TY - JOUR A1 - Schälicke, Svenja A1 - Heim, Silvia A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Inter- and intraspecific differences in rotifer fatty acid composition during acclimation to low-quality food JF - Philosophical transactions of the Royal Society of London : B, Biological sciences N2 - Biochemical food quality constraints affect the performance of consumers and mediate trait variation among and within consumer species. To assess inter- and intraspecific differences in fatty acid retention and conversion in freshwater rotifers, we provided four strains of two closely related rotifer species,Brachionus calyciflorussensustricto andBrachionus fernandoi, with food algae differing in their fatty acid composition. The rotifers grazed for 5 days on eitherNannochloropsis limneticaorMonoraphidium minutum, two food algae with distinct polyunsaturated fatty acid (PUFA) profiles, before the diets were switched to PUFA-freeSynechococcus elongatus, which was provided for three more days. We found between- and within-species differences in rotifer fatty acid compositions on the respective food sources and, in particular, highly specific acclimation reactions to the PUFA-free diet. The different reactions indicate inter- but also intraspecific differences in physiological traits, such as PUFA retention, allocation and bioconversion capacities, within the genusBrachionusthat are most likely accompanied by differences in their nutritional demands. Our data suggest that biochemical food quality constraints act differently on traits of closely related species and of strains of a particular species and thus might be involved in shaping ecological interactions and evolutionary processes. This article is part of the theme issue 'The next horizons for lipids as 'trophic biomarkers': evidence and significance of consumer modification of dietary fatty acids'. KW - Brachionus KW - fatty acids KW - food quality KW - PUFA composition KW - rotifer KW - strains KW - trait variation Y1 - 2020 U6 - https://doi.org/10.1098/rstb.2019.0644 SN - 0962-8436 SN - 1471-2970 VL - 375 IS - 1804 PB - Royal Society CY - London ER - TY - JOUR A1 - Obreht, Igor A1 - Wörmer, Lars A1 - Brauer, Achim A1 - Wendt, Jenny A1 - Alfken, Susanne A1 - De Vleeschouwer, David A1 - Elvert, Marcus A1 - Hinrichs, Kai-Uwe T1 - An annually resolved record of Western European vegetation response to Younger Dryas cooling JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - The regional patterns and timing of the Younger Dryas cooling in the North Atlantic realm were complex and are mechanistically incompletely understood. To enhance understanding of regional climate patterns, we present molecular biomarker records at subannual to annual resolution by mass spectrometry imaging (MSI) of sediments from the Lake Meerfelder Maar covering the Allerod-Younger Dryas transition. These analyses are supported by conventional extraction-based molecular-isotopic analyses, which both validate the imaging results and constrain the sources of the target compounds. The targeted fatty acid biomarkers serve as a gauge of the response of the local aquatic and terrestrial ecosystem to climate change. Based on the comparison of our data with existing data from Meerfelder Maar, we analyse the short-term environmental evolution in Western Europe during the studied time interval and confirm the previously reported delayed hydrological response to Greenland cooling. However, despite a detected delay of Western European environmental change of similar to 135 years, our biomarker data show statistically significant correlation with deuterium excess in Greenland ice core at - annual resolution during this time-transgressive cooling. This suggests a coherent atmospheric forcing across the North Atlantic realm during this transition. We propose that Western European cooling was postponed due to major reorganization of the westerlies that were intermittently forcing warmer and wetter air masses from lower latitudes to Western Europe and thus resulted in delayed cooling relative to Greenland. KW - lateglacial KW - paleoclimatology KW - Western Europe KW - Meerfelder Maar KW - high-resolution biomarkers KW - fatty acids KW - FT-ICR-MS KW - mass spectrometry KW - imaging Y1 - 2020 U6 - https://doi.org/10.1016/j.quascirev.2020.106198 SN - 0277-3791 VL - 231 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Mertens, Monique A1 - Hilsch, Malte A1 - Haralampiev, Ivan A1 - Volkmer, Rudolf A1 - Wessig, Pablo A1 - Müller, Peter T1 - Synthesis and characterization of a new Bifunctionalized, Fluorescent, and Amphiphilic molecule for recruiting SH-Containing molecules to membranes JF - ChemBioChem N2 - This study describes the synthesis and characterization of an amphiphilic construct intended to recruit SH-containing molecules to membranes. The construct consists of 1)an aliphatic chain to enable anchoring within membranes, 2)a maleimide moiety to react with the sulfhydryl group of a soluble (bio)molecule, and 3)a fluorescence