Squishy lipids: Temperature effects on the betaine and galactolipid profiles of a C₁₈/C₁₈ peridinin‐containing dinoflagellate, Symbiodinium microadriaticum (Dinophyceae), isolated from the mangrove jellyfish, Cassiopea xamachana

Abstract

Summary Previous work from our laboratory has shown dinoflagellates, which possess the carotenoid peridinin, have been divided into two clusters based on plastid galactolipid fatty acid composition. In one cluster major forms of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), lipids that comprise the majority of photosynthetic membranes, were C18/C18 (sn‐1/sn‐2), with octadecapentaenoic [18:5(n‐3)] and octadecatetraenoic [18:4(n‐3)] acid as principal fatty acids. The other cluster contained C20/C18 major forms, with eicosapentaenoic acid [20:5(n‐3)] being the predominant sn‐1 fatty acid. In this study, we have found that Symbiodinium microadriaticum isolated from the jellyfish, Cassiopea xamachana, when grown at 30°C, produced MGDG and DGDG with a more saturated fatty acid, 18:4(n‐3), at the sn‐2 carbon than when grown at 20°C where 18:5(n‐3) predominates. This modulation of the sn‐2 fatty acid's level of saturation is mechanistically similar to what has been observed in Pyrocystis, a C20/C18 dinoflagellate. We have also examined the effect of growth temperature on the betaine lipid, diacylglycerylcarboxyhydroxymethylcholine (DGCC), which has been observed by others to be the predominant non plastidial polar lipid in dinoflagellates. Temperature effects on it were minimal, with very few modulations in fatty acid unsaturation as observed in MGDG and DGDG. Rather, the primary difference seen at the two growth temperatures was the alteration of the amount of minor forms of DGCC, as well as a second betaine lipid, diacylglyceryl‐N,N,N‐trimethylhomoserine.

Lipidomic profile in three species of dinoflagellates ( Amphidinium carterae , Cystodinium sp., and Peridinium aciculiferum ) containing very long chain polyunsaturated fatty acids

“…Both 28:7 and 28:8 acids were found only in the fraction of phospholipids, not in glycolipids (Leblond and Dahmen, 2012) such as MGDG, DGDG, and SQDG, which, on the contrary, contained 18:4 and 18:5 with the major molecular species 18:4/18:5-MGDG and 18:4/18:5-DGDG (Leblond et al, 2015). These findings indicate that the C28 fatty acids are located and probably synthesized in the cytoplasm or in an organelle other than the chloroplast, whereas the C 18 fatty acids e 18:4n-3 and 18:5n-3 -are glycolipid constituents apparently synthesized within the chloroplast.…”

“…Betaine lipids such as diacylglycerylcarboxy-Nhydroxymethylcholine (DGCC) were found to contain highly unsaturated molecular species of the types 44:15-and 46:15-DGCC (Flaim et al, 2014) or 44:12-DGCC (Leblond et al, 2015) while diacylglyceryltrimethyl-homoserine (DGTS) was found to contain only saturated and monoenoic species, e.g. 32:1-DGTS (Leblond et al, 2015).…”

Multifaceted characterization of a Lemanea fluviatilis population (Batrachospermales, Rhodophyta) from a glacial stream in the south-eastern Alps

“…To our knowledge, there have been no studies regarding the lipid content of this taxon and how this may relate to thermal niche. However, the effects of temperature on fatty acids composition patterns have been addressed by some studies on micro-(e.g., FuSChino et al 2011;Flaim et al 2012;Leblond et al 2015) and macroalgae (e.g., BeCKer et al 2010).…”

The role of >i<Symbiodinium>/i< membrane lipids in response to heat shock: implications for coral bleaching

“…Furthermore, the high abundance of DHA in Symbiodinium phylotypes and in other flagellate microalgae (Leblond et al, 2000(Leblond et al, , 2006(Leblond et al, , 2015Gray et al, 2009;Awai et al, 2012;Armada et al, 2013;Dahmen et al, 2013;Anesi & Guella, 2015;Anesi et al, 2016) sustains the idea proposed by Valentine (2009): phytoplankton represents the global stock of DHA production in the marine ecosystem. Life cycle of zooplankton species depend on the nutritional quality of phytoplankton, which is defined by lipid content (Søreide et al, 2010).…”

“…For example, a great diversity of glyco and amino membrane lipids in Symbiodinium spp. and other dinoflagellates has been described by LC-MS analysis, including few alterations when growing in distinct temperatures (Leblond et al, 2000(Leblond et al, , 2006(Leblond et al, , 2010(Leblond et al, , 2015Gray et al, 2009;Dahmen et al, 2013;Flaim et al, 2014;Anesi et al, 2015Anesi et al, , 2016. These studies were mostly focused on a specific class of polar lipid such as glycolipids or aminolipids, and not aimed at characterizing the global lipidome together with specialized lipids, such as plastoquinone and pigments using LC-MS.…”