Characterizing new genes that govern mitochondrial function in the axon

摘要 线粒体是神经元健康不可或缺的一部分。随后，线粒体功能的缺陷会导致 大量的神经退行性疾病，轴突功能障碍和死亡通常先于细胞体 死亡。然而，我们对线粒体生物发生的基本生物学知之甚少， 轴突体内轴突的形态变化、运输或功能。新的发现和表征 调节轴突中线粒体生物学基本方面的分子可能会完全打开 神经退行性疾病的新研究方向。在这项提案中，我们的目标是发现新的监管机构 一种新型高通量无偏正向遗传筛查方法在轴突线粒体功能研究中的应用 最近在实验室中开发的方法。这种方法使我们能够分析线粒体的形态， 轴突的数量和分布具有史无前例的单轴突和单线粒体分辨率 活着。然后，新发现的线粒体基因将使用我们拥有的一系列新工具进行表征 针对果蝇的线粒体研究进行了优化，我们将准确地确定线粒体如何 生理学已经在体内发生了改变。我们还将从基因上确定新的线粒体调节 基因在特定的途径中发挥作用，控制线粒体的维持。鉴于线粒体的健康状况 而功能与神经退行性疾病密切相关，很可能这些基因中的一些 将在神经退行性变中起因果和/或辅助作用。因此，我们还将调查是否 这些新的线粒体相关分子在多巴胺神经元中具有加剧的表型， 因为它们在帕金森氏病(PD)中选择性退化，这种情况下线粒体功能障碍 氧化应激被认为在疾病进展中起着基础性作用。功能守恒 这些新分子中的一部分将在体外哺乳动物神经元中进行测试。这一努力代表着(对 据我们所知)第一次高通过正向遗传筛查所需的分子 线粒体在轴突中的运输和维持。因此，出现了丰富的新型神经元调节因子 线粒体在神经系统疾病中具有潜在作用，目前尚待鉴定。

Abstract Mitochondria are integral to neuronal health. Subsequently, deficits in mitochondrial function contribute to a wealth of neurodegenerative diseases, where axonal dysfunction and die back usually precedes cell body demise. However, we know relatively little about the basic biology of mitochondrial biogenesis, morphological changes, transport, or function in axons in vivo. The discovery and characterization of new molecules regulating fundamental aspects of mitochondrial biology in axons may `open the door' to entirely new lines of research in neurodegenerative disease. In this proposal we aim to discover new regulators of mitochondria function in the axon using a novel and high throughput unbiased forward genetic screening approach recently developed in the lab. This approach allows us to assay mitochondrial morphology, number, and distribution in axons with unprecedented single axon and single mitochondrion resolution in vivo. Newly identified mitochondrial genes will then be characterized using an array of new tools we have optimized for mitochondrial studies in Drosophila, and we will determine precisely how mitochondrial physiology has been altered in vivo. We will also genetically determine how novel mitochondrial regulating genes function in defined pathways to control mitochondrial maintenance. Given that mitochondrial health and function is tightly correlated with neurodegenerative disease, it is likely that a number of these genes will play causal and/or accessory roles in neurodegeneration. We will therefore also investigate whether these novel mitochondria associated molecules have an exacerbated phenotype in dopamine neurons, since they selectively degenerate in Parkinson's disease (PD), a condition where mitochondrial dysfunction and oxidative stress is thought to play a fundamental role in disease progression. Functional conservation of these new molecules will then be assayed in mammalian neurons in vitro. This effort represents (to the best of our knowledge) the first high through forward genetic screen for molecules required for mitochondrial transport to and maintenance in axons. Thus a wealth of novel regulators of neuronal mitochondria, which have potential roles in neurological disease, await identification.