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Lydy VR, Regn OZ, Bouldin JL. Toxicant Responses and Culturing Characteristics of Long-Term Laboratory-Reared and Field Populations of Ceriodaphnia dubia. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:159-169. [PMID: 37861383 DOI: 10.1002/etc.5772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/26/2023] [Accepted: 10/17/2023] [Indexed: 10/21/2023]
Abstract
Ceriodaphnia dubia is a standardized test organism for regulatory toxicity testing of surface waters and commercial chemicals because of its simplicity to culture and responsiveness to toxicants. For testing convenience, C. dubia is often cultured for extended periods in the laboratory with little knowledge of the impact on subsequent generations. Extended laboratory rearing could impact how they respond to stressors and decrease the accuracy of test results. The present study investigated if C. dubia cultured for an extended period were representative of three recently collected field populations by comparing their culturing characteristics and sensitivities to toxicants. For culturing characteristics, the field cultures were more challenging because they had shorter body lengths, fewer neonates, and higher mortality rates than the laboratory culture. Comparative chronic toxicity tests with sodium chloride and the neonicotinoid insecticide thiamethoxam indicated that the laboratory and field organisms did not differ much in their toxicological responses but did differ in the variability of responses (percentage of coefficient of variation). The differences between the laboratory and field cultures found in the present study highlight the challenges of addressing discrepancies between laboratory and field applications in existing standardized methodologies. Environ Toxicol Chem 2024;43:159-169. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Victoria R Lydy
- Ecotoxicology Research Facility, Arkansas State University, Jonesboro, Arkansas, USA
| | - Orithea Z Regn
- Ecotoxicology Research Facility, Arkansas State University, Jonesboro, Arkansas, USA
| | - Jennifer L Bouldin
- Ecotoxicology Research Facility, Arkansas State University, Jonesboro, Arkansas, USA
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2
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Schür C, Beck J, Lambert S, Scherer C, Oehlmann J, Wagner M. Effects of microplastics mixed with natural particles on Daphnia magna populations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166521. [PMID: 37640069 DOI: 10.1016/j.scitotenv.2023.166521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023]
Abstract
The toxicity of microplastics on Daphnia magna as a key model for freshwater zooplankton is well described. While several studies predict population-level effects based on short-term, individual-level responses, only very few have validated these predictions experimentally. Thus, we exposed D. magna populations to irregular polystyrene microplastics and diatomite as natural particle (both ≤63 μm) over 50 days. We used mixtures of both particle types at fixed particle concentrations (50,000 particles mL-1) and recorded the effects on overall population size and structure, the size of the individual animals, and resting egg production. Particle exposure adversely affected the population size and structure and induced resting egg production. The terminal population size was 28-42 % lower in exposed compared to control populations. Interestingly, mixtures containing diatomite induced stronger effects than microplastics alone, highlighting that natural particles are not per se less toxic than microplastics. Our results demonstrate that an exposure to synthetic and natural particles has negative population-level effects on zooplankton. Understanding the mixture toxicity of microplastics and natural particles is important given that aquatic organisms will experience exposure to both. Just as for chemical pollutants, better knowledge of such joint effects is essential to fully understand the environmental impacts of complex particle mixtures. ENVIRONMENTAL IMPLICATIONS: While microplastics are commonly considered hazardous based on individual-level effects, there is a dearth of information on how they affect populations. Since the latter is key for understanding the environmental impacts of microplastics, we investigated how particle exposures affect the population size and structure of Daphnia magna. In addition, we used mixtures of microplastics and natural particles because neither occurs alone in nature and joint effects can be expected in an environmentally realistic scenario. We show that such mixtures adversely affect daphnid populations and highlight that population-level and mixture-toxicity designs are one important step towards more environmental realism in microplastics research.
