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Gölz L, Pannetier P, Fagundes T, Knörr S, Behnstedt L, Coordes S, Matthiessen P, Morthorst J, Vergauwen L, Knapen D, Holbech H, Braunbeck T, Baumann L. Development of the integrated fish endocrine disruptor test-Part B: Implementation of thyroid-related endpoints. Integr Environ Assess Manag 2024; 20:830-845. [PMID: 37578010 DOI: 10.1002/ieam.4828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/21/2023] [Accepted: 08/10/2023] [Indexed: 08/15/2023]
Abstract
Given the vital role of thyroid hormones (THs) in vertebrate development, it is essential to identify chemicals that interfere with the TH system. Whereas, among nonmammalian laboratory animals, fish are the most frequently utilized test species in endocrine disruptor research, for example, in guidelines for the detection of effects on the sex hormone system, there is no test guideline (TG) using fish as models for thyroid-related effects; rather, amphibians are used. Therefore, the objective of the present project was to integrate thyroid-related endpoints for fish into a test protocol combining OECD TGs 229 (Fish Short-Term Reproduction Assay) and 234 (Fish Sexual Development Test). The resulting integrated Fish Endocrine Disruption Test (iFEDT) was designed as a comprehensive approach to covering sexual differentiation, early development, and reproduction and to identifying disruption not only of the sexual and/or reproductive system but also the TH system. Two 85-day exposure tests were performed using different well-studied endocrine disruptors: 6-propyl-2-thiouracil (PTU) and 17α-ethinylestradiol (EE2). Whereas the companion Part A of this study presents the findings on effects by PTU and EE2 on endpoints established in existing TGs, the present Part B discusses effects on novel thyroid-related endpoints such as TH levels, thyroid follicle histopathology, and eye development. 6-Propyl-2-thiouracil induced a massive proliferation of thyroid follicles in any life stage, and histopathological changes in the eyes proved to be highly sensitive for TH system disruption especially in younger life stages. For measurement of THs, further methodological development is required. 17-α-Ethinylestradiol demonstrated not only the well-known disruption of the hypothalamic-pituitary-gonadal axis, but also induced effects on thyroid follicles in adult zebrafish (Danio rerio) exposed to higher EE2 concentrations, suggesting crosstalk between endocrine axes. The novel iFEDT has thus proven capable of simultaneously capturing endocrine disruption of both the steroid and thyroid endocrine systems. Integr Environ Assess Manag 2024;20:830-845. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Lisa Gölz
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Pauline Pannetier
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Laboratoire de Ploufragan-Plouzané-Niort, Site de Plouzané, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail, Plouzané, France
| | - Teresa Fagundes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Susanne Knörr
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Laura Behnstedt
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Jane Morthorst
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Lucia Vergauwen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Dries Knapen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Henrik Holbech
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section Environmental Health & Toxicology, Vrije Universiteit Amsterdam, HV Amsterdam, The Netherlands
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Pannetier P, Gölz L, Pissarreira Mendes Fagundes MT, Knörr S, Behnstedt L, Coordes S, Matthiessen P, Morthorst JE, Vergauwen L, Knapen D, Holbech H, Braunbeck T, Baumann L. Development of the integrated fish endocrine disruptor test (iFEDT)-Part A: Merging of existing fish test guidelines. Integr Environ Assess Manag 2024; 20:817-829. [PMID: 37483114 DOI: 10.1002/ieam.4819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/21/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
There has been increasing interest in endocrine-disrupting chemicals (EDCs) among scientists and public authorities over the last 30 years, notably because of their wide use and the increasing evidence of detrimental effects on humans and the environment. However, test systems for the detection of potential EDCs as well as testing strategies still require optimization. Thus, the aim of the present project was the development of an integrated test protocol that merges the existing OECD test guidelines (TGs) 229 (fish short-term reproduction assay) and 234 (fish sexual development test) and implements thyroid-related endpoints for fish. The integrated fish endocrine disruptor test (iFEDT) represents a comprehensive approach for fish testing, which covers reproduction, early development, and sexual differentiation, and will thus allow the identification of multiple endocrine-disruptive effects in fish. Using zebrafish (Danio rerio) as a model organism, two exposure tests were performed with well-studied EDCs: 6-propyl-2-thiouracil (PTU), an inhibitor of thyroid hormone synthesis, and 