Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus
Freezing temperatures is an important stressor in the arctic regions and has a significant influence on the population dynamics and geographic distribution of terrestrial invertebrates. Toxic metals in the environment can interfere with protective cold-acclimation responses of organisms. It is there...
Published in: | Ecotoxicology and Environmental Safety |
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2020
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Online Access: | https://pure.au.dk/portal/en/publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 https://doi.org/10.1016/j.ecoenv.2020.111005 http://www.scopus.com/inward/record.url?scp=85088628525&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 2024-02-11T09:59:25+01:00 Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus Gerlich, Hannah Sørine Holmstrup, Martin Bjerregaard, Poul Slotsbo, Stine 2020-11 https://pure.au.dk/portal/en/publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 https://doi.org/10.1016/j.ecoenv.2020.111005 http://www.scopus.com/inward/record.url?scp=85088628525&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/en/publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 info:eu-repo/semantics/restrictedAccess Gerlich , H S , Holmstrup , M , Bjerregaard , P & Slotsbo , S 2020 , ' Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus ' , Ecotoxicology and Environmental Safety , vol. 204 , 111005 . https://doi.org/10.1016/j.ecoenv.2020.111005 Cold stress Contaminants Cryoprotectant Lipid peroxidation Membrane function article 2020 ftuniaarhuspubl https://doi.org/10.1016/j.ecoenv.2020.111005 2024-01-18T00:00:27Z Freezing temperatures is an important stressor in the arctic regions and has a significant influence on the population dynamics and geographic distribution of terrestrial invertebrates. Toxic metals in the environment can interfere with protective cold-acclimation responses of organisms. It is therefore important to evaluate the combined effects of cold stress and environmental contaminants. Here, we aimed to investigate the effects of Hg (HgCl 2 ) on various physiological aspects of freeze-tolerance in the earthworm (Enchytraeus albidus). We measured the levels of the cryoprotectant glucose, the glycogen content (source of glucose molecules for cryoprotection and fuel for metabolism), and changes in the composition of membrane phospholipid fatty acids (PLFA) as an indicator of lipid peroxidation. Freezing at −6 °C had no effect on survival in uncontaminated soil, however, survival of freezing in Hg contaminated soil was clearly reduced, especially at extended exposure times. Thus, the LC 50 value in frozen soil decreased from 8.3 mg Hg kg −1 (when exposed for 17 days) to only 4.2 mg Hg kg −1 after 36 days’ exposure indicating that combined effects of Hg and freezing became larger at prolonged exposure times. Hg caused a depletion of glycogen reserves (almost 50% at 12 mg kg −1 dry soil), but despite this effect worms were able to maintain a constant cryoprotectant level (about 0.12 mg glucose mg −1 dry weight) at all Hg concentrations. Hg had clear negative effects on the proportion of unsaturated PLFAs, which could be an indication of lipid peroxidation. Since a high proportion of unsaturated fatty acids in the membrane is important for invertebrate freeze-tolerance, our results suggest that the negative effect of Hg on freeze-tolerance in E. albidus is related to degraded membrane functionality at low temperature. Article in Journal/Newspaper Arctic Arctic Aarhus University: Research Arctic Ecotoxicology and Environmental Safety 204 111005 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Cold stress Contaminants Cryoprotectant Lipid peroxidation Membrane function |
spellingShingle |
Cold stress Contaminants Cryoprotectant Lipid peroxidation Membrane function Gerlich, Hannah Sørine Holmstrup, Martin Bjerregaard, Poul Slotsbo, Stine Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
topic_facet |
Cold stress Contaminants Cryoprotectant Lipid peroxidation Membrane function |
description |
Freezing temperatures is an important stressor in the arctic regions and has a significant influence on the population dynamics and geographic distribution of terrestrial invertebrates. Toxic metals in the environment can interfere with protective cold-acclimation responses of organisms. It is therefore important to evaluate the combined effects of cold stress and environmental contaminants. Here, we aimed to investigate the effects of Hg (HgCl 2 ) on various physiological aspects of freeze-tolerance in the earthworm (Enchytraeus albidus). We measured the levels of the cryoprotectant glucose, the glycogen content (source of glucose molecules for cryoprotection and fuel for metabolism), and changes in the composition of membrane phospholipid fatty acids (PLFA) as an indicator of lipid peroxidation. Freezing at −6 °C had no effect on survival in uncontaminated soil, however, survival of freezing in Hg contaminated soil was clearly reduced, especially at extended exposure times. Thus, the LC 50 value in frozen soil decreased from 8.3 mg Hg kg −1 (when exposed for 17 days) to only 4.2 mg Hg kg −1 after 36 days’ exposure indicating that combined effects of Hg and freezing became larger at prolonged exposure times. Hg caused a depletion of glycogen reserves (almost 50% at 12 mg kg −1 dry soil), but despite this effect worms were able to maintain a constant cryoprotectant level (about 0.12 mg glucose mg −1 dry weight) at all Hg concentrations. Hg had clear negative effects on the proportion of unsaturated PLFAs, which could be an indication of lipid peroxidation. Since a high proportion of unsaturated fatty acids in the membrane is important for invertebrate freeze-tolerance, our results suggest that the negative effect of Hg on freeze-tolerance in E. albidus is related to degraded membrane functionality at low temperature. |
format |
Article in Journal/Newspaper |
author |
Gerlich, Hannah Sørine Holmstrup, Martin Bjerregaard, Poul Slotsbo, Stine |
author_facet |
Gerlich, Hannah Sørine Holmstrup, Martin Bjerregaard, Poul Slotsbo, Stine |
author_sort |
Gerlich, Hannah Sørine |
title |
Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
title_short |
Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
title_full |
Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
title_fullStr |
Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
title_full_unstemmed |
Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus |
title_sort |
mercury (hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm enchytraeus albidus |
publishDate |
2020 |
url |
https://pure.au.dk/portal/en/publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 https://doi.org/10.1016/j.ecoenv.2020.111005 http://www.scopus.com/inward/record.url?scp=85088628525&partnerID=8YFLogxK |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arctic |
genre_facet |
Arctic Arctic |
op_source |
Gerlich , H S , Holmstrup , M , Bjerregaard , P & Slotsbo , S 2020 , ' Mercury (Hg 2+ ) interferes with physiological adaptations to freezing in the arctic earthworm Enchytraeus albidus ' , Ecotoxicology and Environmental Safety , vol. 204 , 111005 . https://doi.org/10.1016/j.ecoenv.2020.111005 |
op_relation |
https://pure.au.dk/portal/en/publications/0053f1b3-b400-4a70-a1f6-51f6ee636b33 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.ecoenv.2020.111005 |
container_title |
Ecotoxicology and Environmental Safety |
container_volume |
204 |
container_start_page |
111005 |
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1790595334955597824 |