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Hu Z, Feng J, Song H, Zhou C, Yang MJ, Shi P, Yu ZL, Guo YJ, Li YR, Zhang T. Metabolic response of Mercenaria mercenaria under heat and hypoxia stress by widely targeted metabolomic approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151172. [PMID: 34710412 DOI: 10.1016/j.scitotenv.2021.151172] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/20/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
In the context of global climatic changes, marine organisms have been exposed to environmental stressors including heat and hypoxia. This calls for the design of multi-stressors to uncover the impact of oceanic factors on aquatic organisms. So far, little is known about the metabolic response of marine organisms, especially bivalves, to the combined effects of heat and hypoxia. In this study, we employed widely targeted metabolomic analysis to study the metabolic response of gills in hard clam, a heat- and hypoxia-tolerant bivalve. A total of 810 metabolites were identified. Results showed that the heat group (HT) and heat plus hypoxia group (HL) had a higher number of differential metabolites than the hypoxia group (LO). Glycolysis was affected by the heat and heat plus hypoxia stress. Moreover, anaerobic metabolic biomarkers were accumulated marking the onset of anaerobic metabolism. Environmental stresses may affect Tricarboxylic acid (TCA) cycle. Accumulation of carnitine and glycerophospholipid may promote fatty acid β oxidation and maintain cell membrane stability, respectively. The high content of oxidized lipids (i.e., Leukotriene) in HL and HT groups implied that the organisms were under ROS stress. The significantly differential metabolites of organic osmolytes and vitamins might relieve ROS stress. Moreover, accumulation of thermoprotective osmolytes (monosaccharide, Trimethylamine N-oxide (TMAO)) accumulation was helpful to maintain protein homeostasis. This investigation provided new insights into the adaptation mechanisms of hard clam to heat, hypoxia and combined stress at the metabolite level and highlighted the roles of molecules and protectants.
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Affiliation(s)
- Zhi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Feng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Hao Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Cong Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mei-Jie Yang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Pu Shi
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng-Lin Yu
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | - Yong-Jun Guo
- Tianjin Key Laboratory of Aqua-ecology and Aquaculture, Fisheries College, Tianjin Agricultural University, Tianjin 300384, China
| | - Yong-Ren Li
- Tianjin Key Laboratory of Aqua-ecology and Aquaculture, Fisheries College, Tianjin Agricultural University, Tianjin 300384, China
| | - Tao Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
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Effect of Air Exposure-Induced Hypoxia on Neurotransmitters and Neurotransmission Enzymes in Ganglia of the Scallop Azumapecten farreri. Int J Mol Sci 2022; 23:ijms23042027. [PMID: 35216143 PMCID: PMC8878441 DOI: 10.3390/ijms23042027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 02/04/2023] Open
Abstract
The nervous system expresses neuromolecules that play a crucial role in regulating physiological processes. Neuromolecule synthesis can be regulated by oxygen-dependent enzymes. Bivalves are a convenient model for studying air exposure-induced hypoxia. Here, we studied the effects of hypoxia on the expression and dynamics of neurotransmitters, and on neurotransmitter enzyme distribution, in the central nervous system (CNS) of the scallop Azumapecten farreri. We analyzed the expression of the neurotransmitters FMRFamide and serotonin (5-HT) and the choline acetyltransferase (CHAT) and universal NO-synthase (uNOS) enzymes during air exposure-induced hypoxia. We found that, in early-stage hypoxia, total serotonin content decreased in some CNS regions but increased in others. CHAT-lir cell numbers increased in all ganglia after hypoxia; CHAT probably appears de novo in accessory ganglia. Short-term hypoxia caused increased uNOS-lir cell numbers, while long-term exposure led to a reduction in their number. Thus, hypoxia weakly influences the number of FMRFamide-lir neurons in the visceral ganglion and does not affect peptide expression in the pedal ganglion. Ultimately, we found that the localization and level of synthesis of neuromolecules, and the numbers of cells expressing these molecules, vary in the scallop CNS during hypoxia exposure. This indicates their possible involvement in hypoxia resistance mechanisms.
