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  • 1.
    Banjop Kharlyngdoh, Joubert
    Örebro University, School of Science and Technology.
    Modulation of androgen receptor function by brominated flame retardants2015Doctoral thesis, comprehensive summary (Other academic)
    List of papers
    1. Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters
    Open this publication in new window or tab >>Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters
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    2015 (English)In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 74, p. 60-70Article in journal (Refereed) Published
    Abstract [en]

    Brominated flame-retardants (BFRs) are used in industrial products to reduce the risk of fire. However, their continuous release into the environment is a concern as they are often persistent, bioaccumulating and toxic. Information on the impact these compounds have on human health and wildlife is limited and only a few of them have been identified to disrupt hormone receptor functions. In the present study we used in silico modeling to determine the interactions of selected BFRs with the human androgen receptor (AR). Three compounds were found to dock into the ligand-binding domain of the human AR and these were further tested using in vitro analysis. Allyl 2,4,6-tribromophenyl ether (ATE), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) were observed to act as AR antagonists. These BFRs have recently been detected in the environment, in house dust and in aquatic animals. The compounds have been detected at high concentrations in both blubber and brain of seals and we therefore also assessed their impact on the expression of L-type amino acid transporter system (LAT) genes, that are needed for amino acid uptake across the blood-brain barrier, as disruption of LAT gene function has been implicated in several brain disorders. The three BFRs down-regulated the expression of AR target genes that encode for prostate specific antigen (PSA), 5. α-reductases and β-microseminoprotein. The potency of PSA inhibition was of the same magnitude as the common prostate cancer drugs, demonstrating that these compounds are strong AR antagonists. Western blot analysis of AR protein showed that ATE, BATE and DPTE decreased the 5. α-dihydrotestosterone-induced AR protein levels, further confirming that these BFRs act as AR antagonists. The transcription of the LAT genes was altered by the three BFRs, indicating an effect on amino-acid uptake across cellular membranes and blood-brain barrier. This study demonstrated that ATE, BATE and DPTE are potent AR antagonists and the alterations in LAT gene transcription suggest that these compounds can affect neuronal functions and should be considered as potential neurotoxic and endocrine disrupting compounds.

    Keywords
    Gene regulation; Human; PSA; LAT
    National Category
    Environmental Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-41508 (URN)10.1016/j.envint.2014.09.002 (DOI)000346681700008 ()25454221 (PubMedID)2-s2.0-84908626070 (Scopus ID)
    Funder
    Knowledge Foundation, 20110183
    Note

    Funding Agency:

    Örebro University J61900

    Available from: 2015-01-14 Created: 2015-01-14 Last updated: 2017-12-05Bibliographically approved
    2. The brominated flame retardant TBECH activates the zebrafish (Danio rerio) androgen receptor, alters gene transcription and causes developmental disturbances
    Open this publication in new window or tab >>The brominated flame retardant TBECH activates the zebrafish (Danio rerio) androgen receptor, alters gene transcription and causes developmental disturbances
    2013 (English)In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 142, p. 63-72Article in journal (Refereed) Published
    Abstract [en]

    Tetrabromoethylcyclohexane (TBECH) is a brominated flame retardant that has been shown to be a potent agonist to the human androgen receptor (AR). However, while it is present in the environment, it is not known if it interacts with AR from aquatic species. The present study was therefore aimed at improving our understanding of how TBECH affects aquatic animals using zebrafish as a model organism. In silica modeling demonstrated that TBECH diastereomers bind to the zebrafish androgen receptor (zAR) and in vitro and in vivo data showed that TBECH has androgenic properties. Deleterious effects of TBECH were studied on embryonic and juvenile zebrafish and qRT-PCR analysis in vitro and in vivo was performed to determine TBECH effects on gene regulation. TBECH was found to delay hatching at 1 mu M and 10 mu M doses while morphological abnormalities and juvenile mortality was observed at 10 mu M. The qRT-PCR analysis showed alterations of multiple genes involved in chondrogenesis (cartilage development), metabolism and stress response. Thus, TBECH induces androgenic activity and has negative effects on zebrafish physiology and therefore its impact on the environment should be carefully monitored. (C) 2013 Elsevier B.V. All rights reserved.

    Keywords
    Androgens, Endocrine, Endocrine disruptor, Gene regulation
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:oru:diva-32902 (URN)10.1016/j.aquatox.2013.07.018 (DOI)000328093900007 ()23958786 (PubMedID)
    Funder
    Knowledge Foundation
    Available from: 2014-01-02 Created: 2014-01-02 Last updated: 2017-12-06Bibliographically approved
    3. Androgen receptor mutations associated with prostate cancer lead to differential activation by DBE-DBCH diastereomers
    Open this publication in new window or tab >>Androgen receptor mutations associated with prostate cancer lead to differential activation by DBE-DBCH diastereomers
    (English)Manuscript (preprint) (Other academic)
    Keywords
    steroid hormone receptor, endocrine disruptor, human carcinoma, androgen agonists
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-44665 (URN)
    Available from: 2015-05-20 Created: 2015-05-20 Last updated: 2017-10-17Bibliographically approved
    4. Combination effects on human cell lines following exposure to brominated flame-retardants that interact with the androgen receptor
    Open this publication in new window or tab >>Combination effects on human cell lines following exposure to brominated flame-retardants that interact with the androgen receptor
    (English)Manuscript (preprint) (Other academic)
    Keywords
    DBE-DBCH/TBECH, TBP-AE/ATE, TBP-BAE/BATE, TBP-DBPE/DPTE, endocrine disruptors, PSA, steroidogenesis
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-44666 (URN)
    Available from: 2015-05-20 Created: 2015-05-20 Last updated: 2017-10-17Bibliographically approved
  • 2.
    Boström, Björn
    Örebro University, Department of Natural Sciences.
    Achieving carbon isotope mass balance in northern forest soils, soil respiration and fungi2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Northern forests contain a large part of the global terrestrial carbon pool and it is unclear whether they will be sinks or sources for atmospheric carbon if the climate warms as predicted. Stable isotope techniques provide unique tools to study the carbon cycle at different scales but the interpretation of the isotope data is impaired by our inability to close the carbon isotope mass balance of ecosystems. This involves the paradox that the soil organic matter becomes increasingly 13C-enriched with increasing soil depth relative to the carbon input, plant litter, at the same time as soil respiration, the major carbon outflow from the soil, and fungi, organisms dependent on plant derived carbon, both are relatively 13C-enriched. I have determined the δ13C of the respired CO2 and the organic matter from different ecosystem components in a Norway spruce forest aiming at finding an explanation to the observed carbon isotope pattern.

    In the first study the soil surface respiration rate and isotopic composition was found to be governed by aboveground weather conditions the preceding 1-6 days. This suggests there is a fast flux of recent photosynthates to root respiration. In the second study I compared the respired CO2 from decomposition with the δ13C of the root free soil organic matter sampled from the litter layer down to 50 cm depth. Discrimination against 13C during respiration could not explain the 13C enrichment of soil organic matter with depth because the δ13C of the respired CO2 became increasingly 13C-enriched relative to the organic matter with soil depth. However, ~1.5‰ of the 2‰ 13C-gradient could be explained by the 13C depletion of atmospheric CO2 that has proceeded since the beginning of the 18th century due to the burning of fossil fuels and deforestation. The remaining shift was hypothesized to be due to a belowground contribution of 13C-enriched ectomycorrhizal derived carbon. In the third study I compared the δ13C of respired CO2 and sporocarps of ectomycorrhizal and saprotrophic fungi sampled in the spruce forest. The δ13C of respired CO2 and sporocarps were positively correlated and the differences in δ13C between CO2 and sporocarps were small, <±1‰ in nine out of 16 species, although three out of six species of ectomycorrhizal basidiomycetes respired 13C-enriched CO2 (up to 1.6‰), whereas three out of five species of polypores respired 13C-depleted CO2 (up to 1.7‰; P<0.05). Loss of 13C-depleted CO2 may have enriched the biomass of some fungal species in 13C. However, the consistent 13C enrichment of fungal sporocarps and respired CO2 relative to the plant materials implies that other processes must be found to explain the consistent 13C-enrichment of fungal biomass compared to plant materials. In the final study, compound specific stable isotope analyses provided further evidence for the hypothesis that the biomass of ectomycorrhizal fungi are 13C-enriched relative to host biomass because the carbon provided by the host is 13C-enriched Furthermore, ectomycorrhizal fungi showed lower average δ13C values of metabolites than saprotrophs which gives further support for the so-called saprotrophic-mycorrhizal divide. I conclude that a belowground allocation of 13C-enriched carbon to ectomycorrhizal fungi closes the carbon isotope mass balance in boreal and temperate forest soils and explains the 13C-enriched soil respiration.

    List of papers
    1. Forest soil respiration rate and d13C is regulated by recent above ground weather conditions
    Open this publication in new window or tab >>Forest soil respiration rate and d13C is regulated by recent above ground weather conditions
    2005 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 143, no 1, p. 136-142Article in journal (Refereed) Published
    Abstract [en]

    Soil respiration, a key component of the global carbon cycle, is a major source of uncertainty when estimating terrestrial carbon budgets at ecosystem and higher levels. Rates of soil and root respiration are assumed to be dependent on soil temperature and soil moisture yet these factors often barely explain half the seasonal variation in soil respiration. We here found that soil moisture (range 16.5-27.6% of dry weight) and soil temperature (range 8-17.5 degrees C) together explained 55% of the variance (cross-validated explained variance; Q2) in soil respiration rate (range 1.0-3.4 micromol C m(-2) s(-1)) in a Norway spruce (Picea abies) forest. We hypothesised that this was due to that the two components of soil respiration, root respiration and decomposition, are governed by different factors. We therefore applied PLS (partial least squares regression) multivariate modelling in which we, together with below ground temperature and soil moisture, used the recent above ground air temperature and air humidity (vapour pressure deficit, VPD) conditions as x-variables. We found that air temperature and VPD data collected 1-4 days before respiration measurements explained 86% of the seasonal variation in the rate of soil respiration. The addition of soil moisture and soil temperature to the PLS-models increased the Q2 to 93%. delta13C analysis of soil respiration supported the hypotheses that there was a fast flux of photosynthates to root respiration and a dependence on recent above ground weather conditions. Taken together, our results suggest that shoot activities the preceding 1-6 days influence, to a large degree, the rate of root and soil respiration. We propose this above ground influence on soil respiration to be proportionally largest in the middle of the growing season and in situations when there is large day-to-day shifts in the above ground weather conditions. During such conditions soil temperature may not exert the major control on root respiration.

