The cell membrane serves as the first line of defense against adverse environmental factors and is first to adapt to changing conditions. Cell membranes in both coral and its symbionts, which use different membrane adaptation strategies, have to acclimatize to various abiotic stressors. As our molecular-genetics analysis showed, colonies of Junceella fragilis were associated with dinoflagellates Cladocopium thermophilum, Gerakladium endoclionum and Breviolum minutum. We analyzed the phospholipid (PL) molecular species of the wild and cultivated Junceella fragilis and their dinoflagellates (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), ceramideaminoethylphosphonate (CAEP)), as well as thylakoid membrane lipids of dinoflagellates (glycolipids and betaine lipids). When comparing wild and cultivated J. fragilis colonies, there were no significant differences in thylakoid lipids, but there were differences in host membrane phospholipids, namely in PC, PE and PS. Thus, the profile of PL molecular species of the membrane is very sensitive to environmental factors, which probably explains the observed differences in the profiles of molecular PL species in this study.
Bizikashvili et al. (Fri,) studied this question.