REVSYS: Phylogenetics and Taxonomic Revision of the Rhizophydium Clade (Chytridiomycota)

REVSYS：Rhizophydium Clade（壶菌门）的系统发育和分类学修订

• 批准号: 0516173
• 负责人: Martha Powell
• 金额: --
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0516173&HistoricalAwards=false
• 关键词: REVSYS; Phylogenetics; Taxonomic; Revision; Rhizophydium

Chytrids are microscopic fungi with flagellated (motile) life stages ("zoosporic fungi") that are nearly ubiquitous in nature, yet are poorly known and often unrecognized. Some of the most important chytrid fungi are members of the Rhizophydium clade or lineage, including the deadly amphibian parasite Batrachochytrium dendrobatidis, numerous algal parasites, and soil-inhabiting degraders of refractory materials such as pollen grains, cellulose, chitin, and keratin. The current taxonomic classification, published in 1960, is out of date and is based primarily on obscure morphological features that exhibit plasticity, making it difficult to identify genera and species. Modern biological techniques in gene sequencing and electron microscopy provide an opportunity to re-evaluate these organisms using phylogenetically informative characters, both morphological and molecular. Recent analyses of nuclear ribosomal DNA sequences have helped define membership and revealed unexpected genetic diversity within the Rhizophydium clade, indicating that the biodiversity of this group has been under-appreciated. Drs. Martha Powell and Peter Letcher at the University of Alabama propose to use molecular and zoospore ultrastructural (cell-anatomical) characters to revise the taxonomy of this group. They will expand the geographic areas and habitats sampled to include temperate and tropical rainforests in both hemispheres, the number of genes analyzed, and the details of ultrastructural characters of zoospores. Their goals are to make identification of chytrids easier, document their occurrence in nature by geographic region and habitat, provide laboratory cultures authenticating classical species names, and train a graduate student who is an underrepresented minority student, and work with other collaborators in chytrid systematics and taxonomy. The outcome of the project will be a modern systematic synthesis of the Rhizophydium clade. The work will be the first monographic synthesis of a large group of chytrids based on both molecular and ultrastructural characters. Through collaboration with scientists in Australia, Argentina, and Costa Rica, the investigators will reveal chytrid diversity in tropical and temperate forests, habitats that are rapidly being degraded by deforestation and other anthropogenic activities. Tools that make chytrid systematics more accessible will be added to an existing web site with digital images, a database of chytrid laboratory cultures, and interactive identification keys. Molecular sequences added to GenBank will be valuable for studies exploring the functional role of chytrids in nature. Working in concert with the Center for Communication and Educational Technology, the graduate student trainee will learn about video production, interactive web education, and appropriate content for students at different levels. Newly produced materials will introduce numerous middle-school students in the Alabama system to fungal biology and chytrid diversity through print and digital formats. Once introduced to chytrids, most students, teachers, and laypersons find these organisms fascinating.

壶菌是具有鞭毛（能动）生命阶段的微观真菌（“游动孢子真菌”），在自然界中几乎无处不在，但知之甚少，往往无法识别。一些最重要的壶菌属真菌是根生菌属分支或谱系的成员，包括致命的两栖类寄生虫Batrachochytrium dendrobatim，许多藻类寄生虫和土壤中的难降解物质，如花粉粒，纤维素，几丁质和角蛋白。目前的分类学分类，发表于1960年，已经过时，主要是基于模糊的形态特征，表现出可塑性，使其难以识别属和种。基因测序和电子显微镜的现代生物技术提供了一个机会，重新评估这些生物体的形态学和分子生物学信息字符。最近的核核糖体DNA序列的分析有助于确定成员资格，并揭示了出乎意料的遗传多样性内的根生菌分支，这表明该组的生物多样性一直被低估。亚拉巴马大学的玛莎·鲍威尔和彼得·莱彻博士建议利用分子和游动孢子超微结构（细胞解剖学）特征来修改这一类群的分类。他们将扩大采样的地理区域和栖息地，包括两个半球的温带和热带雨林，分析的基因数量以及游动孢子超微结构特征的细节。他们的目标是使壶菌更容易识别，记录它们在自然界中的地理区域和栖息地，提供实验室文化认证经典物种名称，并培训一名研究生谁是一个代表性不足的少数民族学生，并与其他合作者在壶菌系统学和分类学。该项目的成果将是一个现代系统的合成Rhizophydium分支。这项工作将是第一个专题合成的一大群壶菌的分子和超微结构的特点。通过与澳大利亚、阿根廷和哥斯达黎加的科学家合作，研究人员将揭示热带和温带森林中壶菌的多样性，这些森林和栖息地正因森林砍伐和其他人为活动而迅速退化。使壶菌系统学更容易获得的工具将被添加到现有的网站上，包括数字图像、壶菌实验室培养物数据库和交互式识别键。基因库中的分子序列将有助于研究壶菌在自然界中的功能。与通信和教育技术中心合作，研究生实习生将学习视频制作，交互式网络教育以及适合不同层次学生的内容。新制作的材料将通过印刷和数字格式向亚拉巴马系统的许多中学生介绍真菌生物学和壶菌多样性。一旦被介绍给壶菌，大多数学生，教师和外行人发现这些生物很迷人。