The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group...The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group.This research aims to evaluate for the first time the effect of a glyphosate-based herbicide on a freshwater mussel(Unionid)using a battery of biomarkers.Themussel Elliptio complanata was exposed for 21 days to CreditR Xtreme(at 0,50,100,and 150μg/L a.i.of glyphosate).An integrated biomarker response(IBRv2)was used to visualize the overall impact of each glyphosate-based herbicide concentration on mussels’health conditions.The biomarker results showed that glyphosate(used at 100μg/L and 150μg/L)induced lipid peroxidation in the gills and digestive gland and inhibited acetylcholinesterase in the foot and gills,indicating oxidative damage and neurotoxicity.Other biomarkerswere influenced at the lowest concentration of glyphosate tested(50μg/L):lipids(decrease),triglycerides(increase)and,to a lesser extent,vitellogenin(decrease).For the latter biomarkers,the sexeswere not affected similarly,and theywere only sensitive at 50μg/L,only females showed a trend toward a decrease for vitellogenin and a decrease for lipids.Using IBRv2,we found a clear discrimination between concentrations,and the index values increased with glyphosate concentration,attesting to the deterioration in biomarker-defined mussel health when exposed to Credit® Xtreme at realistic glyphosate concentrations in agricultural rivers.This study shows that glyphosate-based herbicides can alter neurological function,induce oxidative damage,and selectively modify the E.complanata metabolism at relatively low concentrations.展开更多
A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using elect...A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using electrotopological state indices （ESI） and partial least squares （PLS） regression. The cross validated 2 Qcum and the correlation coefficient R for the model were determined to be 0.845 and 0.954, respectively. The satisfactory Q2cum and R values indicated significantly high robustness and good predictive ability for the model. The model was tested and found acceptable for the prediction of logkd （the logarithm of the deputation rate constants） by validation set. According to the model, an increase in the values of Saasc, S5＇, S4, S5 and S4＇, led to increased logkd, and a decrease in the values of Na, S2, and S6 also resulted in increased logkd. Among these descriptors, Ncl, S aasC, S5＇,, S4 and S5 made significant contributions to the value of logkd. These significant descriptors showed that the depuration of PCBs in Elliptio complanata may be mainly attributed to an equilibrium partitioning process among compartments with different lipid contents, while the reactivity of PCBs with enzymes or other molecules may play a subordinate role.展开更多
The purpose of this study was to examine the cumulative effects of exposure to a pathogenic bacteria and municipal effluent in the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentratio...The purpose of this study was to examine the cumulative effects of exposure to a pathogenic bacteria and municipal effluent in the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations of an ozone-treated effluent at 15°C for 7 days. A sub-group of mussels was inoculated with Vibrio anguillarum and exposed to the same conditions as above.After the exposure period, mussels were collected to assess hemocyte count and viability,immunocompetence（phagocytosis and nitrite production）, oxidative stress/inflammation（cyclooxygenase and lipid peroxidation） and oxygen radical/xenobiotic scavenging activity（metallothioniens, glutathione S-transferase）. The results showed that mussels exposed to municipal effluent had increased hemocyte counts, phagocytosis, nitrites, lipid peroxidation and metallothioneins. In the inoculated mussels, the same responses were observed, in addition to cyclooxygenase and glutathione S-transferase activities. Multivariate analyses revealed that（1）the response pattern changed with effluent concentration, where increased responses observed at low effluent concentrations（〉10%, V/V） were attenuated at higher effluent concentrations,（2）the effluent produced more pronounced changes in lipid peroxidation, metallothionein and hemocyte viability, and（3） the simultaneous presence of V. anguillarum led to more important changes in hemocyte count and viability and nitrite levels. In conclusion, the presence of V.anguillarum could alter the response of mussels to municipal effluent, which could lead to increased inflammation in mussels.展开更多
本文研究了云南中甸地区亚高山暗针叶林的优势树种油麦吊云杉(Picea brachytyla var. complanata)和长苞冷杉(Abies georgei)幼树(20年生)的光合特征、光合速率的变化规律及其与环境主要生态因子的关系。结果表明两种杉树光合作用的光...本文研究了云南中甸地区亚高山暗针叶林的优势树种油麦吊云杉(Picea brachytyla var. complanata)和长苞冷杉(Abies georgei)幼树(20年生)的光合特征、光合速率的变化规律及其与环境主要生态因子的关系。结果表明两种杉树光合作用的光饱和点均较低,且长苞冷杉较油麦吊云杉更喜阴,它的光合速率(3.24CO_2mgg^(-1)DWh^(-1))也比云杉的低(3.74CO_2mgg^(-1)DWh^(-1))。在试验海拔3300m地段上,云、冷杉的光合作用都存在日中压制现象,采伐迹地上的幼苗尤为突出;受温度和蒸发量的影响在一年中以7月份光合速率最高。两树种的光合速率都是随着海拔的升高而降低。森林被大面积皆伐后,迹地上云、冷杉幼树的光合速率明显下降,其中以长苞冷杉的降低幅度最大。展开更多
基金funded by Environment and Climate Change Canada(Fonds pour dommages a l’environnement)under a grant given to L.Vandelac and L.Parentthe Fondation UQAM(2020 to 2022)+2 种基金the Collectif de recherche Ecosante sur les pesticides,les politiques et les alternatives(CREPPA)the Natural Sciences and Engineering Research Council of Canada(NSERC)under a grant given to M.Boily(No.RGPIN-2016–05142)the Centre de recherche en ecotoxicologie du Quebec(EcotoQ) and the Centre interdisciplinaire de recherche en operationnalisation du developpement durable(CIRODD)for scholarships attributed to Y.Nombre.
