| 1. |
- Andersson, Carin, et al.
(författare)
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A chemometrical approach to study interactions between ethynylestradiol and an AhR-agonist in stickleback (Gasterosteus aculeatus)
- 2010
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Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 24:11-12, s. 768-778
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Tidskriftsartikel (refereegranskat)abstract
- Quantifiable responses in fish, such as induction of certain proteins, can be used as indicators of chemical contamination of waterways. In order to evaluate differences in ethoxyresorufin-O-deethylase (EROD) induction capacity of the gill and the liver and effects on organs and biomarker proteins, e.g. gill and liver EROD, hepatosomatic index (HSI), nephrosomatic index (NSI), gonadosomatic index (GSI), spiggin, vitellogenin and sperm motility were analysed in male three-spined sticklebacks (Gasterosteus aculeatus) exposed for 21 days to β-naphthoflavone (βNF) alone (Exp 1) or in combination with 17α-ethynylestradiol (EE2) (Exp 2). The sperm motility variables were studied using computer-assisted sperm analysis (CASA). Exp 1: Gill EROD activity was significantly induced in fish exposed to ≥1.2 µg/l and hepatic EROD activity in fish exposed to ≥6 µg/l. No significant effect of ßNF on the production of spiggin or vitellogenin or on sperm variables was found. Exp 2: A significant additative effect of EE2 + βNF was shown for gill EROD. A significant antagonistic effect of the two compounds was found on NSI where an increased EE2 concentration led to an increase in NSI while an increased concentration of βNF led to a decreased NSI. Interestingly, the results showed that exposure to intermediate concentrations of EE2 and ßNF led to a significant increase in the sperm variables. In the aquatic environment mixtures of numerous chemicals with oestrogenic activity are present, so if the capacity to induce gill EROD activity is a general property of oestrogen-acting chemicals, our findings are important.
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| 2. |
- Andersson, Carin, et al.
(författare)
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Effects of 17α-ethynylestradiol on EROD activity, spiggin and vitellogenin in three-spined stickleback (Gasterosteus aculeatus)
- 2007
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 83:1, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- The three-spined stickleback (Gasterosteus aculeatus) has quantifiable biomarkers of exposure to estrogens (vitellogenin), androgens (spiggin) and aryl hydrocarbon receptor (AhR) agonists (EROD activity) and is therefore a promising test species for biomonitoring of reprotoxic chemicals in aquatic environments. In this study we evaluated the effects of 17α-ethynylestradiol (EE2) on EROD activity, induction of vitellogenin and spiggin, hepatosomatic index (HSI), ovarian somatic index (OSI) and nephrosomatic index (NSI). Adult male and female three-spined sticklebacks were exposed to concentrations of 0–170 ng EE2/l (measured concentrations) in a flow-through system for 21 days. Exposure to 170 ng EE2/l resulted in a significant 8- and 9-fold induction of gill EROD activity in males and females, respectively. In livers, EROD activity expressed in relation to microsomal protein content was suppressed due to a significant increase in microsomal protein content. Hepatic EROD activity per se expressed as picomol/min was not affected by exposure to EE2. The lowest observed effect concentration for induction of vitellogenin in males was 53.7 ng EE2/l. In females, vitellogenin levels were significantly higher in those exposed to170 ng EE2/l compared to controls. Spiggin production was significantly inhibited and NSI lower in males exposed to 170 ng EE2/l. In both females and males LSI was significantly higher in fish exposed to 170 ng EE2/l than in controls. In females exposed to 170 ng EE2/l, OSI was significantly lower and NSI higher than controls. The observed results from this study show that a synthetic estrogen can affect the well-known biomarker of exposure for dioxin-like compounds, EROD activity, and further that this response can differ between tissues. These findings are important for interpretation of biomonitoring data.
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| 3. |
- Björkblom, Carina, et al.
