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Gerber, Lucie; Helle-Valle, Tellef; Resseguier, Julien Alain Andre; Torp, May-Kristin; Dahl, Helge Andre & Nilsson, Göran Erik
[Show all 8 contributors for this article]
(2022).
Prolyl Hydroxylase Domains in the Anoxia Tolerant Crucian Carp (c. carassius): Insights into the Regulation of the HIF Response to Anoxia-Reoxygenation.
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Gerber, Lucie; Helle-Valle, Tellef; Resseguier, Julien Alain Andre; Torp, May-Kristin; Dahl, Helge Andre & Nilsson, Göran Erik
[Show all 8 contributors for this article]
(2022).
Prolyl Hydroxylase Domains in the Anoxia Tolerant Crucian Carp (c. carassius): Insights into the Regulation of the HIF Response to Anoxia-Reoxygenation.
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Stensløkken, Kåre-Olav & Lefevre, Sjannie
(2022).
Mitochondrial Functions in the Anoxia Tolerant Crucian Carp. .
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2022).
Improving organ preservation: Another lesson from the champion of anoxia tolerance, the crucian carp (C. carassius).
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Gerber, Lucie; Torp, May-Kristin; Nilsson, Göran Erik; Lefevre, Sjannie & Stensløkken, Kåre-Olav
(2022).
Improving organ preservation: Another lesson from the champion of anoxia tolerance, the crucian carp (C. carassius).
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Valencia Pesqueira, Laura Maria; Jentoft, Sissel & Lefevre, Sjannie
(2022).
De novo assembly of the crucian carp genome .
Show summary
The crucian carp (Carassius carassius) is a champion of anoxia tolerance and the physiological mechanisms are well documented. Still, there is a need for better understanding at the molecular and genetic level, and a fully sequenced, assembled and annotated genome will facilitate such studies. To obtain a high-quality genome assembly, we sequenced the crucian carp genome using methods such as chromosome conformation capture (HiC) and PacBio long-read sequencing, in addition to short-read sequencing for error correction. For annotation we are using full-length transcripts (IsoSeq data) as well as regular RNAseq data from both normoxic, anoxic and re-oxygenated crucian carp. The genome of crucian carp and other cyprinids consists of 50 chromosomes that originated from several whole-genome duplication events, with the most recent occurring 14 Mya. The presence of duplicated genes offers the possibility for evolutionary changes through the mechanism of expression dominance: one paralog remains most expressed, while the other paralog is free to change without compromising the expression integrity of the biological systems required for normal function. This is hypothesized to be the genetic mechanism having allowed the crucian carp and goldfish (Carassius auratus) pyruvate dehydroxylases to obtain the decarboxylation function necessary for conversion of pyruvate to acetaldehyde; an important metabolic process in the crucian carp’s survival strategy in anoxia. We expect that paralogs of other important genes may have undergone similar changes, and aim to elucidate any differences that may have arisen between the crucian carp and the goldfish due to the long domestication history of the latter.
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Lefevre, Sjannie & Dahl, Helge Andre
(2022).
Insights from ‘omics’ about crucian carp anoxia tolerance.
Show summary
The crucian carp (Carassius carassius) is extremely tolerant to the absence of oxygen. Its metabolically most active organs, such as the brain, can maintain function over extended periods of anoxia. Our research seeks to understand the cellular and molecular mechanisms involved in regulating the response of the crucian carp to anoxia. We take a discovery-driven approach, using metabolomics, transcriptomics and translatomics, to identify key mechanisms and signalling pathways behind the extreme anoxia tolerance. In this talk, I will present results on sequencing and quantification of mRNA and ribosome-protected (i.e. translated) mRNA fragments in brain tissue from crucian carp exposed to normoxia, anoxia and re-oxygenation, as well as metabolites from multiple tissues.
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Lefevre, Sjannie
(2022).
Partitioning of oxygen uptake in air-breathing fishes.
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Lefevre, Sjannie; Downie, Adam; Rummer, Jodie L. & Nilsson, Göran Erik
(2022).
Changes in haemoglobin gene expression during development of a coral reef fish.
Show summary
Tropical reef fishes, such as the orange clownfish and other anemonefishes share a particular life history: The larvae hatch at the reef, go through a pelagic stage, after which the larvae return to the reef for settlement and maturation into adults. The two environments – coral reef and open sea – are vastly different, and poses unique challenges to the physiology of the fish. It has been shown that several species start out by having high maximum oxygen consumptions rates as larvae, but low hypoxia tolerance, a pattern that then reverses before or during the time of settlement. It has been hypothesised that shifting from low-affinity to high-affinity haemoglobin could be responsible for this pattern, but due to the very small size of the larvae, it has been difficult to investigate. In this study we used RNA sequencing to look at transcriptomic changes during larval development of the cinnamon clownfish (Amphiprion melanopus), focusing on the haemoglobin genes, which have different paralogs of the alpha and beta subunits. Larvae were bred and hatched in the lab, and sampled at 4, 6 and 9 days post-hatch. We found a clear shift from 4 to 9 days in the paralogs dominating the expression of both alpha and beta subunits. While investigation of the functional properties are still necessary to confirm that they switch from low- to high-affinity isoforms, specifically, the data supports the hypothesis that haemoglobin isoform switching occurs just before the larvae settle on the reef.
