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1.
Multi-year investigations in northern San Francisco Bay by United States Geological Survey have linked reduced condition indices in populations of Asian clam (Potamocorbula amurensis) with elevated cadmium tissue concentrations. Our study seeks to determine whether levels of hsp70 proteins in P. amurensis can be correlated with these findings, and/or are related to histopathologic alterations and concentrations of metallothionein-like proteins. Here we present our results on stress proteins in clams collected monthly from four field stations between July 1996 and January 1998. In addition, animals were exposed in the laboratory to a range of salinities. Stress proteins were analyzed by Western blotting using monoclonal antibodies. Hsp70 protein levels in field-collected clams were significantly higher at the seaward (high salinity/low cadmium) stations (12.5, 8.1) than at the landward (low salinity/high cadmium) stations (6.1, 4.1). Laboratory studies showed that clams exposed to 0.1 ppt salinity had markedly lower hsp70 levels than clams exposed to higher salinities. In view of our previous laboratory studies showing that cadmium induces hsp70 in P. amurensis, our present results indicate that reduced hsp70 protein levels in field-collected clams may be linked to salinity effects rather than cadmium tissue concentrations.  相似文献   

2.
Short-term variability in biomarker responses and the effects of temperature and salinity variation were explored in three fish species (Dicentrarchus labrax, Solea senegalensis and Pomatoschistus microps) occurring in the Tejo estuary. Short-term variability in biomarkers was observed in all species although no pattern was discerned over time (days to weeks). Antioxidant enzymes activity (superoxide dismutase (SOD) and catalase (CAT)) showed low temporal variability, indicating some constancy or baseline level in antioxidant responses. Only CAT activity in S.?senegalensis was correlated with temperature, suggesting that exposure to contaminants triggered antioxidant acclimation. Higher short-term variability was observed in xenobiotic biotransformation enzymes activity (phase I ethoxyresorufin O-deethylase (EROD) and phase II glutathione S-transferase (GST)). Yet a significant correlation between EROD and GST in D.?labrax and S.?senegalensis suggests a concomitant response to contaminants. Moreover the lack of correlation between xenobiotic biotransformation enzymes and abiotic variables on concordant time scales, suggest a high specificity of these biomarkers to chemical exposure, rather than high variability due to environmental dynamics.  相似文献   

3.
The influence of capture stress, salinity and reproductive status on zinc associated with the metallothionein-like (MT-like) proteins in the livers of three marine teleost species was investigated. In striped mullet, Mugil cephalus L., the zinc associated with the MT-like protein, as determined by gel-permeation HPLC, increased significantly from approximately 102 to 1162 nmol zinc bound/g wet wt 7 days following capture in the field, handling, transportation to the laboratory and transfer to holding tanks. Significant increases were also observed following exposure to reduced salinity for 7 days. Smaller increases were observed in cultured red drum, Sciaenops ocellatus, livers following exposure to reduced salinity and physical trauma for 7 days. Finally, there was approximately a 2·5-fold increase in the zinc associated with the MT-like protein in livers of female spotted seatrout, Cynoscion nebulosus, collected during the reproductive season compared to regressed animals. These findings emphasize the need for establishing the natural fluctuations in MT levels as well as the response to common physical environmental variables before measurement of MT can be used reliably as a biochemical indicator of environmental contamination.  相似文献   

4.
盐度骤变对仿刺参hsp70及hsp90基因表达的影响   总被引：2，自引：0，他引：2  
为研究夏季暴雨导致的养殖池塘盐度变化对仿刺参(Apostichopus japonicus)生理的影响,在实验室内模拟野外盐度变化,采用半定量RT-PCR的方法研究了其hsp70、hsp90a及hsp90b基因的表达。实验中,盐度先以每6h降2.5的速度由30降至20;保持96h后,再以同样的速度由20升至30,随后在盐度为30条件下保持96h。在盐度变化过程中随机取样。hsp70和hsp90b基因在盐度降至20后表达量开始显著升高(P<0.05),hsp90a基因在盐度降至22.5时表达量开始显著升高(P<0.05);但保持在盐度为20条件下,3个基因的表达量均逐渐降低至初始值。在之后的盐度升高及恢复阶段,3个基因表达量均有先升高后降低的趋势,表明hsp70、hsp90a和hsp90b基因是仿刺参在盐度胁迫下的重要响应因子。  相似文献   