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Affiliation(s)
- Christoph Schür
- Department of Environmental Toxicology, Eawag, Überlandstrasse 133, 8600 Dübendorf, Switzerland; Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany
| | - Joana Beck
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany
| | - Scott Lambert
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany
| | - Christian Scherer
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany; Federal Institute of Hydrology, Department Biochemistry and Ecotoxicology, Am Mainzer Tor 1, 56002, Koblenz, Germany
| | - Jörg Oehlmann
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany
| | - Martin Wagner
- Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway.
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3
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Pouil S, Stevenson LM, Goñez-Rodríguez L, Mathews TJ. Stannous chloride as a tool for mercury stripping in contaminated streams: Experimental assessment of toxicity in an invertebrate model species. CHEMOSPHERE 2022; 296:133762. [PMID: 35093417 DOI: 10.1016/j.chemosphere.2022.133762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/05/2022] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
The chronic toxicity of an innovative Hg water treatment system using tin (Sn) (II) chloride (SnCl2) followed by air stripping was assessed through measurements of survival, growth, and reproduction rate in the freshwater cladoceran Ceriodaphnia dubia, a model species for toxicity testing. We first calculated the concentrations of Hg causing 25% reduction in survival and reproduction (Lethal or Inhibition Concentrations, or LC25 and IC25, for survival and reproduction, respectively) through exposure to aqueous Hg at concentrations ranging from 0 to 25,000 ng L-1. Then, we treated media (DMW and natural stream water) contaminated with Hg at LC25 and IC25 concentrations with SnCl2 at a Sn:Hg stoichiometric ratio of 8:1 and air stripping and exposed C. dubia to this Sn-amended media. Our results showed that Hg significantly affected survival, reproduction rates and impaired growth. SnCl2-treatment removed 100% of the Hg from the media at all concentrations tested with no deleterious effects on survival, growth and reproduction. Our results confirmed the efficacy of SnCl2 in removing aqueous Hg from stream water and showed that the added Sn did not impact C. dubia at the concentrations tested, supporting the suitability of SnCl2-based treatments in appropriate Hg-contaminated environments.
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Affiliation(s)
- Simon Pouil
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Louise M Stevenson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Leroy Goñez-Rodríguez
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Teresa J Mathews
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
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4
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Maggio SA, Janney PK, Jenkins JJ. Neurotoxicity of chlorpyrifos and chlorpyrifos-oxon to Daphnia magna. CHEMOSPHERE 2021; 276:130120. [PMID: 33706179 DOI: 10.1016/j.chemosphere.2021.130120] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/08/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Chlorpyrifos (CPF) is a widely used broad-spectrum organophosphate insecticide. CPF elicits neurotoxic effects in exposed organisms by inhibiting the activity of acetylcholinesterase enzymes (AChE), which prolongs nerve transmission and results in neurotoxic symptoms and death at high doses. While CPF is capable of eliciting neurotoxic effects, chlorpyrifos-oxon (CPFO) is the primary neurotoxicant agent. Aquatic organisms bioactivate CPF to CPFO through the Cytochrome P450 phase I metabolic pathway following exposure to CPF. Additionally, in the environment, CPF transforms to CPFO, primarily through photo-oxidation. As both compounds can be transported in air and water to aquatic ecosystems, there is the potential for exposure to non-target organisms. The potential for adverse impacts on aquatic receptors depends on patterns of exposure and toxicity of individual compounds and the mixture. To study the neurotoxicity of these compounds, a 48 h acute and 21 d chronic Daphnia magna bioassay was conducted independently with CPF and CPFO. Acute bioassay results show a median lethal concentration (LC50) of 0.76 μg L-1 for CPF and 0.32 μg L-1 for CPFO, suggesting that CPFO is 2.4 times more acutely toxic to D. magna. Acute assay results were also used to derive Benchmark Dose Levels of 0.58 μg L-1 for CPF and 0.25 μg L-1 for CPFO. However, neither compound elicited an effect on reproduction or growth at relevant chronic exposures. As D. magna are a small and relatively sensitive species, and the AChE inhibition adverse outcome pathway is highly conserved, these results may be cautiously extrapolated in assessing adverse impacts on aquatic receptors.1.
