Effect of elevated temperature on membrane lipid saturation in Antarctic notothenioid fish
- Published
- Accepted
- Subject Areas
- Aquaculture, Fisheries and Fish Science, Biochemistry, Marine Biology, Aquatic and Marine Chemistry, Environmental Impacts
- Keywords
- Membrane remodelling, Climate change, Homeoviscous adaptation, Antarctic fish, Notothenioids, Phospholipids, Membrane fluidity, Temperature acclimation, Thermal adaptation, lipid saturation
- Copyright
- © 2018 Malekar et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Effect of elevated temperature on membrane lipid saturation in Antarctic notothenioid fish. PeerJ Preprints 6:e26472v1 https://doi.org/10.7287/peerj.preprints.26472v1
Abstract
Homeoviscous adaptation (HVA) is a key cellular response by which fish protect their membranes against thermal stress. We investigated evolutionary HVA (long time scale) in Antarctic and non-Antarctic fish. Membrane lipid composition was determined for four Perciformes fish: two closely related Antarctic notothenioid species (Trematomus bernacchii and Pagothenia borchgrevinki); a diversified related notothenioid Antarctic icefish (Chionodraco hamatus); and a New Zealand species (Notolabrus celidotus). The membrane lipid compositions were consistent across the three Antarctic species and these were significantly different from that of the New Zealand species. Furthermore, acclimatory HVA (short time periods with seasonal changes) was investigated to determine whether stenothermal Antarctic fish, which evolved in the cold, stable environment of the Southern Ocean, have lost the acclimatory capacity to modulate their membrane saturation states, making them vulnerable to anthropogenic global warming. We compared liver membrane lipid composition in two closely related Antarctic fish species acclimated at 0 °C (control temperature), 4 °C for a period of 14 days in Trematomus bernacchii and 28 days for Pagothenia borchgrevinki, and 6 °C for 7 days in both species. Thermal acclimation at 4 °C did not result in changed membrane saturation states in either Antarctic species. Despite this, membrane functions were not compromised, as indicated by declining serum osmolality, implying positive compensation by enhanced hypo-osmoregulation. Increasing the temperature to 6 °C did not change the membrane lipids of P. borchgrevinki. However, in T. bernacchii, thermal acclimation at 6 °C resulted in an increase of membrane saturated fatty acids and a decline in unsaturated fatty acids. This is the first study to show a homeoviscous response to higher temperatures in an Antarctic fish, although for only one of the two species examined.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Raw Data of percent phospholipid fatty acids, membrane cholestrol and osmolality in fish species and thermally aclimated Antarctic fish species
Each work sheet includes raw data of the respective figure or table mentioned in the file name .