moiety to allow the construct to be followed by fluorescence spectroscopy and microscopy. It is shown that the construct can be incorporated into preformed membranes, thus allowing application of the approach with biological membranes. The close proximity between the fluorophore and the maleimide moiety within the construct causes fluorescence quenching. This allows monitoring of the reaction with SH-containing molecules by measurement of increases in fluorescence intensity and lifetime. Notably, the construct distributes into laterally ordered membrane domains of lipid vesicles, which is probably triggered by the length of its membrane anchor. The advantages of the new construct can be employed for several biological, biotechnological, and medicinal applications. KW - DBD dyes KW - fatty acids KW - liposomes KW - maleimide KW - membranes KW - palmitoylation Y1 - 2018 U6 - https://doi.org/10.1002/cbic.201800268 SN - 1439-4227 SN - 1439-7633 VL - 19 IS - 15 SP - 1643 EP - 1647 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schell, Mareike A1 - Chudoba, Chantal A1 - Leboucher, Antoine A1 - Alfine, Eugenia A1 - Flore, Tanina A1 - Ritter, Katrin A1 - Weiper, Katharina A1 - Wernitz, Andreas A1 - Henkel, Janin A1 - Kleinridders, André T1 - Interplay of Dietary Fatty Acids and Cholesterol Impacts Brain Mitochondria and Insulin Action JF - Nutrients N2 - Overconsumption of high-fat and cholesterol-containing diets is detrimental for metabolism and mitochondrial function, causes inflammatory responses and impairs insulin action in peripheral tissues. Dietary fatty acids can enter the brain to mediate the nutritional status, but also to influence neuronal homeostasis. Yet, it is unclear whether cholesterol-containing high-fat diets (HFDs) with different combinations of fatty acids exert metabolic stress and impact mitochondrial function in the brain. To investigate whether cholesterol in combination with different fatty acids impacts neuronal metabolism and mitochondrial function, C57BL/6J mice received different cholesterol-containing diets with either high concentrations of long-chain saturated fatty acids or soybean oil-derived poly-unsaturated fatty acids. In addition, CLU183 neurons were stimulated with combinations of palmitate, linoleic acid and cholesterol to assess their effects on metabolic stress, mitochondrial function and insulin action. The dietary interventions resulted in a molecular signature of metabolic stress in the hypothalamus with decreased expression of occludin and subunits of mitochondrial electron chain complexes, elevated protein carbonylation, as well as c-Jun N-terminal kinase (JNK) activation. Palmitate caused mitochondrial dysfunction, oxidative stress, insulin and insulin-like growth factor-1 (IGF-1) resistance, while cholesterol and linoleic acid did not cause functional alterations. Finally, we defined insulin receptor as a novel negative regulator of metabolically stress-induced JNK activation. KW - cholesterol KW - insulin signaling KW - mitochondria KW - brain KW - inflammation KW - fatty acids KW - JNK KW - insulin receptor Y1 - 2020 U6 - https://doi.org/10.3390/nu12051518 SN - 2072-6643 VL - 12 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Piepho, Maike A1 - Arts, Michael T. A1 - Wacker, Alexander T1 - Species-specific variation in fatty acid concentrations of four phytoplankton species does phosphorus supply influence the effect of light intensity of temperature? JF - Journal of phycology N2 - We tested, in the laboratory, the influence of light intensity, temperature, and phosphorus (P) supply on fatty acid (FA) concentrations of four freshwater algae: the green algae Scenedesmus quadricauda (Turpin) Breb. and Chlamydomonas globosa J. Snow, the cryptophyte Cryptomonas ovata Ehrenb., and the diatom Cyclotella meneghiniana Kutz. We investigated the main and interactive effects of two variables on algal FA concentrations (i.e., light intensity and P supply or temperature and P supply). Interactive effects of light intensity and P supply were most pronounced in C. meneghiniana, but were also found in S. quadricauda and C. ovata. Changes in several saturated and unsaturated FA concentrations with light were more distinct in the low-P treatments than in the high-P treatments. Interactive effects of temperature and P supply on various FA concentrations were observed in all four species, but there was no consistent pattern. In lake ecosystems, P limitation often coincides with high light intensities and temperatures in summer. Therefore, it is important to examine how combinations of these environmental conditions affect FA concentrations of primary producers that are important sources of FAs for higher trophic levels. KW - Chlamydomonas KW - Cryptomonas KW - Cyclotella KW - fatty acids KW - light KW - lipids KW - phosphate KW - PUFA KW - Scenedesmus KW - temperature Y1 - 2012 U6 - https://doi.org/10.1111/j.1529-8817.2011.01103.x SN - 0022-3646 VL - 48 IS - 1 SP - 64 EP - 73 PB - Wiley-Blackwell CY - Malden ER -