create chimeric proteins useful for the establishment of a model system for transvection. Trials in both yeast and Drosophila will be performed to test detailed hypotheses for the role of the zeste gene product in this phenomenon. Possibilities to be investigated include: (a) zeste mediates the looping and pairing of DNA sequences; (b) zeste function requires synergistic interactions with other transcription factors, (c) zeste functions in a manner similar to other transcription factors, but unique elements of its structure are required for transvection, and (d) cooperative binding of zeste subunits is central to its function in transvection.