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Poulsen R, De Fine Licht HH, Hansen M, Cedergreen N. Grandmother's pesticide exposure revealed bi-generational effects in Daphnia magna. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 236:105861. [PMID: 34049113 DOI: 10.1016/j.aquatox.2021.105861] [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: 01/01/2021] [Revised: 05/02/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Man-made chemicals are a significant contributor to the ongoing deterioration of numerous ecosystems. Currently, risk assessment of these chemicals is based on observations in a single generation of animals, despite potential adverse intergenerational effects. Here, we investigate the effect of the fungicide prochloraz across three generations of Daphnia magna. We studied both the effects of continuous exposure over all generations and the effects of first-generation (F0) exposure on two subsequent generations. Effects at different levels of biological organization from genome-wide gene expression, whole organism metabolite levels, CYP enzyme activity and key phenotypic effects, such as reproduction, were monitored. Acclimation to prochloraz was found after continuous exposure. Following F0-exposure, embryonically exposed F1-offspring showed no significant effects. However, in the potentially germline exposed F2 animals, several parameters differed significantly from controls. A direct association between these F2 effects and the toxic mode of action of prochloraz was found, showing that chemicals can be harmful not only to the directly exposed generation, but also to prenatally exposed generations and in that way effects may even appear to skip a generation. This implies that current risk assessment practices are neglecting an important aspect of toxicity, such as delayed effects across generations due to a time gap between chemical exposure and emergence of effects.
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Affiliation(s)
- Rikke Poulsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark; Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
| | - Henrik H De Fine Licht
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Martin Hansen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Nina Cedergreen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
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6
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Laursen SF, Hansen LS, Bahrndorff S, Nielsen HM, Noer NK, Renault D, Sahana G, Sørensen JG, Kristensen TN. Contrasting Manual and Automated Assessment of Thermal Stress Responses and Larval Body Size in Black Soldier Flies and Houseflies. INSECTS 2021; 12:380. [PMID: 33922364 PMCID: PMC8146041 DOI: 10.3390/insects12050380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 11/16/2022]
Abstract
Within ecophysiological and genetic studies on insects, morphological and physiological traits are commonly assessed and phenotypes are typically obtained from manual measurements on numerous individuals. Manual observations are, however, time consuming, can introduce observer bias and are prone to human error. Here, we contrast results obtained from manual assessment of larval size and thermal tolerance traits in black soldier flies (Hermetia illucens) and houseflies (Musca domestica) that have been acclimated under three different temperature regimes with those obtained automatically using an image analysis software (Noldus EthoVision XT). We found that (i) larval size estimates of both species, obtained by manual weighing or by using the software, were highly correlated, (ii) measures of heat and cold tolerance using manual and automated approaches provided qualitatively similar results, and (iii) by using the software we obtained quantifiable information on stress responses and acclimation effects of potentially higher ecological relevance than the endpoint traits that are typically assessed when manual assessments are used. Based on these findings, we argue that automated assessment of insect stress responses and largescale phenotyping of morphological traits such as size will provide new opportunities within many disciplines where accurate and largescale phenotyping of insects is required.