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Sánchez-Marín P, Vidal-Liñán L, Fernández-González LE, Montes R, Rodil R, Quintana JB, Carrera M, Mateos J, Diz AP, Beiras R. Proteomic analysis and biochemical alterations in marine mussel gills after exposure to the organophosphate flame retardant TDCPP. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 230:105688. [PMID: 33316748 DOI: 10.1016/j.aquatox.2020.105688] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/27/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
Organophosphate flame retardants (OPFRs) are (re-)emergent environmental pollutants increasingly being used because of the restriction of other flame retardants. The chlorinated OPFR, tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is among those of highest environmental concern, but its potential effects in the marine environment have rarely been investigated. We exposed a widely used sentinel marine mussel species, Mytilus galloprovincialis, to 10 μg L-1 of TDCPP during 28 days and studied: (i) the kinetics of bioaccumulation and elimination of the compound, (ii) the effect on two molecular biomarkers, glutathione S-transferase (GST) and acetylcholinesterase (AChE) activities, and (iii) proteomic alterations in the gills, following an isobaric labeling quantitative shotgun proteomic approach, at two exposure times (7 and 28 days). Uptake and elimination of TDCPP by mussels were very fast, and the bioconcentration factor of this compound in mussels was 147 L kgww-1, confirming that this compound is not very bioaccumulative, as predicted by its chemical properties. GST activity was not affected by TDCPP exposure, but AChE activity was inhibited by TDCPP at both 7 and 28 days of exposure. Proteomic analysis revealed subtle effects of TDCPP in mussel gills, since few proteins (less than 2 % of the analysed proteome) were significantly affected by TDCPP, and effect sizes were low. The most relevant effects detected were the up-regulation of epimerase family protein SDR39U1, an enzyme that could be involved in detoxification processes, at both exposure times, and the down-regulation of receptor-type tyrosine-protein phosphatase N2-like (PTPRN2) after 7 days of exposure, which is involved in neurotransmitter secretion and might be related to the neurotoxicity described for this compound. Exposure time rather than TDCPP exposure was the most important driver of protein abundance changes, with 33 % of the proteome being affected by this factor, suggesting that stress caused by laboratory conditions could be an important confounding factor that needs to be controlled in similar ecotoxicology studies. Proteomic data are available via ProteomeXchange with identifier PXD019720.
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Affiliation(s)
- Paula Sánchez-Marín
- Department of Ecology and Animal Biology, University of Vigo, 36310 Vigo, Galicia, Spain; Centro Oceanográfico de Vigo, Instituto Español de Oceanografía, 36390 Vigo, Spain.
| | - Leticia Vidal-Liñán
- Department of Ecology and Animal Biology, University of Vigo, 36310 Vigo, Galicia, Spain; Centro Oceanográfico de Vigo, Instituto Español de Oceanografía, 36390 Vigo, Spain
| | - Laura Emilia Fernández-González
- Department of Ecology and Animal Biology, University of Vigo, 36310 Vigo, Galicia, Spain; Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310 Vigo, Spain; Marine Research Centre, University of Vigo (CIM-UVIGO), Isla de Toralla, Vigo, Spain
| | - Rosa Montes
- Department of Analytical Chemistry, Nutrition and Food Sciences, Institute of Research in Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Rosario Rodil
- Department of Analytical Chemistry, Nutrition and Food Sciences, Institute of Research in Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - José Benito Quintana
- Department of Analytical Chemistry, Nutrition and Food Sciences, Institute of Research in Chemical and Biological Analysis (IAQBUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Mónica Carrera
- Institute of Marine Research (IIM), Spanish National Research Council (CSIC), 36208 Vigo, Spain
| | - Jesús Mateos
- Institute of Marine Research (IIM), Spanish National Research Council (CSIC), 36208 Vigo, Spain
| | - Angel P Diz
- Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310 Vigo, Spain; Marine Research Centre, University of Vigo (CIM-UVIGO), Isla de Toralla, Vigo, Spain
| | - Ricardo Beiras
- Department of Ecology and Animal Biology, University of Vigo, 36310 Vigo, Galicia, Spain; Marine Research Centre, University of Vigo (CIM-UVIGO), Isla de Toralla, Vigo, Spain
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Casas SM, La Peyre JF. Heat shock protein 70 levels and post-harvest survival of eastern oysters following sublethal heat shock in the laboratory or conditioning in the field. Cell Stress Chaperones 2020; 25:369-378. [PMID: 31916124 PMCID: PMC7058772 DOI: 10.1007/s12192-019-01056-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 10/25/2022] Open
Abstract
A major problem of storing and shipping eastern oysters (Crassostrea virginica) from the Northern Gulf of Mexico in summer and early fall is their elevated mortality. A study was therefore conducted to determine whether heat shocking the oysters or conditioning them to aerial exposure prior to harvest could reduce their mortality during cold storage. Increasing the levels of stress proteins in bivalves has been shown to reduce their mortality when exposed to additional stressors. In this study, the levels of heat shock protein 70 (HSP70) proteins and cumulative mortality during cold storage, out of water, of market-sized oysters were measured, in summer, following (1) sublethal heat shocks (41 °C, 1 h) in the laboratory or (2) 3 weeks to 6 weeks of daily exposures to air (0 h, ~ 10 h, or ~ 18 h) in the field. In total, four heat shock and two aerial exposure studies were done. Consistently, heat shocks or 6 weeks of daily aerial exposures increased HSP70 levels in oysters but did not reduce their mortality during cold storage. Three weeks of daily aerial exposure did not increase HSP70 levels and only marginally reduced mortality; a significant reduction in cumulative mortality occurred in one of the aerial exposure studies after 7 days of cold storage (0 h [26%], ~ 18 h [8%]). In conclusion, upregulation of HSP70 proteins or aerial exposure during grow-out was not an effective tool in reducing the mortality of oysters harvested in summer and held in cold storage.
