Files and links (2)
Published VersionCC BY V4.0, Open Access
Journal article
Histological and transcriptomic analysis of muscular atrophy associated with depleted flesh pigmentation in Atlantic salmon (Salmo salar) exposed to elevated seawater temperatures
Scientific Reports, Vol.13, pp.1-16
2023
Abstract
Tasmania is experiencing increasing seawater temperatures during the summer period which often leads to thermal stress-induced starvation events in farmed Atlantic salmon, with consequent flesh pigment depletion. Our previous transcriptomic studies found a link between flesh pigmentation and the expression of genes regulating lipid metabolism accompanied by feeding behavior in the hindgut. However, the impact of prolonged exposure to elevated water temperature on muscle structural integrity and molecular mechanisms in muscle underlying pigment variation has not been elucidated to date. In this study, we investigated the effect of prolonged exposure to elevated water temperature on the farmed salmon flesh pigmentation and structural integrity, using muscle histological and transcriptomic analysis. On April 2019, after the end of the summer, two muscle regions of the fish fillet, front dorsal and back central (usually the most and least affected by depletion, respectively), were sampled from fifteen fish (weighing approximately 2 kg and belonging to the same commercial population split in two cages). The fish represented three flesh color intensity groups (n = 5 fish per group) categorized according to general level of pigmentation and presence of banding (i.e. difference in color between the two regions of interest) as follows: high red color-no banding (HN), high red color-banded (HB) and Pale fish. Histological analysis showed a distinction between the flesh color intensity phenotypes in both muscle regions. Muscle fibers in the HB fish were partly degraded, while they were atrophied and smaller in size in Pale fish compared to HN fish. In the Pale fish, interstitial spaces between muscle fibers were also enlarged. Transcriptomic analysis showed that in the front dorsal region of the HN fish, genes encoding collagens, calcium ion binding and metabolic processes were upregulated while genes related to lipid and fatty acid metabolism were downregulated when compared to HB fish. When comparing the back central region of the three phenotypes, actin alpha skeletal muscle and myosin genes were upregulated in the HN and HB fish, while tropomyosin genes were upregulated in the Pale fish. Also, genes encoding heat shock proteins were upregulated in the HN fish, while genes involving lipid metabolism and proteolysis were upregulated in the Pale fish. Starvation, likely caused by thermal stress during prolonged periods of elevated summer water temperatures, negatively affects energy metabolism to different extents, leading to localized or almost complete flesh color depletion in farmed Atlantic salmon. Based on our results, we conclude that thermal stress is responsible not only for flesh discoloration but also for loss of muscle integrity, which likely plays a key role in pigment depletion.
Details
- Title
- Histological and transcriptomic analysis of muscular atrophy associated with depleted flesh pigmentation in Atlantic salmon (Salmo salar) exposed to elevated seawater temperatures
- Authors
- Thu Thi Minh Vo (Corresponding Author) - University of the Sunshine Coast, Queensland, Centre for BioinnovationGianluca Amoroso (Corresponding Author) - University of TasmaniaTomer Ventura (Corresponding Author) - University of the Sunshine Coast, Queensland, Centre for BioinnovationAbigail Elizur (Corresponding Author) - University of the Sunshine Coast, Queensland, Centre for Bioinnovation
- Publication details
- Scientific Reports, Vol.13, pp.1-16
- Publisher
- Nature Publishing Group
- Date published
- 2023
- DOI
- 10.1038/s41598-023-31242-2
- ISSN
- 2045-2322
- Copyright note
- This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
- Organisation Unit
- School of Science, Technology and Engineering; Centre for Bioinnovation
- Language
- English
- Record Identifier
- 99710398502621
- Output Type
- Journal article
Metrics
169 File views/ downloads
50 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- International collaboration
- Web Of Science research areas
- Fisheries