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Affiliation(s)
- Stine Frey Laursen
- Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark; (S.B.); (N.K.N.); (T.N.K.)
| | - Laura Skrubbeltrang Hansen
- Center for Quantitative Genetics and Genomics, Faculty of Technical Sciences, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (L.S.H.); (H.M.N.); (G.S.)
| | - Simon Bahrndorff
- Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark; (S.B.); (N.K.N.); (T.N.K.)
| | - Hanne Marie Nielsen
- Center for Quantitative Genetics and Genomics, Faculty of Technical Sciences, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (L.S.H.); (H.M.N.); (G.S.)
| | - Natasja Krog Noer
- Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark; (S.B.); (N.K.N.); (T.N.K.)
| | - David Renault
- University of Rennes, CNRS, ECOBIO (Ecosystémes, Biodiversité, Evolution)-UMR, 6553 Rennes, France;
- Institut Universitaire de France, 1 Rue Descartes, CEDEX 05, 75231 Paris, France
| | - Goutam Sahana
- Center for Quantitative Genetics and Genomics, Faculty of Technical Sciences, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (L.S.H.); (H.M.N.); (G.S.)
| | - Jesper Givskov Sørensen
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark;
| | - Torsten Nygaard Kristensen
- Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark; (S.B.); (N.K.N.); (T.N.K.)
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
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7
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DNMT3.1 controls trade-offs between growth, reproduction, and life span under starved conditions in Daphnia magna. Sci Rep 2021; 11:7326. [PMID: 33795753 PMCID: PMC8016896 DOI: 10.1038/s41598-021-86578-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/25/2021] [Indexed: 02/01/2023] Open
Abstract
The cladoceran crustacean Daphnia has long been a model of energy allocation studies due to its important position in the trophic cascade of freshwater ecosystems. However, the loci for controlling energy allocation between life history traits still remain unknown. Here, we report CRISPR/Cas-mediated target mutagenesis of DNA methyltransferase 3.1 (DNMT3.1) that is upregulated in response to caloric restriction in Daphnia magna. The resulting biallelic mutant is viable and did not show any change in growth rate, reproduction, and longevity under nutrient rich conditions. In contrast, under starved conditions, the growth rate of this DNMT3.1 mutant was increased but its reproduction was reciprocally reduced compared to the wild type when the growth and reproduction activities competed during a period from instar 4 to 8. The life span of this mutant was significantly shorter than that of the wild type. We also compared transcriptomes between DNMT3.1 mutant and wild type under nutrient-rich and starved conditions. Consistent with the DNMT3.1 mutant phenotypes, the starved condition led to changes in the transcriptomes of the mutant including differential expression of vitellogenin genes. In addition, we found upregulation of the I am not dead yet (INDY) ortholog, which has been known to shorten the life span in Drosophila, explaining the shorter life span of the DNMT3.1 mutant. These results establish DNMT3.1 as a key regulator for life span and energy allocation between growth and reproduction during caloric restriction. Our findings reveal how energy allocation is implemented by selective expression of a DNMT3 ortholog that is widely distributed among animals. We also infer a previously unidentified adaptation of Daphnia that invests more energy for reproduction than growth under starved conditions.
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8
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Nguyen ND, Matsuura T, Kato Y, Watanabe H. Caloric restriction upregulates the expression ofDNMT3.1, lacking the conserved catalytic domain, inDaphnia magna. Genesis 2020; 58:e23396. [DOI: 10.1002/dvg.23396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Nhan Duc Nguyen
- Department of Biotechnology, Graduate School of Engineering Osaka University Osaka Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering Osaka University Osaka Japan
| | - Yasuhiko Kato
- Department of Biotechnology, Graduate School of Engineering Osaka University Osaka Japan
- Frontier Research Base for Global Young Researchers, Graduate School of Engineering Osaka University Osaka Japan
| | - Hajime Watanabe
- Department of Biotechnology, Graduate School of Engineering Osaka University Osaka Japan
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9
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Sherborne N, Galic N. Modeling Sublethal Effects of Chemicals: Application of a Simplified Dynamic Energy Budget Model to Standard Ecotoxicity Data. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7420-7429. [PMID: 32364711 DOI: 10.1021/acs.est.0c00140] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To assess ecological risks from chemical exposure, we need tools to extrapolate from the sublethal effects observed in the laboratory under constant exposure to realistic time-varying exposures. Dynamic energy budget (DEB) theory offers a mechanistic modeling approach to describe the entire life history of a single organism and the effects of toxicant exposure. We use a simplified model, which can be wholly calibrated from standard chronic bioassay data. Case studies on standard test organisms (Americamysis bahia and Pimephales promelas) are presented to demonstrate the calibration procedure, and for the second case, data are available to pseudovalidate model performance. We use these results to highlight gaps and shortcomings in the current state of the science, and we discuss how these can be overcome to maximize the potential of DEB theory in ecological risk assessment.
