Community Structure and Dynamics of Small Eukaryotes Targeted by New Oligonucleotide Probes: New Insight into the Lacustrine Microbial Food Web
Community Structure and Dynamics of Small Eukaryotes Targeted by New Oligonucleotide Probes: New Insight into the Lacustrine Microbial Food Web
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DOI：
10.1128/aem.00607-09
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发表时间：
2009-10-01
影响因子：
4.4
通讯作者：
Domaizon, Isabelle
中科院分区：
文献类型：
--
作者：
Mangot, Jean-Francois;Lepere, Cecile;Domaizon, Isabelle
通过酪酰胺信号放大-荧光原位杂交，研究了中营养湖中小型真核生物部分（细胞直径为 0.2 至 5 μm）的季节动态，针对七个不同的系统发育类群：绿藻纲、金藻纲、隐藻纲、尾虫纲、LKM11、Perkinsozoa（两个进化枝）和真菌。小型真核生物的丰度范围为 1,692 至 10,782 个细胞 ml(-1)。优势类群是金藻纲和绿藻纲，分别占小型真核生物的 19.6% 和 17.9%。结果还证实了假定的寄生虫、真菌和帕金索动物门在小型异养真核生物群中的数量重要性。夏季，Perkinsozoa 类群的相对丰度高达目标真核生物总数的 31.6%。 Perkinsozoa clade 1 的动态与 Peridinium 和 Ceratium spp 的丰度变化一致。 （甲藻），而 Perkinsozoa clade 2 的动态与 Dinobryon spp 的存在有关。 （金藻纲）。以壶菌为代表的真菌在12月达到最大丰度(569个细胞ml(-1))，主要与硅藻尤其是Melosira variians的动态相关。这项研究的另一个新发现是尾虫 (6.2%) 和 LKM11 (4.5%) 细胞的反复存在。这种基于新设计的探针的定量方法为深入分析湖泊中的微生物食物网提供了一种有希望的方法，特别是通过揭示小型异养鞭毛虫组合的系统发育组成，其中一个重要的细胞部分通常无法通过经典显微镜识别（平均而言，96.8％的小型异养鞭毛虫被我们在本研究中使用的特定探针识别）。
The seasonal dynamics of the small eukaryotic fraction (cell diameter, 0.2 to 5 mu m) was investigated in a mesotrophic lake by tyramide signal amplification-fluorescence in situ hybridization targeting seven different phylogenetic groups: Chlorophyceae, Chrysophyceae, Cryptophyceae, Cercozoa, LKM11, Perkinsozoa (two clades), and Fungi. The abundance of small eukaryotes ranged from 1,692 to 10,782 cells ml(-1). The dominant groups were the Chrysophyceae and the Chlorophyceae, which represented 19.6% and 17.9% of small eukaryotes, respectively. The results also confirmed the quantitative importance of putative parasites, Fungi and Perkinsozoa, in the small heterotrophic eukaryotic assemblage. The relative abundances recorded for the Perkinsozoa group reached as much as 31.6% of total targeted eukaryotes during the summer. The dynamics of Perkinsozoa clade 1 coincided with abundance variations in Peridinium and Ceratium spp. (Dinoflagellates), while the dynamics of Perkinsozoa clade 2 was linked to the presence of Dinobryon spp. (Chrysophyceae). Fungi, represented by chytrids, reached maximal abundance in December (569 cells ml(-1)) and were mainly correlated with the dynamics of diatoms, especially Melosira varians. A further new finding of this study is the recurrent presence of Cercozoa (6.2%) and LKM11 (4.5%) cells. This quantitative approach based on newly designed probes offers a promising means of in-depth analysis of microbial food webs in lakes, especially by revealing the phylogenetic composition of the small heterotrophic flagellate assemblage, for which an important fraction of cells are generally unidentified by classical microscopy (on average, 96.8% of the small heterotrophic flagellates were identified by the specific probes we used in this study).