17α-ethinylestradiol (EE2), an estrogen receptor agonist. In part A of this article, the effects of PTU and EE2 on established endpoints of the two existing TGs are reported, whereas part B focuses on the novel thyroid-related endpoints. Results of part A document that, as expected, both PTU and EE2 had strong effects on various endocrine-related endpoints in zebrafish and their offspring. Merging of TGs 229 and 234 proved feasible, and all established biomarkers and endpoints were responsive as expected, including reproductive and morphometric changes (PTU and EE2), vitellogenin levels, sex ratio, gonad maturation, and histopathology (only for EE2) of different life stages. A validation of the iFEDT with other well-known EDCs will allow verification of the sensitivity and usability and confirm its capacity to improve the existing testing strategy for EDCs in fish. Integr Environ Assess Manag 2024;20:817-829. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Pauline Pannetier
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Laboratoire de Ploufragan-Plouzané-Niort, Site de Plouzané, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail, Plouzané, France
| | - Lisa Gölz
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Susanne Knörr
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Laura Behnstedt
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | | | - Jane E Morthorst
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Lucia Vergauwen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Dries Knapen
- Department of Veterinary Sciences, Veterinary Physiology and Biochemistry, Zebrafishlab, University of Antwerp, Wilrijk, Belgium
| | - Henrik Holbech
- Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section Environmental Health and Toxicology, Vrije Universiteit Amsterdam, HV Amsterdam, The Netherlands
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Palejowski H, Bylemans J, Ammann V, Marques da Cunha L, Nusbaumer D, Castro I, Uppal A, Mobley KB, Knörr S, Wedekind C. Sex-Specific Life History Affected by Stocking in Juvenile Brown Trout. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.869925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Salmonids are a socioeconomically and ecologically important group of fish that are often managed by stocking. Little is known about potential sex-specific effects of stocking, but recent studies found that the sexes differ in their stress tolerances already at late embryonic stage, i.e., before hatchery-born larvae are released into the wild and long before morphological gonad formation. It has also been speculated that sex-specific life histories can affect juvenile growth and mortality, and that a resulting sex-biassed demography can reduce population growth. Here we test whether juvenile brown trout (Salmo trutta) show sex-specific life histories and whether such sex effects differ in hatchery- and wild-born fish. We modified a genetic sexing protocol to reduce false assignment rates and used it to study the timing of sex differentiation in a laboratory setting, and in a large-scale field experiment to study growth and mortality of hatchery- and wild-born fish in different environments. We found no sex-specific mortality in any of the environments we studied. However, females started sex differentiation earlier than males, and while growth rates were similar in the laboratory, they differed significantly in the field depending on location and origin of fish. Overall, hatchery-born males grew larger than hatchery-born females while wild-born fish showed the reverse pattern. Whether males or females grew larger was location-specific. We conclude that juvenile brown trout show sex-specific growth that is affected by stocking and by other environmental factors that remain to be identified.
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Selmoni OM, Maitre D, Roux J, Wilkins LGE, Marques da Cunha L, Vermeirssen ELM, Knörr S, Robinson-Rechavi M, Wedekind C. Correction to: Sex-specific changes in gene expression in response to estrogen pollution around the onset of sex differentiation in grayling (Salmonidae). BMC Genomics 2020; 21:371. [PMID: 32434468 PMCID: PMC7240987 DOI: 10.1186/s12864-020-06782-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Oliver M Selmoni
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Present Address: Swiss Federal Institute of Technology (EPFL), 1015, Lausanne, Switzerland
| | - Diane Maitre
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland
| | - Julien Roux
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland.,Present Address: Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Laetitia G E Wilkins
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Present Address: Department of Environmental Sciences, Policy and Management, University of California, Berkeley, CA, 94720, USA
| | - Lucas Marques da Cunha
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland
| | | | - Susanne Knörr
- Aquatic Ecology and Toxicology Group Center of Organismic Studies, University of Heidelberg, Heidelberg, Germany
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Claus Wedekind
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.
