Genes Involved in Paternal Mitochondrial Degradation in C. elegans

参与线虫父本线粒体降解的基因

• 批准号: 6820585
• 负责人: CRAIG W LAMUNYON
• 金额: $ 12.35万
• 依托单位: CALIFORNIA STATE POLY U POMONA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6820585
• 关键词: Caenorhabditis elegans; embryology; gene expression; gene mutation; gene targeting; genetic susceptibility; health science research support; helminth genetics; immunocytochemistry; mitochondria; mitochondrial disease /disorder; mutant; nucleic acid sequence; sperm; ubiquitin

The proposed research continues a genetic investigation of mitochonddal inheritance. Mitochondria are universally inherited only from the egg, not from the sperm. Rare instances of abnormal inheritance of paternal mitochondria in humans can result in developmental problems or metabolic disorders. Recent cell biological studies have shown that mammalian sperm mitochondria are marked with ubiquitin, the universal degradation signal in eukaryotic cells. However, we do not yet know the suite of genes involved in this process, and whether this suite includes only sperm genes or both sperm and egg genes. Also, it is not clear whether non-mammalian taxa use ubiquitin for paternal mitochondrial degradation, in our previous studies with the nematode C. elegans, we have generated four mutant strains that fail to eliminate the sperm mitochondria from the embryo. These are the first such mutants ever generated in any species. The research proposed here will continue our genetic investigations of the mechanism of paternal mitochondrial destruction in C. elegans using the powerful genetic and genomic tools available for this species. Specifically, we aim to test the hypothesis that sperm mitochondria are uniquely tagged for destruction inside the embryo. We will continue our random mutagenesis for mutations that block the degradation of sperm mitochondria. Our previous mutations and new ones we isolate will be mapped and their sequence determined. We will test a second hypothesis that the oocyte actively recognizes the sperm mitochondria and degrades them. We will mutegenize and select for mutant oocytes that fail to eliminate the sperm mitochondria, and we will then map and determine the sequence of the mutated genes. Finally, we will test a third hypothesis that ubiquitin is the degradation label for sperm mitochondria. In a collaborative study, we will continue to knock out sperm specific genes that are associated with the ubiquitination pathway and examine the mutants for paternal mitochondrial inheritance. This project represents a comprehensive effort to study mitochondrial inheritance, and it provides the first genetic approach to the problem. Furthermore, identification of the genes involved in paternal mitochondrial degradation will help elucidate the mechanism of mitochondrial inheritance.

拟议的研究继续对线粒体遗传进行遗传学研究。线粒体通常仅从卵子遗传，而不是从精子遗传。人类父系线粒体异常遗传的罕见情况可能会导致发育问题或代谢紊乱。最近的细胞生物学研究表明，哺乳动物精子线粒体带有泛素标记，泛素是真核细胞中的普遍降解信号。然而，我们还不知道参与这一过程的基因组，以及该组基因是否仅包括精子基因或同时包括精子和卵子基因。此外，目前还不清楚非哺乳动物类群是否使用泛素来降解父系线粒体，在我们之前对线虫秀丽隐杆线虫的研究中，我们已经产生了四种无法从胚胎中消除精子线粒体的突变株。这是任何物种中首次产生的此类突变体。这里提出的研究将利用该物种可用的强大遗传和基因组工具，继续对线虫父本线粒体破坏机制进行遗传研究。具体来说，我们的目标是检验精子线粒体在胚胎内部被独特标记为破坏的假设。我们将继续对阻止精子线粒体降解的突变进行随机诱变。我们之前的突变和我们分离的新突变将被绘制出来并确定它们的序列。我们将测试第二个假设，即卵母细胞主动识别精子线粒体并降解它们。我们将诱变并选择无法消除精子线粒体的突变卵母细胞，然后我们将绘制并确定突变基因的序列。最后我们来测试一下 第三个假设是泛素是精子线粒体的降解标签。在一项合作研究中，我们将继续敲除与泛素化途径相关的精子特异性基因，并检查突变体的父系线粒体遗传。该项目代表了研究线粒体遗传的全面努力，并为解决该问题提供了第一个遗传学方法。此外，鉴定参与父本线粒体降解的基因将有助于阐明线粒体遗传机制。