SEX-SPECIFIC REGULATION OF TRANSCRIPTION IN DROSOPHILA

这个项目将研究一种主要的， 果蝇发育调控层次结构的研究进展 黑素基因调控靶基因转录的性别特异性。这个 该项目的意义在于其对结构的高级分析 高等生物体的细胞增强剂及其功能及其研究 发育调节因子之间的直接分子联系 层级和目标基因。了解发育调节和 细胞增强子功能是理解基因缺陷的关键 导致人类疾病和人类发育的表达 异常现象。 该项目将研究一种特定的增强剂，这种增强剂可以传递雄性- 从层级结构到一对靶基因的特异性抑制信号。 我们将确定增强子是如何接收该抑制信号的 然后送到发起人手中。处于监管机构底部的基因 层级编码男性特有的女性基因阻遏器和女性- 男性基因的特异性阻遏因子。在体外，无论是男性还是女性抑制者 结合增强子的男性特有的调节元件。我们会 检查在体内运行的机制，以确定男性是否 抑制者足以造成男性的压抑，而女性是否 抑制子不结合这些元素，或者确实结合了它们但不结合 压抑。这将通过使用体外诱变/生殖系来完成 转换方法来标识 并确定结合的抑制子是否作用于其他 增强子元件或直接在启动子上。这些研究将表明 这种抑制作用是通过空间位阻还是通过DNA环发生的 机械装置。我们还将研究相互作用的生物化学。 在DNA位点和纯化的、表达的抑制子之间。这 该项目的生化部分旨在解释男性和 女性抑制子在这种男性特有的增强子上的活动。到时候我们会的 使用来自适当的纯化组织的转录系统 为了在体外复制这种性别特异性的抑制并研究 在抑制机制中运作的蛋白质的功能。

This project will investigate the molecular mechanism by which a major, well-characterized developmental regulatory hierarchy of Drosophila melanogaster directs the sex-specificity of target gene transcription. The significance of the project lies in its advanced analysis of the structure and function of a cellular enhancer from a higher organism and in its study of the direct molecular connection between a developmental regulatory hierarchy and target genes. Understanding developmental regulation and cellular enhancer function is crucial to understanding defects in gene expression that lead to human disease and human developmental abnormalities. The project will investigate a particular enhancer that conveys the male- specific repression signal from the hierarchy to a pair of target genes. We will determine how this repression signal is received by the enhancer and then sent to the promoters. A gene at the bottom of the regulatory hierarchy encodes a male-specific repressor of female genes and a female- specific repressor of male genes. In vitro both male and female repressors bind to the male-specific regulatory elements of the enhancer. We will examine the mechanism operating in vivo to determine whether the male repressor is sufficient to cause repression in males and whether the female repressor does not bind these elements, or does bind them but does not repress. This will be done by using in vitro mutagenesis/germline transformation methods to identify the functional elements within the enhancer and to determine whether the bound repressor acts on other enhancer elements or directly on the promoter. These studies will show whether this repressor action occurs by steric hindrance or DNA looping mechanisms. We will also investigate the biochemistry of the interactions between the DNA sites and the purified, expressed, repressors. This biochemical portion of the project aims at an explanation for the male and female repressor activities at this male-specific enhancer. We will then use a transcription system derived from an appropriate purified tissue in order to reproduce this sex-specific repression in vitro and investigate the function of proteins that operate in the repression mechanism.