    Keywords
    Air temperature, 13C, PLS time series analysis, Root respiration, Soil temperature
    National Category
    Biomaterials Science Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-2966 (URN)10.1007/s00442-004-1776-z (DOI)
    Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2017-12-14Bibliographically approved
    2. Isotope fractionation and 13C enrichment in soil profiles during the decomposition of soil organic matter
    Open this publication in new window or tab >>Isotope fractionation and 13C enrichment in soil profiles during the decomposition of soil organic matter
    2007 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 153, no 1, p. 89-98Article in journal (Refereed) Published
    Abstract [en]

    The mechanisms behind the 13C enrichment of organic matter with increasing soil depth in forests are unclear. To determine if 13C discrimination during respiration could contribute to this pattern, we compared d13C signatures of respired CO2 from sieved mineral soil, litter layer and litterfall with measurements of d13C and d15N of mineral soil, litter layer, litterfall, roots and fungal mycelia sampled from a 68-year-old Norway spruce forest stand planted on previously cultivated land. Because the land was subjected to ploughing before establishment of the forest stand, shifts in d13C in the top 20 cm reflect processes that have been active since the beginning of the reforestation process. As 13C-depleted organic matter accumulated in the upper soil, a 1.0 o/oo d13C gradient from –28.5 o/oo in the litter layer to –27.6 o/oo at a depth of 2–6 cm was formed. This can be explained by the 1 o/oo drop in d13C of atmospheric CO2 since the beginning of reforestation together with the mixing of new C (forest) and old C (farmland). However, the isotopic change of the atmospheric CO2 explains only a portion of the additional 1.0& increase in d13C below a depth of 20 cm. The d13C of the respired CO2 was similar to that of the organic matter in the upper soil layers but became increasingly 13C enriched with depth, up to 2.5 o/oo relative to the organic matter. We hypothesise that this 13C enrichment of the CO2 as well as the residual increase in d13C of the organic matter below a soil depth of 20 cm results from the increased contribution of 13C-enriched microbially derived C with depth. Our results suggest that 13C discrimination during microbial respiration does not contribute to the 13C enrichment of organic matter in soils. We therefore recommend that these results should be taken into consideration when natural variations in d13C of respired CO2 are used to separate different components of soil respiration or ecosystem respiration.

    Place, publisher, year, edition, pages
    Berlin: Springer, 2007
    Keywords
    C:N ratio, d13C, Forest soil organic matter, Isotopic discrimination, Microbial respiration
    National Category
    Natural Sciences Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-4241 (URN)10.1007/s00442-007-0700-8 (DOI)17401582 (PubMedID)
    Available from: 2007-12-07 Created: 2007-12-07 Last updated: 2017-12-14Bibliographically approved
    3. Can isotopic fractionation during respiration explain the 13C-enriched sporocarps of ectomycorrhizal and saprotrophic fungi?
    Open this publication in new window or tab >>Can isotopic fractionation during respiration explain the 13C-enriched sporocarps of ectomycorrhizal and saprotrophic fungi?
    2008 (English)In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 177, no 4, p. 1012-1019Article in journal (Refereed) Published
    Abstract [en]

    • The mechanism behind the 13C enrichment of fungi relative to plant materials is unclear and constrains the use of stable isotopes in studies of the carbon cycle in soils.

    • Here, we examined whether isotopic fractionation during respiration contributes to this pattern by comparing δ13C signatures of respired CO2, sporocarps and their associated plant materials, from 16 species of ectomycorrhizal or saprotrophic fungi collected in a Norway spruce forest.

    • The isotopic composition of respired CO2 and sporocarps was positively correlated. The differences in δ13C between CO2 and sporocarps were generally small, < ±1‰ in nine out of 16 species, and the average shift for all investigated species was 0.04‰. However, when fungal groups were analysed separately, three out of six species of ectomycorrhizal basidiomycetes respired 13C-enriched CO2 (up to 1.6‰), whereas three out of five species of polypores respired 13C-depleted CO2 (up to 1.7‰; P < 0.05). The CO2 and sporocarps were always 13C-enriched compared with wood, litter or roots.

    • Loss of 13C-depleted CO2 may have enriched some species in 13C. However, that the CO2 was consistently 13C-enriched compared with plant materials implies that other processes must be found to explain the consistent 13C-enrichment of fungal biomass compared with plant materials.

    Place, publisher, year, edition, pages
    Cambridge: Cambridge University Press, 2008
    Keywords
    Carbon/*metabolism, Carbon Dioxide/metabolism, Carbon Isotopes, Fungi/*metabolism, Nitrogen/metabolism, Nitrogen Isotopes, Oxygen Consumption/*physiology, Picea/microbiology, Time Factors, Trees/microbiology
    National Category
    Ecology Soil Science Natural Sciences Agricultural Sciences
    Research subject
    biologi
    Identifiers
    urn:nbn:se:oru:diva-4647 (URN)10.1111/j.1469-8137.2007.02332.x (DOI)18086229 (PubMedID)
    Available from: 2008-10-20 Created: 2008-10-20 Last updated: 2017-12-14Bibliographically approved
    4. Carbon isotope ratios in ectomycorrhizal and saprotrophic metabolites in relation to the δ13C of substrate, sporocarps and respired CO2
    Open this publication in new window or tab >>Carbon isotope ratios in ectomycorrhizal and saprotrophic metabolites in relation to the δ13C of substrate, sporocarps and respired CO2
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15539 (URN)
    Available from: 2011-05-11 Created: 2011-05-11 Last updated: 2017-10-17Bibliographically approved
  • 3.
    Caspillo, Nasim Reyhanian
    Örebro University, School of Science and Technology.
    Hitting the mark: studies of alterations in behaviour and fertility in ethinyl estradiol-exposed zebrafish and search related biomarkers2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, we have analysed the effects of EE2 on non-reproductive behaviours and fertility. We have showed that two doses of EE2 in male adult short-term exposures evokes opposite behaviours in the novel tank test. A lower dose induced increased bottom-dwelling, a sign of increased anxiety and a higher dose increased surface-dwelling, which would likely expose themselves to predation in a natural environment. Increased shoaling was observed in both exposures, possibly affecting feeding and reproduction opportunities. Fertility analysis of these fish demonstrated a complete inhibition of spawning in the highest dose group. To investigate mechanisms behind the spawning failure, we examined expression levels of genes involved in zebrafish sex differentiation and maintenance of gonadal function. We found downregulated transcription levels of male-predominant genes, suggesting a demasculinization of the testes contributing to functional sterility in these fish. We have demonstrated that non-reproductive behaviour in zebrafish is highly sensitive to EE2 exposure during development. After exposing male and female zebrafish to low doses of EE2 followed by remediation in clean water until adulthood, the fish displayed increased anxiety and shoaling behaviour, demonstrating persistent effects of EE2. Furthermore, behavioural effects were transferred to their progeny. Decreased fertilisation success of the developmentally exposed fish was observed in both sexes when mated to untreated animals of the opposite sex. These fertility effects persisted although the fish had a long remediation period, implying likely reduced fitness of fish populations in aquatic environments. Based on our findings on non-reproductive behaviours and fertility, we performed RNAsequencing analysis of the brain and testes in order to investigate possible biological mechanisms behind the persistent effects. There is a need for biomarkers allowing detection of both reversible and irreversible effects in animals exposed to estrogenic substances, hopefully contributing to better risk assessments for EDCs. Results from RNA-sequencing would serve as a basis for continued studies in pursuit of potential biomarkers.

    List of papers
    1. 17 alpha-Ethinyl estradiol affects anxiety and shoaling behavior in adult male zebra fish (Danio rerio)
    Open this publication in new window or tab >>17 alpha-Ethinyl estradiol affects anxiety and shoaling behavior in adult male zebra fish (Danio rerio)
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    2011 (English)In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 105, no 1-2, p. 41-48Article in journal (Refereed) Published
    Abstract [en]

    Ethinyl estradiol is a potent endocrine disrupting compound in fish and ubiquitously present in the aquatic environment. In this study, we exposed adult zebra fish (Danio rerio) males to 0,5 or 25 ng Ethinyl estradiol/L for 14 days and analyzed the effects on non-reproductive behavior. Effects of treatment of the exposed males was shown by vitellogenin induction, while brain aromatase (CYP 19B) activity was not significantly altered. Both concentrations of Ethinyl estradiol significantly altered the behavior in the Novel tank test, where anxiety is determined as the tendency to stay at the bottom when introduced into an unfamiliar environment. The effects were, however, opposite for the two concentrations. Fish that were exposed to 5 ng/L had longer latency before upswim, fewer transitions to the upper half and shorter total time spent in the upper half compared with control fish, while 25 ng Ethinyl estradiol treatment resulted in shorter latency and more and longer visits to the upper half. The swimming activity of 25, but not 5 ng-exposed fish were slightly but significantly reduced, and these fish tended to spend a lot of time at the surface. We also studied the shoaling behavior as the tendency to leave a shoal of littermates trapped behind a Plexiglas barrier at one end of the test tank. The fish treated with Ethinyl estradiol had significantly longer latency before leaving shoal mates and left the shoal fewer times. Further, the fish exposed to 5 ng/L also spent significantly less time away from shoal than control fish. Fertilization frequency was higher in males exposed to 5 ng/L Ethinyl estradiol when compared with control males, while no spawning was observed after treatment with 25 ng/L The testes from both treatment groups contained a normal distribution of spermatogenesis stages, and no abnormality in testis morphology could be observed. In conclusion, we have observed effects on two behaviors not related to reproduction in zebra fish males after treatment with Ethinyl estradiol, adding to the ecological consequences of contamination of aquatic environments with estrogenic substances. (C) 2011 Elsevier B.V. All rights reserved.

    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-18647 (URN)10.1016/j.aquatox.2011.05.009 (DOI)000294317500005 ()
    Available from: 2011-09-30 Created: 2011-09-29 Last updated: 2018-05-03Bibliographically approved
    2. Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.
    Open this publication in new window or tab >>Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.
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    2014 (English)In: Comparative Biochemistry and Physiology - Part C: Toxicology & Pharmacology, ISSN 1532-0456, E-ISSN 1878-1659, Vol. 164, p. 35-42Article in journal (Refereed) Published
    Abstract [en]

    The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25ng/L EE2for 14days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25ng/L, but not 5ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment.

    Place, publisher, year, edition, pages
    New York: Elsevier, 2014
    Keywords
    17 alpha-Ethinyl estradiol; Biomarker; Endocrine disruptors; Gene regulation; Gonads; Sex differentiation; Zebrafish
    National Category
    Natural Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-35475 (URN)10.1016/j.cbpc.2014.04.003 (DOI)000337769100005 ()24747828 (PubMedID)2-s2.0-84899872779 (Scopus ID)
    Note

    Funding Agencies:

    Swedish Baltic Sea Foundation

    Stockholm County Council

    Available from: 2014-06-24 Created: 2014-06-24 Last updated: 2018-06-07Bibliographically approved
    3. Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
    Open this publication in new window or tab >>Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
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    2015 (English)In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 73, p. 30-38Article in journal (Refereed) Published
    Abstract [en]

    Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and nonreproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17 alpha-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6 ng/L EE2. After remediation for 82 days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2 ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 12 and 1.6 ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2 ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects.

