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Kossack ME, Bowie K, Tian L, Plavicki JS. Building methodological consensus to ensure rigor and reproducibility in zebrafish fertility research. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 272:106930. [PMID: 38744123 DOI: 10.1016/j.aquatox.2024.106930] [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: 06/14/2023] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 05/16/2024]
Abstract
The summary included in the text: Zebrafish are an increasingly popular model for studying the genetic and environmental factors that shape male and female fertility; however, the field currently lacks a standardized approach to fertility assessment. The current lack of consensus makes comparisons across studies more challenging and is an obstacle to reproducibility in the fields of reproductive biology and toxicology. Here, we review the diversity of spawning approaches used in zebrafish reproductive toxicology research to asses fertility and provide evidence that spawning parameters can result in meaningful differences in egg production and spawning success.
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Affiliation(s)
- M E Kossack
- Department of Pathology and Laboratory Medicine, Brown University, United States
| | - K Bowie
- Department of Pathology and Laboratory Medicine, Brown University, United States
| | - L Tian
- Department of Pathology and Laboratory Medicine, Brown University, United States
| | - J S Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, United States.
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2
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Pan D, Zhang C, Wang CS, Zhang P, Jiao XY, Ma QR, Wang LT, Li DJ, Li LP. Unravelling hidden threats of water disinfection: Toxicity evaluation and toxic products identification during diclofenac degradation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123424. [PMID: 38278408 DOI: 10.1016/j.envpol.2024.123424] [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: 10/20/2023] [Revised: 12/04/2023] [Accepted: 01/21/2024] [Indexed: 01/28/2024]
Abstract
Diclofenac (DCF) is a widely-used nonsteroidal anti-inflammatory drug that is routinely found in surface water bodies. While ozonation and ultraviolet (UV) radiation are commonly employed as disinfection methods in water treatment processes, the degradation of DCF in these processes occurs due to the strong oxidizing activity of the reactive oxygen species produced during both ozonation and UV radiation. Despite extensive studies reporting the removal and transformation of DCF through ozone and UV treatments, the potential hidden hazards of toxicity arising from these processes as well as the identification of the toxic transformation products have often been overlooked. In this study, various toxicities including microtoxicity, genotoxicity and antiestrogenicity were evaluated using multiple in-vitro bioassays. The transformation products were identified via ultra-performance liquid chromatography equipped with mass spectrometry (UPLC-MS). Correlation analysis was employed to gain deeper insight into the contributions of degradation products to overall toxicity. The results revealed that DCF possessed significant genotoxic and antiestrogenic effects, but displayed minimal microtoxicity. Microtoxic products such as those containing carbazole were generated during DCF degradation with ozone, UVA and UVC. Antiestrogenic products with dichloroaniline structures were observed in DCF ozonation but not in photodegradation by UVA and UVC. These findings highlighted the hidden risks associated with the disinfection of water containing micropollutants such as DCF.
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Affiliation(s)
- Ding Pan
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China; School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Cheng Zhang
- Instrumentation and Service Center for Science and Technology, Beijing Normal University, Zhuhai, 519087, China
| | - Cai-Shan Wang
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China; School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Peng Zhang
- Guangdong Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xin-Yi Jiao
- College of Environmental Science and Engineering, China West Normal University, Nanchong, 637009, China
| | - Qian-Ru Ma
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China
| | - Li-Ting Wang
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China
| | - Dai-Jun Li
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China
| | - Li-Ping Li
- Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, China; School of Environment, Beijing Normal University, Beijing, 100875, China.
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Baekelandt S, Leroux N, Burattin L, Gérard C, Delierneux C, Robert JB, Cornet V, Kestemont P. Estetrol has a lower impact than 17α-ethinylestradiol on the reproductive capacity of zebrafish (Danio rerio). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106505. [PMID: 37058791 DOI: 10.1016/j.aquatox.2023.106505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 05/15/2023]
Abstract
Natural and synthetic oestrogens are commonly found in aquatic ecosystems. The synthetic oestrogen 17α-ethinylestradiol (EE2) is widely used in oral contraceptives and its ecotoxicological effects on aquatic organisms have been widely reported. The natural oestrogen estetrol (E4) was recently approved for use in a new combined oral contraceptive and, after therapeutic use, is likely to be found in the aquatic environment. However, its potential effects on non-target species such as fish is unknown. In order to characterize and compare the endocrine disruptive potential of E4 with EE2, zebrafish (Danio rerio) were exposed to E4 or EE2 in a fish short-term reproduction assay conducted according to OECD Test Guideline 229. Sexually mature male and female fish were exposed to a range of concentrations, including environmentally relevant concentrations of E4 and EE2, for 21 days. Endpoints included fecundity, fertilization success, gonad histopathology, head/tail vitellogenin concentrations, as well as transcriptional analysis of genes related to ovarian sex steroid hormones synthesis. Our data confirmed the strong impact of EE2 on several parameters including an inhibition of fecundity, an induction of vitellogenin both in male and female fish, an alteration of gonadal structures and the modulation of genes involved in sex steroid hormone synthesis in female fish. In contrast, only few significant effects were observed with E4 with no impact on fecundity. The results suggest that the natural oestrogen, E4, presents a more favorable environmental profile than EE2 and is less likely to affect fish reproductive capacity.
