Food availability, more than body temperature, drives correlated shifts in ATP-generating and antioxidant enzyme capacities in a population of intertidal mussels (Mytilus californianus)

Dowd, W. Wesley; Felton, C.; Heymann, Helen; Kost, Laurie; Somero, George N.

doi:10.1016/j.jembe.2013.09.020

Cited by 42 publications

(31 citation statements)

References 46 publications

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“…via increasing metabolic rates to compensate for ATP deficiency) or indirectly, by limiting the amount of energy available for antioxidant production. A close relationship between the potential for ATP generation and the capacity to counteract oxidative stress has been earlier documented in other species (Dowd et al, 2013) and may be a common feature of marine bivalves. The impressive resilience to oxidative damage in spring oysters may reflect upregulation of the antioxidant defenses in preparation for the warmer season and/or lower susceptibility of the warm-acclimated membranes to oxidation (Lau et al, 2004;Regoli et al, 2004b;Malanga et al, 2007;Crockett, 2008).…”

Section: Cellular Energy Status and Oxidative Stresssupporting

confidence: 58%

Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

2015

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Cadmium (Cd) and elevated temperatures are common stressors in estuarine and coastal environments. Elevated temperature can sensitize estuarine organisms to the toxicity of metals such as Cd and vice versa, but the physiological mechanisms of temperature-Cd interactions are not well understood. We tested a hypothesis that interactive effects of elevated temperature and Cd stress involve Cd-induced reduction of the aerobic scope of an organism thereby narrowing the thermal tolerance window of oysters. We determined the effects of prolonged Cd exposure (50 μg Cd l(-1)for 30 days) on the upper critical temperature of aerobic metabolism (assessed by accumulation of anaerobic end products L-alanine, succinate and acetate), cellular energy status (assessed by the tissue levels of adenylates, phosphagen/aphosphagen and glycogen and lipid reserves) and oxidative damage during acute temperature rise (20-36 °C) in the eastern oysters Crassostrea virginica. The upper critical temperature (TcII) was shifted to lower values (from 28 to 24 °C) in Cd-exposed oysters in spring and was lower in both control and Cd-exposed groups in winter (24 and <20 °C, respectively). This indicates a reduction of thermal tolerance of Cd-exposed oysters associated with a decrease of the aerobic scope of the organism and early transition to partial anaerobiosis. Acute warming had no negative effects on tissue energy reserves or parameters of cellular energy status of oysters (except a decrease in adenylate content at the extreme temperature of 36 °C) but led to an increase in oxidative lesions of proteins at extreme temperatures. These data show that transition to partial anaerobiosis (indicated by the accumulation of anaerobic end products) is the most sensitive biomarker of temperature-induced transition to energetically non-sustainable state in oysters, whereas disturbances in the cellular energy status (i.e. decline in adenylate and phosphagen levels) and oxidative stress ensue at considerably higher temperatures, nearing the lethal range. This study indicates that long-term exposure of oysters to environmentally relevant levels of Cd may increase their sensitivity to elevated temperatures during seasonal warming and/or the global climate change in polluted estuaries.

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Section: Cellular Energy Status and Oxidative Stresssupporting

confidence: 58%

Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

2015

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“…The southwest-facing, wave-protected site experienced less wave splash and more direct irradiance, contributing to warmer body temperatures ('protected'). See [18,43] for data characterizing the environment at each site. Differences exist between these sites in mean activities of antioxidant and aerobic enzymes [43].…”

Section: Methodsmentioning

confidence: 99%

“…See [18,43] for data characterizing the environment at each site. Differences exist between these sites in mean activities of antioxidant and aerobic enzymes [43]. All experiments were conducted on individuals of similar size (approx.…”

Section: Methodsmentioning

confidence: 99%

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Micro-scale environmental variation amplifies physiological variation among individual mussels

et al. 2015

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The contributions of temporal and spatial environmental variation to physiological variation remain poorly resolved. Rocky intertidal zone populations are subjected to thermal variation over the tidal cycle, superimposed with micro-scale variation in individuals' body temperatures. Using the sea mussel (Mytilus californianus), we assessed the consequences of this microscale environmental variation for physiological variation among individuals, first by examining the latter in field-acclimatized animals, second by abolishing micro-scale environmental variation via common garden acclimation, and third by restoring this variation using a reciprocal outplant approach. Common garden acclimation reduced the magnitude of variation in tissuelevel antioxidant capacities by approximately 30% among mussels from a wave-protected (warm) site, but it had no effect on antioxidant variation among mussels from a wave-exposed (cool) site. The field-acclimatized level of antioxidant variation was restored only when protected-site mussels were outplanted to a high, thermally stressful site. Variation in organismal oxygen consumption rates reflected antioxidant patterns, decreasing dramatically among protected-site mussels after common gardening. These results suggest a highly plastic relationship between individuals' genotypes and their physiological phenotypes that depends on recent environmental experience. Corresponding context-dependent changes in the physiological meanvariance relationships within populations complicate prediction of responses to shifts in environmental variability that are anticipated with global change.

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“…For example, analysis of the oyster genome revealed an expansion of the genes coding for heat shock protein 70 and apoptosis inhibitors, which was interpreted as an adaptation to intertidal stressors (Zhang et al, 2012). One advantage of studying sessile organisms is that the same mussel assemblage can be sampled repeatedly over periods of days, weeks and even years, thus allowing phenotype to be interpreted within the context of both prevailing and prior abiotic events (Dowd et al, 2013;Gracey et al, 2008;Letendre et al, 2009;Regoli et al, 2004). This has made mussels particularly appropriate animals for investigating adaptive physiological processes that allow life to flourish in a fluctuating environment (Braby and Somero, 2006a;Fields et al, 2006;Hofmann and Somero, 1995;Logan et al, 2012;Williams and Somero, 1996).…”

Section: Introductionmentioning

confidence: 99%

The environmentally tuned transcriptomes ofMytilusmussels

Lockwood

Connor

Gracey

2015

Journal of Experimental Biology

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Transcriptomics is a powerful tool for elucidating the molecular mechanisms that underlie the ability of organisms to survive and thrive in dynamic and changing environments. Here, we review the major contributions in this field, and we focus on studies of mussels in the genus Mytilus, which are well-established models for the study of ecological physiology in fluctuating environments. Our review is organized into four main sections. First, we illustrate how the abiotic forces of the intertidal environment drive the rhythmic coupling of gene expression to diel and tidal cycles in Mytilus californianus. Second, we discuss the challenges and pitfalls of conducting transcriptomic studies in field-acclimatized animals. Third, we examine the link between transcriptomic responses to environmental stress and biogeographic distributions in blue mussels, Mytilus trossulus and Mytilus galloprovincialis. Fourth, we present a comparison of transcriptomic datasets and identify 175 genes that share common responses to heat stress across Mytilus species. Taken together, these studies demonstrate that transcriptomics can provide an informative snapshot of the physiological state of an organism within an environmental context. In a comparative framework, transcriptomics can reveal how natural selection has shaped patterns of transcriptional regulation that may ultimately influence biogeography.

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Food availability, more than body temperature, drives correlated shifts in ATP-generating and antioxidant enzyme capacities in a population of intertidal mussels (Mytilus californianus)

Cited by 42 publications

References 46 publications

Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

Micro-scale environmental variation amplifies physiological variation among individual mussels

The environmentally tuned transcriptomes ofMytilusmussels

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