901 research outputs found

    The consequences of feminization in breeding groups of wild fish

    Get PDF
    EHP is a publication of the U.S. government. Publication of EHP lies in the public domain and is therefore without copyright. Research articles from EHP may be used freely; however, articles from the News section of EHP may contain photographs or figures copyrighted by other commercial organizations and individuals that may not be used without obtaining prior approval from both the EHP editors and the holder of the copyright. Use of any materials published in EHP should be acknowledged (for example, "Reproduced with permission from Environmental Health Perspectives") and a reference provided for the article from which the material was reproduced.BACKGROUND: The feminization of nature by endocrine-disrupting chemicals (EDCs) is a key environmental issue affecting both terrestrial and aquatic wildlife. A crucial and as yet unanswered question is whether EDCs have adverse impacts on the sustainability of wildlife populations. There is widespread concern that intersex fish are reproductively compromised, with potential population-level consequences. However, to date, only in vitro sperm quality data are available in support of this hypothesis. OBJECTIVE: The aim of this study was to examine whether wild endocrine-disrupted fish can compete successfully in a realistic breeding scenario. METHODS: In two competitive breeding experiments using wild roach (Rutilus rutilus), we used DNA microsatellites to assign parentage and thus determine reproductive success of the adults. RESULTS: In both studies, the majority of intersex fish were able to breed, albeit with varying degrees of success. In the first study, where most intersex fish were only mildly feminized, body length was the only factor correlated with reproductive success. In the second study, which included a higher number of more severely intersex fish, reproductive performance was negatively correlated with severity of intersex. The intersex condition reduced reproductive performance by up to 76% for the most feminized individuals in this study, demonstrating a significant adverse effect of intersex on reproductive performance. CONCLUSION: Feminization of male fish is likely to be an important determinant of reproductive performance in rivers where there is a high prevalence of moderately to severely feminized males.Funding for this work was derived through the Endocrine Disruption in Catchments project, which was supported by the U.K. Department for Environment Food and Rural Affairs and the U.K. Environment Agency

    The relationship between obesity, pregnancy, and levels of indoleamine 2,3-dioxygenase

    Get PDF
    For a successful pregnancy to occur, foreign genetic material such as the allogeneic fetus must be tolerated within the maternal host. Indoleamine 2,3-dioxygenase (IDO) is an enzyme induced by pro-inflammatory cytokines that has been shown to be key to this process. Obesity as a pro-inflammatory state is associated with poor obstetric outcomes. The primary objective of this study is to investigate the relationship between obesity and IDO activity

    Investigation into Adaptation in Genes Associated with Response to Estrogenic Pollution in Populations of Roach (Rutilus rutilus) Living in English Rivers

    Get PDF
    UK Natural Environmental Research Council (NERC; NE/K004263/1); NERC Biomolecular Analysis Facility for funding (NBAF866); Medical Research Council Clinical Infrastructure award (MR/M008924/1); Wellcome Trust Institutional Strategic Support Fund (WT097835MF); Wellcome Trust Multi User Equipment Award (WT101650MA); BBSRC LOLA award (BB/ K003240/1)

    Landscape transcriptomics as a tool for addressing global change effects across diverse species

    Get PDF
    Landscape transcriptomics is an emerging field studying how genome-wide expression patterns reflect dynamic landscape-scale environmental drivers, including habitat, weather, climate, and contaminants, and the subsequent effects on organismal function. This field is benefitting from advancing and increasingly accessible molecular technologies, which in turn are allowing the necessary characterization of transcriptomes from wild individuals distributed across natural landscapes. This research is especially important given the rapid pace of anthropogenic environmental change and potential impacts that span levels of biological organization. We discuss three major themes in landscape transcriptomic research: connecting transcriptome variation across landscapes to environmental variation, generating and testing hypotheses about the mechanisms and evolution of transcriptomic responses to the environment, and applying this knowledge to species conservation and management. We discuss challenges associated with this approach and suggest potential solutions. We conclude that landscape transcriptomics has great promise for addressing fundamental questions in organismal biology, ecology, and evolution, while providing tools needed for conservation and management of species

    Exposure Effects of Environmentally Relevant Concentrations of the Tricyclic Antidepressant, Amitriptyline in Early Life Stage Zebrafish

    Get PDF
    This is the final version. Available from the American Chemical Society via the DOI in this record. Antidepressants are one of the most globally prescribed classes of pharmaceuticals, and drug target conservation across phyla means that nontarget organisms may be at risk from the effects of exposure. Here, we address the knowledge gap for the effects of chronic exposure (28 days) to the tricyclic antidepressant amitriptyline (AMI) on fish, including for concentrations with environmental relevance, using zebrafish (Danio rerio) as our experimental model. AMI was found to bioconcentrate in zebrafish, readily transformed to its major active metabolite nortriptyline, and induced a pharmacological effect (down- regulation of the gene encoding the serotonin transporter; slc6a4a) at environmentally relevant concentrations (0.03 μg/L and above). Exposures to AMI at higher concentrations accelerated the hatch rate and reduced activity levels, the latter of which was abolished after a 14 day period of depuration. The lack of any response on the features of physiology and behavior we measured at concentrations found in the environment would indicate that AMI poses a relatively low level of risk to fish populations. The pseudopersistence and likely presence of multiple drugs acting via the same mechanism of action, however, together with a global trend for increased prescription rates, mean that this risk may be underestimated using current ecotoxicological assessment paradigms.Innovative Medicines Initiative (IMI) Joint UndertakingEU’s Seventh Framework ProgrammeEuropean Federation of Pharmaceutical Industries and Associations (EFPIA)MerckUniversity of Exete

    Feminizing effects of ethinylestradiol in roach (Rutilus rutilus) populations with different estrogenic pollution exposure histories

    Get PDF
    This is the final version. Available on open access from Elsevier via the DOI in this record. Experimental exposures aimed at assessing the risks posed by estrogens in waste-water treatment work (WwTW) effluents to fish populations have rarely considered whether populations differ in their sensitivity to estrogenic compounds. This is despite evidence that selection at genes involved in the estrogen response has occurred in wild populations, and evidence that genotype can influence estrogen-response. In this study we compare the effects of a two-year exposure to a low measured concentration (1.3 ng/L) of ethinylestradiol (EE2) on the sexual development of roach (Rutilus rutilus) whose parental generation was sampled from two river stretches heavily contaminated with WwTW effluent and from two without any known WwTW effluent contamination. Exposure to EE2 significantly reduced the proportion of genetic males and induced a range of feminized phenotypes in males. Significantly, exposure also increased the proportion of genetic females with vitellogenic oocytes from 51 to 96%, raising the possibility that estrogen pollution could impact populations of annually spawning fish species through advancing female reproduction by at least a year. However, there was no evidence that river origin affected sensitivity to estrogens in either sex. Thus, we conclude that chronic exposure to low level EE2 has reproductive health outcomes for both male and female roach, but we find no evidence that the nature or magnitude of the response is affected by the population origin.Natural Environment Research Counci

    Neuroscience, Ethics, and National Security: The State of the Art

    Get PDF
    Military involvement and research in neuroscience generates unique ethical, legal, and social issues that require careful elucidation and consideration in order to align the potentially conflicting needs of national defense, public interest, and scientific progress
    • …
    corecore