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Svanholm S, Roza M, Marini D, Brouard V, Karlsson O, Berg C. Pubertal sexual development and endpoints for disrupted spermatogenesis in the model Xenopus tropicalis. Reprod Toxicol 2023; 120:108435. [PMID: 37400040 DOI: 10.1016/j.reprotox.2023.108435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/27/2023] [Accepted: 06/30/2023] [Indexed: 07/05/2023]
Abstract
Peripubertal models to determine effects of anti-androgenic endocrine disrupting chemicals are needed. Using the toxicological model species Xenopus tropicalis, the aims of the study were to 1) provide data on sexual maturation and 2) characterise effects of short-term exposure to an anti-androgenic model substance. Juvenile (2.5 weeks post metamorphosis old) X. tropicalis were exposed to 0, 250, 500 or 1000 µg flutamide/L (nominal) for 2.5 weeks. Upon exposure termination, histology of gonads and Müllerian ducts was characterised in detail. New sperm stages were identified: pale and dark spermatogonial stem cells (SSCs). The testes of control males contained spermatozoa, indicating pubertal onset. The ovaries were immature, and composed of non-follicular and pre-vitellogenic follicular oocytes. The Müllerian ducts were more mature in females than males indicating development/regression in the females and males, respectively. In the 500 µg/L group, the number of dark SSCs per testis area was decreased and the number of secondary spermatogonia was increased. No treatment effects on ovaries or Müllerian ducts were detected. To conclude, our present data provide new knowledge on spermatogenesis, and pubertal onset in X. tropicalis. New endpoints for evaluating spermatogenesis are suggested to be added to existing assays used in endocrine and reproductive toxicology.
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Affiliation(s)
- Sofie Svanholm
- Department of Environmental Toxicology, Uppsala University, Uppsala 754 36, Sweden.
| | - Mauricio Roza
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, Stockholm 114 18, Sweden
| | - Daniele Marini
- Department of Environmental Toxicology, Uppsala University, Uppsala 754 36, Sweden; Department of Veterinary Medicine, University of Perugia, Perugia 06126, Italy
| | - Vanessa Brouard
- Department of Environmental Toxicology, Uppsala University, Uppsala 754 36, Sweden
| | - Oskar Karlsson
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, Stockholm 114 18, Sweden
| | - Cecilia Berg
- Department of Environmental Toxicology, Uppsala University, Uppsala 754 36, Sweden
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2
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Mannai A, Hmida L, Bouraoui Z, Guerbej H, Gharred T, Jebali J. Does thermal stress modulate the biochemical and physiological responses of Ruditapes decussatus exposed to the progestin levonorgestrel? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:85211-85228. [PMID: 35794321 DOI: 10.1007/s11356-022-21786-7] [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: 10/20/2021] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
In this study, we investigated the effects of 1000 ng/l levonorgestrel (LNG) alone or combined with increased temperature of 20, 24, and 28 °C on the biochemical and physiological responses of the clam (Ruditapes decussatus) for 28 days. Our results revealed that female clams treated with levonorgestrel (LNG) alone showed enhancement of the antioxidant defense against oxidative stress related to the inductions of catalase (CAT), gluthatione -S -transferase (GST), and protein sulfhydryl (PSH), while the elevated temperatures of 20, 24, and 28 °C diminished most of the specific responses to LNG and was the main factor in the determining the responses to combine exposures. The responses of lysosomal membrane stability, alkaline phosphatase, and NADP+-dependent isocitrate dehydrogenase detected were the most common signs of an adverse effect in all exposures. Female clams' testosterone and estradiol responses to LNG were the most particular manifestations depending on the exposure. Overall, these findings showed clearly that chronic warming stress caused disruption in physiological, biochemical parameters of the female clam R. decussatus, and this may have implications for the whole organism and populations.
