A Five-Gene Region Phylogeny for Cordyceps and the Clavicipitaceae (Ascomycota)

[129212]冬虫夏草是子囊菌真菌的一个属，包括300多种已描述的物种，其中大多数是昆虫和其他真菌的病原体。它是Clavicipitaceae家族的一员，该家族还包括许多种植物病原体。Clavicipitaceae的迷人之处在于，所有物种都必须与自然界中的其他生物联系在一起，才能完成它们的生命周期。这种联系通常是拮抗的，导致宿主生物的疾病和死亡。许多这些真菌病原体只在无性繁殖状态下被发现，这往往阻碍了对其进化起源的准确识别和推断。先前由Spatafora博士支持的NSF研究结果与宿主通过进化时间跳跃和多次有性生殖损失的解释一致。这些数据拒绝了先前关于这组真菌进化的假设，这反映在一个过时的分类中，不能反映真实的关系或具有预测价值。这项资助的研究将通过收集和分析来自五个核和线粒体基因的DNA序列来建立先前的数据。本研究的总体目标是为虫草及其相关真菌的进化关系提出可靠且可测试的假设，从而为宿主关联、致病性和繁殖模式的进化提供基本的理解。为了发展这样的假设，将对冬虫夏草物种的多样性进行采样，并特别强调东亚，这是世界上该属物种最丰富的地区。为了对这种多样性进行采样，Spatafora博士将与来自日本、韩国和泰国的研究人员合作。他们将协助收集物种，他将为来自这些国家的有限数量的研究生提供真菌分子进化方面的培训机会。学生们将访问俄勒冈州立大学的实验室大约六个月，之后他们将回到自己的家乡机构，目标是转让这项技术。虫草属的许多种类及其相关真菌在农业和医学上都具有重要意义。冬虫夏草是多种昆虫的致病菌，是生物防治害虫的理想选择。生物防治是一个活跃的研究领域，可以减少对农药的依赖和对环境的影响。开发有效的生物防治系统的核心是准确理解候选物种之间的关系以及宿主关联和生态位专业化的总体模式。此外，许多种类的冬虫夏草和虫草科产生具有致病性的生物活性化合物。其中一些化合物已被开发用于医学用途（例如，从冬虫夏草中提取的环孢素A），但其他化合物可能有待发现。对这些真菌的进化关系的理解将提供一个预测框架，在这个框架中，其他生物学领域（例如，生物控制，药物发现等）的更集中和有针对性的研究可以进行。

0129212SpataforaCordyceps is a genus of ascomycete fungi that includes over 300 described species, most of which are pathogens of insects and other fungi. It is a member of the family Clavicipitaceae, which also includes numerous species of plant pathogens. The Clavicipitaceae are fascinating in that all species must associate with other organisms in nature in order to complete their life cycle. This association is usually antagonistic, resulting in disease and death of the host organism. Many of these fungal pathogens are only known from asexually reproducing states, which often inhibits accurate identification and inferences about their evolutionary origins. Results from prior NSF supported research by Dr. Spatafora are consistent with an interpretation of host jumping through evolutionary time and multiple losses of sexual reproduction. The data reject previous hypotheses pertaining to the evolution of this group of fungi, which is reflected in an outdated classification that does not reflect true relationships or possess predictive value. Research funded by this grant will build upon previous data by collecting and analyzing DNA sequences from five nuclear and mitochondrial genes. The overall goal of this research is to develop robust and testable hypotheses for the evolutionary relationships of Cordyceps and related fungi, which in turn will provide a basic understanding of the evolution of host association, pathogenicity, and mode of reproduction. To develop such hypotheses, the diversity of Cordyceps species will be sampled with a special emphasis on East Asia, the most species rich region of the world for the genus. In order to sample this diversity, Dr. Spatafora will collaborate with researchers from Japan, Korea, and Thailand. They will assist in collecting of species and he will provide training opportunities in molecular evolution of fungi for a limited number of graduate students from each of these countries. The students will visit the laboratory at Oregon State University for a period of approximately six months, after which they will return to their home institutions with the goal of transferring this technology.Many species of Cordyceps and related fungi of the Clavicipitaceae are important in both agriculture and medicine. Numerous species of Cordyceps are pathogens of insects and are promising candidates for biological control of insect pests. Biological control is an active area of research that may lessen the dependence on, and environmental impact of, pesticides. Central to development of efficient biological control systems is an accurate understanding of both the relationships of candidate species and the overall pattern of host association and niche specialization. In addition, many species of Cordyceps and the Clavicipitaceae produce biologically active compounds that function in pathogenicity. Some of these compounds have been exploited for use in medicine (e.g., Cyclosporin A from Cordyceps subsessilis), but others likely await discovery. An understanding of the evolutionary relationships of these fungi will provide a predictive framework in which more focused and directed research in other fields of biology (e.g., biological control, drug discovery, etc.) can proceed.