Abstract
Syndiniales (Dinophyceae, Alveolata) are a diverse parasitic group common in all marine environments, but their ecological role remains poorly understood. Here we show an unprecedented dominance of a single Syndiniales group I operational taxonomic unit (OTU) across 3000 km of Southern Ocean transects near the sea-ice edge. This super-abundant OTU consistently represented >20%, and in some locations >50%, of eukaryote 18S rDNA sequences. Identical 18S V4 sequences have been isolated from seven Northern Hemisphere locations, and the OTU’s putative V9 rDNA sequence was detected at every station of the global Tara Oceans voyage. Although Syndiniales taxa display some host specificity, our identification of candidate Southern Ocean hosts suggests this OTU associates with distinct phyla in different parts of the world. Our results indicate Syndiniales are key players in surface waters near the vast and dynamic sea-ice edge in the world’s most biologically productive ocean.
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Acknowledgements
We thank the Australian Antarctic Division (AAD) Science Technical Support Team and Aurora Australis crew for making this work happen. Karen Westwood and Imojen Pearce (AAD) provided chlorophyll data. Ben Raymond and Mike Sumner (AAD) helped access and interpret sea-ice melt data. Ruth Eriksen (CSIRO), Andrea Polanowski, Andrew Davidson and Karen Westwood (AAD) provided assistance with lab work. Martin Ostrowski (Macquarie University) ran the OTU taxonomy assignment. Rowan Trebilco (ACE CRC) provided advice on analyses. Contribution to the Australian Antarctic Science Kerguelen Axis project (AAS-4344). Molecular work funded through the Australian Antarctic Science Program (AAS-4313) and a Bioplatforms Australia Industry Access Voucher. This work was supported by the Australian Government’s Business Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems Cooperative Research Centre, and the Australia Research Council’s Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001).
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Clarke, L.J., Bestley, S., Bissett, A. et al. A globally distributed Syndiniales parasite dominates the Southern Ocean micro-eukaryote community near the sea-ice edge. ISME J 13, 734–737 (2019). https://doi.org/10.1038/s41396-018-0306-7
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DOI: https://doi.org/10.1038/s41396-018-0306-7
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