5.
Mixing of freshwater and seawater creates the well-known salinity gradients along the estuaries. In order to investigate how phytoplankton respond to the acute salinity changes, we exposed natural phytoplankton assemblies from the Jiulong River Estuary to differential saline field water while continuously monitoring their photosynthetic performances under both indoor-and outdoor-growth conditions. When the natural cell assemblies from salinity 30 field water were exposed to series low saline field water(salinity 25, 17, 13 and 7.5), the effective Photosystem II quantum yield(ΔF/F_m′) decreased sharply, e.g., to one-fifth of its initials after 5 min exposure to salinity 7.5 field water, and then increased fast during the following 40 min and almost completely recovered after 320 min. During such an exposure process, non-photochemical quenching(NPQ) sharply increased from 0 to 0.85 within 5 min, and then decreased to nearly 0 within the following 70 min. When these cells re-acclimated to salinity 7.5 field water were exposed to series high saline field water(salinity 13, 17, 25 and 30), a similar response pattern was observed, with the decreased ΔF/F_m′ accompanied with increased NPQ, and followed by the recovery-induced increase in ΔF/F_m′ and decrease in NPQ. A similar response pattern as ΔF/F_m′to the acute osmotic stress was also observed in the photosynthetic carbon fixation capacity according to radiocarbon(~(14)C) incorporation. Our results indicate that estuarine phytoplankton assemblies could rapidly recover from the acute osmotic stress, implying a potential cause for their frequent blooms in coastal-estuarine waters where despite drastically varying salinity, available nutrients are abundant due to the land-derived runoffs or mixing-caused relaxations from sediments.  相似文献   

6.
The US Geological Survey has reported the presence of a metal contamination gradient in clam tissues, decreased condition indices, and irregular reproductive patterns have been reported in the Asian clam, Potamocorbula amurensis, from San Francisco Bay. If metals are driving the observed patterns in the field, then biomarkers of exposure, and possibly deleterious effect, should show a corresponding gradient. In this study, biomarkers from sub-cellular to tissue levels of biological organization were assessed in P. amurensis collected from the Bay or exposed to cadmium in the laboratory. Cellular and tissue alterations were assessed using histopathology and enzyme histochemistry (EH). Alterations in the ovary, testis, kidney, and gill tissues were most common at the most contaminated station when data were averaged over a 12-month sampling period. EH analysis indicated decreased active transport, energy status, and glucose oxidation in kidney and digestive gland at the most contaminated site which may indicate a decreased potential for growth. Ovarian lesions observed in feral Asian clams were experimentally induced in healthy clams by cadmium exposure in laboratory exposures. Our results suggest a contaminant etiology for tissue alterations.  相似文献   

7.
Organisms have evolved a highly conserved cellular response called the heat-shock or stress proteins response (SPR) that increases their tolerance to adverse environmental conditions. We have tested the hypothesis that the tissues of two molluscs, Mytilus edulis and Collisella pelta, respond to stressful situations by eliciting this response. We found that both heat-shock and Cd can induce the SPR in both species and are presently carrying out experiments to correlate the induction of stress proteins with an increased capacity to tolerate subsequent stressful conditions. These experiments should help us determine if the SPR plays an important role in the physiological adaptation of these species to their environment.  相似文献   

8.
The use of biomarkers such as cytochrome P4501A (CYP1A) or metallothionein (MT) for pollution monitoring is based on the assumption that an increased activity or concentration is primarily caused by exposure to contaminants. Previous studies have shown that the response of biomarkers may be affected by factors such as season, temperature, gender, nutritional status or size. The objective of the present study was to identify natural factors that affect the hepatic activity of CYP1A and hepatic concentration of MT in flounder (Platichthys flesus L.). Thirty flounder were sampled at each of two sites in the Hvaler archipelago, southern Norway, monthly through one year. A set of variables were recorded for each sampling and individual including water temperature, salinity, external and internal lesions, intestinal content, sex, size and organ weights. Hepatic CYP1A activity (EROD), MT and metal concentrations were determined for each individual flounder. The influence of environmental and endogenous factors on the response of these two biomarkers was assessed in multiple regression models. For both biomarkers, 50–60% of the total variability could be explained from factors directly related to season, gender and maturation. Season contributed significantly in the model for EROD, as did external lesions. Size, condition and diet did not contribute greatly when the above factors were included. The results confirm previous findings that season, gender and maturation must be taken into account in biomarker monitoring, but also indicate that other factors such as external lesions should be considered.  相似文献   

