Data from: Short term dynamics of diversity patterns: evidence of continual reassembly within lacustrine small eukaryotes

The short-term variation in the community structure of freshwater small eukaryotes (0.2-5 μm) was investigated in a mesotrophic lake every 2-3 days over one summer by coupling three molecular methods: 454 amplicon pyrosequencing, qPCR and TSA-FISH. The pyrosequencing approach unveiled a much more extensive small-eukaryotic diversity (991 OTUs) than has been described previously. The vast majority of the diversity described was represented by rare OTUs (≤ 0.01% of reads) belonging primarily to Cryptomycota, Dikarya and photosynthetic organisms, which were never detected as abundant in any of the samples. The small eukaryote community was characterized by a continual and important reassembly. These rearrangements involved the 20 “core taxa” (≥ 1% of reads), and, were essentially due to a handful of OTUs that were detected in intermediate abundance (0.01-1% of reads) and sporadically in dominant taxa. Putative bacterivorous (Ciliophora and Cercozoa) as well as parasitic and saprotrophic taxa (Perkinsozoa and Cryptomycota) were involved in these changes of diversity. A putative infection of microalgae by a lacustrine perkinsozoan was also reported for the first time in this study. Open questions regarding both the patterns that govern the rapid small eukaryote reassemblies and the possible biogeography of these organisms arise from this study.本研究在一个夏季期间，以每2至3天一次的采样频率，对一座中营养型湖泊中的淡水小型真核生物（0.2-5μm）群落结构的短期变化展开了调查，结合了三种分子生物学方法：454扩增子焦磷酸测序、定量PCR（qPCR）以及酪胺信号放大荧光原位杂交（TSA-FISH）。焦磷酸测序结果揭示的小型真核生物多样性（共计991个操作分类单元（Operational Taxonomic Unit，OTU））远多于此前已有报道。绝大多数已探明的多样性由稀有操作分类单元（占读长总数≤0.01%）构成，这些类群主要隶属于隐真菌门（Cryptomycota）、双核真菌亚界（Dikarya）以及光合生物，且在所有样本中均未被检测为优势类群。该小型真核生物群落呈现出持续且显著的群落重构现象。此类重构过程涉及20个“核心类群”（占读长总数≥1%），其变动主要由少量丰度处于中等水平（占读长总数0.01%-1%）、且偶尔成为优势类群的操作分类单元所驱动。推测的食细菌性类群（纤毛虫门（Ciliophora）、丝足虫门（Cercozoa））以及寄生与腐生类群（帕金虫门（Perkinsozoa）、隐真菌门（Cryptomycota））参与了此次多样性变化。本研究还首次报道了湖生帕金虫类群对微藻的潜在感染现象。本研究提出了两项尚未解决的科学问题：一是驱动小型真核生物快速群落重构的模式机制，二是这类生物潜在的生物地理学分布特征。