| Differences in cold and drought tolerance of high arctic and sub-arctic populations of Megaphorura arctica Tullberg 1876 (Onychiuridae: Collembola). | |
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MedLine Citation:
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PMID: 17959162 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The springtail Megaphorura arctica (Onychiuridae: Collembola) inhabits the arctic and sub-arctic parts of the northern hemisphere where it on a seasonal basis will be exposed to severe cold and desiccating conditions. In the present study we compared how traits of stress resistance differed between two populations of M. arctica that were collected at a high arctic site (Spitsbergen) and a sub-arctic site (Akureyri, Iceland) with contrasting thermal environments. In addition we investigated how cold and desiccation affected the phospholipid fatty acid composition of M. arctica from Spitsbergen. The springtails from Spitsbergen were the most cold tolerant and this was linked to an almost three times higher level of trehalose accumulation during cryoprotective dehydration (15% and 5% of tissue dry weight in the Spitsbergen and Iceland populations, respectively). Although cryoprotective dehydration is intimately related to desiccation stress it was shown that M. arctica had a higher mortality when dehydrated over ice (-10 or -20 degrees C) than when dehydrated at temperatures above 1 degrees C. Thus, survival was lower after exposure to -10 degrees C than after exposure to a relative humidity of 91.2% RH at +1 degrees C although both treatments led to the same level of dehydration. Exposure to both cold (-10 and -20 degrees C) and desiccation at +1 degrees C caused significant changes in the phospholipid fatty acid composition with some similarities. These changes included a decrease in average chain length of the fatty acids due primarily to an increase in the phospholipid fatty acids 16:0 and a decrease in 18:3 and 20:4 omega6. |
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Authors:
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S Bahrndorff; S O Petersen; V Loeschcke; J Overgaard; M Holmstrup |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't Date: 2007-09-19 |
Journal Detail:
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Title: Cryobiology Volume: 55 ISSN: 1090-2392 ISO Abbreviation: Cryobiology Publication Date: 2007 Dec |
Date Detail:
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Created Date: 2007-11-26 Completed Date: 2008-02-19 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0006252 Medline TA: Cryobiology Country: United States |
Other Details:
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Languages: eng Pagination: 315-23 Citation Subset: IM |
Affiliation:
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Ecology and Genetics, Department of Biological Sciences, University of Aarhus, Ny Munkegade, Build. 1540, DK-8000 Aarhus C, Denmark. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adaptation, Physiological* Animals Arctic Regions Arthropods / physiology* Body Water Body Weight Cold Temperature* Cryoprotective Agents / metabolism Dehydration* Disasters Fatty Acids / metabolism Glucose / metabolism Humidity Iceland Trehalose / metabolism |
| Chemical | |
Reg. No./Substance:
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0/Cryoprotective Agents; 0/Fatty Acids; 50-99-7/Glucose; 99-20-7/Trehalose |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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