    Keywords
    Endocrine disruptors, 17 alpha-Ethinylestradiol, Stress behavior, Developmental exposure, Zebrafish, Neuroendocrinology, Social behavior, Anxiety, F1 effects, Fertility
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-45884 (URN)10.1016/j.yhbeh.2015.05.014 (DOI)000360251800005 ()26072466 (PubMedID)2-s2.0-84934983120 (Scopus ID)
    Note

    Funding Agency:

    Swedish Baltic Sea Foundation 1742/42/2008 1556/42/2011

    Available from: 2015-09-23 Created: 2015-09-21 Last updated: 2017-12-01Bibliographically approved
    4. Testis transcriptome alterations in zebrafish (Danio rerio) with reduced fertility due to developmental exposure to 17α-ethinyl estradiol
    Open this publication in new window or tab >>Testis transcriptome alterations in zebrafish (Danio rerio) with reduced fertility due to developmental exposure to 17α-ethinyl estradiol
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Biological Topics
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-47887 (URN)
    Available from: 2016-02-02 Created: 2016-02-02 Last updated: 2017-10-17Bibliographically approved
    5. Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
    Open this publication in new window or tab >>Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Zoology Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:oru:diva-45958 (URN)
    Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-10-17Bibliographically approved
  • 4.
    Comstedt, Daniel
    Örebro University, Department of Natural Sciences.
    Explaining temporal variations in soil respiration rates and delta13C in coniferous forest ecosystems2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Soils of Northern Hemisphere forests contain a large part of the global terrestrial carbon (C) pool. Even small changes in this pool can have large impact on atmospheric [CO2] and the global climate. Soil respiration is the largest terrestrial C flux to the atmosphere and can be divided into autotrophic (from roots, mycorrhizal hyphae and associated microbes) and heterotrophic (from decomposers of organic material) respiration. It is therefore crucial to establish how the two components will respond to changing environmental factors. In this thesis I studied the effect of elevated atmospheric [CO2] (+340 ppm, 13C-depleted) and elevated air temperature (2.8-3.5 oC) on soil respiration in a whole-tree chamber (WTC) experiment conducted in a boreal Norway spruce forest. In another spruce forest I used multivariate modelling to establish the link between day-to-day variations in soil respiration rates and its δ13C, and above and below ground abiotic conditions. In both forests, variation in δ13C was used as a marker for autotrophic respiration. A trenching experiment was conducted in the latter forest in order to separate the two components of soil respiration. The potential problems associated with the trenching, increased root decomposition and changed soil moisture conditions were handled by empirical modelling. The WTC experiment showed that elevated [CO2] but not temperature resulted in 48 to 62% increased soil respiration rates. The CO2-induced increase was in absolute numbers relatively insensitive to seasonal changes in soil temperature and data on δ13C suggest it mostly resulted from increased autotrophic respiration. From the multivariate modelling we observed a strong link between weather (air temperature and vapour pressure deficit) and the day-to-day variation of soil respiration rate and its δ13C. However, the tightness of the link was dependent on good weather for up to a week before the respiration sampling. Changes in soil respiration rates showed a lag to weather conditions of 2-4 days, which was 1-3 days shorter than for the δ13C signal. We hypothesised to be due to pressure concentration waves moving in the phloem at higher rates than the solute itself (i.e., the δ13C–label). Results from the empirical modelling in the trenching experiment show that autotrophic respiration contributed to about 50% of total soil respiration, had a great day-to-day variation and was correlated to total soil respiration while not to soil temperature or soil moisture. Over the first five months after the trenching, an estimated 45% of respiration from the trenched plots was an artefact of the treatment. Of this, 29% was a water difference effect and 16% resulted from root decomposition. In conclusion, elevated [CO2] caused an increased C flux to the roots but this C was rapidly respired and has probably not caused changes in the C stored in root biomass or in soil organic matter in this N-limited forest. Autotrophic respiration seems to be strongly influenced by the availability of newly produced substrates and rather insensitive to changes in soil temperature. Root trenching artefacts can be compensated for by empirical modelling, an alternative to the sequential root harvesting technique.

    List of papers
    1. Effects of elevated atmospheric carbon dioxide and temperature on soil respiration in a boreal forest using δ13C as a labeling tool
    Open this publication in new window or tab >>Effects of elevated atmospheric carbon dioxide and temperature on soil respiration in a boreal forest using δ13C as a labeling tool
    Show others...
    2006 (English)In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 9, no 8, p. 1266-1277Article in journal (Refereed) Published
    National Category
    Environmental Sciences Natural Sciences Chemical Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-2965 (URN)10.1007/s10021-006-0110-5 (DOI)
    Note

    Part of thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-2055

    Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2017-12-14Bibliographically approved
    2. Forest soil respiration rate and d13C is regulated by recent above ground weather conditions
    Open this publication in new window or tab >>Forest soil respiration rate and d13C is regulated by recent above ground weather conditions
    2005 (English)In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 143, no 1, p. 136-142Article in journal (Refereed) Published
    Abstract [en]

    Soil respiration, a key component of the global carbon cycle, is a major source of uncertainty when estimating terrestrial carbon budgets at ecosystem and higher levels. Rates of soil and root respiration are assumed to be dependent on soil temperature and soil moisture yet these factors often barely explain half the seasonal variation in soil respiration. We here found that soil moisture (range 16.5-27.6% of dry weight) and soil temperature (range 8-17.5 degrees C) together explained 55% of the variance (cross-validated explained variance; Q2) in soil respiration rate (range 1.0-3.4 micromol C m(-2) s(-1)) in a Norway spruce (Picea abies) forest. We hypothesised that this was due to that the two components of soil respiration, root respiration and decomposition, are governed by different factors. We therefore applied PLS (partial least squares regression) multivariate modelling in which we, together with below ground temperature and soil moisture, used the recent above ground air temperature and air humidity (vapour pressure deficit, VPD) conditions as x-variables. We found that air temperature and VPD data collected 1-4 days before respiration measurements explained 86% of the seasonal variation in the rate of soil respiration. The addition of soil moisture and soil temperature to the PLS-models increased the Q2 to 93%. delta13C analysis of soil respiration supported the hypotheses that there was a fast flux of photosynthates to root respiration and a dependence on recent above ground weather conditions. Taken together, our results suggest that shoot activities the preceding 1-6 days influence, to a large degree, the rate of root and soil respiration. We propose this above ground influence on soil respiration to be proportionally largest in the middle of the growing season and in situations when there is large day-to-day shifts in the above ground weather conditions. During such conditions soil temperature may not exert the major control on root respiration.

    Keywords
    Air temperature, 13C, PLS time series analysis, Root respiration, Soil temperature
    National Category
    Biomaterials Science Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-2966 (URN)10.1007/s00442-004-1776-z (DOI)
    Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2017-12-14Bibliographically approved
    3. A link between above ground weather conditions and the δ13C of forest soil respiration is not always observed
    Open this publication in new window or tab >>A link between above ground weather conditions and the δ13C of forest soil respiration is not always observed
    (English)Manuscript (Other academic)
    National Category
    Natural Sciences Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2967 (URN)
    Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2017-10-18Bibliographically approved
    4. Autotrophic and heterotrophic soil respiration in a Norway spruce forest: estimating the root decomposition and soil moisture effects in a trenching experiment
    Open this publication in new window or tab >>Autotrophic and heterotrophic soil respiration in a Norway spruce forest: estimating the root decomposition and soil moisture effects in a trenching experiment
    (English)Manuscript (Other academic)
    National Category
    Natural Sciences Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2968 (URN)
    Available from: 2008-04-14 Created: 2008-04-14 Last updated: 2017-10-18Bibliographically approved
  • 5.
    Lam, Monika M.
    Örebro University, School of Science and Technology.
    Characterization of PAC-contaminated soil with the focus on availability, leachability and biological activities2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Current risk assessments of polycyclic aromatic compounds (PACs)-contaminated soil are often based on the 16 priority PAHs and do not consider availability of PACs in soil sufficiently. This may lead to uncertainties of the assessment, since important contaminants can be overlooked and only a small fraction of contaminants is available for the uptake for organisms. The overall aim of this thesis was to develop a refined and enhanced analytical approach based on both chemical and bioassay analysis coupled to passive sampling with polyoxymethylene (POM) and leaching tests that can provide a more comprehensive picture of chemical pollution at PAC-contaminated sites. To achieve this, bioassay-specific relative potency factors (REPs) of PACs were determined for the H4IIE-luc bioassay, detecting AhR-mediated activity, and for the VM7luc4E2 transactivation assay, detecting ER-mediated activity for the use in potency-balance analysis. Results of uptake-experiments of PACs in earthworms and POM suggested that POM is a suitable tool to study availability of AhR and ER agonists in soil. Availability and mobility of PACs in soil were investigated by the use of POM and leaching tests. The results of potency-balance analysis showed that in soil samples, in POM-fractions or in leachates, a large fraction of AhR- or ER-agonists remained unexplained, despite the use of a large number of REPs. In addition, coupling of chemical and biological analysis to passive sampling or leaching tests revealed that only a small fraction of the total mass of PACs in the soil is available or leachable in soil. The results suggests that the use of only the total concentration in soil while ignoring unknown toxicants will lead to great uncertainties in the risk assessment. Therefore, effect-based screening using bioassays, taking availability and mobility of compounds into account, as well as a widened chemical analysis should be included in modern hazard- and risk assessment of PAH contaminated soils.

    List of papers
    1. Methylated PACs are more potent than their parent compounds: a study on AhR-mediated activity, degradability and mixture interactions in the H4IIE-luc assay
    Open this publication in new window or tab >>Methylated PACs are more potent than their parent compounds: a study on AhR-mediated activity, degradability and mixture interactions in the H4IIE-luc assay
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Biological Topics
    Identifiers
    urn:nbn:se:oru:diva-64293 (URN)
    Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-01-16Bibliographically approved
    2. Methylated polycyclic aromatic hydrocarbons and/or their metabolites are important contributors to the overall estrogenic activity of polycyclic aromatic hydrocarbon-contaminated soils
    Open this publication in new window or tab >>Methylated polycyclic aromatic hydrocarbons and/or their metabolites are important contributors to the overall estrogenic activity of polycyclic aromatic hydrocarbon-contaminated soils
    2018 (English)In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 37, no 2, p. 385-397Article in journal (Refereed) Published
    Abstract [en]

    In the present study 42 polycyclic aromatic compounds (PACs) were investigated for their estrogenic potential using the VM7Luc4E2 transactivation assay. Relative potencies were determined for mass-balance analysis. In addition, compounds were tested in combination with the estrogen receptor (ER) antagonist vertical bar C vertical bar 182,780 (vertical bar C vertical bar) and the aryl hydrocarbon receptor antagonist/CYP1A1 inhibitor a-naphthoflavone. Luciferase induction and CYP1A1-dependent ethoxyresorufin-O-deethylase (EROD) activity were measured to assess whether the estrogenic activity was elicited by the compound itself and/or by its metabolites. Relative potencies ranged between 10(-7) and 10(-4). The ability of ICI to decrease luciferase activity stimulated by all compounds indicated that the induction responses were ER-dependent. The aryl hydrocarbon receptor antagonist/CYP1A1 inhibitor a-naphthoflavone decreased luciferase induction and EROD activity by several compounds, including the methylated chrysenes, suggesting that metabolites of these chemicals contributed to ER activation. Several PACs, such as acridine and its derivatives, appear to directly activate the ER. Furthermore, extracts of soils from industrial areas were examined using this bioassay, and estrogenic activity was detected in all soil samples. Mass-balance analysis using a combination of relative potencies and chemical analysis of the samples suggested that polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs, such as 1-and 3-methylchrysene, are important contributors to the overall estrogenic activity. However, these results revealed that a considerable proportion of the estrogenic activity in the soil remained unexplained, indicating the presence of other significant estrogenic compounds.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2018
    Keywords
    Estrogen receptor–mediated activity; Relative potency; Metabolite; VM7Luc4E2 transactivation assay; Mass-balance analysis
    National Category
    Environmental Sciences Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:oru:diva-61710 (URN)10.1002/etc.3958 (DOI)000423425700009 ()28834568 (PubMedID)2-s2.0-85041099349 (Scopus ID)
    Funder
    Knowledge Foundation, 2013/0157
    Available from: 2017-11-13 Created: 2017-11-13 Last updated: 2018-02-12Bibliographically approved
    3. Polyoxymethylene (POM) is a suitable tool for effect-based hazard assessment of PAC-contaminated soil
    Open this publication in new window or tab >>Polyoxymethylene (POM) is a suitable tool for effect-based hazard assessment of PAC-contaminated soil
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Other Biological Topics
    Identifiers
    urn:nbn:se:oru:diva-64300 (URN)
    Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-01-26Bibliographically approved
    4. Occurrence and leachability of polycyclic aromatic compounds in contaminated soils: Chemical and bioanalytical characterization
    Open this publication in new window or tab >>Occurrence and leachability of polycyclic aromatic compounds in contaminated soils: Chemical and bioanalytical characterization
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    2018 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 622-623, p. 1476-1484Article in journal (Refereed) Published
    Abstract [en]

