Widespread distribution of a unique marine protistan lineage.

@article{citeulike:2731206, abstract = {Unicellular eukaryotes (protists) are key components of marine food webs, yet knowledge of their diversity, distributions and respective ecologies is limited. We investigated uncultured protists using 18S rRNA gene sequencing, phylogenetic analyses, specific fluorescence in situ hybridization (FISH) probes and other methods. Because few studies have been conducted in warm water systems, we focused on two Atlantic subtropical regions, the Sargasso Sea and the Florida Current. Cold temperate waters were also sampled. Gene sequences comprising a unique eukaryotic lineage, herein termed 'biliphytes', were identified in most samples, whether from high- (30 degrees C) or from low- (5 degrees C) temperature waters. Sequences within this uncultured group have previously been retrieved from high latitudes. Phylogenetic analyses suggest biliphytes are a sister group to the cryptophytes and katablepharids, although the relationship is not statistically supported. Bootstrap-supported subclades were delineated but coherence was not obvious with respect to geography or physicochemical parameters. Unlike results from the initial publication on these organisms (therein 'picobiliphytes'), we could not detect a nucleomorph, either visually, or by targeted primers. Phycobilin-like fluorescence associated with biliphyte-specific FISH-probed cells supports the hypothesis that they are photosynthetic. Our data indicate the biliphytes are nanoplanktonic in size, averaging 4.1 +/- 1.0 x 3.5 +/- 0.8 mum (+/-SD) for one probed group, and 3.5 +/- 0.9 x 3.0 +/- 0.9 mum (+/-SD) for another. We estimate biliphytes contributed 28 (+/-6)\% of the phytoplanktonic biomass in tropical eddy-influenced surface waters. Given their broad thermal and geographic distribution, understanding the role these protists play in biogeochemical cycling within different habitats is essential.}, address = {Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd, Moss Landing, CA 95039, USA.}, author = {Cuvelier, Marie L L. and Ortiz, Alejandra and Kim, Eunsoo and Moehlig, Heike and Richardson, David E E. and Heidelberg, John F F. and Archibald, John M M. and Worden, Alexandra Z Z. }, citeulike-article-id = {2731206}, comment = {An interesting paper that extends that published in Science.}, doi = {http://dx.doi.org/10.1111/j.1462-2920.2008.01580.x}, issn = {1462-2920}, journal = {Environmental microbiology}, keywords = {18s, distribution, eukaryote, fish, ocean, picobiliphytes, picoplankton}, month = {March}, posted-at = {2008-04-28 23:36:52}, priority = {0}, title = {Widespread distribution of a unique marine protistan lineage.}, url = {http://dx.doi.org/10.1111/j.1462-2920.2008.01580.x}, year = {2008} }

TY - JOUR ID - citeulike:2731206 L3 - citeulike-article-id:2731206 TI - Widespread distribution of a unique marine protistan lineage. JF - Environmental microbiology AD - Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd, Moss Landing, CA 95039, USA. SN - 1462-2920 N2 - Unicellular eukaryotes (protists) are key components of marine food webs, yet knowledge of their diversity, distributions and respective ecologies is limited. We investigated uncultured protists using 18S rRNA gene sequencing, phylogenetic analyses, specific fluorescence in situ hybridization (FISH) probes and other methods. Because few studies have been conducted in warm water systems, we focused on two Atlantic subtropical regions, the Sargasso Sea and the Florida Current. Cold temperate waters were also sampled. Gene sequences comprising a unique eukaryotic lineage, herein termed 'biliphytes', were identified in most samples, whether from high- (30 degrees C) or from low- (5 degrees C) temperature waters. Sequences within this uncultured group have previously been retrieved from high latitudes. Phylogenetic analyses suggest biliphytes are a sister group to the cryptophytes and katablepharids, although the relationship is not statistically supported. Bootstrap-supported subclades were delineated but coherence was not obvious with respect to geography or physicochemical parameters. Unlike results from the initial publication on these organisms (therein 'picobiliphytes'), we could not detect a nucleomorph, either visually, or by targeted primers. Phycobilin-like fluorescence associated with biliphyte-specific FISH-probed cells supports the hypothesis that they are photosynthetic. Our data indicate the biliphytes are nanoplanktonic in size, averaging 4.1 +/- 1.0 x 3.5 +/- 0.8 mum (+/-SD) for one probed group, and 3.5 +/- 0.9 x 3.0 +/- 0.9 mum (+/-SD) for another. We estimate biliphytes contributed 28 (+/-6)% of the phytoplanktonic biomass in tropical eddy-influenced surface waters. Given their broad thermal and geographic distribution, understanding the role these protists play in biogeochemical cycling within different habitats is essential. KW - 18s KW - distribution KW - eukaryote KW - fish KW - ocean KW - picobiliphytes KW - picoplankton N1 - An interesting paper that extends that published in Science. AU - Cuvelier, Marie L AU - Ortiz, Alejandra AU - Kim, Eunsoo AU - Moehlig, Heike AU - Richardson, David E AU - Heidelberg, John F AU - Archibald, John M AU - Worden, Alexandra Z PY - 2008/03/12/ UR - http://dx.doi.org/10.1111/j.1462-2920.2008.01580.x ER -