MULTIGENE FAMILIES: STRUCTURE, EXPRESSION AND EVOLUTION

多基因家族：结构、表达和进化

• 批准号: 3280282
• 负责人: Thomas H. Eickbush
• 金额: $ 13.02万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-04-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3280282
• 关键词: biochemical evolution; deoxyribonuclease I; developmental genetics; egg shell; endonuclease; gel electrophoresis; gene expression; genetic manipulation; genetic regulation; genetic strain; genetic transcription; messenger RNA; molecular cloning; nucleic acid methylation; nucleic acid sequence; structural genes; ultracentrifugation

The long-term objective of this project is to obtain an understanding of how an elaborate developmental process is accomplished by the integrated expression of a large number of genes. Failure to integrate the expression of various structural genes is the basis for a variety of human developmental defects. The model system chosen for this study is the production of the chorion (eggshell) by the monolayer of follicle cells surrounding the maturing oocyte of the silkmoth, Bombyx mori. In these cells the synthesis of over 100 chorion proteins follows a precise temporal pattern corresponding to a program of specific mRNA production. One useful property of this system is that all chorion genes are tightly clustered on a small segment of one chromosome. The size of this region is estimated to be 700 kilobases. Recovery of the entire locus on recombinant clones (500 kb of which is already accomplished) along with detailed characterizations of the genes encountered, will provide a rare opportunity to trace the evolution of a complex developmental process, as well as provide the groundwork for studies designed to understand how the locus is coordinately regulated. Our study of gene regulation will involve two major approaches. First, utilizing the synchronous populations of cells that can be dissected from the silkmoth ovary, we will examine the structural changes of the chorion genes within the nucleus prior to and during their expression. These structural changes will be monitored by determining the accessibility of the genes to DNase I digestions. Such experiments address the important question of how genes are marked in the nucleus for subsequent expression. Second, we will determine whether the chorion locus is divided into looped chromosomal domains. Evidence for such loops will be obtained by if segments of the chorion locus are found to be associated with the nuclear matrix, an elaborate protein network within the nucleus. The use of mutations containing breakage points within the chorion locus will be extremely helpful in determining the functional role of such putative attachment sites.

这个项目的长期目标是了解 如何通过整合来完成一个精心设计的发展过程 大量基因的表达。未能整合表达式 各种结构基因是人类各种基因的基础 发育缺陷。本研究所选用的模式系统为 单层卵泡细胞产生绒毛膜(蛋壳) 围绕着家蚕蛾成熟的卵母细胞。在这些 细胞100多个绒毛膜蛋白的合成遵循精确的时间 与特定的信使核糖核酸生产程序相对应的模式。一件有用的事 这个系统的特点是所有的绒毛膜基因都紧密地聚集在 一个染色体的一小段。据估计，这一地区的面积为 是700千个碱基。在重组克隆上恢复整个基因座(500 KB)以及详细的特征描述 将提供一个难得的机会来追踪 复杂发展过程的演变，以及提供 为理解轨迹如何协调而设计的研究奠定基础 受监管的。我们对基因调控的研究将涉及两个主要方面 接近了。首先，利用同步的细胞群体，可以 从蚕蛾卵巢中解剖出来，我们将检查其结构 核内绒毛膜基因在受孕前后的变化 表情。这些结构性变化将通过确定 基因对DNase I酶的可及性。这样的实验解决了 重要的问题是基因在细胞核中是如何标记的 后续表达式。第二，我们将确定绒毛膜轨迹是否 被分成环状的染色体区域。这类循环的证据将 如果发现绒毛膜轨迹的片段相关联，则通过 在核基质的作用下，核内形成了一个复杂的蛋白质网络。 绒毛膜基因座内含有断裂点的突变的应用 将极大地有助于确定这种 假定的依恋地点。