    An important concern regarding sites contaminated with polycyclic aromatic compounds (PACs) is the risk of groundwater contamination by release of the compounds from soils. The goal of this study was to investigate the occurrence and leachability of 77 PACs including polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic compounds (NSO-PACs) among total aryl hydrocarbon receptor (AhR) agonists in soils from historical contaminated sites. A novel approach combining chemical and bioanalytical methods in combination with characterization of leachability by use of a column leaching test was used. Similar profiles of relative concentrations of PACs were observed in all soils, with parent PAHs accounting for 71 to 90% of total concentrations in soils. Contribution of oxy-PAHs, alkyl-PAHs and N-PACs ranged from 2 to 9%, 3 to 9% and 1 to 14%, respectively. Although the contributions of groups of PACs were small, some compounds were found in similar or greater concentrations than parent PAHs. Leachable fractions of 77 PACs from soils were small and ranged from 0.002 to 0.54%. Polar PACs were shown to be more leachable than parent PAHs. The contribution of analyzed PACS to overall AhR-mediated activities in soils and leachates suggests presence of other AhR agonists in soils, and a potential risk. Only a small fraction of AhR agonists was available in soils, indicating an overestimation of the risk if only total initial concentrations in soils would be considered in risk assessment. The results of the study strongly support that focus on 16US EPA PAHs may result in inadequate assessment of risk and hazard of PACs in complex environmental samples.

    Place, publisher, year, edition, pages
    Elsevier, 2018
    Keywords
    Alkyl-PAHs; Oxy-PAHs; NSO-heterocyclic compounds; Ah receptor; H4IIE-luc bioassay; Column leaching test
    National Category
    Environmental Sciences
    Identifiers
    urn:nbn:se:oru:diva-64301 (URN)10.1016/j.scitotenv.2017.12.015 (DOI)000426349000143 ()2-s2.0-85038841340 (Scopus ID)
    Funder
    Knowledge Foundation, 2013/0157
    Note

    Funding Agencies:

    Applicera and Formas  210-2014-87 

    Canada Research Chair program  

    State Administration of Foreign Experts Affairs  GDT20143200016 

    P.R. China  

    Chinese Academy of Sciences  

    Distinguished Visiting Professorship in the School of Biological Sciences of the University of Hong Kong  

    Natural Science and Engineering Research Council of Canada  326415-07 

    Western Economic Diversification Canada  6578  6807  000012711 

    Canada Foundation for Infrastructure  

    Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-08-16Bibliographically approved
  • 6.
    Malmgren, Jan C.
    Örebro University, Department of Natural Sciences.
    Evolutionary ecology of newts2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sexual dimorphism, predator avoidance and migratory behaviour are adaptive traits that show variation at the population and species level. Such features respond to the environment in the broad sense, that is, when both abiotic and biotic components are included. Newts of the genus Triturus have several unique features and therefore make interesting model organisms.

    I use multivariate methods to test predictions about the evolution of sex differences in morphological traits. There was no evidence for dimorphism due to diverging feeding niche specialisation between the sexes in great crested and smooth newts (Triturus cristatus and T. vulgaris, respectively). The sexes, on the other hand, diverged in traits related to female fecundity and male reproductive success. Within the genus Triturus, there was no overall allometry for sexual size dimorphism (SSD), but subgenus Triturus, a lineage comprised by medium- to large-bodied species, were significantly allometric, and SSD decreased with increasing body size for male-biased taxa and increased with size for female-biased taxa. Species in the marmoratus-cristatus species group were almost perfectly isometric, but female-biased. With respect to an ancestral state, I suggest that differences in mating system have caused medium- and small-bodied species (subgenus Palaeotriton) to decrease SSD with smaller body size, whereas subgenus Triturus have evolved larger body size with a reversal from male- to female-biased SSD. Several peculiar traits are common to the latter group. I argue, and present a conceptual model, that the reversal is an adaptation to genetic constraints posed by a balanced lethal system (the developmental arrest syndrome). Several life history traits, as well as morphological and reproductive traits, may be interpreted as evidence for the scenario. Predictions from the model are presented and future research to test the validity of the model is encouraged.

    Newts are threatened by the introduction of fish and predictions from a predator-prey model on the evolution of predator avoidance behaviour, are tested. The results suggest that the great crested newt may be able to detect chemical cues from the ninespined stickleback, Pungitius pungitius, and adjust its behaviour accordingly. The response could be a predator avoidance response that enables adults to increase reproductive success by eliminating predation risk. I also studied migration behaviour in response to surrounding landscape elements after breeding and metamorphosis in great crested and smooth newts. Fragmentation effects reduce the chance for newts to disperse to suitable habitat patches in the landscape. I demonstrate that newts appear to orientate towards forest non-randomly, regardless of age-class or species, and their responses may be used to predict where critical elements for population persistence are located, in relation to a breeding pond. Overall, the results from my studies suggest that the great crested newt may be more prone to local extinction than previously believed, much due to genetic constraints and possible habitat specialisation. I use the results to present avenues for future research and discuss implications from my studies for management and conservation of newts and newt-friendly landscapes.

    List of papers
    1. Sexual size and shape dimorphism in two species of newts, Triturus cristatus and T-vulgaris (Caudata: Salamandridae):  
    Open this publication in new window or tab >>Sexual size and shape dimorphism in two species of newts, Triturus cristatus and T-vulgaris (Caudata: Salamandridae):  
    1999 (English)In: Journal of Zoology, ISSN 0952-8369, E-ISSN 1469-7998, Vol. 249, no 2, p. 127-136Article in journal (Refereed) Published
    Abstract [en]

    Morphometric data from Fennoscandian populations of the crested newt Triturus cristatus and the smooth newt Triturus vulgaris were analysed for the presence of sexual size and shape dimorphism. The data sets included nine body-related and nine head-related measurements and were examined with univariate, bivariate and multivariate methods. Sexual dimorphism was demonstrated in both species. The separation of specimens was highly related to sex. Although the expression of sexual dimorphism differed between the two species, some patterns were shared. These are discussed in terms of evolution of intersexual dimorphism according to models of ecology, fecundity and sexual selection. In multivariate analyses, sexual dimorphism was restricted to body-related variables such as standard length and distance of extremities (with high values for females), contrasting against cloaca and limb-related characters (with high values for males). In both species, the 'distance of extremities' measure (i.e. trunk length) was one of the strongest sexually dimorphic traits. No evidence of sexual dimorphism in head morphology was found. The results are interpreted as primarily concordant with theories on fecundity selection. For example, it has been suggested that females with larger trunk volumes increase their reproductive capacity. The fact that males had longer extremities, in relation to other characters measured, could be attributed to sexual selection. Long limbs in male newts may be beneficial for courtship performance. Since head-related characters did not show any patterns of sexual dimorphism, no evidence was found to suggest that male and female crested and smooth newts have adapted to different feeding strategies.

    Keywords
    Triturus cristatus, Triturus vulgaris, sexual dimorphism, sexual selection, fecundity
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15972 (URN)10.1111/j.1469-7998.1999.tb00750.x (DOI)000083118600001 ()
    Available from: 2011-06-16 Created: 2011-06-16 Last updated: 2017-12-11Bibliographically approved
    2. Allometry for sexual size dimorphism in newts of the genus Triturus (Caudata: Salamandridae)
    Open this publication in new window or tab >>Allometry for sexual size dimorphism in newts of the genus Triturus (Caudata: Salamandridae)
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15973 (URN)
    Available from: 2011-06-16 Created: 2011-06-16 Last updated: 2017-10-17Bibliographically approved
    3. Escape from the developmental arrest: the peculiar case of the marbled newt and the crested newt superspecies
    Open this publication in new window or tab >>Escape from the developmental arrest: the peculiar case of the marbled newt and the crested newt superspecies
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15974 (URN)
    Available from: 2011-06-16 Created: 2011-06-16 Last updated: 2017-10-17Bibliographically approved
    4. Predator avoidance response by adult newts to fish cues
    Open this publication in new window or tab >>Predator avoidance response by adult newts to fish cues
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15975 (URN)
    Available from: 2011-06-16 Created: 2011-06-16 Last updated: 2017-10-17Bibliographically approved
    5. How does a newt find its way from a pond?: Migration patterns after breeding and metamorphosis in great crested newts (Triturus cristatus) and smooth newts (T-vulgaris)
    Open this publication in new window or tab >>How does a newt find its way from a pond?: Migration patterns after breeding and metamorphosis in great crested newts (Triturus cristatus) and smooth newts (T-vulgaris)
    2002 (English)In: Herpetological Journal, ISSN 0268-0130, Vol. 12, no 1, p. 29-35Article in journal (Refereed) Published
    Abstract [en]

    Migration patterns across adrift fence with pitfall traps were studied between 1997 and 1999 at a breeding pond with populations of great crested newts, Triturus cristatus, and smooth newts, T. vulgaris, at a study site in south-central Sweden. Metamorphs and older newts emigrated from the pond non-randomly and seemed to avoid exiting where open fields adjoined, but were oriented towards a patch of forest immediately to the east of the pond. Movement patterns changed slightly over the years, but metamorphs were more dispersed and less concentrated than older newts, and did not choose directions identical to those of older newts. Older great crested and smooth newts showed similar directional orientation. Great crested newt metamorphs dispersed towards both edges of the forest patch, and possible explanations for this are discussed. The results suggest that orientation in relation to cues from the surroundings of a breeding pond may be used by newts to make migratory decisions.

    Keywords
    amphibia, behaviour, conservation, dispersion, circular statistics
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-15971 (URN)000175926000004 ()
    Available from: 2011-06-16 Created: 2011-06-16 Last updated: 2017-12-11Bibliographically approved
  • 7.
    Nordén, Marcus
    Örebro University, School of Science and Technology.
    Comparative avian developmental toxicity of PFAAs2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Perfluoroalkyl acids (PFAAs) are persistent organic pollutants that can commonly be found in environmental matrixes and wildlife from all over the globe. The PFAAs have been used in applications such as water and dirt repelling treatments for textiles, oil-resistant paper coatings and fire-fighting foams. Four studies were designed to evaluate the occurrence of PFAAs in Swedish populations of birds, the developmental toxicity of different PFAAs and species sensitivity differences as well as possible modes of action for the toxicity. The studied species were domestic chicken, and the wild species great cormorant and herring gull. Cormorant and gull eggs were collected from bird colonies in Lake Vänern, Sweden. Chemical analyses were performed on some of the eggs to determine the occurrence of 15 PFAAs in the eggs. The other eggs and eggs of domestic chicken were incubated and injected with solutions of the PFAAs PFOS, PFOA, PFBS and PFUnDA. The eggs were candled every 1-3 days to determine viability. High levels of PFAAs, mainly PFOS followed by PFUnDA, were found in the herring gull and great cormorant eggs. PFOS was found at concentrations up to 1163 ng/g and 771 ng/g in cormorant and herring gull, respectively. In the toxicity tests, chicken was found to be more sensitive than the wild species and cormorant was in general the least sensitive species. PFOA was found to be the most toxic of the chemicals followed by PFOS, PFBS and PFUnDA in decreasing order. Comparing these results with the levels of these chemicals found in the eggs of herring gull and great cormorant, PFOS is the chemical of most concern. Although PFOA had the highest toxicity, the levels found in the eggs were very low. In an additional study, the hepatic β-oxidation in developing chicken embryos after in ovo exposure to PFOS was studied with a tritium release assay. PFOS was found to increase the β-oxidation of palmitic acid at PFOS concentrations 3-7 times lower than the average egg levels in cormorant and herring gull. Therefore the occurrence of effects on the fatty acid metabolism cannot be ruled out. The doses of effect on embryo survival in the toxicity and the levels found in the herring gulls and cormorants gives a small margin of safety for the wild populations. Continued environmental monitoring and further studies on the toxicity of PFAAs that occur at high environmental concentrations is important.

