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）：线粒体仅遗传自 卵子，不是来自精子。这里提出的研究调查了其机制 这份传承。线粒体是半自主细胞器，包含 他们自己的基因组参与氧化呼吸，这一过程 产生破坏性的氧自由基。除了加工能源之外， 线粒体可以刺激细胞凋亡。线粒体遗传缺陷已在许多人类疾病中被发现。多项研究表明 父系线粒体的遗传可能对后代有害甚至致命 发育中的胚胎。最近来自哺乳动物的证据已经开始解开这个谜团 母体线粒体遗传机制。看来期间 在精子发生过程中，精子线粒体被泛素标记，泛素是一种小的 靶向分子降解的蛋白质。在这里，我建议使用一个 遗传学方法研究父系线粒体的机制 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。 具体来说，我们将研究父本线粒体是 在精子发生过程中被标记，以便在发育中的胚胎内被破坏。我们 首先会随机诱变蠕虫并选择阻止 精子线粒体的破坏。我们有初步证据表明我们可以 获得这样的突变。突变基因将被绘制图谱并确定其序列 通过与相连的精子特定基因进行比较来确定；基本上全部 DNA 微阵列的结果现在已知精子基因组中的特定基因 分析。其次，在一个合作项目中，我们将淘汰 已知精子特异性的泛素相关基因。如果这些 突变阻止了精子线粒体的精子降解，然后泛素 参与线虫精子线粒体的破坏。最后，在 另一个合作项目，我们将检查精子是否存在 通过 (i) Western 分析和 (ii) 免疫细胞化学检测泛素。结果 这些实验可能会鉴定出参与降解的基因 精子线粒体。因为线虫基因组中的所有基因都是已知的， 大多数具有预测功能，识别参与的基因 线粒体遗传将有助于阐明这一机制 遗产。此外，研究父系后代的表型 线粒体将识别遗传父系的潜在健康影响 线粒体。