title: The effects of model androgen 5α-dihydrotestosterone on mummichog (Fundulus heteroclitus) reproduction under different salinities.
abstract: Endocrine disrupting substances (EDSs) have the potential to disturb sensitive hormone pathways, particularly those involved in development and reproduction. Both fresh and estuarine water bodies receive inputs of EDSs from a variety of sources, including sewage effluent, industrial effluent and agricultural runoff. Based on current literature, freshwater species appear to respond to lower levels of EDSs than estuarine or marine species. Therefore, effects elicited by EDSs in freshwater teleosts may not be an accurate representation of how EDSs affect teleosts in estuarine and marine environments. To address this potential difference, a short-term reproductive bioassay was conducted under conditions of low and high salinity using mummichog (Fundulus heteroclitus), a euryhaline species that is native to the east coast of North America. The goals of this study were to determine the response of mummichog when exposed to an androgenic EDS and whether salinity affected the response. A model androgen, 5α-dihydrotestosterone (DHT), was selected for this experiment. Impacts on reproduction were evaluated at multiple biological levels, including physiological (sex steroid levels), organismal (gonad size and gonad morphology), and functional (egg production) endpoints. Under conditions of high salinity, egg production was significantly reduced at all exposure concentrations. Under conditions of low salinity, there were no significant differences based on DHT treatment; however, egg production in all treatment groups including the control were significantly reduced relative to the high salinity control group. Other reproductive endpoints, such as sex steroid production, showed stronger correlation to fecundity in females than males. This study demonstrates that mummichog fecundity is sensitive to androgenic endocrine disruption while also underscoring the importance of how changes in salinity, an environmental variable, can impact reproduction.
authors.affiliation: Department of Natural Resources and the Environment, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Chelsea O
authors.initials: CO
authors.lastname: Glinka
authors.affiliation: Department of Pathobiology and Veterinary Science, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Frasca
authors.affiliation: Center for Environmental Science and Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Provatas
authors.affiliation: Department of Natural Resources and the Environment, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Tanya
authors.initials: T
authors.lastname: Lama
authors.affiliation: Department of Pathobiology and Veterinary Science, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Sylvain
authors.initials: S
authors.lastname: DeGuise
authors.affiliation: Department of Natural Resources and the Environment, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT 06269, USA; Center for Environmental Science and Engineering, University of Connecticut, Storrs, CT 06269, USA. Electronic address: t.bosker@luc.leidenuniv.nl.
authors.forename: Thijs
authors.initials: T
authors.lastname: Bosker
mesh_terms: D000818:Animals; D013196:Dihydrotestosterone / Q000633:toxicity*; D005260:Female; D005298:Fertility / Q000187:drug effects; D023781:Fundulidae / Q000502:physiology; D006066:Gonads / Q000187:drug effects; D008297:Male; D009656:North America; D012098:Reproduction / Q000187:drug effects*; D054712:Salinity; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D013196:Dihydrotestosterone
keywords: 5α-dihydrotestosterone; Androgen; Endocrine disrupting substance; Fundulus heteroclitus; Reproductive steroids; Short-term reproductive bioassay