(författare)
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Estrogenic and androgenic effects of municipal wastewater effluent on reproductive endpoint biomarkers in three-spined stickleback (Gasterosteus aculeatus)
- 2009
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley-Blackwell. - 0730-7268 .- 1552-8618. ; 28:5, s. 1063-1071
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Tidskriftsartikel (refereegranskat)abstract
- Municipal wastewater treatment plants have been associated with the release of endocrine-disrupting chemicals, which consequently lead to alterations of reproductive function in aquatic organisms. The three-spined stickleback (Gasterosteus aculeatus) has quantifiable biomarkers for assessment of both estrogen (vitellogenin) and androgen (spiggin) activity, which makes this species very valuable in the research of endocrine disruption. The estrogenic and androgenic biomarkers were used for evaluating exposure effects of municipal wastewater effluent. We evaluated the effects of 17alpha-ethinylestradiol (EE2), 17alpha-methyltestosterone (MT), and wastewater effluents on induction of vitellogenin and spiggin production, gonadosomatic index, hepatosomatic index, nephrosomatic index, plasma steroid levels, and histopathology. Adult female and male sticklebacks were exposed to 20 ng/L of EE2, 10 microg/L of MT, and wastewater effluent (10, 50, and 80% of original concentration) in a flow-through system for an exposure of one week and an extended exposure of four weeks. Chemical analyses of the steroids were done for verification of exposure concentrations and presence in the used wastewater. Our results show that municipal wastewater effluent exerts estrogenic action on three-spined stickleback as observed by elevated vitellogenin levels in exposed fish, corresponding to the effect seen in fish exposed to EE2. Furthermore, wastewater and EE2 exerted similar histopathological effects on testis of exposed fish. Although domestic effluent is suspected to have a high content of natural androgens, no obvious androgenic effect of wastewater was observed in the present study.
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| 4. |
- Björkbom, Carina, et al.
(författare)
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Assessment of reproductive biomarkers in three-spined stickleback (Gasterosteus aculeatus) from sewage effluent recipients
- 2013
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Ingår i: Environmental Toxicology. - : Wiley-Blackwell. - 1520-4081 .- 1522-7278. ; 28:4, s. 229-237
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the occurrence of endocrine disruption close to sewage treatment plant effluent discharges along the Finnish Baltic Sea coast using a set of reproductive biomarkers present in adult three-spined stickleback (Gasterosteus aculeatus). Possible variation and sensitivity of the biomarkers during an entire reproductive period were also examined. The analysis of vitellogenin (VTG) for estrogenic activity and spiggin for androgenic activity, together with histopathological analysis indicated that sticklebacks were exposed to estrogenic loads sufficient to cause inappropriate production of VTG and to disrupt normal testicular structure in adult male sticklebacks. No androgenic disruption was observed. The results emphasize the need of a combination of several reproductive biomarkers in fish and repeated sampling for the detection of potential endocrine modulating substances under field condition
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| 5. |
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| 6. |
- Hahlbeck, Edda, et al.
(författare)
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The juvenile three-spined stickleback (Gasterosteus aculeatus L.) as a model organism for endocrine disruption II : kidney hypertrophy, vitellogenin and spiggin induction
- 2004
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Ingår i: Aquatic Toxicology. - : Elsevier B.V.. - 0166-445X .- 1879-1514. ; 70:4, s. 311-326
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the suitability of juvenile three-spined sticklebacks, Gasterosteus aculeatus L., for detecting both androgen- and oestrogen-induced endocrine disruption. The investigated endpoints were kidney hypertrophy and the induction of the protein markers spiggin and vitellogenin. Juveniles were exposed to steroid hormones 17β-oestradiol (E2: nominal 0.01, 1.0 and 10 μg/L), 17α-ethinylestradiol (EE2: nominal 0.05 μg/L) and 17α-methyltestosterone (MT: nominal 1.0 μg/L) from the day of hatching until the termination of the experiments between 39 and 58 days after hatching. E2 (10 μg/L) and MT were applied during different time windows: (a) 14 days after hatching only and (b) continuously with start 14 days after hatching. Kidney hypertrophy is an androgen-dependent secondary sexual character in adult male sticklebacks and corresponds to the production of the glue protein spiggin during the breeding season. The kidneys were hypertrophied and spiggin levels were elevated in juvenile sticklebacks after treatment with MT. Paradoxically, slightly elevated spiggin levels and kidney hypertrophy were observed also in fish treated with high dose E2. Levels of vitellogenin, the oestrogen-inducible yolk precursor protein, were elevated in juvenile sticklebacks after E2 medium and high dose and EE2 treatment. The tested endpoints are suitable for the study of endocrine disruption in juvenile sticklebacks, a fish species that is easy to handle in laboratory and relevant for temperate geographical regions.
