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Abstract Salinity stress occurs when salt concentration in the environment changes rapidly, for example because of tidal water flow, rainstorms, drought, or evaporation from small bodies of water. However, gradual changes in salt concentration can also cause osmotic stress in aquatic habitats if levels breach thresholds that reduce the fitness of resident organisms. The latter scenario is exemplified by climate change driven salinization of estuaries and by dilution of ocean surface salinity through changes in the water cycle. In this review, we discuss how fish employ the evolutionarily conserved cellular stress response (CSR) to cope with these different forms of salinity stress. Macromolecular damage is identified as the cause of impaired physiological performance during salinity stress and serves as the signal for inducing a CSR. Basic aspects of the CSR have been observed in fish exposed to salinity stress, including repair and protection of cellular macromolecules, reallocation of energy, cell cycle arrest, and in severe cases, programmed cell death. Osmosensing and signal transduction events that regulate these aspects of the CSR provide a link between environmental salinity and adaptive physiological change required for survival. The CSR has evolved to broaden the range of salinities tolerated by certain euryhaline fish species, but is constrained in stenohaline species that are sensitive to changes in environmental salinity. Knowledge of how the CSR diverges between euryhaline and stenohaline fish enables understanding of physiological mechanisms that underlie salt tolerance and facilitates predictions as to the relative vulnerabilities of different fish species to a rapidly changing hydrosphere.
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Evolution of cellular stress response mechanisms
Abstract The cellular stress response (CSR) is pervasive to all domains of life. It has shaped the interaction between organisms and their environment since the origin of the first cell. Although the CSR has been subject to a myriad of nuanced modifications in the various branches of life present today, its core features remain preserved. The scientific literature covering the CSR is enormous and the broad scope of this brief overview was challenging. However, it is critical to conceptually understand how cells respond to stress in a holistic sense and to point out how fundamental aspects of the CSR framework are integrated. It was necessary to be extremely selective and not feasible to even mention many interesting and important developments in this expansive field. The purpose of this overview is to sketch out general and emerging CSR concepts with an emphasis on the initial cellular strain resulting from stress (macromolecular damage) and the evolutionarily most highly conserved elements of the CSR. Examples emphasize fish and aquatic invertebrates to highlight what is known in organisms beyond mammals, yeast, and other common models. Nonetheless, select pioneering studies using canonical models are also considered and the concepts discussed are applicable to all cells. More detail on important aspects of the CSR in aquatic animals is provided in the accompanying articles of this special issue.
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- Award ID(s):
- 1656371
- PAR ID:
- 10131671
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Experimental Zoology Part A: Ecological and Integrative Physiology
- Volume:
- 333
- Issue:
- 6
- ISSN:
- 2471-5638
- Page Range / eLocation ID:
- p. 359-378
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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