Lipid composition in response to temperature changes in blue musselsMytilus edulisL. from the White Sea

Abstract

Alterations of membrane lipid composition (cholesterol, phospholipids and their fatty acids) in response to various temperature changes were studied in blue mussels Mytilus edulis L. from the White Sea. Lipid composition changes after acute temperature stress, especially a temperature drop, included a significant reduction of the membrane phospholipid content directly (1 h) after return to the initial temperature, which was presumably a consequence of a non-specific stress reaction in the mussels. A longer recovery period (24 h) as well as long-term temperature acclimation (14 days) induced changes in gill fatty acid composition (for instance, a rise in phospholipid unsaturated fatty acids under low temperature impact), indicating ‘homeoviscous adaptation’ to maintain the membranes in response to temperature fluctuations. Moreover, the gill cholesterol level in mussels varied especially at long-term temperature exposure.

Lipid Composition Modifications in the Blue Mussels (Mytilus edulis L.) from the White Sea

“…The role of minor membrane phospholipids (namely, phosphatidylserine and sphingomyelin) in the acclimation of mussels to elevated ambient temperature was also demonstrated in gills. They are believed to facilitate adaptive modiications of the luidity and permeability of cell membranes in response to elevation of the ambient temperature [35,36]. Let us remark that a similar efect involving these phospholipids was observed in gills of mussels acclimating to variable seawater salinity [44].…”

“…Whereas the gill lipid composition response in White Sea mussels in the temperature experiment was the opposite: a signiicant rise of the cholesterol concentration in response to prolonged (14 days) impact of both low and high temperatures, while shortterm temperature stress (1 day) inluenced the content of phospholipids and their faty acids [36]. Since the synthesis of polyunsaturated faty acids in bivalves is limited as well as an involvement of essential faty acids in/from membrane lipids is strictly regulated [18,19], presumably, the mussels' adaptive strategy is to use a less energy-intensive mechanism for maintaining optimal membrane luidity by redistributing polyunsaturated faty acids among storage and membrane lipid fractions (in the absence of additional cholesterol synthesis) that bivalves employ to adapt to rapid temperature changes [35,36]. The role of minor membrane phospholipids (namely, phosphatidylserine and sphingomyelin) in the acclimation of mussels to elevated ambient temperature was also demonstrated in gills.…”

“…It was demonstrated that when exposed to rapid (several hours) temperature luctuations gills of bivalves experience modiications in cholesterol levels, whereas prolonged (several weeks) temperature impacts induce changes in the amount of phospholipids enriched in polyunsaturated faty acids [41,43]. Whereas the gill lipid composition response in White Sea mussels in the temperature experiment was the opposite: a signiicant rise of the cholesterol concentration in response to prolonged (14 days) impact of both low and high temperatures, while shortterm temperature stress (1 day) inluenced the content of phospholipids and their faty acids [36]. Since the synthesis of polyunsaturated faty acids in bivalves is limited as well as an involvement of essential faty acids in/from membrane lipids is strictly regulated [18,19], presumably, the mussels' adaptive strategy is to use a less energy-intensive mechanism for maintaining optimal membrane luidity by redistributing polyunsaturated faty acids among storage and membrane lipid fractions (in the absence of additional cholesterol synthesis) that bivalves employ to adapt to rapid temperature changes [35,36].…”

“…In the White Sea, M. edulis L. is the dominant species of coastal (intertidal) ecosystems. Numerous studies on White Sea mussels' response to various environmental efects have identiied adaptive mechanisms on molecular, biochemical, cellular, physiological and behavioural levels of biological organization [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”

Alteration of Lipid Composition of Blue Mussels Mytilus Edulis L. As a Result of Their Acclimation to Laboratory Conditions

“…Необходимо отметить, что значительные изме-нения в составе высокоэнергетических липидов в организме двустворчатых моллюсков проис-ходят в условиях ограниченного доступа пищи в экспериментальных условиях [Bayne, 1973;. Возможным решением этой проблемы может служить использование в качестве источника пищи в лабораторных ус-ловиях монокультур фитопланктона Khardin et al, 2003;Pettersen et al, 2010], а также искусственных кормов Nogueira et al, 2015;Fokina et al, 2015]. Однако применение искусствен-ного корма может изменить баланс состава ли-пидов и их жирных кислот у двустворчатых мол-люсков, сформированный в естественной среде обитания, что в свою очередь может отразиться на адаптивных возможностях их липидного ме-таболизма.…”