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| 7. |
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| 8. |
- Porseryd, Tove
(författare)
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Endocrine disruption in fish : Effects of 17α-ethinylestradiol exposure on non-reproductive behavior, fertility and brain and testis transcriptome
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aquatic environments are the end recipient for most anthropogenic chemical pollutants. One common chemical pollutant found in the aquatic environment is 17α-ethinylestradiol (EE2), a synthetic estrogen used in contraceptive pills. EE2 is found in sewage treatment plant effluents and surface waters in concentrations from non-detectable up to 300 ng/L. EE2 has the ability to bioaccumulate and is more than 10 fold more potent in fish than the natural counterpart estradiol. Exposure has led to skewed sex ratios, decreased egg and sperm production, and altered reproductive behavior. The aim of this thesis was to investigate the effects of EE2 exposure on non-reproductive behavior and fertility in fish. We found that zebra fish exposed to low concentrations of EE2 during development showed increased anxiety-like behavior and decreased fertility that were persistent in adulthood, even after a long remediation period in clean water. The altered behavior and lowered fertility were accompanied by alterations in the testis and brain transcriptome of possible significance for the behavior and fertility effects. The zebrafish was also used in adult exposures of EE2 and citalopram, alone and in combination to investigate if behavioral effects can be detected at very low concentrations, and if so, if the two compounds would interact and affect the behavioral outcome. Anxiety-like behavior was altered by EE2 and the two compounds in combination affected the outcome of each other. Further, when developmental exposure of progeny to wild caught three spined stickleback was used as a link between laboratory fish and natural fish populations, EE2 was found to decrease the anxiety-like behavior in the adult stickleback as well as cause ovotestis and intersex, feminization and sex reversal of genetic males. In conclusion, fertility and non-reproductive behaviors in the zebrafish and three spined stickleback are sensitive to EE2 exposure and effects from developmental exposures seem to be persistent. Fertility and behavior are of high ecological significance for fish and alterations due to EE2 exposure might have negative effects on population fitness. The persistent alterations in the transcriptome of the zebrafish testis and brain lead to generation of hypotheses of mechanisms involved in the behavior and reproductive phenotypes caused by developmental exposure to EE2.
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| 9. |
- Roufidou, Chrysoula, et al.