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Selmoni OM, Maitre D, Roux J, Wilkins LGE, Marques da Cunha L, Vermeirssen ELM, Knörr S, Robinson-Rechavi M, Wedekind C. Sex-specific changes in gene expression in response to estrogen pollution around the onset of sex differentiation in grayling (Salmonidae). BMC Genomics 2019; 20:583. [PMID: 31307399 PMCID: PMC6631537 DOI: 10.1186/s12864-019-5955-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/03/2019] [Indexed: 12/11/2022] Open
Abstract
The synthetic 17α-ethinylestradiol (EE2) is a common estrogenic pollutant that has been suspected to affect the demography of river-dwelling salmonids. One possibility is that exposure to EE2 tips the balance during initial steps of sex differentiation, so that male genotypes show female-specific gene expression and gonad formation. Here we study EE2 effects on gene expression around the onset of sex differentiation in a population of European grayling (Thymallus thymallus) that suffers from sex ratio distortions. We exposed singly-raised embryos to one dose of 1 ng/L EE2, studied gene expression 10 days before hatching, at the day of hatching, and around the end of the yolk-sac stage, and related it to genetic sex (sdY genotype). We found that exposure to EE2 affects expression of a large number of genes, especially around hatching. These effects were strongly sex-dependent. We then raised fish for several months after hatching and found no evidence of sex reversal in the EE2-exposed fish. We conclude that ecologically relevant (i.e. low) levels of EE2 pollution do not cause sex reversal by simply tipping the balance at early stages of sex differentiation, but that they interfere with sex-specific gene expression.
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Affiliation(s)
- Oliver M Selmoni
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Present Address: Swiss Federal Institute of Technology (EPFL), 1015, Lausanne, Switzerland
| | - Diane Maitre
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland
| | - Julien Roux
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland.,Present Address: Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Laetitia G E Wilkins
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Present Address: Department of Environmental Sciences, Policy and Management, University of California, Berkeley, CA, 94720, USA
| | - Lucas Marques da Cunha
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland
| | | | - Susanne Knörr
- Aquatic Ecology and Toxicology Group Center of Organismic Studies, University of Heidelberg, Heidelberg, Germany
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Claus Wedekind
- Department of Ecology and Evolution Biophore, University of Lausanne, Lausanne, Switzerland.
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6
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Maitre D, Selmoni OM, Uppal A, Marques da Cunha L, Wilkins LGE, Roux J, Mobley KB, Castro I, Knörr S, Robinson-Rechavi M, Wedekind C. Sex differentiation in grayling (Salmonidae) goes through an all-male stage and is delayed in genetic males who instead grow faster. Sci Rep 2017; 7:15024. [PMID: 29101375 PMCID: PMC5670243 DOI: 10.1038/s41598-017-14905-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 10/19/2017] [Indexed: 01/05/2023] Open
Abstract
Fish populations can be threatened by distorted sex ratios that arise during sex differentiation. Here we describe sex differentiation in a wild grayling (Thymallus thymallus) population that suffers from distorted sex ratios. We verified that sex determination is linked to the sex determining locus (sdY) of salmonids. This allowed us to study sex-specific gene expression and gonadal development. Sex-specific gene expression could be observed during embryogenesis and was strong around hatching. About half of the fish showed immature testes around eleven weeks after fertilization. This phenotype was mostly replaced by the "testis-to-ovary" or "ovaries" phenotypes during development. The gonads of the remaining fish stayed undifferentiated until six months after fertilization. Genetic sexing revealed that fish with undifferentiated gonads were all males, who grew larger than the genetic females during the observational period. Only 12% of the genetic males showed testicular tissue six months after fertilization. We conclude that sex differentiation starts before hatching, goes through an all-male stage for both sexes (which represents a rare case of "undifferentiated" gonochoristic species that usually go through an all-female stage), and is delayed in males. During these juvenile stages males grow faster than females instead of developing their gonads.
