Genetics of Mitochondrial Inheritance in C. elegans

线虫线粒体遗传的遗传学

• 批准号: 6786958
• 负责人: CRAIG W LAMUNYON
• 金额: $ 5.02万
• 依托单位: CALIFORNIA STATE POLY U POMONA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6786958
• 关键词: Caenorhabditis elegans; cell death; developmental genetics; extrachromosomal DNA; gene expression; gene mutation; genetic mapping; genetic markers; immunocytochemistry; mitochondria; phenotype; polymerase chain reaction; protein degradation; spermatogenesis; tissue /cell culture; ubiquitin; western blottings

DESCRIPTION (provided by applicant): Mitochondria are inherited only from the egg, not from the sperm. The research proposed here investigates the mechanism of this inheritance. Mitochondria are semiautonomous organelles that contain their own genome and that are involved in oxidative respiration, a process that generates damaging oxygen radicals. In addition to processing energy, mitochondria can stimulate apoptosis. Mitochondrial genetic defects have been identified in a number of human diseases. Several studies suggest that inheritance of paternal mitochondria may be harmful or even fatal to the developing embryo. Recent evidence from mammals has begun to unravel the mechanism of maternal mitochondrial inheritance. It appears that during spermatogenesis, the sperm mitochondria are marked with ubiquitin, a small protein that targets molecules for degradation. Here, I propose to use a genetic approach to investigate the mechanism of paternal mitochondrial destruction in the nematode C. elegans. The study will make use of the powerful genetic and genomic tools that have been developed for this species. Specifically, we will investigate the hypothesis that paternal mitochondria are tagged during spermatogenesis for destruction inside the developing embryo. We will first randomly mutagenize worms and select for mutations that block the destruction of sperm mitochondria. We have preliminary evidence that we can obtain such mutations. The mutated genes will be mapped and their sequence determined by comparison with linked sperm specific genes; essentially all sperm specific genes in the genome are now known as a result of DNA microarray analyses. Second, in a collaborative project, we will knock out ubiquitin-associated genes that are known to be sperm specific. If these mutations block sperm degradation of sperm mitochondria, then ubiquitin is involved in the destruction of sperm mitochondria in C. elegans. Finally, in another collaborative project, we will examine sperm for the presence of ubiquitin by (i) Western analysis, and (ii) by immunocytochemistry. The results of these experiments will likely identify genes involved in the degradation of sperm mitochondria. Because all the genes in the C. elegans genome are known, and most have predicted functions, identification of genes involved in mitochondrial inheritance will help elucidate the mechanism of this inheritance. Also, studying the phenotypes of offspring with paternal mitochondria will identify potential health impacts of inheriting paternal mitochondria.

描述（由申请人提供）：线粒体仅继承 鸡蛋，不是精子。这里提出的研究调查了机制 这种继承。线粒体是包含的半自主细胞器 它们自己的基因组，并参与氧化呼吸，这一过程 产生损害的氧自由基。除了处理能量之外， 线粒体可以刺激凋亡。线粒体遗传缺陷已在许多人类疾病中鉴定出来。几项研究表明 父亲线粒体的继承可能有害甚至是致命的 开发胚胎。哺乳动物的最新证据已经开始揭示 母体线粒体遗传的机制。看来在 精子发生，精子线粒体用泛素标记，一个小 靶向分子降解的蛋白质。在这里，我建议使用 研究父亲线粒体机制的遗传方法 线虫秀丽隐杆线虫的破坏。该研究将利用强大的 为该物种开发的遗传和基因组工具。 具体而言，我们将研究父亲线粒体是 在生理发生期间标记为在发育中的胚胎内部破坏。我们 首先将随机诱变蠕虫，然后选择阻止该蠕虫的突变 精子线粒体的破坏。我们有初步证据表明我们可以 获得此类突变。突变的基因将被映射并序列 通过与链接的精子特定基因进行比较来确定；本质上是全部 基因组中的精子特异性基因现在被称为DNA微阵列的结果 分析。第二，在一个协作项目中，我们将淘汰 泛素相关的基因，已知是精子特异性的。如果这些 突变阻断精子线粒体的精子降解，然后泛素是 参与秀丽隐杆线虫中精子线粒体的破坏。最后，在 另一个协作项目，我们将检查精子的存在 （i）西方分析和（ii）免疫细胞化学的泛素。结果 这些实验可能会确定涉及降解的基因 精子线粒体。因为秀丽隐杆线虫基因组中的所有基因都是已知的，所以 大多数人都预测了功能，鉴定了涉及的基因 线粒体遗传将有助于阐明这种机制 遗产。同样，研究后代的表型 线粒体将确定继承父亲的潜在健康影响 线粒体。