The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity
Antarctic krill (Euphausia superba), a key species in the Southern Ocean, reduce their metabolism as an energy saving mechanism in response to the harsh environmental conditions during the Antarctic winter. Although the adaptive significance of this seasonal metabolic shift seems obvious, the drivin...
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ftdoajarticles:oai:doaj.org/article:ffb6507255e2463880aa4d216e961507 2023-05-15T13:31:16+02:00 The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity Fabio Piccolin Lavinia Suberg Robert King So Kawaguchi Bettina Meyer Mathias Teschke 2018-12-01T00:00:00Z https://doi.org/10.3389/fphys.2018.01715 https://doaj.org/article/ffb6507255e2463880aa4d216e961507 EN eng Frontiers Media S.A. https://www.frontiersin.org/article/10.3389/fphys.2018.01715/full https://doaj.org/toc/1664-042X 1664-042X doi:10.3389/fphys.2018.01715 https://doaj.org/article/ffb6507255e2463880aa4d216e961507 Frontiers in Physiology, Vol 9 (2018) growth oxygen consumption enzyme activity gene expression clock genes circannual clock Physiology QP1-981 article 2018 ftdoajarticles https://doi.org/10.3389/fphys.2018.01715 2022-12-31T15:52:16Z Antarctic krill (Euphausia superba), a key species in the Southern Ocean, reduce their metabolism as an energy saving mechanism in response to the harsh environmental conditions during the Antarctic winter. Although the adaptive significance of this seasonal metabolic shift seems obvious, the driving factors are still unclear. In particular, it is debated whether the seasonal metabolic cycle is driven by changes in food availability, or if an endogenous timing system entrained by photoperiod might be involved. In this study, we used different long-term photoperiodic simulations to examine the influence of light regime and endogenous rhythmicity on the regulation of krill seasonal metabolic cycle. Krill showed a seasonal cycle of growth characterized by null-to-negative growth rates during autumn-winter and positive growth rates during spring-summer, which was manifested also in constant darkness, indicating strong endogenous regulation. Similar endogenous cycles were observed for the activity of the key-metabolic enzyme malate dehydrogenase (MDH) and for the expression levels of a selection of metabolic-related genes, with higher values in spring-summer and lower values in autumn-winter. On the other side, a seasonal cycle of oxygen consumption was observed only when krill were exposed to simulated seasonal changes in photoperiod, indicating that light-related cues might play a major role in the regulation of krill oxygen consumption. The influence of light-regime on oxygen consumption was minimal during winter, when light-phase duration was below 8 h, and it was maximal during summer, when light-phase duration was above 16 h. Significant upregulation of the krill clock genes clk, cry2, and tim1, as well as of the circadian-related opsins rh1a and rrh, was observed after light-phase duration had started to decrease in early autumn, suggesting the presence of a signaling cascade linking specific seasonal changes in the Antarctic light regime with clock gene activity and the regulation of krill metabolic dormancy ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean The Antarctic Frontiers in Physiology 9 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
growth oxygen consumption enzyme activity gene expression clock genes circannual clock Physiology QP1-981 |
spellingShingle |
growth oxygen consumption enzyme activity gene expression clock genes circannual clock Physiology QP1-981 Fabio Piccolin Lavinia Suberg Robert King So Kawaguchi Bettina Meyer Mathias Teschke The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
topic_facet |
growth oxygen consumption enzyme activity gene expression clock genes circannual clock Physiology QP1-981 |
description |
Antarctic krill (Euphausia superba), a key species in the Southern Ocean, reduce their metabolism as an energy saving mechanism in response to the harsh environmental conditions during the Antarctic winter. Although the adaptive significance of this seasonal metabolic shift seems obvious, the driving factors are still unclear. In particular, it is debated whether the seasonal metabolic cycle is driven by changes in food availability, or if an endogenous timing system entrained by photoperiod might be involved. In this study, we used different long-term photoperiodic simulations to examine the influence of light regime and endogenous rhythmicity on the regulation of krill seasonal metabolic cycle. Krill showed a seasonal cycle of growth characterized by null-to-negative growth rates during autumn-winter and positive growth rates during spring-summer, which was manifested also in constant darkness, indicating strong endogenous regulation. Similar endogenous cycles were observed for the activity of the key-metabolic enzyme malate dehydrogenase (MDH) and for the expression levels of a selection of metabolic-related genes, with higher values in spring-summer and lower values in autumn-winter. On the other side, a seasonal cycle of oxygen consumption was observed only when krill were exposed to simulated seasonal changes in photoperiod, indicating that light-related cues might play a major role in the regulation of krill oxygen consumption. The influence of light-regime on oxygen consumption was minimal during winter, when light-phase duration was below 8 h, and it was maximal during summer, when light-phase duration was above 16 h. Significant upregulation of the krill clock genes clk, cry2, and tim1, as well as of the circadian-related opsins rh1a and rrh, was observed after light-phase duration had started to decrease in early autumn, suggesting the presence of a signaling cascade linking specific seasonal changes in the Antarctic light regime with clock gene activity and the regulation of krill metabolic dormancy ... |
format |
Article in Journal/Newspaper |
author |
Fabio Piccolin Lavinia Suberg Robert King So Kawaguchi Bettina Meyer Mathias Teschke |
author_facet |
Fabio Piccolin Lavinia Suberg Robert King So Kawaguchi Bettina Meyer Mathias Teschke |
author_sort |
Fabio Piccolin |
title |
The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
title_short |
The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
title_full |
The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
title_fullStr |
The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
title_full_unstemmed |
The Seasonal Metabolic Activity Cycle of Antarctic Krill (Euphausia superba): Evidence for a Role of Photoperiod in the Regulation of Endogenous Rhythmicity |
title_sort |
seasonal metabolic activity cycle of antarctic krill (euphausia superba): evidence for a role of photoperiod in the regulation of endogenous rhythmicity |
publisher |
Frontiers Media S.A. |
publishDate |
2018 |
url |
https://doi.org/10.3389/fphys.2018.01715 https://doaj.org/article/ffb6507255e2463880aa4d216e961507 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean |
op_source |
Frontiers in Physiology, Vol 9 (2018) |
op_relation |
https://www.frontiersin.org/article/10.3389/fphys.2018.01715/full https://doaj.org/toc/1664-042X 1664-042X doi:10.3389/fphys.2018.01715 https://doaj.org/article/ffb6507255e2463880aa4d216e961507 |
op_doi |
https://doi.org/10.3389/fphys.2018.01715 |
container_title |
Frontiers in Physiology |
container_volume |
9 |
_version_ |
1766017138838994944 |