The total pool of coral lipids consists of lipids produced by both the coral host and its symbiotic dinoflagellates of the family Symbiodiniaceae. Betaine lipids (BL) are characteristic of plasma membranes of microalgae. Composition of such BL as 1,2-diacylglyceryl-3-O-carboxy-(hydroxymethyl)-choline (DGCC) that occur in coral symbionts may depend on either Symbiodiniaceae species or coral species. Membrane-forming lipids DGCC have a zwitterion structure similar to that of phosphatidylcholine (PC). They can substitute for each other to a substantial extent, certainly in relation to membrane functions. In the present study, the profiles of DGCC and diacyl PC molecular species of symbiotic dinoflagellates from Acropora sp., Millepora platyphylla and Sinularia flexibilis were determined by high-performance liquid chromatography with high-resolution mass-spectrometry. Colonies of Acropora sp. were characterized by higher contents of DGCC with eicosapentaenoic acid (20:5n-3) and C₂₈ polyunsaturated fatty acids; S. flexibilis, by a higher content of DGCC with palmitic acid (16:0); and M. platyphylla, by a higher content of DGCC with docosahexaenoic acid (22:6n-3). Although the DGCC profile of the corals under study has distinctive features, it shows both similarities with and differences from the DGCC profiles of previously studied corals. Probably, each coral symbiont species has its own specific DGCC molecular species profile that is additionally modified in a certain way depending on environmental conditions created by the coral host. Molecular species DGCC and PC profiles were different. The most abundant PC molecular species were 16:0/22:5 and 38:4 in Acropora sp.; 39:5 and 38:4 in S. flexibilis; and 38:6, 16:0/22:5 and 18:0/22:6 in M. platyphylla. Thus, there is no clear evidence for any compensation or interchangeability between PC and DGCC.

中文翻译：

---

印度-太平洋珊瑚寄生的共生科甜菜碱脂质

珊瑚脂质的总库由珊瑚宿主及其共生甲藻科共生甲藻产生的脂质组成。甜菜碱脂质（BL）是微藻质膜的特征。珊瑚共生体中存在的 1,2-二酰基甘油-3- O-羧基-(羟甲基)-胆碱 (DGCC)等 BL 的组成可能取决于共生藻科物种或珊瑚物种。成膜脂质 DGCC 具有与磷脂酰胆碱 (PC) 相似的两性离子结构。它们可以在很大程度上相互替代，尤其是在膜功能方面。在本研究中，来自Acropora sp.、Millepora platyphylla和通过高效液相色谱法和高分辨率质谱法测定柔韧海藻。鹿角珊瑚菌落。其特点是DGCC中二十碳五烯酸(20:5 n -3)和C ₂₈多不饱和脂肪酸含量较高；S. flexibilis，由较高含量的 DGCC 与棕榈酸 (16:0) 组成；和M. platyphylla，通过较高含量的 DGCC 和二十二碳六烯酸 (22:6 n-3）。尽管所研究的珊瑚的 DGCC 剖面具有鲜明的特征，但它与先前研究的珊瑚的 DGCC 剖面既有相似之处，也有不同之处。也许，每个珊瑚共生体物种都有自己特定的 DGCC 分子物种特征，并根据珊瑚宿主创造的环境条件以某种方式进行额外修改。分子种类 DGCC 和 PC 特征不同。Acropora sp.中最丰富的PC分子种类为16:0/22:5和38:4；39:5 和 38:4 在S. flexibilis中；以及白桦中的 38:6、16:0/22:5 和 18:0/22:6 。因此，没有明确的证据表明 PC 和 DGCC 之间存在任何补偿或互换性。