caa a22 4500 605514267 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00360-015-0895-7 doi (NATIONALLICENCE)springer-10.1007/s00360-015-0895-7 Membrane properties of Enchytraeus albidus originating from contrasting environments: a comparative analysis [Elektronische Daten] [Karina Fisker, Hélène Bouvrais, Johannes Overgaard, Konrad Schöttner, John Ipsen, Martin Holmstrup] Ectothermic animals adapted to different environmental temperatures are hypothesized to have biological membranes with different chemical and physical properties such that membrane properties are optimized for their particular thermal environments. To test this hypothesis we analyzed the composition of phospholipid fatty acids (PLFAs) in seven different populations of Enchytraeus albidus originating from different thermal environments. The seven populations differ markedly in origin (polar-temperate) and are also characterized by marked difference in cold tolerance. The dominant PLFAs of E. albidus were C20:5, C20:4 and C20:2 (53-61% of total PLFA) followed by C18:0, C20:1 and C22:2 (17-20% of total PLFA). As hypothesized the PLFA composition varied significantly between populations and molar percentage of several of the PLFAs (particularly C18:2) correlated with the lower lethal temperature (LT50) of the seven populations. Unsaturation ratio (UFA/SFA) and average PLFA chain length also correlated significantly with LT50, such that cold sensitive populations had a shorter chain length and a lower UFA/SFA compared to cold tolerant populations. Reconstituted membranes of the least and most cold tolerant populations were used to compare membranes' physical properties by fluorescence anisotropy and bending rigidity. Measurements of anisotropy did not show any overall difference between populations with different cold tolerance. This could be interpreted as if E. albidus populations have achieved a similar "optimal” fluidity of the membrane with a somewhat different PLFA composition. Our study suggests that membrane lipid composition could be important for the cold tolerance of E. albidus; however, these differences are not easily differentiated in the measurements of the membranes' physical properties. Other parameters such as accumulation of glucose for cryoprotection and energy supply may also be important components of enchytraeid freeze tolerance. Springer-Verlag Berlin Heidelberg, 2015 Membrane fluidity nationallicence Fluorescence anisotropy nationallicence Bending rigidity nationallicence Freeze tolerance nationallicence Invertebrates nationallicence Fisker Karina Section of Soil fauna Ecology and Ecotoxicology, Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark aut Bouvrais Hélène Department of Physics, Chemistry and Pharmacy, MEMPHYS—Center for Biomembrane Physics, University of Southern Denmark, 5230, Odense M, Denmark aut Overgaard Johannes Zoophysiology, Department of Bioscience, Aarhus University, Building 131, 8000, Aarhus C, Denmark aut Schöttner Konrad Institute of Entomology, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05, České Budějovice, Czech Republic aut Ipsen John Department of Physics, Chemistry and Pharmacy, MEMPHYS—Center for Biomembrane Physics, University of Southern Denmark, 5230, Odense M, Denmark aut Holmstrup Martin Section of Soil fauna Ecology and Ecotoxicology, Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 389-400 0174-1578 185:4<389 2015 185 360 https://doi.org/10.1007/s00360-015-0895-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0895-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fisker Karina Section of Soil fauna Ecology and Ecotoxicology, Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark aut NATIONALLICENCE 700 1- Bouvrais Hélène Department of Physics, Chemistry and Pharmacy, MEMPHYS—Center for Biomembrane Physics, University of Southern Denmark, 5230, Odense M, Denmark aut NATIONALLICENCE 700 1- Overgaard Johannes Zoophysiology, Department of Bioscience, Aarhus University, Building 131, 8000, Aarhus C, Denmark aut NATIONALLICENCE 700 1- Schöttner Konrad Institute of Entomology, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05, České Budějovice, Czech Republic aut NATIONALLICENCE 700 1- Ipsen John Department of Physics, Chemistry and Pharmacy, MEMPHYS—Center for Biomembrane Physics, University of Southern Denmark, 5230, Odense M, Denmark aut NATIONALLICENCE 700 1- Holmstrup Martin Section of Soil fauna Ecology and Ecotoxicology, Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 389-400 0174-1578 185:4<389 2015 185 360