文摘The active ingredient(a.i.)glyphosate is frequently detected in waterways at relatively high concentrations,posing a risk to aquatic organisms including freshwater mussels,North America’s most endangered animal group.This research aims to evaluate for the first time the effect of a glyphosate-based herbicide on a freshwater mussel(Unionid)using a battery of biomarkers.Themussel Elliptio complanata was exposed for 21 days to CreditR Xtreme(at 0,50,100,and 150μg/L a.i.of glyphosate).An integrated biomarker response(IBRv2)was used to visualize the overall impact of each glyphosate-based herbicide concentration on mussels’health conditions.The biomarker results showed that glyphosate(used at 100μg/L and 150μg/L)induced lipid peroxidation in the gills and digestive gland and inhibited acetylcholinesterase in the foot and gills,indicating oxidative damage and neurotoxicity.Other biomarkerswere influenced at the lowest concentration of glyphosate tested(50μg/L):lipids(decrease),triglycerides(increase)and,to a lesser extent,vitellogenin(decrease).For the latter biomarkers,the sexeswere not affected similarly,and theywere only sensitive at 50μg/L,only females showed a trend toward a decrease for vitellogenin and a decrease for lipids.Using IBRv2,we found a clear discrimination between concentrations,and the index values increased with glyphosate concentration,attesting to the deterioration in biomarker-defined mussel health when exposed to Credit® Xtreme at realistic glyphosate concentrations in agricultural rivers.This study shows that glyphosate-based herbicides can alter neurological function,induce oxidative damage,and selectively modify the E.complanata metabolism at relatively low concentrations.
基金supported by the Major State Basic Research Development Program(No. 2009CB421605)the National Natural Science Foundation of China(No.40871218)+1 种基金the Special Fund of State Key Laboratory(No.08ESPCT-Y)the Program for New Century Excellent Talents in Universities
文摘A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using electrotopological state indices （ESI） and partial least squares （PLS） regression. The cross validated 2 Qcum and the correlation coefficient R for the model were determined to be 0.845 and 0.954, respectively. The satisfactory Q2cum and R values indicated significantly high robustness and good predictive ability for the model. The model was tested and found acceptable for the prediction of logkd （the logarithm of the deputation rate constants） by validation set. According to the model, an increase in the values of Saasc, S5＇, S4, S5 and S4＇, led to increased logkd, and a decrease in the values of Na, S2, and S6 also resulted in increased logkd. Among these descriptors, Ncl, S aasC, S5＇,, S4 and S5 made significant contributions to the value of logkd. These significant descriptors showed that the depuration of PCBs in Elliptio complanata may be mainly attributed to an equilibrium partitioning process among compartments with different lipid contents, while the reactivity of PCBs with enzymes or other molecules may play a subordinate role.
基金funded by Environment Canada's St. Lawrence Action Plan
文摘The purpose of this study was to examine the cumulative effects of exposure to a pathogenic bacteria and municipal effluent in the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations of an ozone-treated effluent at 15°C for 7 days. A sub-group of mussels was inoculated with Vibrio anguillarum and exposed to the same conditions as above.After the exposure period, mussels were collected to assess hemocyte count and viability,immunocompetence（phagocytosis and nitrite production）, oxidative stress/inflammation（cyclooxygenase and lipid peroxidation） and oxygen radical/xenobiotic scavenging activity（metallothioniens, glutathione S-transferase）. The results showed that mussels exposed to municipal effluent had increased hemocyte counts, phagocytosis, nitrites, lipid peroxidation and metallothioneins. In the inoculated mussels, the same responses were observed, in addition to cyclooxygenase and glutathione S-transferase activities. Multivariate analyses revealed that（1）the response pattern changed with effluent concentration, where increased responses observed at low effluent concentrations（〉10%, V/V） were attenuated at higher effluent concentrations,（2）the effluent produced more pronounced changes in lipid peroxidation, metallothionein and hemocyte viability, and（3） the simultaneous presence of V. anguillarum led to more important changes in hemocyte count and viability and nitrite levels. In conclusion, the presence of V.anguillarum could alter the response of mussels to municipal effluent, which could lead to increased inflammation in mussels.
文摘本文研究了云南中甸地区亚高山暗针叶林的优势树种油麦吊云杉(Picea brachytyla var. complanata)和长苞冷杉(Abies georgei)幼树(20年生)的光合特征、光合速率的变化规律及其与环境主要生态因子的关系。结果表明两种杉树光合作用的光饱和点均较低,且长苞冷杉较油麦吊云杉更喜阴,它的光合速率(3.24CO_2mgg^(-1)DWh^(-1))也比云杉的低(3.74CO_2mgg^(-1)DWh^(-1))。在试验海拔3300m地段上,云、冷杉的光合作用都存在日中压制现象,采伐迹地上的幼苗尤为突出;受温度和蒸发量的影响在一年中以7月份光合速率最高。两树种的光合速率都是随着海拔的升高而降低。森林被大面积皆伐后,迹地上云、冷杉幼树的光合速率明显下降,其中以长苞冷杉的降低幅度最大。