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Affiliation(s)
- Neil Sherborne
- Jealott's Hill International Research Centre, Syngenta, Bracknell, Berkshire RG42 6EY, U.K
| | - Nika Galic
- Syngenta Crop Protection, LLC, Greensboro, North Carolina 27419, United States
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10
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Gergs A, Rakel KJ, Liesy D, Zenker A, Classen S. Mechanistic Effect Modeling Approach for the Extrapolation of Species Sensitivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9818-9825. [PMID: 31356070 DOI: 10.1021/acs.est.9b01690] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In the higher-tier environmental risk assessment of chemicals, species sensitivity distributions (SSDs) are used to statistically describe differences in sensitivity between species and derive community level endpoints. SSDs are usually based on the results from short-term laboratory experiments performed under constant environmental conditions. However, different species may be kept at different "optimal" temperatures, which influence their apparent sensitivity and thus the derivation of endpoints. Also, the extrapolation capacity of SSDs is largely limited to the tested species and conditions. Time-variable exposures and effects at higher levels of biological organization, including biological interactions, are not considered. The quantitative effect prediction at higher tiers would ultimately require the extrapolation of toxicokinetics and toxicodynamics to untested species and the involvement of population and community modeling. In this regard, we tested a toxicokinetic-toxicodynamic modeling approach to mechanistically consider and correct endpoints for ambient temperature and demonstrate the significance for SSDs. We explored correlations in toxicokinetic-toxicodynamic model parameters which would allow for the extrapolation of sensitivities to untested species. Finally, we illustrate the applicability of the approach for higher level effect predictions using an individual-based model. Our results suggest that mechanistic effect modeling approaches can reduce the uncertainties in higher tier effect assessments related to knowledge gaps.
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Affiliation(s)
- André Gergs
- Research Institute for Ecosystem Analysis and Assessment (gaiac) , Kackertstrasse 10 , 52072 Aachen , Germany
| | - Kim J Rakel
- Research Institute for Ecosystem Analysis and Assessment (gaiac) , Kackertstrasse 10 , 52072 Aachen , Germany
| | - Dino Liesy
- Institute for Environmental Sciences , University of Koblenz-Landau , Fortstraße 7 , 76829 Landau , Germany
| | - Armin Zenker
- Institute for Ecopreneurship, School of Life Sciences , University of Applied Sciences and Arts Northwestern Switzerland , Hofackerstrasse 30 , 4132 Muttenz , Switzerland
| | - Silke Classen
- Research Institute for Ecosystem Analysis and Assessment (gaiac) , Kackertstrasse 10 , 52072 Aachen , Germany
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11
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Duckworth J, Jager T, Ashauer R. Automated, high-throughput measurement of size and growth curves of small organisms in well plates. Sci Rep 2019; 9:10. [PMID: 30626881 PMCID: PMC6327043 DOI: 10.1038/s41598-018-36877-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/20/2018] [Indexed: 11/09/2022] Open
Abstract
Organism size and growth curves are important biological characteristics. Current methods to measure organism size, and in particular growth curves, are often resource intensive because they involve many manual steps. Here we demonstrate a method for automated, high-throughput measurements of size and growth in individual aquatic invertebrates kept in microtiter well-plates. We use a spheroid counter (Cell3iMager, cc-5000) to automatically measure size of seven different freshwater invertebrate species. Further, we generated calibration curves (linear regressions, all p < 0.0001, r2 >=0.9 for Ceriodaphnoa dubia, Asellus aquaticus, Daphnia magna, Daphnia pulex; r2 >=0.8 for Hyalella azteca, Chironomus spec. larvae and Culex spec. larvae) to convert size measured on the spheroid counter to traditional, microscope based, length measurements, which follow the longest orientation of the body. Finally, we demonstrate semi-automated measurement of growth curves of individual daphnids (C. dubia and D. magna) over time and find that the quality of individual growth curves varies, partly due to methodological reasons. Nevertheless, this novel method could be adopted to other species and represents a step change in experimental throughput for measuring organisms’ shape, size and growth curves. It is also a significant qualitative improvement by enabling high-throughput assessment of inter-individual variation of growth.