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Affiliation(s)
- Sébastien Baekelandt
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium.
| | - Nathalie Leroux
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium
| | - Laura Burattin
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium
| | - Céline Gérard
- Estetra SRL, an affiliated company of Mithra Pharmaceuticals, Rue Saint-Georges 5, Liège 4000, Belgium
| | - Céline Delierneux
- Estetra SRL, an affiliated company of Mithra Pharmaceuticals, Rue Saint-Georges 5, Liège 4000, Belgium
| | - Jean-Baptiste Robert
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium
| | - Valérie Cornet
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium
| | - Patrick Kestemont
- Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, B-5000, Belgium
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Kim MJ, Kim JA, Song JA, Kho KH, Choi CY. Synthetic microfiber exposure negatively affects reproductive parameters in male medaka (Oryzias latipes). Gen Comp Endocrinol 2023; 334:114216. [PMID: 36681254 DOI: 10.1016/j.ygcen.2023.114216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Microplastics not only accumulate in the bodies of fishes and cause damage to the organs, but also cause many other problems, such as reduced reproductive capacity, by acting directly or indirectly on the hypothalamus-pituitary-gonad axis (HPG axis). In this study, we investigated the changes in HPG axis-related genes in male medaka (Oryzias latipes) exposed to fiber-type microplastics. We confirmed the progression of vitellogenesis, a sign of endocrine disruption, in male fish. In the microfiber-exposed group, microfiber accumulation was confirmed in the gills and intestines. One week after exposure to two different concentrations of microfibers (500 and 1,000 fibers/L), the fish showed increased expression of gonadotropin-releasing hormone (GnRH) and luteinizing hormone receptor (LH-R) mRNA. From day 10 of exposure to the microfibers, there was an increase in the expression of the gonadotropin-inhibitory hormone (GnIH) mRNA and a decrease in the expression of GnRH and LH-R mRNA. There was an increase in the cytochrome P450 aromatase (CYP19a) mRNA expression and plasma estradiol (E2) concentration in the 1,000 fibers/L exposure group. High vitellogenin (VTG) mRNA expression was confirmed seven days after exposure in the 1,000 fibers/L group, which was consistent with the VTG mRNA expression signals detected in the liver using in situ hybridization. These results suggest that microfiber ingestion may cause short-term endocrinal disruption of the HPG axis in male medaka, which in turn may interfere with their normal maturation process.
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Affiliation(s)
- Min Ju Kim
- Department of Convergence Study on the Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Republic of Korea
| | - Jin A Kim
- Department of Convergence Study on the Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Republic of Korea
| | - Jin Ah Song
- Marine Bio-Resources Research Unit, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea
| | - Kang Hee Kho
- Department of Fisheries Science, Chonnam National University, Yeosu 59626, Republic of Korea
| | - Cheol Young Choi
- Department of Convergence Study on the Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Republic of Korea; Division of Marine BioScience, Korea Maritime and Ocean University, Busan 49112, Republic of Korea.