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Affiliation(s)
- Diane Maitre
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
| | - Oliver M Selmoni
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
- Swiss Federal Institute of Technology (EPFL), Bâtiment GC, 1015, Lausanne, Switzerland
| | - Anshu Uppal
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
| | - Lucas Marques da Cunha
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
| | - Laetitia G E Wilkins
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
- Department of Environmental Sciences, Policy and Management, 130 Mulford Hall #3114, University of California, Berkeley, CA 94720, USA
| | - Julien Roux
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
- Department of Biomedicine, University of Basel, Hebelstr. 20, 4031, Basel, Switzerland
| | - Kenyon B Mobley
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
- Max-Planck Institute for Evolutionary Biology, Department of Evolutionary Ecology, August Thienemann Str. 2, 24306, Plön, Germany
| | - Isabelle Castro
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
| | - Susanne Knörr
- Aquatic Ecology and Toxicology Group, Center of Organismic Studies, University of Heidelberg, Heidelberg, Germany
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
| | - Claus Wedekind
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland.
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Baumann L, Knörr S, Keiter S, Nagel T, Segner H, Braunbeck T. Prochloraz causes irreversible masculinization of zebrafish (Danio rerio). Environ Sci Pollut Res Int 2015; 22:16417-16422. [PMID: 25163568 DOI: 10.1007/s11356-014-3486-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/18/2014] [Indexed: 06/03/2023]
Abstract
The aim of the present study was to investigate the persistence of endocrine effects by prochloraz, a fungicide known to have multiple effects on the endocrine system of vertebrates. Since discontinuous exposure is particularly relevant in aquatic ecosystems, an exposure scenario with an exposure phase and a subsequent recovery period was chosen to assess the potential for reversibility of effects by prochloraz on the sexual development of zebrafish (Danio rerio). Zebrafish were exposed to different concentrations of prochloraz (10-300 μg/L) until 60 days post hatch (dph), which includes the period of sexual differentiation. For the subsequent 40 days, fish were either held in clean water for depuration or under further continuous exposure. Histological investigations of the gonads revealed persistent effects on sexual differentiation. The sex ratio was skewed towards males and significantly more intersex individuals were found after exposure to prochloraz at 60 dph. No intersex fish, but masculinized sex ratios were still present after the depuration period, documenting that prochloraz irreversibly affects the sexual development of zebrafish.
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Affiliation(s)
- Lisa Baumann
- Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, PO Box 8466, CH-3001, Bern, Switzerland.
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Susanne Knörr
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Susanne Keiter
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Tina Nagel
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| | - Helmut Segner
- Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, PO Box 8466, CH-3001, Bern, Switzerland.
| | - Thomas Braunbeck
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
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Baumann L, Knörr S, Keiter S, Nagel T, Rehberger K, Volz S, Oberrauch S, Schiller V, Fenske M, Holbech H, Segner H, Braunbeck T. Persistence of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the androgen 17β-trenbolone. Environ Toxicol Chem 2014; 33:2488-2496. [PMID: 25070268 DOI: 10.1002/etc.2698] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/08/2014] [Accepted: 07/24/2014] [Indexed: 06/03/2023]
Abstract
The aim of the present study was to investigate the effects of the androgenic endocrine disruptor 17β-trenbolone on the sexual development of zebrafish (Danio rerio) with special emphasis on the question of whether adverse outcomes of developmental exposure are reversible or persistent. An exposure scenario including a recovery phase was chosen to assess the potential reversibility of androgenic effects. Zebrafish were exposed to environmentally relevant concentrations of 17β-trenbolone (1 ng/L-30 ng/L) from fertilization until completion of gonad sexual differentiation (60 d posthatch). Thereafter, exposure was either followed by 40 d of recovery in clean water or continued until 100 d posthatch, the age when zebrafish start being able to reproduce. Fish exposed for 100 d to 10 ng/L or 30 ng/L 17β-trenbolone were masculinized at different biological effect levels, as evidenced from a concentration-dependent shift of the sex ratio toward males as well as a significantly increased maturity of testes. Gonad morphological masculinization occurred in parallel with decreased vitellogenin concentrations in both sexes. Changes of brain aromatase (cyp19b) mRNA expression showed no consistent trend with respect to either exposure duration or concentration. Gonad morphological masculinization as well as the decrease of vitellogenin persisted after depuration over 40 d in clean water. This lack of recovery suggests that androgenic effects on sexual development of zebrafish are irreversible.