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Affiliation(s)
- Asma Mannai
- Laboratory of Genetics Biodiversity and Valorization of Bio-resources (LR11ES41), Higher Institute of Biotechnology of Monastir, University of Monastir, Monastir, Tunisia.
| | - Leila Hmida
- Research Unit Ecosystems & Aquatic Resources (UR13AGRO1), National Agronomic Institute of Tunisia (INAT), University of Carthage, Charles Nicolle Avenue 43, Mahrajene City, 1082, Tunis, Tunisia
| | - Zied Bouraoui
- National Institute of Marine Sciences and Technology, Laboratory of Blue Biotechnology and Aquatic Bioproducts (LR16INSTM05), Monastir, Tunisia
| | - Hamadi Guerbej
- National Institute of Marine Sciences and Technology, Laboratory of Blue Biotechnology and Aquatic Bioproducts (LR16INSTM05), Monastir, Tunisia
| | - Tahar Gharred
- Laboratory of Bioresources: Integrative Biology & Valorization (LR 14ES06), Higher Institute of Biotechnology of Monastir, Monastir, Tunisia
| | - Jamel Jebali
- Laboratory of Genetics Biodiversity and Valorization of Bio-resources (LR11ES41), Higher Institute of Biotechnology of Monastir, University of Monastir, Monastir, Tunisia
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Thomson P, Pineda M, Yargeau V, Langlois VS. Chronic Exposure to Two Gestagens Differentially Alters Morphology and Gene Expression in Silurana tropicalis. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 80:745-759. [PMID: 33856560 DOI: 10.1007/s00244-021-00831-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Gestagens are active ingredients in human and veterinary drugs with progestogenic activity. Two gestagens-progesterone (P4), and the synthetic P4 analogue, melengestrol acetate (MGA)-are approved for use in beef cattle agriculture in North America. Both P4 and MGA have been measured in surface water receiving runoff from animal agricultural operations. This project aimed to assess the morphometric and molecular consequences of chronic exposures to P4, MGA, and their mixture during Western clawed frog metamorphosis. Chronic exposure (from embryo to metamorphosis) to MGA (1.7 µg/L) or P4 + MGA (0.22 µg/L P4 + 1.5 µg/L MGA) caused a considerable dysregulation of metamorphic timing, as evidenced by an inhibition of growth, narrower head, and lack of forelimb emergence in all animals. Molecular analysis revealed that chronic exposure to the mixture induced an additive upregulation of neurosteroid-related (GABAA receptor subunit α6 (gabra6) and steroid 5-alpha reductase 1 (srd5α1) gene expression in brain tissue. Chronic P4 exposure (0.26 µg/L P4) induced a significant upregulation of the expression hypothalamic-pituitary-gonadal (HPG)-related genes (ipgr, erα) in the gonadal mesonephros complex (GMC). Our data suggest that exposure to P4, MGA, and their mixture induces multiple endocrine responses and adverse effects in larval Western clawed frogs. This study helps to better our understanding of the consequences of chronic gestagen exposure and suggests that the implications and risk of high gestagen use in beef cattle feeding operations may extend to the aquatic environment.
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Affiliation(s)
- Paisley Thomson
- Institut national de la recherche scientifique (INRS) - Centre Eau Terre Environnement, 490 rue de la Couronne, Québec City, QC, G1K 9A9, Canada
| | - Marco Pineda
- Department of Chemical Engineering, McGill University, 3610 University St, Montreal, QC, H3A 0C5, Canada
| | - Viviane Yargeau
- Department of Chemical Engineering, McGill University, 3610 University St, Montreal, QC, H3A 0C5, Canada
| | - Valerie S Langlois
- Institut national de la recherche scientifique (INRS) - Centre Eau Terre Environnement, 490 rue de la Couronne, Québec City, QC, G1K 9A9, Canada.
