The Venn diagram illustrates the relative proportions of the vari

The Venn diagram illustrates the relative proportions of the variation in sequence data click here that could be associated with variation in biological, chemical and physical parameters from the eigenvalues calculated by the CCA. The CCA supported the conclusion obtained from the UNIFRAC analysis, clearly showing that all treatments with increased temperature grouped together. Furthermore, the highest abundances of bacteria, picocyanobacteria, and pigmented

groups such as Cryptophyceae and Bacillariophyceae were tightly associated with treatments receiving an increased temperature (Figure 5). The CCA plot also illustrates the strong negative impact of experimental conditions on Mamiellophyceae in general. Mamiellophyceae represented 28% of sequences in the clone library at T0, but were not detected at T96 h (except 1 OTU detected in the C treatments). In contrast, Pyramimonadales sequences (2 OTUs) appeared at T96 h in 6 out of the 8 types of treatment. Overall, the analysis of

the OTUs dynamics (either generally or for specific phylogenetic groups) showed that, even when the abundance of a given group did not change significantly from one treatment to another, some rearrangements Selleck RG7420 could occur at the OTUs level (Additional file 2: Table S1). The CCA showed that 18.8% of the total variation in the eukaryotic A-1210477 clinical trial structure was explained by temperature, whereas, UVBR and nutrients explained 11% and 8.4%, respectively. Discussion The Thau lagoon, characterised by a high abundance of small eukaryotes and by recent in situ changes in phytoplankton structure due to water temperature increase [27], is an interesting ecosystem to investigate the responses of small eukaryotes to climatic and anthropogenic regulatory factors. Our experimentation does not intend Florfenicol to predict the impact of long-term global change on the structure

of small planktonic eukaryotes. Indeed, only a combination of approaches including laboratory studies on model microbes, microcosm and mesocosm experiments, and in situ comparative studies would help to provide realistic predictions of the effects of environmental changes [23, 54]. Our goal was to reveal the potential rapid responses of small eukaryote assemblage (using molecular and morphological methods) during the productive spring season when plankton may be particularly vulnerable to elevated temperature and UVBR [55]. Molecular analyses revealed the presence of various phylogenetic groups within the “black box” of small eukaryotes, especially non-pigmented eukaryotes (poorly discriminated by microscopy). Some limitations in the PCR-based methods are recognized, for instance, the over-representation of Alveolata (particularly Dinoflagellates and Ciliates) in 18S rRNA gene clone libraries due their high SSU rRNA gene copy number [50–52].

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