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Affiliation(s)
- James Duckworth
- Environment Department, University of York, Wentworth Way, Heslington, York, YO10 5NG, United Kingdom
| | | | - Roman Ashauer
- Environment Department, University of York, Wentworth Way, Heslington, York, YO10 5NG, United Kingdom.
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12
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Agatz A, Schumann MM, French BW, Brown CD, Vidal S. Assessment of acute toxicity tests and rhizotron experiments to characterize lethal and sublethal control of soil-based pests. PEST MANAGEMENT SCIENCE 2018; 74:2450-2459. [PMID: 29575759 DOI: 10.1002/ps.4922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/15/2018] [Accepted: 03/19/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Characterizing lethal and sublethal control of soil-based pests with plant protection products is particularly challenging due to the complex and dynamic interplay of the system components. Here, we present two types of studies: acute toxcity experiments (homogenous exposure of individuals in soil) and rhizotron experiments (heterogeneous exposure of individuals in soil) to investigate their ability to strengthen our understanding of mechanisms driving the effectivness of the plant protection product. Experiments were conducted using larvae of the western corn rootworm Diabrotica virgifera LeConte and three pesticide active ingredients: clothianidin (neonicotinoid), chlorpyrifos (organophosphate) and tefluthrin (pyrethroid). RESULTS The order of compound concentrations needed to invoke a specific effect intensity (EC50 values) within the acute toxicity tests was chlorpyrifos > tefluthrin > clothianidin. This order changed for the rhizotron experiments because application type, fate and transport of the compounds in the soil profile, and sublethal effects on larvae also influence their effectiveness in controlling larval feeding on corn roots. CONCLUSION Beyond the pure measurement of efficacy through observing relative changes in plant injury to control plants, the tests generate mechanistic understanding for drivers of efficacy apart from acute toxicity. The experiments have the potential to enhance efficacy testing and product development, and might be useful tools for assessing resistance development in the future. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Annika Agatz
- Environment Department, University of York, York, UK
| | - Mario M Schumann
- Agricultural Entomology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Bryan W French
- United States Department of Agriculture, North Central Agricultural Research Laboratory, Agricultural Research Service, Brookings, USA
| | - Colin D Brown
- Environment Department, University of York, York, UK
| | - Stefan Vidal
- Agricultural Entomology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
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13
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Dalhoff K, Gottardi M, Rinnan Å, Rasmussen JJ, Cedergreen N. Seasonal sensitivity of Gammarus pulex towards the pyrethroid cypermethrin. CHEMOSPHERE 2018; 200:632-640. [PMID: 29510371 DOI: 10.1016/j.chemosphere.2018.02.153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 02/19/2018] [Accepted: 02/24/2018] [Indexed: 06/08/2023]
Abstract
The aquatic toxicity of insecticides like the pyrethroids have been discussed intensively over the recent years especially in relation to risk assessment and how seasonality may or may not affect the sensitivity of non-target organisms. To address this issue, the crustacean Gammarus pulex was collected once a month for 16 months and acclimated to 10 °C for four days before being exposed to a 90 min pulse of cypermethrin. In vitro cytochrome P450 activity, total lipid content, total protein content, and dry weight were measured in male and female gammarids from each sampling date and used along with the water temperature as variables for sensitivity prediction by Partial Least Squares (PLS) regression models. The 24 h EC50-values varied more than 30 fold across the sampling period from 0.21 ± 0.05 μg L-1 (April 2015) to 6.60 ± 3.46 μg L-1 (October 2015), indicating seasonal variances in the acute sensitivity of G. pulex towards cypermethrin. After 168 h of recovery this difference in EC50-values was reduced to seven-fold. In both male and female gammarids seasonal patterns were observed in the total lipid content and in vitro CYP P450 activity, which peaked in spring and fall, respectively. The current study shows the importance of reporting time of organism collection and experimental execution for risk assessment of pyrethroids as season is important for the acute sensitivity of G. pulex. We suggest prolonged acclimation times of sampled macroinvertebrates to constant laboratory conditions in order to even out possible seasonal differences in sensitivity.