(författare)
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Hormonal changes over the spawning cycle in the female three-spined stickleback, Gasterosteus aculeatus
- 2018
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Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 257:SI, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Female three-spined sticklebacks are batch spawners laying eggs in a nest built by the male. We sampled female sticklebacks at different time points, when they were ready to spawn and 6, 24, 48 and 72 hours post-spawning (hps) with a male. Following spawning, almost all females (15 out of 19) had ovulated eggs again at Day 3 post-spawning (72hps). At sampling, plasma, brain and pituitaries were collected, and the ovary and liver were weighed. Testosterone (T) and estradiol (E2) were measured by radioimmunoassay. Moreover, the mRNA levels of follicle-stimulating hormone (fsh-β) and luteinizing hormone (lh-β) in the pituitary, and of the gonadotropin-releasing hormones (GnRHs: gnrh2, gnrh3) and kisspeptin (kiss2) and its G protein-coupled receptor (gpr54) in the brain were measured by real-time qPCR. Ovarian weights peaked in “ready to spawn” females, dropped after spawning, before again progressively increasing from 6 to 72hps. Plasma T levels showed peaks at 24 and 48hps and decreased at 72hps, while E2 levels increased already at 6hps and remained at high levels up to 48hps. There was a strong positive correlation between T and E2 levels over the spawning cycle. Pituitary lh-β mRNA levels showed a peak at 48hps, while fsh-β did not change. The neuropeptides and gpr54 did not show any changes. The changes in T and E2 over the stickleback spawning cycle were largely consistent with those found in other multiple-spawning fishes whereas the marked correlation between T and E2 does not support T having other major roles over the cycle than being a precursor for E2.
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| 10. |
- Roufidou, Chrysoula, et al.
(författare)
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Overripening of eggs and changes in reproductive hormones in the threespine stickleback, Gasterosteus aculeatus
- 2016
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Ingår i: Evolutionary Ecology Research. - 1522-0613 .- 1937-3791. ; 17:3, s. 583-601
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Tidskriftsartikel (refereegranskat)abstract
- Background: Female threespine sticklebacks, Gasterosteus aculeatus, are batch spawners. As in most teleosts, the ovulated eggs are kept in the ovarian cavity until spawning. If spawning or spontaneous release of the eggs does not take place, they can become overripe and harden, and in most cases remain in the ovary. The overripe eggs are lost for reproduction and also block further spawnings. Reproductive hormones regulate egg production and may be involved in the mechanism of overripening. Question: What are the reproductive endocrinological parameters characterizing overripening of ovulated eggs in the threespine stickleback? Organism: Wild-caught adult threespine sticklebacks from the southern Baltic at Skare in southern Sweden and the island of Asko in northwestern Baltic Proper in Sweden. Experiments: We collected blood samples for hormone measurements, as well as pituitaries and brains for measurement of mRNA from both sexually mature non-overripe (non-ovulated and/or ovulated) and overripe (egg-bound) females. For the Skare fish, sexual maturation was induced under laboratory conditions by exposure to a long photoperiod and we compared the non-overripe (including non-ovulated, with oocytes in different maturing or ripening stages, and ovulated females) with the overripe females. The Asko fish were sampled directly from nature, during the natural summer breeding season and we compared the non-overripe (including non-ovulated, with oocytes in different maturing or ripening stages, and ovulated females) with the overripe females. Methods: In the fish collected from Skare, we used radioimmunoassay to measure the plasma levels of four steroids: testosterone, estradiol, 17,20 beta-dihydroxypregn-4-en-3-one (17,20 beta-P), and 17,20 beta, 21-trihydroxypregn-4-en-3-one (17,20 beta,21-P). We also measured the mRNA levels of gonadotropins [GTHs: follicle-stimulating hormone (fsh-beta) and luteinizing hormone (lh-beta)] in the pituitary, and of gonadotropin-releasing hormones (GnRHs: gnrh2, gnrh3) and kisspeptin (kiss2) and its G protein-coupled receptor (gpr54) in the brain by real-time quantitative PCR. In the fish collected from Asko, we measured only progestogens (17,20 beta-P and 17,20 beta,21-P). Results: In the fish from Skare, overripe female sticklebacks had significantly lower levels of circulating plasma steroid hormones (testosterone, estradiol, 17,20 beta-P), as well as of pituitary lh-beta and brain kiss2 and gpr54 mRNA than the non-overripe females. In the fish caught from Asko, overripe females had lower 17,20 beta-P levels than the non-overripe non-ovulated females, but there was no difference between the non-overripe ovulated and the overripe females. The 17,20 beta,21-P plasma levels were under the limit of detection in all groups.
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