    List of papers
    1. High levels of perfluoroalkyl acids in eggs and embryo livers of great cormorant (Phalacrocorax carbo sinensis) and herring gull (Larus argentatus) from Lake Vanern, Sweden
    Open this publication in new window or tab >>High levels of perfluoroalkyl acids in eggs and embryo livers of great cormorant (Phalacrocorax carbo sinensis) and herring gull (Larus argentatus) from Lake Vanern, Sweden
    2013 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, ISSN 1614-7499, Vol. 20, no 11, p. 8021-8030Article in journal (Refereed) Published
    Abstract [en]

     In the eggs and developing chick livers in the two wild bird species, great cormorant and herring gull, the concentrations of a range of 15 perfluoroalkyl acids (PFAAs) were determined. Eggs of the two species were collected from Lake Vanern, Sweden, and analysed either as undeveloped egg (whole egg or separated into yolk and albumen) or incubated until start of the hatching process when the chick liver was removed and analysed. High levels of PFAAs were found in all matrixes except albumen. The predominant PFAA was perfluorooctane sulfonate (PFOS), which was found in the mug/g wet weight (ww) range in some samples of cormorant whole egg, yolk and liver and herring gull egg yolk and liver. The average concentration in yolk was 1,506 ng/g ww in cormorant and 589 ng/g ww in herring gull. The average liver concentrations of PFOS were 583 ng/g ww in cormorant and 508 ng/g ww in herring gull. At these concentrations, biochemical effects in the developing embryo or effects on embryo survival cannot be ruled out. For perfluoroalkyl carboxylates (PFCAs), the liver/egg and liver/yolk concentration ratios increased with PFCA chain length in cormorant but not in herring gull, indicating that chain length could possibly affect egg-to-liver transfer of PFCAs and that species differences may exist.

    National Category
    Natural Sciences
    Research subject
    Biology; Enviromental Science
    Identifiers
    urn:nbn:se:oru:diva-29083 (URN)10.1007/s11356-013-1567-3 (DOI)000325811600047 ()
    Funder
    Formas
    Available from: 2013-05-21 Created: 2013-05-21 Last updated: 2017-12-06Bibliographically approved
    2. Developmental toxicity of PFOS and PFOA in great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and chicken (Gallus gallus domesticus)
    Open this publication in new window or tab >>Developmental toxicity of PFOS and PFOA in great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and chicken (Gallus gallus domesticus)
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Perfluoroalkyl acids (PFAAs) are found globally in environmental samples and have been studied in various species. In this study we compare the sensitivity of three avian species to the toxic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Eggs of great cormorant (Phalacrocorax carbo sinensis) and herring gull (Larus argentatus) and the domestic White Leghorn chicken (Gallus gallus domesticus) were exposed in ovo by injection into the air sac. Effects on embryo survival were observed following exposure to PFOS and PFOA in chicken and herring gull. Chicken was found to be the most sensitive species with 50% reduced embryo survival at 8.5 μg/g egg for PFOS and 2.5 μg/g egg for PFOA. Cormorant was shown to be the least sensitive species. The difference in sensitivity between chicken and herring gull was a factor of 2.7 for PFOS and 3.5 for PFOA. Between chicken and great cormorant the sensitivity difference was 2.6 for PFOS and 8.2 for PFOA. Effects on embryo survival were seen at egg injection doses of PFOS close to levels found in environmental samples from wild birds, indicating that PFOS could be having effects in highly exposed populations of birds. This study also shows that there are differences in species sensitivity to PFOS and PFOA that should be taken into consideration in avian wildlife risk assessment.

    Keywords
    PFOS, PFOA, chicken, herring gull, great cormorant, developmental toxicity
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-32655 (URN)
    Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-10-17Bibliographically approved
    3. Developmental toxicity of PFBS and PFUnDA in great cormorant (Phalacrocorax carbo sinensis),herring gull (Larus argentatus) and chicken (Gallus gallus domesticus)
    Open this publication in new window or tab >>Developmental toxicity of PFBS and PFUnDA in great cormorant (Phalacrocorax carbo sinensis),herring gull (Larus argentatus) and chicken (Gallus gallus domesticus)
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Perfluorinated alkyl acids (PFAAs) are found in a wide range of biological matrixes due to their persistent nature and widespread and longtime use. Among the most commonly found in wildlife are perfluorooctane sulfonate (PFOS) and perfluoroundecanoic acid (PFUnDA). PFOS and its precursors have been replaced by shorter chained compounds such as perfluorobutane sulfonate (PFBS). PFOS and perfluoroctanoic acid (PFOA) are generally the most studied and studies on wild species of birds are scarce. In this study chicken, great cormorant and herring gull eggs were exposed to solutions of PFBS and PFUnDA. The eggs were incubated and candled to monitor embryo survival. PFBS significantly reduced survival in all species at 17.3 μg/g anion dose. Chicken LD50 was calculated to 29 μg/g. The cormorant was less sensitive. PFUnDA did not affect embryo survival in any of the species but did increase liver somatic index and decrease heart somatic index in chicken. Chemical analysis confirmed that the liver absorption of the chemicals correlated to the injected dose. Chicken was found to accumulate more of the PFAAs in the liver than the wild species. Comparing observed effects and environmental levels, PFBS and PFUnDA are of minor environmental concern compared to PFOS. However, due to their persistent nature and the possibility of cumulative effects of several PFAAs, continued monitoring and moretoxicological studies are needed.

    Keywords
    PFBS, PFUnDA
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-32656 (URN)
    Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-10-17Bibliographically approved
    4. Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver
    Open this publication in new window or tab >>Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver
    2012 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 19, no 5, p. 1859-1863Article in journal (Refereed) Published
    Abstract [en]

    Purpose: Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid β-oxidation in developing chicken embryos.

    Methods: Fertilized chicken eggs were exposed in ovo to PFOS at day 4 of incubation. On day 10, the eggs were dissected and livers were incubated in vitro with (3)H-palmitic acid for 2 h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid β-oxidation.

    Results: PFOS was found to induce fatty acid β-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1 μg/g egg weight. Maximum induction of 77 % compared to control was seen at 0.3 μg/g.

    Conclusions: The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.

    Place, publisher, year, edition, pages
    Heidelberg, Germany: Springer Berlin/Heidelberg, 2012
    Keywords
    Perfluorooctane sulfonate, PFOS, exposure, chicken, palmitic acid, β-oxidation, tritium
    National Category
    Medical and Health Sciences Biological Sciences Biomedical Laboratory Science/Technology
    Research subject
    Biology; Biomedical Laboratory Science
    Identifiers
    urn:nbn:se:oru:diva-24853 (URN)10.1007/s11356-012-0869-1 (DOI)000305884600053 ()22441698 (PubMedID)2-s2.0-84863225035 (Scopus ID)
    Funder
    Swedish Research Council Formas
    Available from: 2012-08-23 Created: 2012-08-23 Last updated: 2017-12-07Bibliographically approved
  • 8.
    Olsman, Helena
    Örebro University, Department of Natural Sciences.
    Bioassay analysis of dioxin-like compounds: response interactions and environmental transformation of Ah receptor agonists2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dioxin-like compounds mediate their toxicity by binding to the aryl hydrocarbon receptor (AhR) and through this receptor a cascade of biochemical and toxic events are triggered. Mechanism-specific dioxin bioassays utilise the AhR coupled induction of endogenous CYP1A proteins or reporter gene systems for detection of dioxin-like compounds and other AhR ligands. The use of mechanism-specific in vitro bioassays as a complement or alternative to conventional GC-MS analysis of dioxin-like compounds has gained acceptance over the last years and is also in part a search for a tool for rapid and facilitated dioxin risk assessment.

    This thesis includes several applications for bioassay analysis using the two bioassays Dioxin Responsive Chemically Activated Luciferase eXpression assay (DR-CALUX) and Chick Embryo Liver Culture Assay for Dioxins (CELCAD). The two dioxin bioassays were used to study the AhR mediated induction for single compounds, as well as for mixtures of AhR active compounds in different sample matrices, also including studies of the influence of clean-up methods and fractionation on bioassay response.

    Bioanalysis gave valuable information on the toxicological relevance of decaBDE UV photoproducts. The bioassay methodology was able to reflect the actual variation in PBDF formation, and enabled a good estimation of toxicity of the congeners formed, regardless of chemical identification and congener specific potency data. The congeners formed had low potencies compared to the most toxic 2,3,7,8-substituted congeners, but the high concentrations resulted in considerable levels of TEQs.

    For complex samples like organic household waste digestates it is advisable to use both bio- and chemical analysis, for confirmation of results, as far as possible. The bioassay-directed fractionation approach requires several fractionation steps (i.e. different methods) in order to obtain well-defined fractions, from which detailed conclusions can be drawn.

    Also, proper analysis of human adipose tissue, although by far less complex than organic household waste, requires fractionation. Bioanalysis of these samples showed large deviations from the additivity assumption applied in the TEF calculation from chemical analysis. Thus, it is not clear how to interpret the bioassay results in relation to chemical results, although both methods gave the same information on relative levels of AhR agonists and showed good reproducibility.

    Both DR-CALUX and CELCAD proved to be useful for AhR agonist analysis in mixtures and for single compounds. The DR-CALUX enables more rapid analysis of large number of samples and is therefore, a more suitable tool for AhR agonist detection, whereas CELCAD has more limitations and is more suitable for the study of AhR mediated toxicity with special emphasis on avian species. In vitro bioassays have many implications for the analysis of AhR agonists, yielding reliable and reproducible results, provided that proper clean-up and fractionation of samples is applied. Bioassays enable fast determinations of total or integrated effects of AhR ligands in samples, as well as specific potency studies. Thus, bioassays are in all a valuable and necessary complement to chemical analysis.