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Gerber, Lucie; Nilsson, Göran Erik & Lefevre, Sjannie
(2021).
Kan en fisk fra Nordmarka hjelpe oss?
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Lefevre, Sjannie
(2021).
The role of transcription and translation dynamics in the response to anoxia and re-oxygenation in the crucian carp.
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Lefevre, Sjannie
(2021).
Strategies that allow the crucian carp to survive periods of anoxia that would kill a mammal.
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Lefevre, Sjannie
(2019).
SENSING AND ADAPTING TO OXYGEN AVAILABILITY:
Fuelling the fire of life and the 2019 Nobel Prize.
NBS-nytt.
ISSN 0801-3535.
4.
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Lefevre, Sjannie; McKenzie, David J. & Nilsson, Göran Erik
(2019).
Global warming and future fish size: thoughts on the gill-oxygen limitation hypothesis.
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Lefevre, Sjannie
(2019).
Global warming and future fish size:What can we learn from the gill-oxygen limitation hypothesis (GOLT)?
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Lefevre, Sjannie; Lau, Gigi Yik Chee; Dahl, Helge-Andre & Nilsson, Göran Erik
(2019).
Re-oxygenation resilience - the other aspect of the crucian carp’s anoxia tolerance.
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Lefevre, Sjannie; Lau, Gigi Yik Chee; Dahl, Helge-Andre & Nilsson, Göran Erik
(2019).
Crucian carp: mitochondria, anoxia and reoxygenation.
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Lefevre, Sjannie
(2018).
Re-oxygenation resilience - the other element of the crucian carp's anoxia tolerance.
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Haugnes, Gunhild M.; Tallaksen, Lena M.; Vogt, Rolf David; Storelvmo, Trude; Hessen, Dag Olav & Stordal, Frode
[Show all 9 contributors for this article]
(2018).
Klimaforskerne tar temperaturen på tropesommeren.
[Journal].
Titan.uio.no.
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Dahl, Helge-Andre & Lefevre, Sjannie
(2018).
Protection against reperfusion injury: can insight be gained from crucian carp?
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Lefevre, Sjannie
(2018).
Long-term hypoxia acclimation has minor effects on respiratory physiology of Alaska blackfish.
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Lefevre, Sjannie
(2018).
Are there CO2 effects on oxygen uptake as predicted by the OCLTT hypothesis?
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Lefevre, Sjannie
(2018).
Global warming and future fish size (or how not to interpret aerobic scope).
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Lefevre, Sjannie
(2018).
Global warming and future fish size: Unfounded assumptions lead to absurd predictions.
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Jutfelt, Fredrik; Norin, Tommy; Ern, Rasmus; Overgaard, Johannes; Wang, Tobias & McKenzie, David J.
[Show all 28 contributors for this article]
(2018).
Oxygen- and capacity-limited thermal tolerance: blurring ecology and physiology.
Journal of Experimental Biology.
ISSN 0022-0949.
221(1).
doi:
10.1242/jeb.169615.
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Lefevre, Sjannie
(2016).
Are respiratory effects of global warming and ocean acidification explained by a unifying OCLTT concept?
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Lefevre, Sjannie
(2016).
The transcriptomic response of crucian carp to anoxia and re-oxygenation.
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Lefevre, Sjannie & Nilsson, Göran E.
(2015).
Temperature acclimation in jumping snails (Gibberulus gibberulus) reduces heart rate, but not oxygen uptake, and only marginally improves heat tolerance.
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Lefevre, Sjannie
(2015).
Snails in the fast-lane: Physiology and Climate Change perspectives.
NBS-nytt.
ISSN 0801-3535.
39(4),
p. 20–21.
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Lefevre, Sjannie; Watson, Sue-Ann; Munday, Philip L. & Nilsson, Göran Erik
(2014).
Golbal warming: Will jumping snails prevail?
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Lefevre, Sjannie; Stecyk, Jonathan A. W.; Torp, May-Kristin & Nilsson, Göran Erik
(2014).
HOW TOLERANT IS AN ANOXIA-TOLERANT VERTEBRATE?
Show summary
The crucian carp Carassius carassius is capable of surviving without oxygen for several months, by carefully matching ATP supply and demand. It does so by exploiting its unique ability to produce ethanol as an anaerobic end-product and undergo partial metabolic rate suppression, shutting down non-vital functions such as vision. Even so, it is unknown if crucian carp are fully able to protect themselves from the damage (i.e. cell death), normally caused by absence and particularly re-entrance of oxygen. Here, we investigated the occurrence of apoptosis in brain of crucian carp exposed to normoxia, anoxia and re-oxygenation in the laboratory, using Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). We also measured mRNA and protein levels of the apoptosis executer protein Caspase 3 using quantitative real-time PCR and Western blotting. Additionally, Caspase 3 expression levels were measured in brains from crucian carp captured in their natural habitat at different months of the year. Overall, crucian carp appear to maintain apoptotic activity in anoxia, but there is a transient increase in the early re-oxygenation phase. In its natural habitat transcription of Caspase 3 is generally much down-regulated during the winter, but protein levels are maintained, with only a slight increase in the spring.