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Affiliation(s)
- Sandra M Casas
- School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA.
| | - Jerome F La Peyre
- School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA
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5
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Collins M, Tills O, Turner LM, Clark MS, Spicer JI, Truebano M. Moderate reductions in dissolved oxygen may compromise performance in an ecologically-important estuarine invertebrate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 693:133444. [PMID: 31362229 DOI: 10.1016/j.scitotenv.2019.07.250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 06/27/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Coastal ecosystems, including estuaries, are increasingly pressured by expanding hypoxic regions as a result of human activities such as increased release of nutrients and global warming. Hypoxia is often defined as oxygen concentrations below 2 mL O2 L-1. However, taxa vary markedly in their sensitivity to hypoxia and can be affected by a broad spectrum of low oxygen levels. To better understand how reduced oxygen availability impacts physiological and molecular processes in invertebrates, we investigated responses of an estuarine amphipod to an ecologically-relevant level of moderate hypoxia (~2.6 mL O2 L-1) or severe hypoxia (~1.3 mL O2 L-1). Moderate hypoxia elicited a reduction in aerobic scope, and widespread changes to gene expression, including upregulation of metabolic genes and stress proteins. Under severe hypoxia, a marked hyperventilatory response associated with maintenance of aerobic performance was accompanied by a muted transcriptional response. This included a return of metabolic genes to baseline levels of expression and downregulation of transcripts involved in protein synthesis, most of which indicate recourse to hypometabolism and/or physiological impairment. We conclude that adverse ecological effects may occur under moderate hypoxia through compromised individual performance and, therefore, even modest declines in future oxygen levels may pose a significant challenge to coastal ecosystems.
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Affiliation(s)
- Michael Collins
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
| | - Oliver Tills
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Lucy M Turner
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Melody S Clark
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
| | - John I Spicer
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Manuela Truebano
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
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Meng J, Wang T, Li L, Zhang G. Inducible variation in anaerobic energy metabolism reflects hypoxia tolerance across the intertidal and subtidal distribution of the Pacific oyster (Crassostrea gigas). MARINE ENVIRONMENTAL RESEARCH 2018; 138:135-143. [PMID: 29724494 DOI: 10.1016/j.marenvres.2018.04.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/10/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Pacific oyster (Crassostrea gigas) distribute a steep gradient of environmental stress between intertidal and subtidal habits and provide insight into population-scale patterns and underlying processes of variation in physiological tolerance. In this study, 1-year-old-F1 oysters, collected from subtidal and intertidal habitats, were obtained after common garden experiment. Genetic differentiation and physiological responses under air exposure were examined to determine whether they had evolved into local adapted subpopulations. Mortality rate, anaerobic glycolysis metabolism, and energy status indicated that oyster had initiated metabolism depression and anaerobic glycolysis metabolism in both intertidal and subtidal oysters under air exposure. However, the subtidal oysters displayed the larger energy metabolism depressions and the earlier anaerobic glycolysis responses. This may indicate that subtidal oysters were more sensitives to hypoxia stress, which may lead the higher mortality rate under long term of air exposure. Based on a common garden experimental design, we propose that this diversification may have a genetic background. Overall, the clear differences between intertidal and subtidal oysters under air exposure have provided an important reference for their aquaculture and transportation used in commercial production.
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Affiliation(s)
- Jie Meng
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China; Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China; National& Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao 266071, Shandong, China
| | - Ting Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, Shandong, China; National& Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao 266071, Shandong, China
| | - Li Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China; Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China; National& Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao 266071, Shandong, China.
| | - Guofan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, Shandong, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, Shandong, China; National& Local Joint Engineering Laboratory of Ecological Mariculture, Qingdao 266071, Shandong, China.