    List of papers
    1. Fractionation and determination of Ah receptor (AhR) agonists in organic waste after anaerobic biodegradation and in batch experiments with PCB and decaBDE
    Open this publication in new window or tab >>Fractionation and determination of Ah receptor (AhR) agonists in organic waste after anaerobic biodegradation and in batch experiments with PCB and decaBDE
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    (English)Manuscript (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2934 (URN)
    Available from: 2005-11-04 Created: 2005-11-04 Last updated: 2017-10-18Bibliographically approved
    2. Ah receptor agonists in UV-exposed toluene solutions of decabromodiphenyl ether (decaBDE) and in soils contaminated with polybrominated diphenyl ethers (PBDEs)
    Open this publication in new window or tab >>Ah receptor agonists in UV-exposed toluene solutions of decabromodiphenyl ether (decaBDE) and in soils contaminated with polybrominated diphenyl ethers (PBDEs)
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    2006 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 13, no 3, p. 161-169Article in journal (Refereed) Published
    Abstract [en]

    GOAL, SCOPE AND BACKGROUND: The use of polybrominated diphenyl ethers (PBDEs) as flame retardants increases the risk for emissions of other brominated compounds, such as polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). The large homology in structure of PBDD/Fs and mechanism of toxic action, i.e. the capacity to activate the Ah receptor (AhR) pathway, compared to their well-studied chlorinated analogues, justifies a raised concern to study the environmental levels and fate of these compounds. Decabromodiphenyl ether (decaBDE) is the most widely used PBDE today. Studies on photolytic debromination of decaBDE in organic solvents have shown debromination of decaBDE, as well as formation of PBDFs. However, little is known about the transformation mechanisms and there are only scarce data on photoproducts and PBDE transformation in environmentally relevant matrices. In this study, mechanism-specific dioxin bioassays were used to study photolytic formation of AhR agonists in toluene solutions of decaBDE. In addition, the influence of irradiation time and UV-light wavelength on the formation was studied. PBDE congener patterns and presence of PBDD/Fs were analysed. Further, AhR agonists were analysed in agricultural soils contaminated with PBDEs. Soils were also exposed to UV-light to study changes in AhR agonist levels. METHODS: Toluene solutions of decaBDE were irradiated using three different spectra of UV-light, simulating UV-A (320-400 nm), UV-AB (280-400 nm), and UV-ABC (250-400 nm). Additionally, decaBDE solutions were exposed to narrow wavelength intervals (10 nm bandwidth) with the central wavelengths 280, 290, 300, 310, 320, 330, 340, 350, 360 nm. AhR agonists in decaBDE solutions were analysed with two different bioassays, the chick embryo liver-cell assay for dioxins (Celcad) and the dioxin responsive, chemically activated luciferase expression assay (DR-Calux). Also, the decaBDE solutions were analysed with LRGC-LRMS to obtain PBDE congener patterns for breakdown of decaBDE, and with HRGC-HRMS, for presence of PBDD/Fs. Four soils were exposed to UV-AB light, under both dry and moist conditions. Levels of AhR agonists in soil extract fractions, before and after UV-exposure, were analysed with the DR-Calux. RESULTS AND DISCUSSION: Significant levels of photoproducts able to activate the AhR pathway, up to 31 ng bio-TEQ/ml, were formed in UV-exposed decaBDE solutions. The transformation yield of decaBDE into AhR agonists was estimated to be at the 0.1%-level, on a molar basis. The net formation was highly dependent on wavelength, with the sample irradiated at 330 nm showing the highest level of dioxin-like activity. No activity was detected in controls. PBDE analysis confirmed decaBDE degradation and a clear time-dependent pattern for debromination of PBDE congeners. AhR agonist effect in the recalcitrant fractions of the soils corresponded to the levels of chemically derived TEQs, based only on chlorinated dioxin-like compounds in an earlier study. It was concluded that no significant levels of other AhR agonists, e.g. PBDFs, were accumulated in the soil. UV-light caused changes in AhR-mediated activity in the more polar and less persistent fractions of the soils, but it is not known which compounds are responsible for this. RECOMMENDATIONS AND PERSPECTIVES: The laboratory experiments in this study show that high levels of AhR agonists can be formed as photoproducts of decaBDE and it is important to elucidate if and under which conditions this might occur in nature. However, soil analysis indicates that photoproducts of PBDE do not contribute to the accumulated levels of persistent dioxin-like compounds in agricultural soil. Still, more data is needed to fully estimate the environmental importance of PBDE photolysis and occurrence of its photoproducts in other environmental compartments. Analysis with dioxin bioassays enabled us to gather information about photoproducts formed from decaBDE even though the exact identities of these compounds were not known. CONCLUSION: Bioassays are valuable for studying environmental transformation processes like this, where chemical analysis and subsequent toxicological evaluation requires available standard compounds and information on toxicological potency. The use of bioassays allows a rapid evaluation of toxicological relevance.

    Keywords
    Animals, Biological Assay, Cell Line; Tumor, Chick Embryo, Flame Retardants/radiation effects/toxicity, Phenyl Ethers/*chemistry/radiation effects/toxicity, Photolysis, Polybrominated Biphenyls/*chemistry/radiation effects/toxicity, Rats, Receptors; Aryl Hydrocarbon/*agonists, Soil Pollutants/radiation effects/toxicity, Solutions, Spectrometry; Mass; Electrospray Ionization, Toluene/chemistry, Ultraviolet Rays
    National Category
    Biological Sciences Chemical Sciences
    Research subject
    Biology; Chemistry
    Identifiers
    urn:nbn:se:oru:diva-4132 (URN)10.1065/espr2005.08.280 (DOI)16758706 (PubMedID)
    Available from: 2008-11-12 Created: 2008-11-12 Last updated: 2017-12-14Bibliographically approved
    3. Chemical and toxicological characterisation of PBDFs from photolytic decomposition of decaBDE in toluene
    Open this publication in new window or tab >>Chemical and toxicological characterisation of PBDFs from photolytic decomposition of decaBDE in toluene
    (English)Manuscript (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2936 (URN)
    Available from: 2005-11-04 Created: 2005-11-04 Last updated: 2017-10-18Bibliographically approved
    4. Differences in Ah receptor mediated response for eighteen polybrominated and mixed halogenated dibenzo-p-dioxins and -furans in cell lines from four different species
    Open this publication in new window or tab >>Differences in Ah receptor mediated response for eighteen polybrominated and mixed halogenated dibenzo-p-dioxins and -furans in cell lines from four different species
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    (English)Manuscript (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2937 (URN)
    Available from: 2005-11-04 Created: 2005-11-04 Last updated: 2017-10-18Bibliographically approved
    5. CALUX-TEQs, PCDD/F and PCB in SFE-extracts of human adipose tissue from breast cancer patients
    Open this publication in new window or tab >>CALUX-TEQs, PCDD/F and PCB in SFE-extracts of human adipose tissue from breast cancer patients
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    (English)Manuscript (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-2938 (URN)
    Available from: 2005-11-04 Created: 2005-11-04 Last updated: 2017-10-18Bibliographically approved
  • 9.
    Rotander, Anna
    Örebro University, School of Science and Technology.
    Monitoring persistent organic pollutants (POPs) in sub-Arctic and Arctic marine mammals, 1984 - 20092011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Arctic has become an important indicator region for assessing persistence and bioaccumulation properties of persistent organic pollutants (POPs). This thesis is aimed at evaluating the occurrence of persistent halogenated POPs in seven species of sub-Arctic and Arctic marine mammals over a 25-year period. The emphasis is on studying temporal variations in concentration of three categories of POPs, including naturally occurring organobromine compounds.

    Polybrominated diphenyl ethers (PBDEs), Metoxylated diphenyl ethers (MeO-PBDEs), and polychlorinated naphtalenes (PCNs) were extracted from blubber tissue and analyzed by GC/MS. Polyfluoroalkyl substances (PFAS) were extracted from livers and analyzed by LC-MS/MS. Although restricted by the number of pooled samples, survey points, and species available from the specimen banks, the results showed some interesting contamination patterns.

    Overall, pollutant concentrations showed signs of declining or levelling out, indicating a decrease in POP exposure in the studied areas in recent years. However, increasing levels of long-chain fluorinated compounds (PFCAs) present in most species is a finding of concern, and implies that a continuous monitoring of these compounds is important. Interestingly, a shift over time in the relative abundance of PFOS isomers in ringed seals was observed, indicating a change in exposure to PFOS in recent years.

    In many of the investigated species the MeO-PBDE levels equalled or exceeded the levels of PBDEs, showing that MeO-PBDEs can be major contributors to the organobromine load in marine mammal species. No apparent relation was found between PBDE and MeO-PBDE levels, adding further support for a natural origin of MeO-PBDEs.

    List of papers
    1. Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986 – 2009
    Open this publication in new window or tab >>Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986 – 2009
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    2012 (English)In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 40, p. 102-109Article in journal (Refereed) Published
    Abstract [en]

    A selection of PBDE congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata),fin whale (Balaenoptera physalus), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986–2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography, and the analysis was performed on a GC-MS system operating in the NCI mode. The highest PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, and the lowest levels in fin whales and ringed seals. One-sided analyses of variance (ANOVA) followed by Tukey comparisons of means were applied to test for differences between years and sampling areas. Due to inter-year sampling variability, only general comparisons of PBDE concentrations between different sampling areas could be made. Differences in PBDE concentrations between three sampling periods, from 1986 to 2007, were evaluated in samples of pilot whales, ringed seals, white-sided dolphins and hooded seals. The highest PBDE levels were found in samples from the late 1990s or beginning of 2000, possibly reflecting the increase in the global production of technical PBDE mixtures in the 1990s. The levels of BDE #153 and #154 increased relative to the total PBDE concentration in some of the species in recent years, which may indicate an increased relative exposure to higher brominated congeners. In order to assess the effect of measures taken in legally binding international agreements, it is important to continuously monitor POPs such as PBDEs in sub-Arctic and Arctic environments.

    Place, publisher, year, edition, pages
    Elsevier, 2012
    Keywords
    Marine mammals; Polybrominated diphenyl ethers (PBDEs); Spatial variations; Temporal variations
    National Category
    Environmental Sciences Chemical Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-17247 (URN)10.1016/j.envint.2011.07.001 (DOI)000301025600014 ()21802148 (PubMedID)2-s2.0-84856222973 (Scopus ID)
    Note

    Funding Agency:

    Nordic Council of Ministers

    Available from: 2011-09-14 Created: 2011-09-14 Last updated: 2018-08-29Bibliographically approved
    2. Increasing levels of long-chain perfluorocarboxylic acids (PFCAs) in Arctic and North Atlantic marine mammals, 1984-2009
    Open this publication in new window or tab >>Increasing levels of long-chain perfluorocarboxylic acids (PFCAs) in Arctic and North Atlantic marine mammals, 1984-2009
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    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hisida), minke whale (Balaenoptera acutorostrata), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus), and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and North West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale livers was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) over time, going from 91% in 1984 to 83% in 2006.

    Keywords
    Marine mammals, PFSAs, PFCAs, Structural isomers, Temporal variations
    National Category
    Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-17248 (URN)
    Available from: 2011-09-14 Created: 2011-09-14 Last updated: 2017-10-17Bibliographically approved
    3. Metoxylated polybrominated diphenyl ethers (MeO-PBDEs) are major contributors to the persistent organobromine load in sub-Arctic and Arctic marine mammals, 1986-2009
    Open this publication in new window or tab >>Metoxylated polybrominated diphenyl ethers (MeO-PBDEs) are major contributors to the persistent organobromine load in sub-Arctic and Arctic marine mammals, 1986-2009
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    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A selection of MeO-PBDE and PBDE congeners were analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using both low resolution and high resolution GC-MS. MeO-PBDE concentrations relative to total PBDE concentrations varied greatly between sampling periods and species. The highest MeO-PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, often exceeding the concentration of the most abundant PBDE, BDE-47. The lowest MeO-PBDE levels were found in fin whales and ringed seals. The main MeO-PBDE congeners were 6MBDE-47 and 2PMBDE-68. A weak correlation only between BDE-47 and its metoxylated analogue 6MBDE-47 was found and is indicative of a natural source for MeO-PBDEs.

