MOLECULAR GENETICS OF THE DROSPHILA ZESTE LOCUS

果蝇zeste基因产物在细胞凋亡中作用的研究 突触依赖的基因表达（transvection）。 的 所描述的实验将扩展先前的发现， 特异性DNA序列，并在体外充当转录因子， 共转染测定。 首先概述的方法需要详细研究 zeste蛋白的功能结构域的组织。 这 然后，这些信息将用于模型系统的设计， 它在transvection活动的具体假设。 使用zeste序列的缺失，其所需的zeste结构域 核定位，可能的多聚化或与其他 蛋白质、协同DNA结合和转录激活 属性将被识别。 这项工作将得到补充， 分析由具有已知遗传特性的突变编码的改变的zeste蛋白 特性. 以这种方式产生的信息应有助于 了解显性关系的分子基础， zeste等位基因和不同的要求，目标基因剂量在 它们的突变表型的表现。 鉴定zeste蛋白的区域， 它的功能方面将被利用来创造嵌合蛋白质 有助于建立一个模型系统的transvection。 试验 酵母和果蝇都将进行测试， zeste基因产物在这一现象中的作用。 可能是 研究包括：（a）zeste介导DNA的成环和配对 （B）zeste功能需要与其它序列的协同相互作用 （c）zeste以类似于其他转录因子的方式起作用 转录因子，但其结构的独特元素是必需的 对于transvection，和（d）zeste亚基的合作结合是中心的 它的横转功能。

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.