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...

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Published in:Philosophical Transactions of the Royal Society B: Biological Sciences
Main Authors: Pörtner, Hans O., Peck, Lloyd S., Somero, George
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
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