    Keywords
    Arctic, Marine mammals, North Atlantic Ocean, Polybrominated diphenyl ethers (PBDEs), Metoxylated polybrominated diphenyl ethers (MeOPBDEs), temporal concentration variations
    National Category
    Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-17249 (URN)
    Available from: 2011-09-14 Created: 2011-09-14 Last updated: 2017-10-17Bibliographically approved
    4. Polychlorinated naphtalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986-2009
    Open this publication in new window or tab >>Polychlorinated naphtalenes (PCNs) in sub-Arctic and Arctic marine mammals, 1986-2009
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A selection of PCN congeners was analyzed in pooled blubber samples of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), fin whale (Balaenoptera physalus), harbour porpoise (Phocoena phocoena), hooded seal (Cystophora cristata) and Atlantic white-sided dolphin (Lagenorhynchus acutus), covering a time period of more than 20 years (1986-2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using high resolution GC-MS. PCN congeners #48, #52, #53, #66 and #69 were found in the blubber samples between 0.03 and 5.9 ng/g lw. Also PCBs were analyzed in minke whales and fin whales from Iceland. The total PCN content accounted for less than 1% of the total coplanar PCB content. The lowest PCN concentrations were found in the samples from the latest sampling period (2006-2009). The results indicate a decline in the PCN load in marine mammals from the studied area in recent years.

    Keywords
    Marine mammals, polychlorinated naphtalenes (PCNs), temporal concentration variations
    National Category
    Chemical Sciences Environmental Sciences
    Research subject
    Environmental Chemistry
    Identifiers
    urn:nbn:se:oru:diva-17250 (URN)
    Available from: 2011-09-14 Created: 2011-09-14 Last updated: 2017-10-17Bibliographically approved
  • 10.
    Sandström, Ulf G.
    Örebro University, Department of Natural Sciences.
    Biodiversity and green infrastructure in urban landscapes2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, I evaluate the extent to which biodiversity is affected, and taken into consideration by, urban planning. Based on landscape ecology, I apply an interdisciplinary approach. In addition to natural science, I have included social and political sciences, as methods from these two disciplines were required to study issues dealing with both biodiversity and urban planning.

    Urbanisation affects biodiversity in several ways. For example, changes in vegetation structures as well as an increased fragmentation of natural habitats will take place. In a fragmented environment an increased nest predation rate occurs. In the smaller spatial scale, predation rate was found to be higher closer to the edge of natural habitat patches than further inside. I also carried out research in order to identify the local and regional effects that cities have on compositional and structural elements of biodiversity. The amount and quality of green space and natural vegetation increased from the centre to the periphery of the city. Avian species richness showed the same trend with the exception of avian generalists, which showed the opposite trend. Certain qualities such as old-growth trees and dead wood, as well as availability of green space, were identified as being important for avian diversity. These findings emphasise the importance of urban green space with natural structures to maintain high ecological diversity.

    Based on analyses of policy documents, I examined whether Swedish local authorities and planners take urban green spaces into consideration as potential multifunctional systems, including the maintenance of biodiversity. The result showed that Swedish planners and local decision-makers have not fully understood the multiple uses of urban green space, for example, the same area can act as a recreation area, improve the local climate, and maintain biodiversity.

    A normative model for conservation planning in urban landscapes was defined and operationalised by using landscape ecological principles. Urban planners were interviewed about their interest, ability, and knowledge with respect to planning for functional networks of green spaces in relation to the normative model. The unanimous view was that planners were interested in the concept of biodiversity. However, they were restricted by the extent of their knowledge, by personnel lacking suitable qualifications, and by inadequacies within their organisations. To deal with this, better integration of natural, social, and political sciences in education, as well as policy implementation should be developed.

    List of papers
    1. Availability and use of natural tree holes by cavity nesting birds in a Swedish deciduous forest
    Open this publication in new window or tab >>Availability and use of natural tree holes by cavity nesting birds in a Swedish deciduous forest
    1998 (English)In: Ardea, ISSN 0373-2266, E-ISSN 2213-1175, Vol. 86, no 1, p. 109-119Article in journal (Refereed) Published
    Abstract [en]

    Cavities in trees are an important resource as nest sites or shelter for many birds and mammals. The aim of this study was to quantify the density of cavities, their characteristics, and their origin, and the implication these have on nest site choice by hole-nesting birds. The study was carried out in a deciduous forest in south central Sweden during two years. The forest was dominated by Pendunculate Oak Quercus robur, Norway Maple Acer plantanoides, Small-leaved Lime Tilia cordata, Rowan Sorbus aucuparia, birch Betula pubescens/verrucosa and Aspen Populus tremula, in decreasing order of abundance. We found an average cavity density of 60.4 ha-1. Limb holes were the most abundant type found (53%) and were also most frequently used by hole-nesting birds (64.8%). Pendunculate Oak and Aspen were the two tree species richest in cavities. Limb holes dominated in Pendunculate Oak while woodpecker-excavated holes dominated in aspen. Cavities with occupied bird nests had narrower entrances, were located higher up, had smaller volumes, thicker walls and a smaller circumference of the stem at the hole compared with unoccupied cavities. Limb holes, woodpecker holes and other hole types were used as nest sites by birds in proportion to their frequency of occurrence in the forest. Each year only 5-10% of available cavities attracted breeding birds. The most salient features that emerge from these results are the high density of cavities and their low occupancy rate.

    National Category
    Biological Sciences
    Research subject
    Biologi med ekologisk inriktning
    Identifiers
    urn:nbn:se:oru:diva-3138 (URN)
    Available from: 2004-05-07 Created: 2004-05-07 Last updated: 2017-12-14Bibliographically approved
    2. Enhanced predation rates on cavity bird nests at deciduous forest edges: an experimental study
    Open this publication in new window or tab >>Enhanced predation rates on cavity bird nests at deciduous forest edges: an experimental study
    1991 (English)In: Ornis Fennica, ISSN 0030-5685, Vol. 68, no 3, p. 93-98Article in journal (Refereed) Published
    Abstract [en]

    The size of a forest tract influences the composition of the fauna. If forests become fragmented this will affect the fauna in several ways. One of the main effects is enhanced nest predation. Several studies which confirm this effect have been carried out, but none has used natural cavities. I tested experimentally whether the predation rate was higher in natural tree-holes close to the forest/farmland edge than in the interior of the wood. In a fragmented deciduous forest, fresh Quail eggs were placed in natural cavities at various distances from the edge. The eggs were exposed during a period corresponding in length to the egg and nestling period of a hole-nesting bird. In the beginning of the period, the predation rate was higher close to the edge (< 20 m) than further inside the wood. This result may indicate that a predator first searches the ecotone and afterwards penetrates deeper inside the forest. The results is in accord with earliest observations than nests in natural cavities seem to be less vulnerable than other types of nests.

    National Category
    Biological Sciences
    Research subject
    Biologi med ekologisk inriktning
    Identifiers
    urn:nbn:se:oru:diva-3139 (URN)
    Available from: 2004-05-07 Created: 2004-05-07 Last updated: 2017-12-14Bibliographically approved
    3. Ecological diversity of birds and the quality of urban green space
    Open this publication in new window or tab >>Ecological diversity of birds and the quality of urban green space
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-3140 (URN)
    Available from: 2004-05-07 Created: 2004-05-07 Last updated: 2017-10-18Bibliographically approved
    4. Green infrastructure planning in urban Sweden
    Open this publication in new window or tab >>Green infrastructure planning in urban Sweden
    2002 (English)In: Planning practice + research, ISSN 0269-7459, E-ISSN 1360-0583, Vol. 17, no 4, p. 373-385Article in journal (Refereed) Published
    National Category
    Biological Sciences
    Research subject
    Biologi med ekologisk inriktning
    Identifiers
    urn:nbn:se:oru:diva-3141 (URN)10.1080/02697450216356 (DOI)
    Available from: 2004-05-07 Created: 2004-05-07 Last updated: 2017-12-14Bibliographically approved
    5. Urban comprehensive planning: identifying barriers for the maintenance of functional habitat networks
    Open this publication in new window or tab >>Urban comprehensive planning: identifying barriers for the maintenance of functional habitat networks
    2006 (English)In: Landscape and Urban Planning, ISSN 0169-2046, E-ISSN 1872-6062, Vol. 75, no 1-2, p. 43-57Article in journal (Refereed) Published
    Abstract [en]

    Maintaining biodiversity requires a wise combination of protection, management and recreation of habitats to secure representative and functional habitat networks. As urbanisation is increasing worldwide, town and cities are becoming the most common habitat for humankind. Accordingly, the urban landscape is becoming increasingly important for maintaining biodiversity on site, as well as for understanding the concept of biodiversity in general, and its maintenance in urban landscapes.

    We evaluated the extent to which Swedish urban planners experience barriers when using comprehensive planning as a tool for the maintenance of biodiversity through the provision of sufficient quantity and quality of green space. All of the six large Swedish cities, having had constant relative population growth since the beginning of the 19th century were chosen as case studies. We first defined a normative model for planning urban biodiversity and operationalised this concept by using landscape ecological principles. Structured in-depth interviews were then carried out with three planners in each city. The respondents were asked about their interest, ability, and knowledge concerning planning for functional networks of green spaces in relation to the normative model.

    The in-depth interviews with 18 urban planners indicated that legislation was an important driver for green space planning, that they paid attention to new knowledge concerning recreation values and public health, but that biodiversity maintenance was not a high priority. There was a general agreement that local governments lack necessary resources to plan for biodiversity. A majority of the respondents mentioned geographical information systems (GIS) as an important tool to integrate knowledge about biodiversity in the planning process, and to evaluate likely consequences caused by deviations from current structure plans related to an efficient use of urban green spaces to maintain biodiversity. However, an evaluation of the answers revealed that the respondents had actually overestimated their capacity to implement the normative model. To conclude, the unanimous view was that planners were interested in the maintenance of biodiversity, but were limited by knowledge and by personnel lacking suitable qualifications, as well as by inadequate organisations. Only a minority of the respondents thought that local governments should have resources for biodiversity conservation planning. Finally, we discuss how the implementation of biodiversity policies could be improved by better integration of natural and social sciences in education and policy implementation.

    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-3142 (URN)10.1016/j.landurbplan.2004.11.016 (DOI)
    Available from: 2004-05-07 Created: 2004-05-07 Last updated: 2017-12-14Bibliographically approved
  • 11.
    Volkova, Kristina
    Örebro University, School of Science and Technology.
    Fishy behavior: persistent effects of early-life exposure to 17α-ethinylestradiol2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The synthetic estrogen 17α-ethinylestradiol (EE2) is an endocrine disrupting chemical (EDC) of concern due to its persistent nature and widespread presence in the aquatic environment. In mammals, effects of developmental EDC exposure on reproduction and behavior not only persist to adulthood after discontinued exposure, but are also inherited by several consecutive unexposed generations. The results presented in this thesis demonstrate that non-reproductive behavior in fish is highly sensitive to the influence of EE2 during development and the effects do not appear to be restored after a long recovery period in clean water. We have shown that exposure to low doses of EE2 during development results in increased anxiety in two fish species (zebrafish and guppy) and their offspring. We have also demonstrated that the effects of EE2 on anxiety are apparent in both sexes and are transgenerationally transmitted to two consecutive generations of unexposed offspring in the guppy. In order to investigate the possible biological mechanisms of the observed persistent effects on non-reproductive behavior, we also performed an RNA sequencing analysis of the whole-brain transcriptome in developmentally exposed zebrafish after remediation in clean water until adulthood. Differential expression of 33 genes in males and 62 genes in females were observed as a result of EE2 exposure, with only one gene affected in both sexes. Functional analysis revealed cholesterol biosynthesis and circadian rhythm to be the top two affected pathways in males and females, respectively. Both pathways have previously been implicated in anxiety behavior and represent possible candidates connecting the transcriptome alterations to the observed behavioral phenotype. The study represents an initial survey of the fish brain transcriptome by means of RNA sequencing after long-term recovery from developmental exposure to an estrogenic compound.

