Plasma membrane lipid diffusion and composition of sea urchin egg membranes vary with ocean temperature

Abstract

A diverse and complex array of lipids plays a vital role in structuring and organizing cell membranes. However, the details of lipid requirements for global membrane organization are poorly understood. One obstacle to this understanding is the difficulty of accurately manipulating the lipid composition of commonly studied mammalian cells. In contrast, the lipid composition of cells of ectotherms changes with changes in environmental temperatures. Thus, comparison of lipid probe diffusion in cells from animals living at different temperatures, together with biochemical analysis, can be used toward understanding membrane organization. We used two dialkyindocarbocyanine iodide (DiI) probes, of differing chain length, to probe lipid organization in terms of their lateral diffusion in eggs of the sea urchin Strongylocentrotus purpuratus. The lateral diffusion of our probes changed in urchins developing in the year of an "El Niño" weather event, which raised the ocean temperature by several degrees, suggesting alterations in membrane domain composition and structure. Indeed the changes in lateral diffusion were correlated with lower levels of unsaturated fatty acids and cholesterol in animals of the "El Niño" year than in animals of the preceding or following years. We found similar trends comparing DiI diffusion in membranes of eggs from 15 degrees C waters with those from 10 degrees C. Our findings establish a new approach for manipulating and studying membrane organization.

Miscibility Transition Temperature Scales with Growth Temperature in a Zebrafish Cell Line

“…The above observations do not discern whether cells sense and maintain T mix to a specified level below growth temperature, or alternatively, if the changes in T mix are a consequence of cellular membrane tuning to maintain some other property such as viscosity, water permeability, or membrane stiffness. Past work in fish and other organisms has argued that adaptation of membrane lipids to temperature changes is primarily to maintain membrane viscosity and ion permeability within an acceptable range for biological functions (6,8,21,22,24,(50)(51)(52). Based on this extensive past work, we anticipate that measurements of average membrane order, which often serve as a proxy for membrane viscosity, would also maintain roughly constant values at different adapted growth temperatures in ZF4 cells.…”

“…It is well established that cells alter their lipid content in response to their environment. For example, bacteria and higher organisms change their membrane composition and physical properties when grown at different temperatures (1)(2)(3)(4)(5)(6)(7)(8); yeast alter their lipid content to counteract the membrane fluidizing effects of ethanol produced during fermentation (9)(10)(11); and mammalian cells adjust their lipids during the cell cycle (12)(13)(14)(15), when undergoing differentiation (16,17), and in response to stress or disease (18)(19)(20). The physical properties of cell membranes are primarily dictated by their complex lipid and protein compositions and facilitate many cellular functions.…”

Phospholipids of the organs and tissues of echinoderms and tunicates from peter the great bay (Sea of Japan)

“…Recent works, as a rule, were devoted to discussions of the special issues of PL biochemistry, publishing results from studying the PL composition of organs or tissues of one or two types of animal, such as ascidians [20] and pelagic tunicates [21,26,28]. We would note the publications that have examined the role of food chains in the fatty acid (FA) composition of lipids of deep sea holothurians and brittle stars [22], considered the structure of the alke nyl, alkyl, and acyl chains of sperm PLs of the sea urchin Hemicentrotus pulcherrimus [27], PL ether forms in the gonads of the sea urchin Strongylocentro tus intermedius and internal organs of the ascidian Halocynthia roretzi [25], defined the role of sphin gosine bases of gonads and internal organs of the sea star Asterias amurensis in the apoptosis of colon cancer [30], and provided information on the temperature effect on the lipid composition of egg membranes of the sea urchin Strongylocentrotus purpuratus [31].…”

“…Recent works, as a rule, were devoted to discussions of the special issues of PL biochemistry, publishing results from studying the PL composition of organs or tissues of one or two types of animal, such as ascidians [20] and pelagic tunicates [21,26,28]. We would note the publications that have examined the role of food chains in the fatty acid (FA) composition of lipids of deep sea holothurians and brittle stars [22], considered the structure of the alke nyl, alkyl, and acyl chains of sperm PLs of the sea urchin Hemicentrotus pulcherrimus [27], PL ether forms in the gonads of the sea urchin Strongylocentro tus intermedius and internal organs of the ascidian Halocynthia roretzi [25], defined the role of sphin gosine bases of gonads and internal organs of the sea star Asterias amurensis in the apoptosis of colon cancer [30], and provided information on the temperature effect on the lipid composition of egg membranes of the sea urchin Strongylocentrotus purpuratus [31].In the study of the PL compositions of organs and tissues in echinoderms and tunicates, as well as their gonads, gametes, and embryos, the embryonic plasma membrane of cells and subcellular particles are most often used [15,16,18,19,25,27,30,31]. The results of analysis of individual organs or tissues, as well as the PL compositions of entire animals, that have been cited in the literature do not reveal the origin (exoge nous or endogenous) and distribution of such PLs as ceramide aminoethylphosphonate (CAEP), sphingo myelin (SM), and phosphatidylglycerol (PG).…”

“…In the study of the PL compositions of organs and tissues in echinoderms and tunicates, as well as their gonads, gametes, and embryos, the embryonic plasma membrane of cells and subcellular particles are most often used [15,16,18,19,25,27,30,31]. The results of analysis of individual organs or tissues, as well as the PL compositions of entire animals, that have been cited in the literature do not reveal the origin (exoge nous or endogenous) and distribution of such PLs as ceramide aminoethylphosphonate (CAEP), sphingo myelin (SM), and phosphatidylglycerol (PG).…”