Cell integrity and activities are largely influenced by membrane fluidity, which is temperature-dependent. Below the so-called transition temperature, phospholipids mobility is drastically reduced. Therefore, life adaptation to extreme environments is supposed to involve significant variations in membrane lipids. We determined the phospholipid composition in three ecologically separated species of Euplotes: one (E. raikovi) from temperate areas, one (E. focardii) endemic to Antarctic, and one (E. polaris) colonizer of both Arctic and Antarctic. Lipids were extracted from cell cultures and analyzed by RPLC-ESI-QqQ-MS in positive mode. E. polaris and E. raikovi contained several species of phosphocholines (PC), lyso-PC (L-PC), phosphatidylethanol-amines (PE), lyso-PE, sphingomyelins (SM), phosphatydilinositol (PI) and phosphatidylglycerol (PG). E. focardii contained all the classes but PE and SM. Very interestingly, E. focardii contained the lowest number of lipid species and showed a greater unsaturation index, while total PE of E. polaris were highly unsaturated compared to PE the other two species.
Changes in membrane lipid composition in marine species of Euplotes adapted to different thermal environments
ALIMENTI, Claudio;VALLESI, Adriana;
2013-01-01
Abstract
Cell integrity and activities are largely influenced by membrane fluidity, which is temperature-dependent. Below the so-called transition temperature, phospholipids mobility is drastically reduced. Therefore, life adaptation to extreme environments is supposed to involve significant variations in membrane lipids. We determined the phospholipid composition in three ecologically separated species of Euplotes: one (E. raikovi) from temperate areas, one (E. focardii) endemic to Antarctic, and one (E. polaris) colonizer of both Arctic and Antarctic. Lipids were extracted from cell cultures and analyzed by RPLC-ESI-QqQ-MS in positive mode. E. polaris and E. raikovi contained several species of phosphocholines (PC), lyso-PC (L-PC), phosphatidylethanol-amines (PE), lyso-PE, sphingomyelins (SM), phosphatydilinositol (PI) and phosphatidylglycerol (PG). E. focardii contained all the classes but PE and SM. Very interestingly, E. focardii contained the lowest number of lipid species and showed a greater unsaturation index, while total PE of E. polaris were highly unsaturated compared to PE the other two species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