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Diz AP, Álvarez-Rodríguez M, Romero MR, Rolán-Alvarez E, Galindo J. Limited proteomic response in the marine snail Melarhaphe neritoides after long-term emersion. Curr Zool 2018; 63:487-493. [PMID: 29492008 PMCID: PMC5804206 DOI: 10.1093/cz/zow110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/29/2016] [Indexed: 11/14/2022] Open
Abstract
Rocky intertidal organisms are commonly exposed to environmental gradients, promoting adaptations to these conditions. Emersion time varies along the intertidal range and in the supralittoral zone is frequently larger than a single tidal cycle, even lasting for weeks. The planktonic-dispersing gastropod Melarhaphe neritoides is a common species of the high shore, adapted to reduce water loss in order to survive during long-term emersion. In this study, we investigated the molecular response, at the proteome level, of M. neritoides collected in high-shore tide pools to a series of emersion periods, from 8 to 24 days, in laboratory conditions. We compared this response to individuals maintained submerged during this period, because this was their original habitat. We also included a reversion treatment in the study, in which emersed individuals were returned to the submerged conditions. Although we detected an increase in overall protein concentration with longer emersion periods, contrary to general expectation, the two dimensional electrophoresis (2DE)-based proteomic analysis did not show significant differences between the treatments at the level of individual protein spots, even after an emersion period of 24 days. Our results suggest that the metabolism remains unaltered independent of the treatment carried out or the changes are very subtle and therefore difficult to detect with our experimental design. We conclude that M. neritoides could be equally adapted to emersion and submersion without drastic physiological changes.
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Affiliation(s)
- Angel P Diz
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, 36310, Spain.,Toralla Marine Science Station (ECIMAT), Universidad de Vigo, Vigo, 36331, Spain
| | - Margarita Álvarez-Rodríguez
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, 36310, Spain.,Institute of Marine Research (IIM), CSIC, Vigo, 36208, Spain
| | - Mónica R Romero
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, 36310, Spain.,Toralla Marine Science Station (ECIMAT), Universidad de Vigo, Vigo, 36331, Spain
| | - Emilio Rolán-Alvarez
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, 36310, Spain.,Toralla Marine Science Station (ECIMAT), Universidad de Vigo, Vigo, 36331, Spain
| | - Juan Galindo
- Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Vigo, 36310, Spain.,Toralla Marine Science Station (ECIMAT), Universidad de Vigo, Vigo, 36331, Spain
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Lucu Č, Ziegler A. The effects of hypoxia on active ionic transport processes in the gill epithelium of hyperregulating crab, Carcinus maneas. Comp Biochem Physiol A Mol Integr Physiol 2017. [PMID: 28629793 DOI: 10.1016/j.cbpa.2017.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Effects of hypoxia on the osmorespiratory functions of the posterior gills of the shore crab Carcinus maenas acclimated to 12ppt seawater (DSW) were studied. Short-circuit current (Isc) across the hemilamella (one epithelium layer supported by cuticle) was substantially reduced under exposure to 1.6, 2.0, or 2.5mg O2/L hypoxic saline (both sides of epithelium) and fully recovered after reoxygenation. Isc was reduced equally in the epithelium exposed to 1.6mg O2/L on both sides and when the apical side was oxygenated and the basolateral side solely exposed to hypoxia. Under 1.6mg O2/L, at the level of maximum inhibition of Isc, conductance was decreased from 40.0mScm-2 to 34.7mScm-2 and fully recovered after reoxygenation. Isc inhibition under hypoxia and reduced 86Rb+ (K+) fluxes across apically located K+ channels were caused preferentially by reversible inhibition of basolaterally located and ouabain sensitive Na+,K+-ATPase mediated electrogenic transport. Reversible inhibition of Isc is discussed as decline in active transport energy supply down regulating metabolic processes and saving energy during oxygen deprivation. In response to a 4day exposure of Carcinus to 2.0mg O2/L, hemolymph Na+ and Cl- concentration decreased, i.e. hyperosmoregulation was weakened. Variations of the oxygen concentration level and exposure time to hypoxia lead to an increase of the surface of mitochondria per epithelium area and might in part compensate for the decrease in oxygen availability under hypoxic conditions.
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Affiliation(s)
- Čedomil Lucu
- Alfred Wegener- Institute Helmholtz Center for Polar and Marine Research Wadden Sea Station/List/Sylt, Germany; Institute Ruđer Bošković, Center for Marine Research Rovinj, Zagreb, Croatia.
| | - Andreas Ziegler
- Central Facility for Electron Microscopy University of Ulm, A. Einstein Alee 11, 89069 Ulm, Germany
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Gleason LU, Burton RS. Genomic evidence for ecological divergence against a background of population homogeneity in the marine snail Chlorostoma funebralis. Mol Ecol 2016; 25:3557-73. [PMID: 27199218 DOI: 10.1111/mec.13703] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 12/19/2022]
Abstract
The balance between natural selection, gene flow and genetic drift is difficult to resolve in marine invertebrates with extensive dispersal and fluctuating population sizes. The intertidal snail Chlorostoma funebralis has planktonic larvae and previous work using mtDNA polymorphism reported no genetic population structure. Nevertheless, recent studies have documented differences in thermal tolerance and transcriptomic responses to heat stress between northern and southern California, USA, populations. To gain insight into the dynamics influencing adaptive divergence, we used double-digest restriction site-associated DNA (ddRAD) sequencing to identify 1861 genomewide, quality-filtered single-nucleotide polymorphism (SNP) loci for C. funebralis collected from three northern and three southern California sites (15 individuals per population). Considering all SNPs, there was no evidence for genetic differentiation among populations or regions (average FST = 0.0042). However, outlier tests revealed 34 loci putatively under divergent selection between northern and southern populations, and structure and SNP tree analyses based on these outliers show clear genetic differentiation between geographic regions. Three of these outliers are known or hypothesized to be involved in stress granule formation, a response to environmental stress such as heat. Combined with previous work that found thermally tolerant southern populations show high baseline expression of stress response genes, these results further suggest that thermal stress is a strong selective pressure across C. funebralis populations. Overall, this study increases our understanding of the factors constraining local adaptation in marine organisms, while suggesting that ecologically driven, strong differentiation can occur at relevant loci in a species with planktonic larvae.