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Svanholm S, Säfholm M, Brande-Lavridsen N, Larsson E, Berg C. Developmental reproductive toxicity and endocrine activity of propiconazole in the Xenopus tropicalis model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:141940. [PMID: 32890874 DOI: 10.1016/j.scitotenv.2020.141940] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
Environmental pollutants and especially endocrine disrupting chemicals (EDCs) are implicated as one of the drivers of the amphibian declines. To advance the understanding of the risks of EDCs to amphibians, methods to determine endocrine-linked adverse effects are needed. The aims were to 1) develop a partial life-cycle assay with the model frog Xenopus tropicalis to determine endocrine perturbation and adverse developmental effects, and 2) determine effects of propiconazole in this assay. Propiconazole is a pesticide with multiple endocrine modes of action in vitro. Its potential endocrine activity and adverse effects in amphibians remain to be elucidated. Tadpoles were exposed to 0, 33 and 384 μg propiconazole/L during critical developmental windows until completed metamorphosis. At metamorphosis, a sub-sample of animals was analysed for endpoints for disruption of estrogen/androgen (sex ratio, brain aromatase activity) and thyroid pathways (time to metamorphosis). The remaining individuals were kept unexposed for 2 months post-metamorphosis to analyze effects on sexual development including gonadal and Müllerian duct maturity and gametogenesis. At metamorphosis, brain aromatase activity was significantly increased in the high-dose group compared to control. In both propiconazole groups, an increased proportion of individuals reached metamorphosis faster than the mean time for controls, suggesting a stimulatory effect on the thyroid system. At 2 months post-metamorphosis, testis size, sperm and Müllerian duct maturity were reduced in the low-dose males, and the liver somatic index in males was increased in both propiconazole groups, compared with controls. In conclusion, our results show that propiconazole exposure caused endocrine perturbations and subsequent hepatic and reproductive effects evident at puberty, indicating persistent disruption of metabolism and male reproductive function. Our findings advance the development of methodology to determine endocrine and adverse effects of EDCs. Moreover, they increase the understanding of endocrine perturbations and consequent risk of adverse effects of azoles in amphibians.
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Affiliation(s)
- Sofie Svanholm
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Sweden.
| | - Moa Säfholm
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Sweden
| | - Nanna Brande-Lavridsen
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Sweden
| | - Erika Larsson
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Sweden
| | - Cecilia Berg
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Sweden
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Trudeau VL, Thomson P, Zhang WS, Reynaud S, Navarro-Martin L, Langlois VS. Agrochemicals disrupt multiple endocrine axes in amphibians. Mol Cell Endocrinol 2020; 513:110861. [PMID: 32450283 DOI: 10.1016/j.mce.2020.110861] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/17/2020] [Accepted: 05/04/2020] [Indexed: 12/20/2022]
Abstract
Concern over global amphibian declines and possible links to agrochemical use has led to research on the endocrine disrupting actions of agrochemicals, such as fertilizers, fungicides, insecticides, acaricides, herbicides, metals, and mixtures. Amphibians, like other species, have to partition resources for body maintenance, growth, and reproduction. Recent studies suggest that metabolic impairments induced by endocrine disrupting chemicals, and more particularly agrichemicals, may disrupt physiological constraints associated with these limited resources and could cause deleterious effects on growth and reproduction. Metabolic disruption has hardly been considered for amphibian species following agrichemical exposure. As for metamorphosis, the key thyroid hormone-dependent developmental phase for amphibians, it can either be advanced or delayed by agrichemicals with consequences for juvenile and adult health and survival. While numerous agrichemicals affect anuran sexual development, including sex reversal and intersex in several species, little is known about the mechanisms involved in dysregulation of the sex differentiation processes. Adult anurans display stereotypical male mating calls and female phonotaxis responses leading to successful amplexus and spawning. These are hormone-dependent behaviours at the foundation of reproductive success. Therefore, male vocalizations are highly ecologically-relevant and may be a non-invasive low-cost method for the assessment of endocrine disruption at the population level. While it is clear that agrochemicals disrupt multiple endocrine systems in frogs, very little has been uncovered regarding the molecular and cellular mechanisms at the basis of these actions. This is surprising, given the importance of the frog models to our deep understanding of developmental biology and thyroid hormone action to understand human health. Several agrochemicals were found to have multiple endocrine effects at once (e.g., targeting both the thyroid and gonadal axes); therefore, the assessment of agrochemicals that alter cross-talk between hormonal systems must be further addressed. Given the diversity of life-history traits in Anura, Caudata, and the Gymnophiona, it is essential that studies on endocrine disruption expand to include the lesser known taxa. Research under ecologically-relevant conditions will also be paramount. Closer collaboration between molecular and cellular endocrinologists and ecotoxicologists and ecologists is thus recommended.
