title: Nitrogen deprivation induces lipid droplet accumulation and alters fatty acid metabolism in symbiotic dinoflagellates isolated from Aiptasia pulchella.
abstract: The stability of cnidarian-dinoflagellate (genus Symbiodinium spp.) endosymbioses depends on the regulation of nutrient transport between Symbiodinium populations and their hosts. Previously, we successfully induced the production of lipid droplets in the free-living cultured Symbiodinium (clade B) under the nitrogen-deprivation condition for 5 days. Therefore, the present study aimed at understanding the disruption of the endosymbiotic relationship between the cnidarians and dinoflagellates by nitrogen deprivation using Aiptasia pulchella as an example. Transmission electron micrographs revealed the formation of lipid droplets induced by nitrogen deprivation, and the lipid analyses further showed that polyunsaturated fatty acids were drastically enriched in Symbiodinium after 30 days of nitrogen deprivation, although these were unaffected after 5 days of nitrogen starvation. The present study also suggested that the host provided nitrogen to the symbiotic cells during short-term environmental stress. However, the relationship started to deteriorate after 30 days. These findings provide a more detailed understanding of the mechanisms of the symbiotic relationship between the symbiotic dinoflagellates in terms of the nitrogen source, which might provide more information for the explanation of the regulatory mechanism underlying endosymbiotic associations.
authors.affiliation: 1] Graduate Institute of Marine Biotechnology, National Dong-Hwa University, Pingtung, 944 Taiwan [2].
authors.forename: Li-Chi
authors.initials: LC
authors.lastname: Weng
authors.affiliation: 1] Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan [2].
authors.forename: Buntora
authors.initials: B
authors.lastname: Pasaribu
authors.affiliation: Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan.
authors.forename: I-Ping
authors.initials: IP
authors.lastname: Lin
authors.affiliation: Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan.
authors.forename: Ching-Hsiu
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: 1] Graduate Institute of Marine Biotechnology, National Dong-Hwa University, Pingtung, 944 Taiwan [2] Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan [3] Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
authors.forename: Chii-Shiarng
authors.initials: CS
authors.lastname: Chen
authors.affiliation: 1] Graduate Institute of Marine Biotechnology, National Dong-Hwa University, Pingtung, 944 Taiwan [2] Taiwan Coral Research Center, National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan.
authors.forename: Pei-Luen
authors.initials: PL
authors.lastname: Jiang
mesh_terms: D000818:Animals; D003470:Culture Media; D004141:Dinoflagellida / Q000166:cytology / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D066292:Lipid Droplets; D050356:Lipid Metabolism; D009584:Nitrogen / Q000378:metabolism*; D010858:Pigmentation; D012615:Sea Anemones / Q000502:physiology*; D013559:Symbiosis
chemical_list: D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D009584:Nitrogen