Ramon Massana

..MAST-4 cells likely contribute substantially to picoplankton grazing and nutrient re-mineralization in vast areas of the oceans and represent a key eukaryotic group in marine food webs...

..This is one of the few reports on a heterotrophic flagellate virus and the implications of this finding in the Indian Ocean are discussed...

..The rRNA approach appears to be less affected by taxon-specific rDNA copy number and likely better depicts the biogeochemical significance of marine protists...

..A tree containing one example of each OTU detected was constructed, and this tree revealed that there were several clusters within archaeal group I and group II. The members of some of these clusters had different depth distributions...

..Picoeukaryotes are convincingly integral members of marine ecosystems in terms of cell abundance, biomass, activity, and diversity and they play crucial roles in food webs and biogeochemical cycles...

..The identified diversity and novelty patterns among marine picoeukaryotes are of great importance for understanding and interpreting their ecology and evolution...

..These results will aid to focus future research, most likely based on new and imaginative culturing efforts and the design and application of specific molecular probes...

..Our original dual FISH protocol applied to grazing experiments reveals important functional differences between distinct uncultured protists and offers the possibility to disentangle the complexity of microbial food webs...

..The implication of this large and novel eukaryotic diversity for biodiversity surveys and ecosystem functioning opens new avenues for future research...

..This first report on the rDNA genomic structure of an uncultured marine alveolate improves their phylogenetic position and helps interpreting data generated during picoeukaryotic molecular surveys...

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..Our study expands our knowledge on the phylogenetic diversity and distribution of novel marine stramenopiles and confirms that they are fundamental members of the marine eukaryotic picoplankton...

..Sequencing of the most predominant DGGE bands failed to detect the SAR11 group despite their high abundance. The combination of the three molecular approaches allowed a comprehensive assessment of seasonal changes in bacterial diversity...

..This Q-PCR assay quickly yielded quantitative data of uncultured MAST-4 cells and confirmed their wide distribution and putative ecological importance...

..This report of the overall diversity of picoeukaryotic prasinophytes reveals a group of ecologically important and diverse marine microorganims that are well represented by isolated cultures...

..However, although the particular taxonomic composition could vary among protocols, the general structure of the microbial assemblages was maintained...

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..Exhaustive data mining in sequence databases allowed the identification of new diversity hidden inside chrysophytes, choanoflagellates and bicosoecids...

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..and both parasites were affiliated with the so-called marine alveolate Group II. This corroborates the hypothesis that marine alveolate Group II is Syndinea...

..This suggests that they may be secondary endosymbiotic algae. Pending the isolation of living cells and their formal description, these algae have been termed picobiliphytes...

..Phenol-chloroform extraction after bead-beating and enzymatic lysis was therefore considered to be the most suitable method for DNA extraction from such highly diverse phototrophic biofilms...

..Culturing ecologically relevant but elusive protists provide invaluable material for ecophysiology, genomics, ecosystem modeling and evolutionary issues...

..These results will be important to interpret the large amount of sequence data that is currently generated by High Throughput Sequencing technologies...

..Thus, MAST diversity seems to be highly partitioned in spatial scales. Altogether, our results shed light on these ecologically very important but poorly known groups of uncultured marine flagellates...

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..In summary, lumping together pico-sized microbes may be convenient for some ecological studies, but it is also important to keep in mind their differences...

..Overall, the genetic divergence of MAST-4 was surprisingly low for an organism with a global population size estimated to be around 10(24), indicating a very low evolutionary diversification within the group...

..Data interpretation must take into account primer specificity and the varying rRNA gene copy number among eukaryotes...

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..Furthermore, using environmental bacterial artificial chromosome (BAC) libraries, we were able to correlate psbA genes with small subunit rRNAs and, therefore, to confirm their phylogenetic affiliation...

..Overall, primer set 357fGC-907rM was the most suitable for the routine use of PCR-DGGE analyses in this environment...

..This clearly reiterates the idea of spatial partitioning of individual cyanobacterial lineages, but at the global scale...

..These variants could represent functionally divergent paralogous genes, derived from the same or similar species, or orthologous proteorhodopsins that are distributed amongst divergent planktonic microbial taxa...

..pusilla. Parameters which can precisely explain the distribution of these cryptic species remain to be elucidated...

..The data show the presence of Roseobacter-like bacteria in Red and Mediterranean Sea AAnP populations in the seasons analyzed...

..Further investigations of the evolutionary relationships within Telonemia should be conducted on isolated cultures of Telonema-like strains using multi-locus sequencing and morphological data...

..Our observations demonstrate that this single-residue switch mechanism is the major determinant of proteorhodopsin wavelength regulation in natural marine environments...