A comprehensive RNAi based screen for genes effecting neural degeneration in C. e

描述(申请人提供)：在人类和其他脊椎动物模型系统中，对线虫神经元退化和再生影响基因的全面RNAi筛选已经研究了100多年，但我们仍然没有一个全面的分子模型，也没有有效的治疗方法来防止退化或诱导再生。令人惊讶的是，如此成功地用于研究身体模式形成、细胞程序性死亡、神经发育和许多其他重要生物学问题的强大遗传模型系统，却没有被用于研究神经元的退化和再生。这是因为很难设计出一种可靠的神经再生筛选试验，无论是在黑腹毛虫还是线虫身上。最近，哈马伦德和我进行了一项观察，现在可以筛选线虫再生所需的基因。我们发现，缺乏血影蛋白的胚胎神经元发育正常(正常的生长锥体运动、寻路和目标识别)，但在孵化后经历了运动诱导的轴突切断和再生。这是一种强健的表型，每种动物的大多数连合轴突在成年之前都会断裂和再生。随着轴突切断和再生的每个周期的发生，再生会逐渐失败，因此成年人的神经系统表现出严重的异常。线虫的这种具有良好特征的再生表型模仿了哺乳动物神经元对轴突切断的反应。我建议使用RNAi基因敲除来分析蠕虫基因组中每个基因在神经元退化和再生过程中的功能。最近，两个使神经元对RNAi敏感的基因突变被发现。这种敏化的遗传背景已经在成功的大规模RNAi筛查中用于功能突触传递的基因并得到验证。有充分的理由相信，这项技术可以用来筛选在退化和再生中起作用的基因，并以光谱蛋白突变表型作为检测的基础。如果成功，这将是第一次对神经元退化和再生起作用的基因进行无偏见的“遗传”筛查，并应确定新的基因作为针对神经元退化和再生的理论的切入点。这一建议代表了对线虫神经元退化和再生功能基因的第一次无偏见的“遗传”筛查。如果成功，它将确定新的基因作为旨在预防神经元变性和诱导神经元再生的治疗的切入点。

DESCRIPTION (provided by applicant): A comprehensive RNAi screen for genes effecting neuron degeneration and regeneration in C. elegans Neuronal degeneration and regeneration has been studied in humans and other vertebrate model systems for over 100 years and yet we still do not have a comprehensive molecular model nor an effective treatment to prevent degeneration or induce regeneration. Surprisingly, the powerful genetic model systems used so successfully to study body pattern formation, programmed cell death, neural development and many other important biological problems have not been used to study neuronal degeneration and regeneration. This is because it has been difficult to devise a robust screening assay for neural regeneration in either D. melanogaster or C. elegans. Recently, Hammarlund and myself made an observation that now makes it possible to screen for genes required for regeneration in C. elegans. We discovered that embryonic neurons lacking ¿-spectrin develop normally (normal growth cone motility, pathfinding, and target recognition), but after hatching undergo a movement-induced axotomy followed by regeneration. This is a robust phenotype, with most commissural axons in each animal breaking and regenerating before the animal reaches adulthood. There is a progressive failure of regeneration as each cycle of axotomy and regeneration takes place so that the adult displays a severely abnormal nervous system. This well-characterized regeneration phenotype in C. elegans mimics the phenotype of mammalian neurons in response to axotomy. I propose to use RNAi knockdown to assay the function of every gene in the worm genome in the process of neuronal degeneration and regeneration. Recently, two genetic mutations were identified that sensitize neurons to RNAi. This sensitized genetic background has been used and validated in a successful large scale RNAi screen for genes that function in synaptic transmission. There is every reason to believe that this technique can be used to screen for genes that function in degeneration and regeneration using the ¿-spectrin mutant phenotype as the basis for the assay. If successful, it would be the first unbiased "genetic" screen for genes functioning in neuron degeneration and regeneration and should identify novel genes as entry points for theurapies targeting neuronal degeneration and regeneration. This proposal represents the first unbiased "genetic" screen for genes functioning in neuron degeneration and regeneration in C. elegans. If successful it will identify novel genes as entry points for therapies aimed at the prevention neuronal degeneration and the induction of neuronal regeneration.