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Costs and benefits of cold acclimation in field-released Drosophila.

https://arctichealth.org/en/permalink/ahliterature95572
Source
Proc Natl Acad Sci U S A. 2008 Jan 8;105(1):216-21
Publication Type
Article
Date
Jan-8-2008
Author
Kristensen Torsten N
Hoffmann Ary A
Overgaard Johannes
Sørensen Jesper G
Hallas Rebecca
Loeschcke Volker
Author Affiliation
Department of Genetics and Biotechnology, University of Aarhus, P.O. Box 50, DK-8830 Tjele, Denmark.
Source
Proc Natl Acad Sci U S A. 2008 Jan 8;105(1):216-21
Date
Jan-8-2008
Language
English
Publication Type
Article
Keywords
Acclimatization
Adaptation, Physiological
Animals
Body Temperature Regulation
Climate
Cold Temperature
Drosophila melanogaster - metabolism - physiology
Evolution
Female
Hot Temperature
Male
Models, Biological
Temperature
Time Factors
Abstract
One way animals can counter the effects of climatic extremes is via physiological acclimation, but acclimating to one extreme might decrease performance under different conditions. Here, we use field releases of Drosophila melanogaster on two continents across a range of temperatures to test for costs and benefits of developmental or adult cold acclimation. Both types of cold acclimation had enormous benefits at low temperatures in the field; in the coldest releases only cold-acclimated flies were able to find a resource. However, this advantage came at a huge cost; flies that had not been cold-acclimated were up to 36 times more likely to find food than the cold-acclimated flies when temperatures were warm. Such costs and strong benefits were not evident in laboratory tests where we found no reduction in heat survival of the cold-acclimated flies. Field release studies, therefore, reveal costs of cold acclimation that standard laboratory assays do not detect. Thus, although physiological acclimation may dramatically improve fitness over a narrow set of thermal conditions, it may have the opposite effect once conditions extend outside this range, an increasingly likely scenario as temperature variability increases under global climate change.
PubMed ID
18162547 View in PubMed
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Extreme temperatures increase the deleterious consequences of inbreeding under laboratory and semi-natural conditions.

https://arctichealth.org/en/permalink/ahliterature95530
Source
Proc Biol Sci. 2008 Sep 7;275(1646):2055-61
Publication Type
Article
Date
Sep-7-2008
Author
Kristensen Torsten N
Barker J Stuart F
Pedersen Kamilla S
Loeschcke Volker
Author Affiliation
Department of Genetics and Biotechnology, University of Aarhus, Blichers Allé 20, Tjele, Denmark. torsten.nygaard@agrsci.dk
Source
Proc Biol Sci. 2008 Sep 7;275(1646):2055-61
Date
Sep-7-2008
Language
English
Publication Type
Article
Keywords
Animals
Drosophila melanogaster - genetics - growth & development - physiology
Female
Greenhouse Effect
Inbreeding
Male
Random Allocation
Sex ratio
Temperature
Abstract
The majority of experimental studies of the effects of population bottlenecks on fitness are performed under laboratory conditions, which do not account for the environmental complexity that populations face in nature. In this study, we test inbreeding depression in multiple replicates of inbred when compared with non-inbred lines of Drosophila melanogaster under different temperature conditions. Egg-to-adult viability, developmental time and sex ratio of emerging adults are studied under low, intermediate and high temperatures under laboratory as well as semi-natural conditions. The results show inbreeding depression for egg-to-adult viability. The level of inbreeding depression is highly dependent on test temperature and is observed only at low and high temperatures. Inbreeding did not affect the developmental time or the sex ratio of emerging adults. However, temperature affected the sex ratio with more females relative to males emerging at low temperatures, suggesting that selection against males in pre-adult life stages is stronger at low temperatures. The coefficient of variation (CV) of egg-to-adult viability within and among lines is higher for inbred flies and generally increases at stressful temperatures. Our results contribute to knowledge on the environmental dependency of inbreeding under different environmental conditions and emphasize that climate change may impact negatively on fitness through synergistic interactions with the genotype.
PubMed ID
18522910 View in PubMed
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