    List of papers
    1. Brain circuit imprints of developmental 17 alpha-Ethinylestradiol exposure in guppies (Poecilia reticulata): Persistent effects on anxiety but not on reproductive behaviour
    Open this publication in new window or tab >>Brain circuit imprints of developmental 17 alpha-Ethinylestradiol exposure in guppies (Poecilia reticulata): Persistent effects on anxiety but not on reproductive behaviour
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    2012 (English)In: General and Comparative Endocrinology, ISSN 0016-6480, E-ISSN 1095-6840, Vol. 178, no 2, p. 282-290Article in journal (Refereed) Published
    Abstract [en]

    The effects of endocrine disruptors may vary with the timing of exposure. The physiological implications of adult exposure are present during and shortly after exposure while embryonic exposure can imprint changes manifested in adulthood. In this study, guppy (Poecilia reticulata) embryos were exposed to 2 and 20 ng/L of 17 alpha-ethinylestradiol during development via the mother and reared in clean water from gestation until 6 months of age. As adults, fish exposed to 20 ng/L during development showed significantly altered behaviour in the Novel Tank test, where anxiety is determined as the tendency to remain at the bottom upon introduction into an unfamiliar tank. 17 alpha-ethinylestradiol treatment increased the latency time before swimming to the upper half of the tank and decreased the number of transitions to the upper half. In control females the basal stress behaviour responses were significantly higher than in males, as indicated by longer latency period and fewer and shorter visits to the upper half, supporting the importance of gonadal hormones for the behaviour. The anxiety increased, however, with treatment in both sexes, suggesting that the observed response is not entirely due to feminisation of the males. Shoaling behaviour, analysed as tendency to leave a shoal of littermates, was neither sex-differentiated nor changed by treatment. Also male reproductive behaviour, brain aromatase activity and testes histology, previously shown to respond to oestrogen exposure in adult guppy, were unaffected by the developmental treatment. This suggests that the stress system in the guppy is very sensitive to 17 alpha-ethinylestradiol, which possibly causes an early organisational imprint on the brain circuit that regulates stress reactions.

    Place, publisher, year, edition, pages
    Elsevier, 2012
    Keywords
    Endocrine disruption, Xenoestrogens, Sexual dimorphism, Anxiety, Stress behaviour, Embryonic exposure
    National Category
    Zoology Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:oru:diva-45956 (URN)10.1016/j.ygcen.2012.05.010 (DOI)000307694100013 ()22687331 (PubMedID)2-s2.0-84863217808 (Scopus ID)
    Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-12-01Bibliographically approved
    2. Transgenerational effects of 17α-Ethinyl Estradiol on anxiety behaviour 4 in the guppy, Poecilia reticulata
    Open this publication in new window or tab >>Transgenerational effects of 17α-Ethinyl Estradiol on anxiety behaviour 4 in the guppy, Poecilia reticulata
    Show others...
    (English)Article in journal (Refereed) Submitted
    National Category
    Zoology Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:oru:diva-45957 (URN)
    Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-10-17Bibliographically approved
    3. Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
    Open this publication in new window or tab >>Developmental exposure of zebrafish (Danio rerio) to 17 alpha-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny
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    2015 (English)In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 73, p. 30-38Article in journal (Refereed) Published
    Abstract [en]

    Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and nonreproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17 alpha-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6 ng/L EE2. After remediation for 82 days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2 ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 12 and 1.6 ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2 ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects.

    Keywords
    Endocrine disruptors, 17 alpha-Ethinylestradiol, Stress behavior, Developmental exposure, Zebrafish, Neuroendocrinology, Social behavior, Anxiety, F1 effects, Fertility
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-45884 (URN)10.1016/j.yhbeh.2015.05.014 (DOI)000360251800005 ()26072466 (PubMedID)2-s2.0-84934983120 (Scopus ID)
    Note

    Funding Agency:

    Swedish Baltic Sea Foundation 1742/42/2008 1556/42/2011

    Available from: 2015-09-23 Created: 2015-09-21 Last updated: 2017-12-01Bibliographically approved
    4. Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
    Open this publication in new window or tab >>Persistent effects of developmental exposure to 17α-ethinylestradiol on the zebrafish (Danio rerio) brain transcriptome and stress behavior
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Zoology Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:oru:diva-45958 (URN)
    Available from: 2015-09-30 Created: 2015-09-30 Last updated: 2017-10-17Bibliographically approved
  • 12.
    Westman, Ola
    Örebro University, School of Science and Technology.
    Development of bioassays for risk assessment of PAHs and PFASs in the environment2013Doctoral thesis, comprehensive summary (Other academic)
    List of papers
    1. Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver
    Open this publication in new window or tab >>Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver
    2012 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 19, no 5, p. 1859-1863Article in journal (Refereed) Published
    Abstract [en]

    Purpose: Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid β-oxidation in developing chicken embryos.

    Methods: Fertilized chicken eggs were exposed in ovo to PFOS at day 4 of incubation. On day 10, the eggs were dissected and livers were incubated in vitro with (3)H-palmitic acid for 2 h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid β-oxidation.

    Results: PFOS was found to induce fatty acid β-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1 μg/g egg weight. Maximum induction of 77 % compared to control was seen at 0.3 μg/g.

    Conclusions: The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.

    Place, publisher, year, edition, pages
    Heidelberg, Germany: Springer Berlin/Heidelberg, 2012
    Keywords
    Perfluorooctane sulfonate, PFOS, exposure, chicken, palmitic acid, β-oxidation, tritium
    National Category
    Medical and Health Sciences Biological Sciences Biomedical Laboratory Science/Technology
    Research subject
    Biology; Biomedical Laboratory Science
    Identifiers
    urn:nbn:se:oru:diva-24853 (URN)10.1007/s11356-012-0869-1 (DOI)000305884600053 ()22441698 (PubMedID)2-s2.0-84863225035 (Scopus ID)
    Funder
    Swedish Research Council Formas
    Available from: 2012-08-23 Created: 2012-08-23 Last updated: 2017-12-07Bibliographically approved
    2. Polycyclic aromatic hydrocarbons (PAHs) reduce hepatic beta-oxidation of fatty acids in chick embryos
    Open this publication in new window or tab >>Polycyclic aromatic hydrocarbons (PAHs) reduce hepatic beta-oxidation of fatty acids in chick embryos
    Show others...
    2013 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 3, p. 1881-1888Article in journal (Refereed) Published
    Abstract [en]

    Polycyclic aromatic hydrocarbons (PAHs) are widespread fused-ring contaminants formed during incomplete combustion of almost all kind of organic materials from both natural and anthropogenic sources. Some PAHs have been shown to be carcinogenic to humans, and a wide range of PAHs are found in wildlife all around the globe including avian species. The purpose of this project was to assess the effects of a standard mixture of 16 PAHs (United States Environmental Protection Agency) on the hepatic fatty acid beta-oxidation in chicken embryos (Gallus gallus domesticus) exposed in ovo. The hepatic beta-oxidation was measured using a tritium release assay with [9,10-H-3]-palmitic acid (16:0) as substrate. Treated groups were divided into groups of 0.05, 0.1, 0.3, 0.5, and 0.8 mg PAHs/kg egg weight. The hepatic beta-oxidation was reduced after exposure in ovo to the 16 PAHs mixture compared to control. The mechanisms causing reduced fatty acid oxidation in the present study are unclear, however may be due to deficient membrane structure, the functionality of enzymes controlling the rate of fatty acid entering into the mitochondria, or complex pathways connected to endocrine disruption. To the best of our knowledge, this is the first time a PAH-caused reduction of hepatic beta-oxidation of fatty acids in avian embryos has been observed. The implication of this finding on risk assessment of PAH exposure in avian wildlife remains to be determined.

    National Category
    Natural Sciences
    Research subject
    Enviromental Science; Biology
    Identifiers
    urn:nbn:se:oru:diva-29081 (URN)10.1007/s11356-012-1418-7 (DOI)000315442500065 ()23274806 (PubMedID)
    Projects
    SOILTOX
    Funder
    Knowledge Foundation
    Available from: 2013-05-21 Created: 2013-05-21 Last updated: 2018-05-17Bibliographically approved
    3. An oxygenated metabolite of benzo[a]pyrene increases hepatic β-oxidation of fatty acids in chick embryos
    Open this publication in new window or tab >>An oxygenated metabolite of benzo[a]pyrene increases hepatic β-oxidation of fatty acids in chick embryos
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences Environmental Biotechnology
    Research subject
    Biology; Enviromental Science
    Identifiers
    urn:nbn:se:oru:diva-33946 (URN)
    Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2017-10-17Bibliographically approved
    4. Comparative study and characterization of mutagenicity and AhR-agonistic potency of contaminated soil, remediated soil, urban city soil and rural soil
    Open this publication in new window or tab >>Comparative study and characterization of mutagenicity and AhR-agonistic potency of contaminated soil, remediated soil, urban city soil and rural soil
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Current risk assessment of PAH-contaminated soils is usually based on chemical analysis of a small number of PAHs. The use of effect-based methods for risk assessment would yield results covering more of the effect of all the chemicals in the soil. To put such effect based data into context we tested a relative approach in which effects of contaminated soil were compared to clean rural and urban soils. This concept of relative risk assessment was tested by studying the mutagenic and AhR-agonistic potency of contaminated soil and urban soil compared to farm soil from selected ecological farms. A set of 21 soil samples was collected: 11 PAH-contaminated samples (collected in collaboration with three Swedish remediation companies), 5 urban samples (collected in Swedish cities) and 5 soil samples from ecological farms. The urban and rural samples were collected at the surface (0-10 cm deep), the contaminated samples were collected from piles during remediation (100-200 cm deep). To evaluate the toxicants in the soil sample, lipophilic sample extracts were tested in two different assays; (i) the Ames Fluctuation Assay (AFA) mutant strains TA98 and TA100 of Salmonella typhimurium with and without a metabolic activation system (rat-liver homogenate S9) to determine the mutagenic potential of the soil samples and (ii) the cell mechanism-specific H4IIE-luc assay to determine the Ahreceptor (AhR) activating potency of the soil extracts. The results showed clear mutagenicity, both direct and indirect, in one of the PAH-contaminated samples and three other PAH samples also demonstrated some mutagenic activity. The extracts from urban city soil showed mutagenicity in three of the 5 samples, while none of the ecological farm samples had mutagenic extracts. The bio-TEQ values were very high for all remediated samples and elevated in one urban sample. Bio-TEQ values were low in the ecological farm extracts. These findings demonstrate that the present investigation scheme using two different bioassays to determine the mutagenic potential and the Ah receptor activating potency of soil extracts is a suitable method for testing toxic properties of soil extracts. The concept of relative risk assessment using background samples from rural and urban areas and effect based testing shows promise for further development.

    Keywords
    contaminated soil; genotoxicity; AhR-inducing; bioassay, toxicity
    National Category
    Biological Sciences
    Research subject
    Biology
    Identifiers
    urn:nbn:se:oru:diva-33947 (URN)
    Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2017-10-17Bibliographically approved
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