CAREER: The developmental response of a parasitic chytrid fungus to amphibian mucus

本奖项全部或部分由《2021年美国救援计划法案》（公法117- 2）资助。壶菌与青蛙的寄生相互作用正在毁灭世界上数百种两栖动物。水蛭生长在被黏液包裹的两栖动物皮肤上。该项目的目标是确定树突双歧杆菌对暴露于两栖动物粘液分子的反应。建立黏液诱导水蛭变化的分子机制，可用于制定补救策略，逆转水蛭感染引起的两栖动物数量下降。在项目期间，将为每年约24名学生开发一个动手实验课程，以获得真实的研究经验。这些学生将获得设计、执行和解释他们自己的实验结果的实践经验，为他们参加STEM工作做好准备。模块化实验课程框架的开发、评估和传播将允许马萨诸塞大学阿默斯特分校的其他教职员工以及校外教职员工开发新课程和/或快速修改现有课程，以提高本科生的科学推理能力。最后，将这些材料改编成一个面向中学女生的研讨会，将扩大她们对STEM领域的参与。dendroatidis是1000种壶菌之一，其中许多与植物、动物和微生物形成生态上重要的共生关系。像所有的壶菌一样，树泡蛭的生命周期包括两个阶段：在水生环境中游动的游动孢子的传播形式，以及生长并产生新的游动孢子的孢子囊的生长形式。扩散和生长形式之间的过渡是一个重要的发育过程，称为环栖。该项目将验证一个中心假设，即B. dendrobatitis游动孢子通过黏液蛋白（黏液的主要成分）的存在来感知宿主，并通过诱导细胞反应来做出反应，从而导致囊化。为了验证这一假设，该项目将结合定量显微镜、发育分析和化学遗传学，以实现以下目标：目的1：确定粘蛋白暴露诱导的石斛芽胞杆菌的发育和细胞改变。目的2：确定控制粘蛋白诱导的胞囊炎的信号通路。目标3：开发、评估和传播模块化实验课程框架，教学生评估科学信息的质量。这个框架将被用来开发一门课程，在这门课程中，学生们将识别可能导致其他共生和自由生活的壶菌物种内寄生的环境线索。这些目标的成功完成将填补在理解发育途径和宿主相互作用介导石线虫感染的空白。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117- 2). The chytrid fungus Batrachochytrium dendrobatidis engages in a parasitic interaction with frogs that is decimating hundreds of amphibian species around the world. B. dendrobatidis grows in amphibian skin that is coated in mucus. The goal of this project is to determine how B. dendrobatidis responds to exposure to molecules found in amphibian mucus. Establishing the molecular mechanism by which mucus induces changes in B. dendrobatidis may be used to develop remediation strategies to reverse the decline in amphibians caused by B. dendrobatidis infection. A hands-on laboratory course will be developed resulting in an authentic research experience for ~24 students per year for the duration of the project. These students will gain practical experience in designing, executing, and interpreting the results of their own experiments, preparing them to participate in the STEM workforce. The development, evaluation, and dissemination of a modular laboratory course framework will allow additional University of Massachusetts Amherst faculty, as well as extra-mural faculty, to develop new courses and/or quickly revise existing courses to improve scientific reasoning in undergraduate students. Finally, the adaptation of these materials into a workshop for middle school girls will broaden participation in STEM fields.B. dendrobatidis is one of 1000 species of chytrid fungus, many of which form ecologically important symbioses with plants, animals, and microbes. Like all chytrids, the lifecyle of B. dendrobatidis comprises two stages: a dispersal form called a zoospore that swims through aquatic environments, and a growth form called a sporangium that grows and produces new zoospores. The transition between the dispersal and growth form is an essential developmental process called encystation. This project will test the central hypothesis that B. dendrobatidis zoospores sense their host by the presence of mucin, the bulk component of mucus, and respond by inducing a cellular response that results in encystation. To test this hypothesis, the project will combine quantitative microscopy, developmental assays, and chemical genetics in the following objectives: OBJECTIVE 1: Identify developmental and cellular alterations of B. dendrobatidis induced by mucin exposure. OBJECTIVE 2: Identify signaling pathways controlling mucin-induced encystation. OBJECTIVE 3: Develop, evaluate, and disseminate a modular lab course framework that teaches students to evaluate the quality of scientific information. This framework will be used to develop a course in which groups of students will identify environmental cues that could induce encystation in other symbiotic and free-living chytrid species. The successful completion of these objectives will fill a gap in the understanding of the developmental pathways and host interactions that mediate B. dendrobatidis infection.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.