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Qiu SQ, Huang GY, Li XP, Lei DQ, Wang CS, Ying GG. A comparative study on endocrine disrupting effects of leachates from virgin and aged plastics under simulated media in marine medaka larvae (Oryzias melastigma). JOURNAL OF HAZARDOUS MATERIALS 2023; 446:130700. [PMID: 36592560 DOI: 10.1016/j.jhazmat.2022.130700] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/18/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Marine plastic pollution has garnered substantial attention, but the potential endocrine disrupting effects of plastic leachates in marine organisms remain unclear. In this study, the larvae of marine medaka (Oryzias melastigma) were exposed to the leachates from virgin and aged plastics soaked in simulated seawater and fish digest for 3 days. The concentrations of vitellogenin (VTG), estradiol (E2), and 11-ketotestosterone (11-KT), as well as the transcripts of endocrine-related genes were measured in the larvae. The results revealed that endogenous E2 was more sensitive to plastic leachates than VTG and 11-KT, which was significantly affected by 26.7 % of all plastic leachates. Among all genes, estrogen receptor α was impacted mostly, being up-regulated by 53.3 % of leachates from aged plastics. The comparative results demonstrated that the leachates from plastics with different statuses caused a greater difference than those from plastics in different simulated media, and the leachates from aged plastics resulted in higher endocrine disrupting effects than those from virgin plastics. In addition, seven leached additives (plasticizers and flame retardants) could explain 25.6 % of the hormonal effects using redundancy analysis, indicating that other additives in the plastic leachates can also play important roles in regulating the endocrine system of O. melastigma larvae.
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Affiliation(s)
- Shu-Qing Qiu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Guo-Yong Huang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
| | - Xiao-Pei Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Dong-Qiao Lei
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Chen-Si Wang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Guang-Guo Ying
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
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Wang L, Wu D, Yu Z, Huang S, Zhang J. Hormone-mediated multi- and trans-generational reproductive toxicities of 1-ethyl-3-methylimidazolium hexafluorophosphate on Caenorhabditis elegans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 863:160958. [PMID: 36535467 DOI: 10.1016/j.scitotenv.2022.160958] [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: 09/06/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Ionic liquids (ILs) are emergent pollutants and their reproductive toxicities show hormesis, earning attentions on their environmental risk. Yet, their reproductive effects over generations and the mechanisms were seldom explored. In the present study, the reproductive effects of 1-ethyl-3-methylimidazolium hexafluorophosphate ([C2mim]PF6) on Caenorhabditis elegans were measured in 11 continuously exposed generations (F1 to F11) to explore the multi-generational effects, and also in the non-exposed generations of F1 and F11 (i.e., their great-grand-daughters, T4 and T4') to explore the trans-generational effects. In multi-generational reproductive effects, there were concentration-dependent hormetic effects with hazard-benefit alteration between low and high concentrations (e.g., in F3). There were also generation-dependent hormetic effects with hazard-benefit alterations over generations (e.g., between F4 and F5, between F8 and F9, and between F10 and F11). Meanwhile, the results also showed benefit-hazard alteration between F2 and F3, between F6 and F7, and between F9 and F10. Trans-generational effects showed common inhibitions in T4 and T4' at both low and high concentrations. In the biochemical analysis, hormones and hormone-like substances including progesterone (P), estradiol (E2), prostaglandin (PG) and testosterone (T) showed multi- and trans-generational changes with inhibition and stimulation, which contributed to the reproductive outcomes in each generation. Such contribution was also observed in the hormones' precursor cholesterol and the proteins that are essential for reproduction including vitellogenin (Vn) and major sperm protein (MSP). Moreover, the biochemicals showed significant involvement in the connection among generations. Furthermore, the multi- and trans-generational effects of [C2mim]PF6 and histidine showed similar modes of actions despite some differences, implying the contribution of their shared imidazole structure.
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Affiliation(s)
- Lei Wang
- College of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai 201418, PR China; Jiaxing Tongji Institute for Environment, Jiaxing, Zhejiang 314051, PR China
| | - Di Wu
- Shuguang Hospital affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PR China
| | - Zhenyang Yu
- Jiaxing Tongji Institute for Environment, Jiaxing, Zhejiang 314051, PR China; College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Shidi Huang
- College of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai 201418, PR China
| | - Jing Zhang
- College of Ecological Technology and Engineering, Shanghai Institute of Technology, Shanghai 201418, PR China.
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Lee G, Park G, Kim S, Jhung SH. Adsorptive removal of aromatic diamines from water using metal-organic frameworks functionalized with a nitro group. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130133. [PMID: 36274546 DOI: 10.1016/j.jhazmat.2022.130133] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Adsorptive removal of aromatic diamines such as methylenedianiline (MDA) and p-phenylenediamine (PPD) was firstly investigated with nitro-functionalized metal-organic frameworks (MOFs, MIL-101(Cr)-NO2). The MIL-101(Cr)-NO2 showed much better performances in the removal of MDA and PPD, in both adsorption capacity and kinetics, than any other adsorbents. For example, MIL-101(Cr)-NO2 had a much higher maximum adsorption capacity for MDA (1111 mg·g-1) than activated carbon (208 mg·g-1) or a reported adsorbent (391 mg·g-1). Based on experimental results, hydrogen bonding (especially, via the formation of a 6-membered ring (6-MR) between -NO2 of the adsorbent and -NH2 of the adsorbates) could be suggested as the main mechanism to interpret the noticeable adsorption of the diamines. Importantly, this is the first example to confirm that MOFs with nitro group can be a competitive adsorbent to remove organics composed of amino group, especially via making 6-MR through hydrogen bonding. Higher adsorption of MDA than that of PPD over MIL-101(Cr)-NO2 might be explained with π-π interaction between aromatic rings (π-lean aromatics of MOF and π-rich aromatics of the adsorbates). Moreover, MIL-101(Cr)-NO2 could be recycled after simple washing, suggesting the potential use of the MOF in adsorptive purification of contaminated water with organics with amino groups.
