Dissertation Research: Population Genetic Structure of Aspergillus nidulans

研究将集中在遗传变异是如何分布在自然种群的丝状霉菌，细粒曲霉，以及它如何在自然中繁殖自己。像芽孢杆菌这样的霉菌可以产生被称为孢子的无性繁殖体，它们的基因与它们的单亲双亲完全相同。或者，它们可以产生孢子，孢子是双亲的基因混合物。这项研究通过调查自然种群的遗传变异来区分这两种事件。遗传标记在自然界中个体之间是可变的。如果在任何给定的个体中只观察到不同的标记组合，则繁殖是无性繁殖。然而，如果一些个体的标记是其他个体的标记的组合，那么就会发生有性繁殖。曲霉是一类重要的生物。许多曲霉及其亲戚被用来生产各种有用的物质，如抗生素。黄曲霉通常生长在储存的粮食产品上，产生一种叫做黄曲霉毒素的强致癌物，对牲畜和人类都有威胁。烟曲霉和寄生曲霉可以是人类病原体，通常致命地感染免疫受损的个体。虽然中性曲霉不是一种病原体，但它是一种发达的研究生物，具有其他物种没有的遗传分析工具。关于它的种群结构和它在自然界中如何传播的信息应该为了解其他霉菌的生活史提供有用的线索。

Research will focus on how genetic variation is distributed in natural populations of a filamentous mold, Aspergillus nidulans, and how it propagates itself in nature. Molds like A. nidulans can produce clonal propagules called spores that are genetically exactly identical to their single parent. Or, they can produce spores that are a genetic mixture of the two parents. This research distinguish will between these two events by surveying genetic variation in natural populations. Genetic markers have been identified that are variable between individuals in nature. If only distinct combinations of markers are observed in any given individual, then reproduction is clonal. However, if some individuals have markers that are combinations of those seen in others, then sexual reproduction occurs. The Aspergilli are an important group of organisms. Many Aspergilli and their relatives are used to produce a variety of useful substances, such as antibiotics. Aspergillus flavus commonly grows on stored grain products, producing a powerful carcinogen called aflatoxin, a threat to livestock and humans. Aspergillus fumigatus and Aspergillus parasiticus can be human pathogens, commonly lethally infecting immune- compromised individuals. While Aspergillus nidulans isn't a pathogen, it is a well-developed research organism, with tools for genetic analysis available that are not developed in other species. Information about its population structure and how it propagates in nature should provide useful clues about the life histories of other molds.