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Affiliation(s)
- Lani U Gleason
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093-0202, USA.,Department of Biology, Loyola Marymount University, Los Angeles, CA, 90045, USA
| | - Ronald S Burton
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093-0202, USA
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Giannetto A, Maisano M, Cappello T, Oliva S, Parrino V, Natalotto A, De Marco G, Barberi C, Romeo O, Mauceri A, Fasulo S. Hypoxia-Inducible Factor α and Hif-prolyl Hydroxylase Characterization and Gene Expression in Short-Time Air-Exposed Mytilus galloprovincialis. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2015; 17:768-781. [PMID: 26277612 DOI: 10.1007/s10126-015-9655-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/02/2015] [Indexed: 06/04/2023]
Abstract
Aquatic organisms experience environmental hypoxia as a result of eutrophication and naturally occurring tidal cycles. Mytilus galloprovincialis, being an anoxic/hypoxic-tolerant bivalve, provides an excellent model to investigate the molecular mechanisms regulating oxygen sensing. Across the animal kingdom, inadequacy in oxygen supply is signalled predominantly by hypoxia-inducible factors (HIF) and Hif-prolyl hydroxylases (PHD). In this study, hif-α 5'-end and partial phd mRNA sequences from M. galloprovincialis were obtained. Phylogenetic and molecular characterization of both HIF-α and PHD putative proteins showed shared key features with the respective orthologues from animals strongly suggesting their crucial involvement in the highly conserved oxygen sensing pathway. Both transcripts displayed a tissue-specific distribution with prominent expression in gills. Quantitative gene expression analysis of hif-α and phd mRNAs from gills of M. galloprovincialis demonstrated that both these key sensors are transcriptionally modulated by oxygen availability during the short-time air exposure and subsequent re-oxygenation treatments proving that they are critical players of oxygen-sensing mechanisms in mussels. Remarkably, hif-α gene expression showed a prompt and transient response suggesting the precocious implication of this transcription factor in the early phase of the adaptive response to hypoxia in Mytilus. HIF-α and PHD proteins were modulated in a time-dependent manner with trends comparable to mRNA expression patterns, thus suggesting a central role of their transcriptional regulation in the hypoxia tolerance strategies in marine bivalves. These results provide molecular information about the effects of oxygen deficiency and identify hypoxia-responsive biomarker genes in mussels applicable in ecotoxicological studies of natural marine areas.
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Affiliation(s)
- Alessia Giannetto
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy.
| | - Maria Maisano
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Tiziana Cappello
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Sabrina Oliva
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Vincenzo Parrino
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Antonino Natalotto
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Giuseppe De Marco
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Chiara Barberi
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Orazio Romeo
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Angela Mauceri
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
| | - Salvatore Fasulo
- Department of Biological and Environmental Sciences, University of Messina, 98166, Messina, Italy
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11
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Biggar KK, Storey KB. Evidence for cell cycle suppression and microRNA regulation of cyclin D1 during anoxia exposure in turtles. Cell Cycle 2014; 11:1705-13. [DOI: 10.4161/cc.19790] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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12
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Biggar KK, Storey KB. New Approaches to Comparative and Animal Stress Biology Research in the Post-genomic Era: A Contextual Overview. Comput Struct Biotechnol J 2014; 11:138-46. [PMID: 25408848 PMCID: PMC4232569 DOI: 10.1016/j.csbj.2014.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/07/2014] [Accepted: 09/11/2014] [Indexed: 02/06/2023] Open
Abstract
Although much is known about the physiological responses of many environmental stresses in tolerant animals, studies evaluating the regulation of stress-induced mechanisms that regulate the transitions to and from this state are beginning to explore new and fascinating areas of molecular research. Current findings have developed a general, but refined, view of the important molecular pathways contributing to stress-survival. However, studies utilizing newly developed technologies that broadly focus on genomic and proteomic screening are beginning to identify many new targets for future study. This minireview will provide a contextual overview on the use of DNA/RNA sequencing, microRNA annotation and prediction software, protein structure and function prediction tools, as well as methods of high-throughput protein expression analysis. We will also use select examples to highlight the existing use of these technologies in stress biology research. Such tools can be used in comparative stress biology in the characterization of animal responses to environmental challenges. Although there are many areas of study left to be explored, research in comparative stress biology will always be continuing as new technologies allow the further analysis of cell function, and new paradigms in gene regulation and regulatory molecules (such as microRNAs) are continuing to be discovered. Building upon the findings of past research, while utilizing new technologies in the appropriate manner, future studies can be carried out in new and exciting areas still unexplored. Proper use of rapidly developing technologies will help to create a complete understanding of the animal stress response and survival mechanisms utilized by many diverse organisms.