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Affiliation(s)
- Kristoffer Dalhoff
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
| | - Michele Gottardi
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Åsmund Rinnan
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | - Jes Jessen Rasmussen
- Department of Bioscience - Stream and Wetland Ecology, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark
| | - Nina Cedergreen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
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Ashauer R, Jager T. Physiological modes of action across species and toxicants: the key to predictive ecotoxicology. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:48-57. [PMID: 29090718 DOI: 10.1039/c7em00328e] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
As ecotoxicologists we strive for a better understanding of how chemicals affect our environment. Humanity needs tools to identify those combinations of man-made chemicals and organisms most likely to cause problems. In other words: which of the millions of species are at risk from pollution? And which of the tens of thousands of chemicals contribute most to the risk? We identified our poor knowledge on physiological modes of action (how a chemical affects the energy allocation in an organism), and how they vary across species and toxicants, as a major knowledge gap. We also find that the key to predictive ecotoxicology is the systematic, rigorous characterization of physiological modes of action because that will enable more powerful in vitro to in vivo toxicity extrapolation and in silico ecotoxicology. In the near future, we expect a step change in our ability to study physiological modes of action by improved, and partially automated, experimental methods. Once we have populated the matrix of species and toxicants with sufficient physiological mode of action data we can look for patterns, and from those patterns infer general rules, theory and models.
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Affiliation(s)
- Roman Ashauer
- Environment Department, University of York, Heslington, York YO10 5NG, UK.
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15
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Gottardi M, Birch MR, Dalhoff K, Cedergreen N. The effects of epoxiconazole and α-cypermethrin on Daphnia magna growth, reproduction, and offspring size. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2155-2166. [PMID: 28145595 DOI: 10.1002/etc.3752] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 12/24/2016] [Accepted: 01/30/2017] [Indexed: 06/06/2023]
Abstract
Two of the main classes of pesticides commonly used in agriculture are azole fungicides and pyrethroid insecticides. Because azoles have been shown to synergize the effect of pyrethroids, the effect of their mixture is of concern. The aim of the present study was to investigate the effect of sublethal concentrations of epoxiconazole and α-cypermethrin and their mixture on growth, reproduction, and in vivo cytochrome P450 activity of the aquatic crustacean Daphnia magna over 42 d. Continuous exposure to nonlethal concentrations of α-cypermethrin at 20 ng/L negatively affected adult growth and number and size of neonates within the first 14 d of exposure. Exposure to epoxiconazole at 25 μg/L increased protein content of adults within 1 to 3 d after initiating exposure and increased cumulative number of offspring at exposure times >31 d. Epoxiconazole enhanced the negative effect of α-cypermethrin up to 3-fold leading to decreased growth, cytochrome P450 activity, and reproduction of D. magna within the first 14 d of exposure. After 14 d, the synergistic interactions disappeared. The reported effects, although lacking direct negative consequence in the long term, might have cumulative toxicity with other stressors such as food scarcity, predation, and pathogens, posing an additional hazard for the organisms at the beginning of their life cycle. Environ Toxicol Chem 2017;36:2155-2166. © 2017 SETAC.
