Abstract：
Fungal parasitism is common in plankton communities and plays a crucial role in the ecosystem by balancing nutrient cycling in the food web. Previous studies of aquatic ecosystems revealed that zoosporic chytrid epidemics represent an important driving factor in phytoplankton seasonal successions. In this study, host-parasite dynamics in Lake Pavin (France) were investigated during the spring diatom bloom while following chytrid epidemics using next generation sequencing (NGS). Metabarcoding analyses were applied to study changes in the eukaryotic microbial community throughout diatom bloom-chytrid epidemics. Relative read abundances of metabarcoding data revealed potential \"beneficiaries\" and \"victims\" during the studied period. Subsequently, metatranscriptomic analyses on samples before and during the chytrid epidemic unveiled the active part of the community and functional/metabolic dynamics in association with the progress of chytrid infection. Diatom functions involving lipases, transporters, histones, vacuolar systems, the proteasome, proteases and DNA/RNA polymerases were more abundant during the diatom bloom. Chytrid functions related to a parasitic lifestyle including invasion, colonization and stress tolerance were up-regulated during the chytrid epidemic. In addition, functions related to the degradation/metabolism of proteins, lipids and chitin were in higher proportion in the community during the epidemic event. Results of NGS and bioinformatics analyses offered a panorama of dynamic biodiversity and biological functioning of the community.
摘要：
真菌寄生在浮游生物群落中很常见，并通过平衡食物网中的养分循环在生态系统中起着至关重要的作用。先前对水生生态系统的研究表明，动物孢子虫的食糜流行是浮游植物季节性演替的重要驱动因素。在这项研究中,在春季硅藻开花期间，使用下一代测序（NGS）研究了Pavin湖（法国）的寄主-寄生虫动力学，同时遵循chytrid流行。Metabarcoding分析用于研究整个硅藻水华-滴虫流行期间真核微生物群落的变化。在研究期间，元编码数据的相对读取丰度揭示了潜在的“受益者”和“受害者”。随后，食糜流行病流行之前和期间对样本的代谢组学分析揭示了与食糜感染进展相关的社区和功能/代谢动力学的活跃部分。涉及脂肪酶的硅藻功能，运输商,组蛋白,液泡系统,蛋白酶体，蛋白酶和DNA/RNA聚合酶在硅藻开花期间更丰富。与寄生虫生活方式有关的Chytrid功能，包括入侵，在食糜流行期间，定植和应激耐受性上调。此外,与蛋白质降解/代谢有关的功能，在流行事件期间，血脂和几丁质在社区中的比例较高。NGS和生物信息学分析的结果提供了动态生物多样性和社区生物功能的全景图。