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Affiliation(s)
- Vance L Trudeau
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, K1N 6N5, Canada.
| | - Paisley Thomson
- Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec (Québec), G1K 9A9, Canada.
| | - Wo Su Zhang
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, K1N 6N5, Canada.
| | - Stéphane Reynaud
- Laboratoire d'Ecologie Alpine, UMR UGA-USMB-CNRS 5553, Université Grenoble Alpes, CS 40700, 38058, Grenoble cedex 9, France.
| | - Laia Navarro-Martin
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Jordi Girona 18, 08034, Barcelona, Spain.
| | - Valérie S Langlois
- Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, 490 de la Couronne, Québec (Québec), G1K 9A9, Canada.
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Abstract
The reproductive cycle encompasses processes such as sex organ differentiation and development in the early life stages and maturation of the gametes in the adult organism. During the early life stages, critical developmental programming of the endocrine and reproductive systems occurs, and exposure to chemicals during these critical developmental windows can result in impaired reproductive function later in life. It is therefore important to evaluate long-term consequences of early life stage exposure to endocrine-disrupting chemicals. The African clawed frog Xenopus tropicalis has several characteristics that facilitate studies of developmental and reproductive toxicity. Here I present a X. tropicalis life cycle test protocol including study design, exposure regimes, and endpoints for chemical disruption of sex differentiation, gonadal and Müllerian duct development, the thyroxin-regulated metamorphosis, estrogen synthesis (activity of the CYP19 aromatase enzyme), spermatogenesis, oogenesis, puberty and fertility.
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Affiliation(s)
- Cecilia Berg
- Department of Environmental Toxicology, The Center for Reproductive Biology in Uppsala (CRU), Uppsala University, Uppsala, Sweden.
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7
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Šauer P, Stará A, Golovko O, Valentová O, Bořík A, Grabic R, Kroupová HK. Two synthetic progestins and natural progesterone are responsible for most of the progestagenic activities in municipal wastewater treatment plant effluents in the Czech and Slovak republics. WATER RESEARCH 2018; 137:64-71. [PMID: 29544204 DOI: 10.1016/j.watres.2018.02.065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/18/2018] [Accepted: 02/28/2018] [Indexed: 06/08/2023]
Abstract
Vast numbers of xenobiotics are known still to be present in treated municipal wastewater treatment plant (WWTP) effluents. Some of these possess endocrine-disrupting potency and pose risks for exposed aquatic animals. We searched for 17 potential environmental contaminants having affinity to the progesterone receptor. Relative potency values of these progesterone receptor-active chemicals were obtained. On the basis of relative potencies and measured environmental concentrations, the contribution of progestins to measured progestagenic activities was evaluated. Wastewaters (influent and effluent) and surrounding surface waters (upstream and downstream) at six municipal WWTPs were screened using instrumental chemical analysis and in vitro reporter gene bioassay. We showed the presence of target compounds and (anti-)progestagenic activities in municipal wastewater and surface water. Nine and seven progestins were identified in influent and effluent wastewaters, respectively. Only two compounds, progesterone and medroxyprogesterone were found in surface waters. Progestagenic agonistic activities in influents were partially masked by strong anti-progestagenic activities that were detected in all influents and ranged from 2.63 to 83 ng/L of mifepristone equivalents (EQs). Progestagenic activities were detected in all effluents and ranged from 0.06 to 0.47 ng/L of reference compound ORG 2058 EQs (a synthetic progestin equivalents), thus indicating incomplete removal of progestins during wastewater treatment processing. This activity poses a continuing risk for the aquatic environment. By contrast, anti-progestagenic activities showed better removal efficiency in WWTPs compared to progestagenic agonistic activities. Anti-progestagenic activities were found in only three of six effluents and ranged from 0.26 to 2.1 ng/L mifepristone EQs. We explained most of the progestagenic activity in municipal WWTP effluents by the presence of synthetic progestins and progesterone, which contributed 65-96% of such activity in samples where no antagonistic activity was found. The progestins medroxyprogesterone acetate, megestrol acetate and progesterone contributed most to the progestagenic activity detected in municipal effluents. Anti-progestagenic activities were found in some municipal effluents, but no causative agents were revealed because two analysed selective progesterone receptor modulators (SPRMs) with anti-progestagenic activities, mifepristone and ulipristal acetate, were not present in the effluents.