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Affiliation(s)
- Michele Gottardi
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Michala Rosa Birch
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Kristoffer Dalhoff
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Nina Cedergreen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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16
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Gergs A, Gabsi F, Zenker A, Preuss TG. Demographic Toxicokinetic-Toxicodynamic Modeling of Lethal Effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6017-6024. [PMID: 27158745 DOI: 10.1021/acs.est.6b01113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aquatic effect assessment of chemicals is largely based on standardized measures of toxicity determined in short-term laboratory tests which are designed to reduce variability. For this purpose, uniform individuals of a species are kept under environmental and chemical exposure conditions which are as constant as possible. In nature, exposure often appears to be pulsed, effects might last longer than a few days, sensitivity might vary among different sized organisms and populations are usually size or age structured and are subject to demographic processes. To overcome this discrepancy, we tested toxicokinetic-toxicodynamic models of different complexities, including body size scaling approaches, for their ability to represent lethal effects observed for Daphnia magna exposed to triphenyltin. The consequences of the different toxicokinetic and toxicodynamic assumptions for population level responses to pulsed exposure are tested by means of an individual based model and are evaluated by confronting model predictions with population data for various pulsed exposure scenarios. We provide an example where increased model complexity reduces the uncertainty in model outputs. Furthermore, our results emphasize the importance of considering population demography in toxicokinetics and toxicodynamics for understanding and predicting potential chemical impacts at higher levels of biological organization.
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Affiliation(s)
- André Gergs
- Research Institute for Ecosystem Analysis and Assessment (gaiac) , Kackertstraße 10, 52072 Aachen, Germany
- Institute for Environmental Research, RWTH Aachen University , Worringer Weg 1, 52074 Aachen, Germany
| | - Faten Gabsi
- Institute for Environmental Research, RWTH Aachen University , Worringer Weg 1, 52074 Aachen, Germany
- RIFCON GmbH , Goldbeckstraße 13, 69493 Hirschberg, Germany
| | - Armin Zenker
- Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland , Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - Thomas G Preuss
- Bayer CropScience , Alfred-Nobel-Straße 50, 40789 Monheim am Rhein, Germany
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Gergs A, Kulkarni D, Preuss TG. Body size-dependent toxicokinetics and toxicodynamics could explain intra- and interspecies variability in sensitivity. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 206:449-455. [PMID: 26275729 DOI: 10.1016/j.envpol.2015.07.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 07/23/2015] [Accepted: 07/26/2015] [Indexed: 06/04/2023]
Abstract
Ecological risk assessment of chemicals aims at quantifying the likelihood of adverse effects posed to non-target populations and the communities they constitute, often based on lethal concentration estimates for standard test species. There may, however, be intra- and interspecific differences in responses to chemical exposure. Here with the help of a toxicokinetic-toxicodynamic model, we explored whether differential body sizes might explain the observed variability in sensitivity between species and between life-stages of each individual species, for three model organisms, Daphnia magna, Chaoborus crystallinus and Mesocyclops leuckarti. While body size-dependent toxicokinetics could be used to predict intraspecies variation in sensitivity, our results also suggest that changes in both toxicokinetic and toxicodynamic parameters might be needed to describe differential species sensitivity. Accounting for biological traits, like body size, in mechanistic effect models will allow more accurate predictions of chemical effects in size structured populations, ultimately providing mechanistic explanations for species sensitivity distributions.
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Affiliation(s)
- André Gergs
- Institute for Environmental Research, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany.
| | - Devdutt Kulkarni
- Institute for Environmental Research, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany; Laboratory of Environmental Ecosystem Ecology, Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Thomas G Preuss
- Institute for Environmental Research, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany; Bayer CropScience, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein, Germany
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