Molecular Response to Extreme Summer Temperatures Differs Between Two Genetically Differentiated Populations of a Coral Reef Fish

Abstract
Extreme thermal events are increasing in frequency and duration as the climate continues to warm, with potential detrimental effects on marine organisms. However, the effects of heatwaves may differ among geographically separated populations depending on their capacity for thermal plasticity. Here, we compared the response to simulated summer heatwave temperatures (+1.5 and +3.0°C above average) in two populations of a coral reef damselfish with different capacities for thermal plasticity. We found that the more thermally tolerant population had greater plasticity of gene expression and had significantly more downregulated genes, which may provide more energy to repair damage associated with thermal stress and to maintain basic functions at these extreme temperatures. In contrast, the thermally sensitive population exhibited higher basal levels of heat shock proteins and had three times fewer changes in gene expression overall. The limited changes in gene regulation suggest that individuals have reduced genome plasticity to tolerate thermal fluctuations and consequently may not have enough energy to repair damage and resume cellular homeostasis at extreme temperatures. Thus, we have identified the molecular signatures of how two genetically distinct fish populations cope with an extreme thermal event, and why they differ in their capacity for thermal plasticity.

Citation
Veilleux HD, Ryu T, Donelson JM, Ravasi T, Munday PL (2018) Molecular Response to Extreme Summer Temperatures Differs Between Two Genetically Differentiated Populations of a Coral Reef Fish. Frontiers in Marine Science 5. Available: http://dx.doi.org/10.3389/fmars.2018.00349.

Acknowledgements
Funding: Funding for this project was provided by Competitive Research Funds OCRF-2014-CRG3-62140408 from the King Abdullah University of Science and Technology (TR and PM); the Australian Research Council (PM); ARC Centre of Excellence for Coral Reef Studies (PM and JD); and APEC Climate Center (TR). Acknowledgments: We thank the Integrative Systems Biology Lab at the King Abdullah University of Science and Technology, and the Marine and Aquaculture Research Facility Unit and the Molecular Ecology and Evolution Laboratory at James Cook University.

Publisher
Frontiers Media SA

Journal
Frontiers in Marine Science

DOI
10.3389/fmars.2018.00349

Additional Links
https://www.frontiersin.org/articles/10.3389/fmars.2018.00349/full

Relations
Is Supplemented By:
  • [Bioproject]
    Title: Acanthochromis polyacanthus TranscriptomePublication Date: 2014-07-18. bioproject: PRJNA255544 Handle: 10754/666481

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