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Affiliation(s)
| | - Kenneth B. Storey
- Institute of Biochemistry, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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13
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Persisting in papyrus: Size, oxidative stress, and fitness in freshwater organisms adapted to sustained hypoxia. Comp Biochem Physiol A Mol Integr Physiol 2013; 165:405-16. [DOI: 10.1016/j.cbpa.2013.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/23/2013] [Accepted: 03/26/2013] [Indexed: 01/26/2023]
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14
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15
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Storey KB, Lant B, Anozie OO, Storey JM. Metabolic mechanisms for anoxia tolerance and freezing survival in the intertidal gastropod, Littorina littorea. Comp Biochem Physiol A Mol Integr Physiol 2013; 165:448-59. [PMID: 23507570 DOI: 10.1016/j.cbpa.2013.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/07/2013] [Accepted: 03/08/2013] [Indexed: 12/20/2022]
Abstract
The gastropod mollusk, Littorina littorea L., is a common inhabitant of the intertidal zone along rocky coastlines of the north Atlantic. This species has well-developed anoxia tolerance and freeze tolerance and is extensively used as a model for exploring the biochemical adaptations that support these tolerances as well as for toxicological studies aimed at identifying effective biomarkers of aquatic pollution. This article highlights our current understanding of the molecular mechanisms involved in anaerobiosis and freezing survival of periwinkles, particularly with respect to anoxia-induced metabolic rate depression. Analysis of foot muscle and hepatopancreas metabolism includes anoxia-responsive changes in enzyme regulation, signal transduction, gene expression, post-transcriptional regulation of mRNA, control of translation, and cytoprotective strategies including chaperones and antioxidant defenses. New studies describe the regulation of glucose-6-phosphate dehydrogenase by reversible protein phosphorylation, the role of microRNAs in suppressing mRNA translation in the hypometabolic state, modulation of glutathione S-transferase isozyme patterns, and the regulation of the unfolded protein response.
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Affiliation(s)
- Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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16
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Lama JL, Bell RAV, Storey KB. Glucose-6-phosphate dehydrogenase regulation in the hepatopancreas of the anoxia-tolerant marine mollusc, Littorina littorea. PeerJ 2013; 1:e21. [PMID: 23638356 PMCID: PMC3628605 DOI: 10.7717/peerj.21] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/08/2013] [Indexed: 12/14/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH) gates flux through the pentose phosphate pathway and is key to cellular antioxidant defense due to its role in producing NADPH. Good antioxidant defenses are crucial for anoxia-tolerant organisms that experience wide variations in oxygen availability. The marine mollusc, Littorina littorea, is an intertidal snail that experiences daily bouts of anoxia/hypoxia with the tide cycle and shows multiple metabolic and enzymatic adaptations that support anaerobiosis. This study investigated the kinetic, physical and regulatory properties of G6PDH from hepatopancreas of L. littorea to determine if the enzyme is differentially regulated in response to anoxia, thereby providing altered pentose phosphate pathway functionality under oxygen stress conditions. Several kinetic properties of G6PDH differed significantly between aerobic and 24 h anoxic conditions; compared with the aerobic state, anoxic G6PDH (assayed at pH 8) showed a 38% decrease in Km G6P and enhanced inhibition by urea, whereas in pH 6 assays Km NADP and maximal activity changed significantly between the two states. The mechanism underlying anoxia-responsive changes in enzyme properties proved to be a change in the phosphorylation state of G6PDH. This was documented with immunoblotting using an anti-phosphoserine antibody, in vitro incubations that stimulated endogenous protein kinases versus protein phosphatases and significantly changed Km G6P, and phosphorylation of the enzyme with 32P-ATP. All these data indicated that the aerobic and anoxic forms of G6PDH were the high and low phosphate forms, respectively, and that phosphorylation state was modulated in response to selected endogenous protein kinases (PKA or PKG) and protein phosphatases (PP1 or PP2C). Anoxia-induced changes in the phosphorylation state of G6PDH may facilitate sustained or increased production of NADPH to enhance antioxidant defense during long term anaerobiosis and/or during the transition back to aerobic conditions when the reintroduction of oxygen causes a rapid increase in oxidative stress.
