GENE EXPRESSION IN CELL ORGANELLES

细胞器中的基因表达

• 批准号: 3288660
• 负责人: RICHARD B HALLICK
• 金额: $ 23.29万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-02-01 至 1997-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3288660
• 关键词: Chlamydomonas; Euglena; RNA binding protein; RNA biosynthesis; RNA splicing; biochemical evolution; chloroplasts; evolution; gene expression; gene mutation; genetic regulatory element; genetically modified plants; immunoprecipitation; messenger RNA; molecular cloning; molecular genetics; mutant; nucleic acid sequence; operon; organelles; polymerase chain reaction; precursor mRNA; protein purification; protein reconstitution; radiotracer; site directed mutagenesis; tissue /cell culture

How have introns evolved? Did they occur early in the prebiotic world and contribute to the formation of ancient genes by "exon shuffling," or have they been inserted into genes as mobile genetic elements throughout evolution? Important insights into intron evolution have come from analysis of the chloroplast genome of the photosynthetic protist Euglena gracilis, which contains at least 120 introns, several introns-within-introns, known as "twintrons", and complex twintrons formed from 3 or 4 individual introns which are sequentially spliced. A detailed study of the group III introns and twintrons of Euglena is proposed. The specific aims include: (1) Characterization of additional group III introns and twintrons and their RNA processing pathways, (2) Determination of the extent and importance of alternative splicing of group III introns, and specifically whether alternative splicing results in alternative polypeptides products from a single gene, (3) A study of how group III introns and twintrons have evolved, addressed through a comparative analysis of group III introns in species related to Euglena gracilis, (4) Studies on a gene within a twintron, orf458 of the psbC locus, to assess if this gene may have a role in the mobility or splicing of group III introns, (5) Development of a system for transformation of Euglena chloroplasts, in order to study cis- and trans-acting factors in intron and twintron splicing in transgenic plastids, and (6) Attempts to develop an in vitro group III intron splicing system. This work is addressed at understanding fundamental question about the origins of introns, splicing mechanisms, and alternative splicing.

内含子是如何进化的？它们发生在益生菌世界的早期吗？ 通过外显子改组有助于古代基因的形成，或者有 它们被作为可移动的遗传元件整个插入到基因中 进化论？对内含子进化的重要见解来自于 光合作用原生生物Euglena叶绿体基因组分析 Gracilis，它包含至少120个内含子， 内含子中的内含子，称为“双内含子”和复杂的双内含子 由3或4个单独的内含子顺序拼接而成。一个 Euglena的第III组内含子和双内含子的详细研究 建议。具体目标包括：(1)表征额外的 第三类内含子和双内含子及其RNA加工途径，(2) 确定基因选择性剪接的程度和重要性 第三组内含子，特别是替代剪接是否会导致 在来自单个基因的替代多肽产品中，(3)研究 第三类内含子和双内含子是如何进化的，通过一个 裸藻属近缘种III类内含子的比较分析 Gracilis，(4)PSBC双内含子orf458基因的研究 以评估该基因是否可能在移动性或剪接中起作用 第三类内含子，(5)建立一个转化系统 Euglena叶绿体，以研究其顺式和反式作用因子 转基因质体中内含子和双内含子的剪接，以及(6)尝试 建立第三组内含子体外剪接系统。这项工作是 在理解关于……起源的基本问题时提出 内含子、剪接机制和选择性剪接。