Analysis of Direct-Repeat Mediated Deletions in Yeast Mitochondrial DNA

在真核细胞中，线粒体负责以ATP的形式产生大部分细胞能量。像核DNA一样，线粒体基因组必须保持高保真度以确保正常的细胞功能。线粒体DNA中相同或几乎相同重复序列之间的DNA序列缺失在酵母、玉米和人类等多种物种中经常观察到。虽然已经提出了几种模型来解释直接重复序列相关缺失的产生，但它们产生的机制尚不清楚。该项目的目的是为了了解这一过程中所涉及的蛋白质及其活动。在脊椎动物中，很少有分子技术可用于线粒体DNA的研究，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，酵母线粒体可以被外源DNA转化，并且这种DNA可以整合到基因组中。这些技术已被用于产生允许测量直接重复介导的缺失事件的遗传报告。这些报告基因将用于鉴定线粒体室中重组所需的蛋白质，并确定这些基因组重排发生的分子机制。可用于酵母研究的分子工具使其成为线粒体生物学研究的强大模型系统。线粒体中许多重要过程所需的蛋白质仍不为人所知。这项工作的完成可能会为线粒体DNA代谢的广泛领域提供信息，包括复制、重组和修复。大多数真核细胞都含有线粒体，这是一种为细胞产生能量的膜结合细胞器。除了细胞核中发现的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大片段的缺失是常见的突变。这种缺失在面包酵母的线粒体DNA中也很常见。该项目的长期目标是了解这些缺失产生的机制。本课题将对生物科学专业本科生的培养产生积极的影响。在过去的五年中，elaine Sia博士指导了16名从事独立项目的本科生。今年夏天，实验室里有四名学生，其中一名有资格获得麦克奈尔的资助。这个奖项将允许这些学生继续得到支持。此外，这项研究是与纽约州立大学布罗克波特分校（SUNY-Brockport）的雷伊·希亚（rey Sia）博士合作进行的，这是一所不授予博士学位的四年制大学。在过去的两年中，rey Sia博士一直支持布罗克波特生物科学系的目标，即进一步促进本科生参与研究。他总共资助了9名学生进行各种独立研究和指导研究项目；其中两名学生是CSTEP/麦克奈尔学者。该奖项将支持纽约州立大学布鲁克波特分校生物学专业本科生未来的研究机会。

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.