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Affiliation(s)
- Pavel Šauer
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic.
| | - Alžběta Stará
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
| | - Oksana Golovko
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
| | - Olga Valentová
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
| | - Adam Bořík
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
| | - Roman Grabic
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
| | - Hana Kocour Kroupová
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic
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Exposure to an anti-androgenic herbicide negatively impacts reproductive physiology and fertility in Xenopus tropicalis. Sci Rep 2018; 8:9124. [PMID: 29904069 PMCID: PMC6002408 DOI: 10.1038/s41598-018-27161-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 05/02/2018] [Indexed: 12/11/2022] Open
Abstract
Amphibians are threatened on a global scale and pollutants may be contributing to population declines, but how chemicals impact on their reproduction is poorly understood. We conducted a life cycle analysis to investigate the impacts of early life exposure to two anti-androgens (exposure until completion of metamorphosis;stage 66): flutamide, (50 µg/L)/linuron (9 and 45 µg/L)) on sexual development and breeding competence in Xenopus tropicalis. Our analyses included: mRNA levels of dmrt1, cyp17, amh, cyp19, foxl2 and ar (tadpoles/metamorphs), gonadal histomorphology (metamorphs/adults), mRNA levels of ar/gr (adult male brain/gonad/forelimb), testosterone/corticosterone levels (adult males), secondary sexual characteristics (forelimb width/nuptial pad: adult males) and breeding competence (amplexus/fertility: adult males). Compared to controls, feminised sex ratios and increased number of spermatogonia (adults) were observed after exposure to flutamide and the lower linuron concentration. Exposure to the lower linuron concentration also resulted in demasculinisation of secondary sexual characteristics and reduced male fertility. Flutamide exposure resulted in masculinisation of the nuptial pad and elevated mRNA levels of dmrt1, cyp17, amh and foxl2 in brains (metamorphs). Testosterone levels were higher in all treatment groups, however, overall few effects were observed in response to the higher linuron concentration. Our findings advance understanding of reproductive biology of X. tropicalis and illustrate negative effects of linuron on reproductive processes at a concentration measured in freshwater environments.
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Lorenz C, Krüger A, Schöning V, Lutz I. The progestin norethisterone affects thyroid hormone-dependent metamorphosis of Xenopus laevis tadpoles at environmentally relevant concentrations. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 150:86-95. [PMID: 29268119 DOI: 10.1016/j.ecoenv.2017.12.022] [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: 09/13/2017] [Revised: 12/06/2017] [Accepted: 12/09/2017] [Indexed: 06/07/2023]
Abstract
Previously, levonorgestrel (LNG) has been shown to be an endocrine disruptor of the amphibian thyroid system. In the present study, we investigated whether anti-thyroidal effects are a common property of progestins other than LNG. Premetamorphic Xenopus laevis tadpoles were exposed to norethisterone (NET) and dienogest DIE (each at 0.1-10nM) and LNG (10nM) until completion of metamorphosis. LNG and NET at all concentrations caused a significant developmental retardation whereas DIE did not impair time to metamorphosis. In LNG and 10nM NET exposed animals, tsh mRNA levels increased considerably later than the developmental delay occurred and thyroid histopathology showed no signs of TSH-hyperstimulation. Instead, thyroid glands from these treatments appeared inactive in producing thyroid hormones. Thyroidal transcript levels of dio2 and dio3 were increased by treatments with LNG and NET at 1nM and 10nM, whereas iyd mRNA was reduced by LNG and 10nM NET. Expression of slc5α5 was not changed by any treatment. Effects of DIE differed from those induced by LNG and NET. No developmental delay was measurable; however, tshβ and dio2 mRNAs were increased in pituitary glands of tadpoles exposed to 1.0nM and 10nM DIE. Thyroid histopathology displayed no abnormalities and thyroidal mRNA expression of the genes analyzed (slc5α5, iyd, dio2, dio3) was not changed by DIE. Overall, our results provide evidence that the anti-thyroidal effects already known from LNG are also present in another progestin, namely NET, even at environmentally relevant concentrations. In conclusion we suggest that progestins do not only pose an environmental risk in terms of their impact on reproductive success of aquatic vertebrates, but also with respect to their anti-thyroidal properties affecting amphibian metamorphosis.
