Katarina Hedlund
Professor
Cold acclimation and lipid composition in the earthworm Dendrobaena octaedra
Författare
Summary, in English
We have investigated the lipid chemistry during cold acclimation in the freeze tolerant earthworm Dendrobaena octaedra. The dominant phospholipid fatty acids (PLFA) of D. octaedra were 20:4, 20:5 and 20:1 (50% of total PLFA) followed by 18:0, 18:1 and 18:2 omega 6,9 (25% of total PLFA). The ability to tolerate freezing in this species was acquired after acclimation at low temperature for 2-4 weeks. During this period one particular membrane PLFA, 18:2 omega 6,9, increased significantly and there was a good correlation between the proportion of this PLFA and the survival of freezing. The composition of neutral lipid fatty acids (NLFA), most likely representing storage lipids (triacylglycerides), also changed during cold acclimation so that the overall degree of unsaturation increased. Using a common-garden experiment approach, we compared lipid composition of three genetically different populations (Denmark, Finland and Greenland) that differed in their freeze tolerance. Inter-populational differences and differences due to cold acclimation in overall fatty acid composition were evident in both PLFAs and NLFAs. Specifically, the PLFAs, 20:4 and 20:5, were considerably more represented in worms from Greenland, and this contributed to a higher U1 of PLFAs in this population. (c) 2007 Elsevier Inc. All rights reserved.
Avdelning/ar
- Biodiversitet
- Markgruppen
Publiceringsår
2007
Språk
Engelska
Sidor
911-919
Publikation/Tidskrift/Serie
Comparative Biochemistry and Physiology A
Volym
147
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Ecology
Nyckelord
- membrane phospholipids
- earthworms
- cold acclimation
- freeze tolerance
- adaptation
- homeoviscous
Status
Published
Forskningsgrupp
- Soil Ecology
ISBN/ISSN/Övrigt
- ISSN: 1531-4332