Analysis of Direct-Repeat Mediated Deletions in Yeast Mitochondrial DNA

在真核细胞中，线粒体负责以三磷酸腺苷的形式产生大部分细胞能量。就像核DNA一样，线粒体基因组必须保持高保真，以确保正常的细胞功能。线粒体DNA中相同或几乎相同重复之间的DNA序列缺失在酵母、玉米和人类等不同物种中经常可以观察到。虽然已经提出了几种产生直接重复相关缺失的模型，但它们产生的机制尚不清楚。这个项目的目的是为了了解参与这一过程的蛋白质及其活动。在脊椎动物中，研究线粒体DNA的分子技术很少，这使得鉴定和研究这些系统中线粒体DNA缺失和重排所需的蛋白质变得困难。然而，酵母线粒体可以用外源DNA转化，这些DNA可以整合到基因组中。这些技术已经被用来产生允许测量直接重复介导的删除事件的遗传报告。这些记者将被用来确定线粒体隔间重组所需的蛋白质，并确定这些基因组重组发生的分子机制。可用于酵母研究的分子工具使其成为研究线粒体生物学的强大模型系统。线粒体中的许多重要过程所需的蛋白质仍然未知。这项工作的完成可能会提供有关线粒体DNA新陈代谢的广泛领域的信息，包括复制、重组和修复。大多数真核细胞含有线粒体，线粒体是为细胞产生能量的膜结合细胞器。除了在细胞核中发现的DNA外，线粒体中也发现了DNA。线粒体DNA的忠实维护对细胞的正常功能至关重要。线粒体DNA的大片段缺失是常见的突变。这种缺失在面包酵母的线粒体DNA中也很常见。这个项目的长期目标是了解这些缺失产生的机制。该项目将对本科生的生物科学教育产生积极影响。在过去的五年里，Elaine Sia博士指导了16名寻求独立项目的本科生。今年夏天，实验室里有四名学生，其中一人有资格获得麦克奈尔的资助。这一奖项将允许继续支持这些学生。此外，这项研究代表了与纽约州立大学布罗克波特分校的Rey Sia博士的合作，这是一所主要是四年制的机构，不授予博士学位。在过去的两年里，Rey Sia博士一直支持布罗克波特生物科学系进一步让本科生参与研究的目标。他总共资助了9名学生参加各种独立研究和指导研究项目；其中两名学生是CSTEP/McNair学者。该奖项将为纽约州立大学布罗克波特分校生物学专业本科生未来的研究机会提供支持。

Mitochondria are responsible for producing the bulk of cellular energy in the form of ATP in eukaryotic cells. Like nuclear DNA, the mitochondrial genome must be maintained with high fidelity to ensure normal cellular functions. Deletion of DNA sequences between identical or nearly identical repeats in the mitochondrial DNA are frequently observed in species as diverse as yeast, corn, and humans. Although several models have been proposed for the generation of direct-repeat-associated deletions, the mechanism by which they arise is not known. The aims of this project are directed at understanding the proteins involved in this process and their activities. In vertebrates, few molecular techniques are available for the study of mitochondrial DNA, making the identification and study of the proteins required for the deletions and rearrangement of mitochondrial DNA in these systems difficult. However, yeast mitochondria can be transformed with exogenous DNA, and this DNA can be integrated into the genome. These techniques have been used to generate genetic reporters that allow the measurement of direct-repeat mediated deletion events. These reporters will be used to identify the proteins required for recombination in the mitochondrial compartment, and to determine the molecular mechanisms by which these genome rearrangements take place. The molecular tools available for research in yeast have made it a powerful model system for the study of mitochondrial biology. Many of the proteins required for essential processes in the mitochondria remain unknown. Completion of this work will likely provide information on the broad area of mitochondrial DNA metabolism, including replication, recombination and repair. Most eukaryotic cells contain mitochondria, the membrane-bound organelles that produce energy for the cell. In addition to DNA found in the nucleus of the cell, DNA is also found in the mitochondria. The faithful maintenance of the mitochondrial DNA is essential to the normal function of cells. Deletions of large segments of the mitochondrial DNA are common mutations. Such deletions are also commonly observed in the mitochondrial DNA of baker's yeast. The long-term goal of this project is to understand the mechanism by which these deletions arise. This project will have a positive impact on the education of undergraduates in the biological sciences. In the past five years, Dr.Elaine Sia has mentored sixteen undergraduate students pursuing independent projects. This summer there are four students in the lab, one of whom qualifies for McNair funding. This award will allow the continued support of such students. In addition, the research represents a collaboration with Dr.Rey Sia at SUNY-Brockport, a primarily four-year institution that does not grant Ph.D. degrees. Over the past two years Dr.Rey Sia has supported the goal of the Department of Biological Sciences at Brockport to further undergraduate involvement in research. He has sponsored a total of nine students in a variety of independent studies and directed research projects; two of these students are CSTEP/McNair Scholars. This award will support future research opportunities for undergraduate biology majors at SUNY Brockport.