9.
The Baltic Sea is a semi-enclosed sea with a steady salinity gradient (3‰–30‰). Organisms have adapted to such low salinities, but are suspected to be more susceptible to stress. Within the frame of the integrated environmental monitoring BONUS + project “BEAST” the applicability of immune responses of the blue mussel was investigated in Danish coastal waters. The sampling sites were characterised by a salinity range (11–19‰) and different mixtures of contaminants (metals, PAHs and POPs), according to chemical analysis of mussel tissues. Variation partitioning (redundancy analysis) was applied to decompose salinity and contamination effects. The results indicated that cellular immune responses (total and differential haemocyte count, phagocytic activity and apoptosis) were mainly influenced by contaminants, whereas humoral factors (haemolytic activity) were mainly impacted by salinity. Hence, cellular immune functions may be suitable as biomarkers in monitoring programmes for the Baltic Sea and other geographic regions with salinity variances of the studied range.  相似文献   

10.
In the present study, heat-shock protein of M(r) 70 kDa (HSP70), a marker of cellular stress response, was validated as a potential biomarker under field conditions. The dab, Limanda limanda (female, size > or = 25 cm, spawning maturity stage 2) was used as the indicator organism. The data on HSP level were correlated with the occurrence of DNA damage, measured in the same specimens of L. limanda, to prove the usefulness of the method. The area under investigation was the North Sea. Four locations were selected: station N01, close to Heligoland, in the North Sea; station N04 at the Dogger Bank; station N06 at the Firth of Forth; and station G08 in the English Channel. Ten animals from each location were selected and their livers used for the experiments. The results show that the highest levels of HSP70 (consisting of two forms of M(r) 75 and 73 kDa) were in fish from station N04, while low values were measured in livers from L. limanda collected at station N01. Intermediate levels were seen in the animals from the two other locations. By application of a novel technique, it was found that the extent of DNA damage (single-strand breaks and alkaline labile sites) in fish liver parallels the levels of both HSP70 forms. Our results suggest that L. limanda may be a useful bioindicator and heat-shock proteins, a useful biomarker for monitoring of environmental pollution.  相似文献   

11.
Osmotic stress represents a limiting physical parameter for marine organisms and especially for sessile scleractinian corals which are known to be basically stenohaline and osmoconformers. The salinity changes may cause important cellular damage since corals lack any developed physiological regulatory system. One mechanism of reaction to deleterious conditions is the rapid increase of the induction of heat shock proteins. This study highlights the modulation of the expression of a mitochondrial heat shock protein, such as the chaperonin Hsp60, in the animal tissues of the scleractinian coral Seriatopora caliendrum under three salinity scenarios (hypersalinity of 45 ppt, hyposalinity of 25 ppt and extreme hyposalinity of 15 ppt). The study was performed during the time course of a 2-day period and accompanied also by the assessment of the coral health condition. For each salinity stress S. caliendrum responds differently at the morphological and cellular levels, since the Hsp60 exhibited specific patterns of expression and the coral showed different tissue appearance. Furthermore, the response reflects the severity and exposure length of the disturbance. However, the results indicate that S. caliendrum seems able to tolerates high salinity better than low salinity. In particular, in extreme hyposalinity conditions, a considerable gradual down-regulation of Hsp60 was detected accompanied by necrosis and degradation of the coral tissues. The study suggests that Hsp60 may be involved in the mechanisms of cellular response to stress caused by exposure to adverse salinity.  相似文献   