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Affiliation(s)
- Judeh L Lama
- Institute of Biochemistry and Department of Biology , Carleton University , Ottawa, Ontario , Canada K1S 5B6
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17
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Ivanina AV, Kurochkin IO, Leamy L, Sokolova IM. Effects of temperature and cadmium exposure on the mitochondria of oysters (Crassostrea virginica) exposed to hypoxia and subsequent reoxygenation. ACTA ACUST UNITED AC 2012; 215:3142-54. [PMID: 22660786 DOI: 10.1242/jeb.071357] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Intertidal bivalves are commonly exposed to multiple stressors including periodic hypoxia, temperature fluctuations and pollution, which can strongly affect energy metabolism. We used top-down control and elasticity analyses to determine the interactive effects of intermittent hypoxia, cadmium (Cd) exposure and acute temperature stress on mitochondria of the eastern oyster Crassostrea virginica. Oysters were acclimated at 20°C for 30 days in the absence or presence of 50 μg l(-1) Cd and then subjected to a long-term hypoxia (6 days at <0.5% O(2) in seawater) followed by normoxic recovery. Mitochondrial function was assessed at the acclimation temperature (20°C), or at elevated temperature (30°C) mimicking acute temperature stress in the intertidal zone. In the absence of Cd or temperature stress, mitochondria of oysters showed high resilience to transient hypoxia. In control oysters at 20°C, hypoxia/reoxygenation induced elevated flux capacity of all three studied mitochondrial subsystems (substrate oxidation, phosphorylation and proton leak) and resulted in a mild depolarization of resting mitochondria. Elevated proton conductance and enhanced capacity of phosphorylation and substrate oxidation subsystems may confer resistance to hypoxia/reoxygenation stress in oyster mitochondria by alleviating production of reactive oxygen species and maintaining high aerobic capacity and ATP synthesis rates during recovery. Exposure to environmental stressors such as Cd and elevated temperatures abolished the putative adaptive responses of the substrate oxidation and phosphorylation subsystems, and strongly enhanced proton leak in mitochondria of oysters subjected to hypoxia/reoxygenation stress. Our findings suggest that Cd exposure and acute temperature stress may lead to the loss of mitochondrial resistance to hypoxia and reoxygenation and thus potentially affect the ability of oysters to survive periodic oxygen deprivation in coastal and estuarine habitats.
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Affiliation(s)
- Anna V Ivanina
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USA
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18
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Strahl J, Brey T, Philipp EER, Thorarinsdóttir G, Fischer N, Wessels W, Abele D. Physiological responses to self-induced burrowing and metabolic rate depression in the ocean quahog Arctica islandica. ACTA ACUST UNITED AC 2012; 214:4223-33. [PMID: 22116766 DOI: 10.1242/jeb.055178] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Arctica islandica is the longest-lived non-colonial animal found so far, and reaches individual ages of 150 years in the German Bight (GB) and more than 350 years around Iceland (IC). Frequent burrowing and physiological adjustments to low tissue oxygenation in the burrowed state are proposed to lower mitochondrial reactive oxygen species (ROS) formation. We investigated burrowing patterns and shell water partial pressure of oxygen (P(O(2))) in experiments with live A. islandica. Furthermore, succinate accumulation and antioxidant defences were recorded in tissues of bivalves in the normoxic or metabolically downregulated state, as well as ROS formation in isolated gills exposed to normoxia, hypoxia and hypoxia/reoxygenation. IC bivalves burrowed more frequently and deeper in winter than in summer under in situ conditions, and both IC and GB bivalves remained burrowed for between 1 and 6 days in laboratory experiments. Shell water P(O(2)) was <5 kPa when bivalves were maintained in fully oxygenated seawater, and ventilation increased before animals entered the state of metabolic depression. Succinate did not accumulate upon spontaneous shell closure, although shell water P(O(2)) was 0 kPa for over 24 h. A ROS burst was absent in isolated gills during hypoxia/reoxygenation, and antioxidant enzyme activities were not enhanced in metabolically depressed clams compared with normally respiring clams. Postponing the onset of anaerobiosis in the burrowed state and under hypoxic exposure presumably limits the need for elevated recovery respiration upon surfacing and oxidative stress during reoxygenation.
