ANALYSIS OF PROGRAMMED CELL DEATH IN FILAMENTOUS FUNGI

这项资助提案的目的是从基因和分子上表征丝状真菌Neuropora crass的营养不亲和性。营养不亲和性是一种程序性细胞死亡，可以防止感染病原体，如真菌病毒，在整个真菌种群中传播。营养不亲和性在丝状真菌中普遍存在，但在酿酒酵母和庞氏链霉菌中明显不存在，这可能是因为它们的单细胞或假菌丝生长习性。与其他丝状真菌不同的是，粗毛新菌有一个明确的营养不亲和系统(het基因座)，并且有遗传和分子工具可用。我们已经克隆并鉴定了三个het基因座，交配型、het-c和het-6。这项资助计划描述了一些实验，以阐明由het-c介导的粗草营养体亲和不亲和性的机制。我们关于het-c介导的营养不亲和性的基础的假说表明，可选的het-c多肽在共同的细胞质中共存，通过干扰有丝分裂的调节而触发死亡。我们相信，对粗面金线莲营养不亲和性的分析将揭示细胞周期调节与简单真核生物中诱导细胞程序性死亡之间的联系。这项资助计划的具体目标是：1.描述het-c等位基因专一性的要求，2.在细胞生长和程序性死亡期间定位het-C，3.利用生化和遗传分析来剖析营养不亲和性的机制。利用生化和遗传分析对营养不亲和性的分析。对丝状真菌营养不亲和性的分析将为细胞程序性死亡的进化提供信息，并可能揭示细胞周期调节和细胞死亡的机制，这是其他方法无法获得的。了解丝状真菌中细胞程序性死亡的途径可能会为开发针对真菌的药物以对抗丝状真菌引起的人类疾病提供独特的靶点。

The aim of this grant proposal is to genetically and molecularly characterize vegetative incompatibility in the filamentous fungus, Neurospora crass. Vegetative incompatibility is a type of programmed cell death that can prevent transfer of infectious agents such as mycoviruses, throughout a fungal population. Vegetative incompatibility is universal in filamentous fungi, but is apparently absent from S. cerevisiae and S. pombe, presumably because of their unicellular or pseudohyphal growth habit. Unlike other filamentous fungi, N. crassa has a genetically well-defined vegetative incompatibility system (het loci) and both genetic and molecular tools are available. We have previously cloned and characterized three het loci, mating-type, het-c and het-6. This grant proposal describes experiments to elucidate the mechanism of vegetative incompatibility mediated by het-c in N. crassa. Our hypothesis concerning the basis of het-c mediated vegetative incompatibility states that the co-localization of alternative het-c polypeptides in a common cytoplasm triggers death by interference with the regulation of mitosis. We believe that an analysis of vegetative incompatibility in N. crassa will reveal links between cell cycle regulation and induction into programmed cell death in a simple eukaryote. The Specific Aims of this grant proposal are 1. To delineate the requirements for het-c allelic specificity, 2. Localize HET-C within the cell during growth and during programmed cell death, 3. To dissect the mechanism of vegetative incompatibility using both biochemical and genetic analyses. The analysis of vegetative incompatibility using both biochemical and genetic analyses. The analysis of vegetative incompatibility in filamentous fungi will provide information on the evolution of programmed cell death and may uncover mechanisms of cell cycle regulation and cell death that are not accessible by other means. Understanding the pathway of programmed cell death in filamentous fungi may provide unique targets for the development of fungal-specific drugs to combat human diseases caused by filamentous fungi.