12.
Normal operation of oil well platforms results in the discharge of produced formation water (PFW). The expression of CYP1A, CYP2M1- and 2K1-like proteins was examined for use as possible biomarkers of PFW exposure. A pilot study on the Northwest Shelf of Australia had indicated that PFW contamination possibly contributes to induction of CYP1A-like proteins in Gold-Spotted Trevally (Carangoides fulvoguttatus). The pilot study samples were re-examined for CYP1A, and, in addition, CYP2K1/2M1-like proteins. In a subsequent caged fish study in the same location a second species, Stripey seaperch (Lutjanus carponotatus), caught at a clean site, were distributed to three caging sites in a PFW gradient from the Harriet A production platform: A (near-field), B (far-field) and C (a non-impacted reference site). Fish were sampled at time (T) T = 0, T = 3 and T = 10 days. Significant increases of CYP1A, one CYP2K1- and two CYP2M1-like proteins were noted at Site A at T = 10d. For another CYP2K1-like protein, a significant increase was observed at Site A only at T = 3d. These results support a previous study indicating that CYP1A protein is sensitive to PFW exposure. Importantly, statistically significant environmental induction of both CYP2M1- and CYP2K1-like proteins in tropical fish due to PFW exposure had not previously been described and induction of enzymes in the CYP2 family suggest new biomarkers for PFW. In addition, the novel response of one CYP2K-like protein requires further verification, but offers promise for improved monitoring of sub-lethal responses in marine organisms.  相似文献   

13.
Viviparous blenny (Zoarces viviparous) were exposed to chrysene and held in natural brackish water as well as in two different synthetic brackish waters, all with a salinity of 6.8%. After 10 weeks of exposure a number of different biomarkers was analysed. The result indicated increased ethoxyresorufin-O-deethylase activity and the formation of two different DNA adduct spots in the liver tissue, as a result of the chrysene exposure. Very similar results of the chrysene exposure were obtained in blenny held in the two synthetic brackish waters. No influence of the synthetically made waters compared to the natural brackish water could be observed on the biomarkers investigated in the study.  相似文献   

14.
The need to develop powerful tools to detect exposure and effects of POPs and emerging contaminants in Mediterranean cetaceans led us to develop a suite of sensitive non-lethal biomarkers in integument biopsies of free-ranging animals. In order to propose induction of CYP1A1 and CYP2B, detected by Western blot analysis, as biomarkers of exposure to OCs, PAHs and PBDEs, a three-phase experimental protocol (in vitro experiments, calibration experiments and field applications) was followed using fibroblast cell cultures and biopsies of Mediterranean Stenella coeruleoalba and Tursiops truncatus. This methodology was confirmed to be sensitive and stable in comparison to previous methods used to detect CYP1A1 in biopsies, enabling analysis of several inducible proteins in non-lethal samples and analysis of material from stranded animals.  相似文献   

15.
Juvenile mud crabs Rhithropanopeus harrisii were exposed for five days to Halowax 1099, a polychlorinated naphthalene (approximately 1:1 ratio of tri- and tetrachlorinated isomers). Exposure concentrations were 0, 20, 50 or 100 μg/litre. The exposure salinity was 15%. At the end of the exposure period, respiratory rates of the crabs were determined at 15% S. The respiratory rates were also determined for control and exposed animals which were osmotically shocked by a move from 15% S to either 5 or 25% S immediately before respirometry. Exposure to PCNs always caused the mean respiratory rates of juvenile crabs to increase over control values. The respiratory response of crabs to PCN exposure was similar at the steady-state salinity (15% S) and after hyperosmotic shock (25% S). However, the mean rate for animals exposed to PCNs and given a hyposmotic shock was significantly higher than that for controls and for PCN-exposed animals at the other two salinities. Since hyperosmotic regulation of body fluids is most active at low salinities in this species, we suggest that the PCNs interfere with hyperosmotic regulation and reduce the efficiency of metabolic compensation for hyposmotic shock. The higher energetic cost of acclimation to transient reductions in salinity would be potentially detrimental to wild populations in impacted areas.  相似文献   

16.
Applied to environmental toxicology, proteome analysis may be used to isolate chemical-specific protein expression signatures (PES). In this project specific PES were isolated in mussels, Mytilus edulis, from the Baltic Sea subjected in the laboratory to treatment with copper (70 ppb), Aroclor 1248 (1 ppb), and to lowered salinity. Four mussels in each treatment group were acclimated in the laboratory for 24 h before beginning the 7-day exposure. Whole body tissue was homogenized and separated using two-dimensional gel electrophoresis. The protein gels were scanned to TIFF files and compared using MELANIE II 2D gel analysis software (BioRad). Protein expression signatures including proteins induced and repressed by exposure were isolated for each treatment group. The specificity of PES due to environmental changes shows promise in bioindication, toxicity testing and in helping identify possible toxicity mechanisms.  相似文献   

