Molecular Genetics of Conidial Morphogenesis in Neurospora Crassa

真菌为调节细胞生长发育过程的分子研究提供了模型真核生物系统。粗神经孢子虫和许多其他真菌种类产生无性孢子，称为分生孢子，这是一种重要的传播手段。这项研究的目的是确定这一简单发育过程的分子基础。几个基因位点调控着粗草的分生孢子发育，其中蓬松基因是最具特征的。预测的蓬松蛋白序列与gal4型转录因子相似。这项工作的主要目的是表征蓬松的功能。这种蓬松的蛋白质有一些区域表明它是一种转录因子。这将受到考验。Fluffy作为形态发生调节剂的作用将通过从异源启动子表达Fluffy来测试。绒毛诱导基因激活的遗传要求将通过检查条件诱导的基因在发育突变体中的表达来确定。众所周知，生理变化伴随着发育，代谢状态与发育之间的关系已经成为30多年来草属植物感兴趣的话题。本研究的结果将为草属植物调控条件的机制提供更深入的理解。营养、光线和生物钟都有助于调节分生孢子产生的时间和数量。阐明调节条件的机制将为理解响应不同环境信号的信号转导途径如何共同控制细胞分化提供基础。本研究的第二个目的是研究生理变化与发育之间的关系。该项目将利用一项新技术，通过微阵列分析转录谱，来评估绒毛蛋白表达升高时发生的代谢变化。丝状真菌是一种对社会产生巨大影响的多样化生物。真菌在有机物的腐烂和循环中起着重要的作用。它们也是植物和动物的重要病原体，并用于酶、化学品和药品的工业生产。更好地了解丝状真菌的生理和发育对提高生产力和人类健康的目标至关重要。本项目将整合调节分生作用的分子事件与真菌发育和对环境信号的反应相关的生理事件。

Fungi provide model eukaryotic systems for molecular studies of the cellular processes regulating growth and development. Neurospora crassa and many other fungal species produce asexual spores, called conidia, that are an important means of dispersal. The goal of this research is to define the molecular basis of this simple developmental process. Several genetic loci regulate conidial development in N. crassa and the fluffy gene is the best characterized of these. The predicted fluffy protein has sequence similarity to Gal4-type transcription factors. The primary objective of the work is to characterize the function of fluffy. The fluffy protein has regions suggesting it is a transcription factor. This will be tested. Fluffy's role as a regulator of morphogenesis will be tested by expression of fluffy from a heterologous promoter. The genetic requirements for fluffy-induced gene activation will be determined by examination of conidiation-induced gene expression in developmental mutants. Physiological changes are known to accompany development and the relationship between metabolic state and development has been a topic of interest in N. crassa for over 30 years. The results of the proposed research will provide a deeper understanding of how N. crassa regulates conidiation. Nutrients, light and the circadian clock all contribute to regulation of the timing and abundance of conidia production. Elucidation of the mechanisms that regulate conidiation will provide a foundation for understanding how signal transduction pathways responding to different environmental signals operate together to control cellular differentiation. A second objective of the proposed research is to examine the relationship between physiological changes and development. This project will take advantage of a new technology, transcriptional profiling through analysis of microarrays, to assess the metabolic changes that occur in response to elevated expression of fluffy. Filamentous fungi are a diverse group of organisms with a tremendous impact on society. Fungi play important roles in the decay and recycling of organic material. They are also important pathogens of plants and animals and are used in industrial production of enzymes, chemicals, and pharmaceuticals. A better understanding of the physiology and development of filamentous fungi is important to the goal of manipulating fungi for the purpose of increasing productivity and human health. This project will integrate the molecular events regulating conidiation with physiological events associated with development and responses of fungi to environmental signals.