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Affiliation(s)
- Julia Strahl
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
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19
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Melatunan S, Calosi P, Rundle SD, Moody AJ, Widdicombe S. Exposure to elevated temperature and Pco(2) reduces respiration rate and energy status in the periwinkle Littorina littorea. Physiol Biochem Zool 2011; 84:583-94. [PMID: 22030851 DOI: 10.1086/662680] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the future, marine organisms will face the challenge of coping with multiple environmental changes associated with increased levels of atmospheric Pco(2), such as ocean warming and acidification. To predict how organisms may or may not meet these challenges, an in-depth understanding of the physiological and biochemical mechanisms underpinning organismal responses to climate change is needed. Here, we investigate the effects of elevated Pco(2) and temperature on the whole-organism and cellular physiology of the periwinkle Littorina littorea. Metabolic rates (measured as respiration rates), adenylate energy nucleotide concentrations and indexes, and end-product metabolite concentrations were measured. Compared with values for control conditions, snails decreased their respiration rate by 31% in response to elevated Pco(2) and by 15% in response to a combination of increased Pco(2) and temperature. Decreased respiration rates were associated with metabolic reduction and an increase in end-product metabolites in acidified treatments, indicating an increased reliance on anaerobic metabolism. There was also an interactive effect of elevated Pco(2) and temperature on total adenylate nucleotides, which was apparently compensated for by the maintenance of adenylate energy charge via AMP deaminase activity. Our findings suggest that marine intertidal organisms are likely to exhibit complex physiological responses to future environmental drivers, with likely negative effects on growth, population dynamics, and, ultimately, ecosystem processes.
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Affiliation(s)
- Sedercor Melatunan
- Marine Biology and Ecology Research Centre, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
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20
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Biggar KK, Kornfeld SF, Storey KB. Amplification and sequencing of mature microRNAs in uncharacterized animal models using stem-loop reverse transcription-polymerase chain reaction. Anal Biochem 2011; 416:231-3. [PMID: 21651887 DOI: 10.1016/j.ab.2011.05.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 05/10/2011] [Accepted: 05/11/2011] [Indexed: 11/15/2022]
Abstract
Expression of mature microRNA (miRNA) transcripts can be easily measured in many established animal model systems but is difficult to evaluate using conventional methods in new and uncharacterized animal models. In this study, we were able to expand an existing protocol to evaluate miRNA expression in both vertebrate and invertebrate animals for which mature miRNAs remain unsequenced. This method allows the researcher to sequence reverse transcription-polymerase chain reaction products, validating miRNA-specific amplification and providing the opportunity to add to the current body of knowledge of miRNA annotation.
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Affiliation(s)
- Kyle K Biggar
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
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21
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Ivanina AV, Froelich B, Williams T, Sokolov EP, Oliver JD, Sokolova IM. Interactive effects of cadmium and hypoxia on metabolic responses and bacterial loads of eastern oysters Crassostrea virginica Gmelin. CHEMOSPHERE 2011; 82:377-389. [PMID: 20971492 DOI: 10.1016/j.chemosphere.2010.09.075] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/20/2010] [Accepted: 09/26/2010] [Indexed: 05/30/2023]
Abstract
Pollution by toxic metals including cadmium (Cd) and hypoxia are important stressors in estuaries and coastal waters which may interactively affect sessile benthic organisms, such as oysters. We studied metabolic responses to prolonged hypoxic acclimation (2 weeks at 5% O2) in control and Cd-exposed (30 d at 50 μg L(-1) Cd) oysters Crassostrea virginica, and analyzed the effects of these stressors on abundance of Vibrio spp. in oysters. Hypoxia-acclimated oysters retained normal standard metabolic rates (SMR) at 5% O2, in contrast to a decline of SMR observed during acute hypoxia. However, oysters spent more time actively ventilating in hypoxia than normoxia resulting in enhanced Cd uptake and 2.7-fold higher tissue Cd burdens in hypoxia. Cd exposure led to a significant decrease in tissue glycogen stores, increase in free glucose levels and elevated activity of glycolytic enzymes (hexokinase and aldolase) indicating a greater dependence on carbohydrate catabolism. A compensatory increase in activities of two key mitochondrial enzymes (citrate synthase and cytochrome c oxidase) was found during prolonged hypoxia in control oysters but suppressed in Cd-exposed ones. Cd exposure also resulted in a significant increase in abundance of Vibrio parahaemolyticus and Vibrio vulnificus levels during normoxia and hypoxia, respectively. Overall, Cd- and hypoxia-induced changes in metabolic profile, Cd accumulation and bacterial flora of oysters indicate that these stressors can synergistically impact energy homeostasis, performance and survival of oysters in polluted estuaries and have significant consequences for transfer of Cd and bacterial pathogens to the higher levels of the food chain.
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Affiliation(s)
- Anna V Ivanina
- Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, United States
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22
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Characterization of the major plasma protein of the eastern oyster, Crassostrea virginica, and a proposed role in host defense. Comp Biochem Physiol B Biochem Mol Biol 2011; 158:9-22. [DOI: 10.1016/j.cbpb.2010.06.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 06/18/2010] [Accepted: 06/23/2010] [Indexed: 11/17/2022]
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