Identification of molecular and physiological responses to chronic environmental challenge in an invasive species The Pacific oyster, Crassostrea gigas
Understanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. In this study, Crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed...
| Published in: | Ecology and Evolution |
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| Main Authors: | , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2013
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10400.1/5424 https://doi.org/10.1002/ece3.719 |
| Summary: | Understanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. In this study, Crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed to the chronic environmental challenges of temperature (19 and 24°C) and pH (ambient seawater and a reduction of 0.4 pH units) in an extended 3-month laboratory-based study. Physiological parameters were measured (condition index, shell growth, respiration, excretion rates, O:N ratios, and ability to repair shell damage) alongside molecular analyses. Temperature was by far the most important stressor, as demonstrated by reduced condition indexes and shell growth at 24°C, with relatively little effect detected for pH. Transcriptional profiling using candidate genes and SOLiD sequencing of mantle tissue revealed that classical “stress” genes, previously reported to be upregulated under acute temperature challenges, were not significantly expressed in any of the treatments, emphasizing the different response between acute and longer term chronic stress. The transcriptional profiling also elaborated on the cellular responses underpinning the physiological results, including the identification of the PI3K/AKT/mTOR pathway as a potentially novel marker for chronic environmental challenge. This study represents a first attempt to understand the energetic consequences of cumulative thermal stress on the intertidal C. gigas which could significantly impact on coastal ecosystem biodiversity and function in the future. This work was supported by an EU Research Infrastructure Action under the EP7 “Capacities” Specific Programme, ASSEMBLE grant agreement no. 227799, CCMAR Ref 00415/2010. We thank Lloyd Peck (BAS) for advice on physiology and critical reading of the manuscript, Simon Morley (BAS) for statistical analyses, John Turner (BAS) for the Hadley Centre predictions, Elizabeth Harper Cambridge University for damage repair ... |
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