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Affiliation(s)
- Lisa Baumann
- Centre for Fish and Wildlife Health, University of Bern, Bern, Switzerland; Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
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Baumann L, Knörr S, Keiter S, Rehberger K, Volz S, Schiller V, Fenske M, Holbech H, Segner H, Braunbeck T. Reversibility of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the estrogen 17α-ethinylestradiol. Toxicol Appl Pharmacol 2014; 278:230-7. [DOI: 10.1016/j.taap.2014.04.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 04/08/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
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10
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Baumann L, Holbech H, Keiter S, Kinnberg KL, Knörr S, Nagel T, Braunbeck T. The maturity index as a tool to facilitate the interpretation of changes in vitellogenin production and sex ratio in the Fish Sexual Development Test. Aquat Toxicol 2013; 128-129:34-42. [PMID: 23261669 DOI: 10.1016/j.aquatox.2012.11.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/16/2012] [Accepted: 11/20/2012] [Indexed: 06/01/2023]
Abstract
In July 2011, the Fish Sexual Development Test (FSDT) has officially been adopted as OECD test guideline 234 for the detection of endocrine disrupting chemicals (EDCs). Sex ratio and vitellogenin (VTG) induction are the mandatory endocrine endpoints within this test, whereas gonad staging is only included as an option. In the present study, five FSDTs with zebrafish (Danio rerio) were conducted with EDCs with different modes of action (17α-ethinylestradiol, dihydrotestosterone, 17β-trenbolone, prochloraz and 4-tert-pentylphenol). Results document that not only sex ratio and VTG production of the exposed fish were massively affected, but also gonad maturation. As a novel approach for the quantification of gonad maturation in zebrafish, the maturity index was developed to allow not only an improved assessment of dose-dependent EDC-related effects on gonad maturation, but also statistical analysis of histological data. VTG induction and maturity index showed an excellent correlation for all five EDCs tested. Most importantly, the maturity index often helped to find appropriate interpretations for results that seemed contradictory at first sight. Results show that histological analyses and their predictive power for population fitness are currently underestimated and should become a standard component in the evaluation of potential EDCs.
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Affiliation(s)
- Lisa Baumann
- Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany.
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Knörr S, Braunbeck T. Decline in reproductive success, sex reversal, and developmental alterations in Japanese medaka (Oryzias latipes) after continuous exposure to octylphenol. Ecotoxicol Environ Saf 2002; 51:187-196. [PMID: 11971639 DOI: 10.1006/eesa.2001.2123] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Japanese medaka (Oryzias latipes) were continuously exposed to concentrations of 0, 2, 20, and 50 microg/L octylphenol, 0.01 per thousand dimethyl sulfoxide, and 100 ng/L 17beta-estradiol from 2 to 4 h postfertilization until maturity. Exposure to > or =2 microg/L octylphenol caused a 20-30% increase in mortality both before and after hatch. Growth was significantly decreased in fish exposed to 50 microg/L octylphenol and in the positive control. Sex ratio changed from 42:58 (females:males) in controls to 57:40 at 50 microg/L octylphenol, and 3 and 4% of the medaka exposed to 50 microg/L octylphenol and 17beta-estradiol developed testes-ova. In cross-mating experiments, mating of exposed males with control females resulted in an up to 11% lower fertilization rate than in controls. Results indicate that continuous exposure to octylphenol causes a broad variety of reproductive effects, which can be correlated with the xenoestrogenic potential of octylphenol.
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Affiliation(s)
- Susanne Knörr
- Aquatic Ecology and Toxicology Group, Department of Zoology I, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany
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