17.
Biomarkers are a common tool in the assessment of potential effects of contaminants in aquatic organisms. In order to identify the effects of anthropogenic pollution it is essential to identify background levels and to know the range of natural variability in the biomarker response. In this study, we examined various biomarkers of stress (glutathione S-transferase and metallothionein), damage (lipid peroxidation (LPO) and DNA damage (DNA)) and reproduction (vitellin-like proteins) in marine mussels (Mytilus spp.) from four locations along a vertical transect from high to low shore and compared them with cultivated long line mussels. High shore and cultivated mussels showed significantly higher LPO and DNA damage expression than the low shore mussels indicating a level of oxidative stress resulting from mussel location. Significant effects in physiological endpoints were also found. This study highlights the need to consider the diversity of natural environmental stress factors when using biomarkers in environmental assessment.  相似文献   

18.
In coastal marshes, fish larvae may be exposed simultaneously to extreme salinities and to atrazine, a widely used herbicide. To assess the effects of salinity on the toxicity of atrazine, newly-hatched mummichog (Fundulus heteroclitus) were exposed to atrazine (0, 5, 50 and 500 microg/L) at three salinities (3, 15 and 35PSU). Whole body cortisol was measured after 24 h. Body length, condition factor, whole body proteins, lipids, residual masses and water contents were assessed after 96 h. Significants effects were found for both condition factor and water content. Condition factors were lower at salinity 3 and 35 compared to near isoosmotic salinity, 15PSU. In addition, atrazine decreased condition factor at 500 microg/L. Reduction in condition was likely due to retardation in axial growth since body length, percentages of proteins or lipids were not affected. In the absence of atrazine, salinity had no effect on the prevalence of dehydrated (81% water) or hyperhydrated (85% water) larvae. In larvae exposed to atrazine, the prevalence of hyperhydrated larvae increased at 3PSU and 5 microg/L atrazine and that of dehydrated larvae increased at 15 and 35PSU and 5 microg/L atrazine. Severity of dehydratation increased with atrazine concentration at salinity 35PSU. Thus, a short-term exposure to environmentally realistic concentrations of atrazine affects osmotic control in mummichog larvae with possible effects on buoyancy, survival and recruitment.  相似文献   

19.
A field experiment was carried out to test the effect of pore water salinity on the macrobenthic assemblages in an estuarine region of the Tagus estuary (Portugal) subjected to wide fluctuations in salinity. The conditions at the experimental site ranged from freshwater (minimum salinity 0.2) to mesohaline (maximum salinity 15.3). The experimental site was affected by an unexpected deposition of fluid mud during summer. Redundancy Analysis discriminated the experimental treatments along the first canonical ordination axis. The analysis also revealed an experimental gradient of increasing environmental stress, in which the minimal presence of organisms corresponded to treatments representing a high level of environmental stress. Sediment dynamics and saline fluctuations were the major factors that, together, determined the low macrofaunal abundance and species diversity at the experimental site. The most abundant macrofaunal species in this harsh environment were the polychaetes Hediste diversicolor and Streblospio shrubsolii.  相似文献   

20.
文章依据相关国家标准,结合海洋环境监测站的实际工作需求,针对环境自动观测系统的盐度传感器,提出新的现场校准方法,即直接比较法;根据不确定度来源,分别计算由测量重复性、盐度标准器、测量环境、测量人员和恒温水槽引入的不确定度分量并合成标准不确定度,据此计算扩展不确定度和合成标准不确定度的有效自由度,由此得出盐度传感器现场校准测量结果的不确定度为0.17。本研究提出的盐度传感器现场校准方法更契合海水盐度的变化规律,可实现盐度分量的量值溯源,具有准确度高和溯源途径清晰的特点;不确定度评定方法科学合理,且具有一定的推广价值。  相似文献   

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