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Affiliation(s)
- Gyudong Lee
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, South Korea
| | - Geondo Park
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, South Korea
| | - Sunghwan Kim
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, South Korea.
| | - Sung Hwa Jhung
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, South Korea.
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Hansen BH, Farkas J, Piarulli S, Vicario S, Kvæstad B, Williamson DR, Sørensen L, Davies EJ, Nordtug T. Atlantic cod ( Gadus morhua) embryos are highly sensitive to short-term 3,4-dichloroaniline exposure. Toxicol Rep 2021; 8:1754-1761. [PMID: 34703771 PMCID: PMC8523877 DOI: 10.1016/j.toxrep.2021.10.006] [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: 06/18/2021] [Revised: 09/15/2021] [Accepted: 10/09/2021] [Indexed: 11/26/2022] Open
Abstract
3,4-dichloroaniline (3,4-DCA) is one of the most widely produced anilines world-wide, used in plastic packaging, fabrics, pharmaceuticals, pesticides, dyes and paints as well as being a degradation product of several pesticides. 3,4-DCA has been detected in freshwater, brackish and marine environments. Although freshwater toxicity thresholds exist, very little toxicological information is available on marine and cold-water species. In this study, we exposed Atlantic cod (Gadus morhua) embryos (3-7 days post fertilization) to 3,4-DCA concentrations ranging from 8-747 μg/L for 4 days followed by a recovery period in clean sea water until 14 days post fertilization (dpf). The cod embryos were significantly more sensitive to acute 3,4-DCA exposure compared to other species tested and reported in the literature. At the highest concentration (747 μg/L), no embryos survived until hatch, and even at the lowest concentration (8 μg/L), a small, but significant increase in mortality was observed at 14 dpf. Delayed and concentration-dependent effects on surviving yolk-sac larvae, manifested as cardiac, developmental and morphometric alterations, more than a week after exposure suggest potential long-term effects of transient embryonic exposure to low concentrations of 3,4-DCA.
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Affiliation(s)
| | | | | | - Silvia Vicario
- University of Milano-Bicocca, Piazza della Scienza 1, Milan, Italy
| | | | - David R. Williamson
- SINTEF Ocean, 7465, Trondheim, Norway
- Centre for Autonomous Marine Operations and System (AMOS), Department of Marine Technology, Norwegian University of Science and Technology, NTNU, Norway
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Reproductive Toxicity of 3,4-dichloroaniline (3,4-DCA) on Javanese Medaka ( Oryziasjavanicus, Bleeker 1854). Animals (Basel) 2021; 11:ani11030798. [PMID: 33809309 PMCID: PMC8000808 DOI: 10.3390/ani11030798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 01/18/2023] Open
Abstract
Compound 3,4-dichloroaniline (3,4-DCA) is a metabolite of several urea herbicides and intermediate chemical of several industrial products. Moreover, 3,4-DCA has been frequently detected in aquatic ecosystems around the world. This aniline is more toxic than the parent chemicals, and it affects non-target organisms. This study evaluated a 21-day reproductive response of an emerging aquatic vertebrate model, Javanese medaka (Oryzias javanicus), exposed to 3,4-DCA. Fecundity and gonads histopathology were observed. The spawning rate and fertilisation reduced significantly in the highest exposed-group (250 µg/L). Gonadosomatic index (GSI) was significantly low in females exposed to 250 µg/L. No substantial structural alteration of male gonads. However, oocyte development and ovarian cell structure were disrupted in 250 µg/L exposed females. The gonadal developmental was not affected in the males; however, a significant reduction in the developmental of female gonads was observed at 250 µg/L. These results show that 3,4-DCA interfere with the reproduction of Javanese medaka through fecundity and alteration of gonadal tissues.
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