Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view
A cause and effect understanding of thermal limitation and adaptation at various levels of biological organization is crucial in the elaboration of how the Antarctic climate has shaped the functional properties of extant Antarctic fauna. At the same time, this understanding requires an integrative v...
Published in: | Philosophical Transactions of the Royal Society B: Biological Sciences |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Royal Society
2007
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/11885/ http://rstb.royalsocietypublishing.org/content/362/1488/2233.full |
id |
ftnerc:oai:nora.nerc.ac.uk:11885 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:11885 2023-05-15T13:45:10+02:00 Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view Pörtner, Hans O. Peck, Lloyd S. Somero, George 2007 http://nora.nerc.ac.uk/id/eprint/11885/ http://rstb.royalsocietypublishing.org/content/362/1488/2233.full unknown Royal Society Pörtner, Hans O.; Peck, Lloyd S. orcid:0000-0003-3479-6791 Somero, George. 2007 Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view. Philosophical Transactions of the Royal Society of London, Series B, 362 (1488). 2233-2258. https://doi.org/10.1098/rstb.2006.1947 <https://doi.org/10.1098/rstb.2006.1947> Marine Sciences Meteorology and Climatology Zoology Biology and Microbiology Ecology and Environment Publication - Article PeerReviewed 2007 ftnerc https://doi.org/10.1098/rstb.2006.1947 2023-02-04T19:27:39Z A cause and effect understanding of thermal limitation and adaptation at various levels of biological organization is crucial in the elaboration of how the Antarctic climate has shaped the functional properties of extant Antarctic fauna. At the same time, this understanding requires an integrative view of how the various levels of biological organization may be intertwined. At all levels analysed, the functional specialization to permanently low temperatures implies reduced tolerance of high temperatures, as a trade-off. Maintenance of membrane fluidity, enzyme kinetic properties (K-m and k(cat)) and protein structural flexibility in the cold supports metabolic flux and regulation as well as cellular functioning overall. Gene expression patterns and, even more so, loss of genetic information, especially for myoglobin (Mb) and haemoglobin (Hb) in notothenioid fishes, reflect the specialization of Antarctic organisms to a narrow range of low temperatures. The loss of Mb and Hb in icefish, together with enhanced lipid membrane densities (e. g. higher concentrations of mitochondria), becomes explicable by the exploitation of high oxygen solubility at low metabolic rates in the cold, where an enhanced fraction of oxygen supply occurs through diffusive oxygen flux. Conversely, limited oxygen supply to tissues upon warming is an early cause of functional limitation. Low standard metabolic rates may be linked to extreme stenothermy. The evolutionary forces causing low metabolic rates as a uniform character of life in Antarctic ectothermal animals may be linked to the requirement for high energetic efficiency as required to support higher organismic functioning in the cold. This requirement may result from partial compensation for the thermal limitation of growth, while other functions like hatching, development, reproduction and ageing are largely delayed. As a perspective, the integrative approach suggests that the patterns of oxygen- and capacity-limited thermal tolerance are linked, on one hand, with the capacity and ... Article in Journal/Newspaper Antarc* Antarctic Icefish Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Philosophical Transactions of the Royal Society B: Biological Sciences 362 1488 2233 2258 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Meteorology and Climatology Zoology Biology and Microbiology Ecology and Environment |
spellingShingle |
Marine Sciences Meteorology and Climatology Zoology Biology and Microbiology Ecology and Environment Pörtner, Hans O. Peck, Lloyd S. Somero, George Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
topic_facet |
Marine Sciences Meteorology and Climatology Zoology Biology and Microbiology Ecology and Environment |
description |
A cause and effect understanding of thermal limitation and adaptation at various levels of biological organization is crucial in the elaboration of how the Antarctic climate has shaped the functional properties of extant Antarctic fauna. At the same time, this understanding requires an integrative view of how the various levels of biological organization may be intertwined. At all levels analysed, the functional specialization to permanently low temperatures implies reduced tolerance of high temperatures, as a trade-off. Maintenance of membrane fluidity, enzyme kinetic properties (K-m and k(cat)) and protein structural flexibility in the cold supports metabolic flux and regulation as well as cellular functioning overall. Gene expression patterns and, even more so, loss of genetic information, especially for myoglobin (Mb) and haemoglobin (Hb) in notothenioid fishes, reflect the specialization of Antarctic organisms to a narrow range of low temperatures. The loss of Mb and Hb in icefish, together with enhanced lipid membrane densities (e. g. higher concentrations of mitochondria), becomes explicable by the exploitation of high oxygen solubility at low metabolic rates in the cold, where an enhanced fraction of oxygen supply occurs through diffusive oxygen flux. Conversely, limited oxygen supply to tissues upon warming is an early cause of functional limitation. Low standard metabolic rates may be linked to extreme stenothermy. The evolutionary forces causing low metabolic rates as a uniform character of life in Antarctic ectothermal animals may be linked to the requirement for high energetic efficiency as required to support higher organismic functioning in the cold. This requirement may result from partial compensation for the thermal limitation of growth, while other functions like hatching, development, reproduction and ageing are largely delayed. As a perspective, the integrative approach suggests that the patterns of oxygen- and capacity-limited thermal tolerance are linked, on one hand, with the capacity and ... |
format |
Article in Journal/Newspaper |
author |
Pörtner, Hans O. Peck, Lloyd S. Somero, George |
author_facet |
Pörtner, Hans O. Peck, Lloyd S. Somero, George |
author_sort |
Pörtner, Hans O. |
title |
Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
title_short |
Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
title_full |
Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
title_fullStr |
Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
title_full_unstemmed |
Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view |
title_sort |
thermal limits and adaptation in marine antarctic ectotherms: an integrative view |
publisher |
Royal Society |
publishDate |
2007 |
url |
http://nora.nerc.ac.uk/id/eprint/11885/ http://rstb.royalsocietypublishing.org/content/362/1488/2233.full |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Icefish |
genre_facet |
Antarc* Antarctic Icefish |
op_relation |
Pörtner, Hans O.; Peck, Lloyd S. orcid:0000-0003-3479-6791 Somero, George. 2007 Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view. Philosophical Transactions of the Royal Society of London, Series B, 362 (1488). 2233-2258. https://doi.org/10.1098/rstb.2006.1947 <https://doi.org/10.1098/rstb.2006.1947> |
op_doi |
https://doi.org/10.1098/rstb.2006.1947 |
container_title |
Philosophical Transactions of the Royal Society B: Biological Sciences |
container_volume |
362 |
container_issue |
1488 |
container_start_page |
2233 |
op_container_end_page |
2258 |
_version_ |
1766214797433503744 |