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Affiliation(s)
- Claudia Lorenz
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany.
| | - Angela Krüger
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany
| | - Viola Schöning
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany
| | - Ilka Lutz
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany
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10
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Ockleford C, Adriaanse P, Berny P, Brock T, Duquesne S, Grilli S, Hernandez-Jerez AF, Bennekou SH, Klein M, Kuhl T, Laskowski R, Machera K, Pelkonen O, Pieper S, Stemmer M, Sundh I, Teodorovic I, Tiktak A, Topping CJ, Wolterink G, Aldrich A, Berg C, Ortiz-Santaliestra M, Weir S, Streissl F, Smith RH. Scientific Opinion on the state of the science on pesticide risk assessment for amphibians and reptiles. EFSA J 2018; 16:e05125. [PMID: 32625798 PMCID: PMC7009658 DOI: 10.2903/j.efsa.2018.5125] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science to support the potential development of a risk assessment scheme of plant protection products for amphibians and reptiles. The coverage of the risk to amphibians and reptiles by current risk assessments for other vertebrate groups was investigated. Available test methods and exposure models were reviewed with regard to their applicability to amphibians and reptiles. Proposals were made for specific protection goals aiming to protect important ecosystem services and taking into consideration the regulatory framework and existing protection goals for other vertebrates. Uncertainties, knowledge gaps and research needs were highlighted.
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11
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Jansson E, Mattsson A, Goldstone J, Berg C. Sex-dependent expression of anti-Müllerian hormone (amh) and amh receptor 2 during sex organ differentiation and characterization of the Müllerian duct development in Xenopus tropicalis. Gen Comp Endocrinol 2016; 229:132-44. [PMID: 26987287 DOI: 10.1016/j.ygcen.2016.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/12/2016] [Accepted: 03/11/2016] [Indexed: 12/31/2022]
Abstract
Amphibian gonadal differentiation involves the action of sex steroids. Recent research indicates that the anti-Müllerian hormone (AMH) is involved in testicular development in some lower vertebrate species. For amphibians there is a lack of data on ontogenetic expression of the AMH receptor AMHR2/amhr2 and of progesterone receptors (PGRS/pgrs). Here we expand the knowledge on amphibian sex differentiation by characterizing ontogenetic mRNA levels of amh, amhr2, intracellular and membrane pgrs (ipgr and mpgr beta) and cytochrome P450 19a1 (cyp19a1) (ovarian marker) in the urogenital complex of the model species Xenopus (Silurana) tropicalis. Furthermore, we characterized the ontogenetic development of the Müllerian ducts (precursors of the female reproductive tract) histologically. The developmental period investigated spanned from beginning of gonadal differentiation, Nieuwkoop and Faber (NF) stage 51, to 4weeks post-metamorphosis. The Müllerian ducts were first observed at NF 64 in both sexes. Male-enhanced amh mRNA levels from NF 53/54 to 6days post-metamorphosis and female-enhanced cyp19a1 levels from NF 53 to 4weeks post-metamorphosis were noted. The sexually dimorphic mRNA level profile was more distinct for amh than for cyp19a1. The pgrs mRNA levels increased over the studied period and showed no sex differences. At later developmental stages, the amhr2 mRNA level was increased in putative females compared with males. Our findings suggest that AMH has a role in gonadal differentiation in X. tropicalis. We propose relative gonadal amh mRNA level as a testicular marker during early gonadal development in amphibians.
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Affiliation(s)
- Erika Jansson
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
| | - Anna Mattsson
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
| | - Jared Goldstone
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States.
| | - Cecilia Berg
- Department of Environmental Toxicology, Uppsala University, Centre for Reproductive Biology in Uppsala (CRU), Uppsala, Sweden.
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