Calling behaviour of male South African clawed frogs (Xenopus laevis) is affected by 17α-ethinyl estradiol

Abstract

Event Abstract Back to Event Calling behaviour of male South African clawed frogs (Xenopus laevis) is affected by 17α-ethinyl estradiol Frauke Hoffmann1* and Werner Kloas1, 2 1 Leibniz Institute of Freshwater Ecology and Inland Fisheries, Department of Ecophysiology and Aquaculture, Germany 2 Humboldt University Berlin, Department of Endocrinology, Germany 17α-ethinyl estradiol (EE2), a main component of many contraceptive pills, is an environmentally relevant model substance for estrogenic endocrine disrupting compounds (EDC). In this study, effects of EE2 on male mate calling behaviour of Xenopus laevis induced by human chorionic gonadotropin treatment were investigated. Adult males were exposed to EE2 at five different concentrations (296 μg/L, 2.96 μg/L, 29.6 ng/L, 2.96 ng/L, and 0.296 ng/L) for 96 h. Effects of the treatments were analyzed by determining the total calling activity as well as the preferred utilization of different call types used in their vocalizations. Additionally, effects of EE2 exposures on temporal and spectral parameters of the advertisement calls (AC) were analyzed. While the absolute calling activity was not affected, the relative proportions of AC, calls indicating a sexually aroused state of the male, were diminished even by the lowest investigated EE2 concentration, 0.296 ng/l. The proportions of produced call types signalling a sexually unaroused state of the male, like rasping, on the other hand increased significantly in all EE2 treatment groups. EE2 exposure also altered several temporal and spectral features of the AC, per se; click durations decreased and accentuation of clicks within the calls diminished. The results of additional playback experiments examining the ecological relevance of these alterations of call features suggest that exposures to environmentally relevant concentrations of EE2 lower the chances of exposed male X. laevis to mate and reproduce successfully. In a supplemental experiment we also show that the alterations of the male advertisement call features are reversible over time. To our knowledge this study provides for the first time evidence that estrogens affect parameters of male calling behaviour of X. laevis and that calling behaviour can be used as highly sensitive non-invasive biomarker for the detection of estrogenic EDC. Acknowledgements We would like to thank the German Environmental Foundation (Deutsche Bundesstiftung Umwelt, DBU, Osnabrück, Germany) for providing a doctoral scholarship for F. H. (AZ 20008/987) Keywords: 17α-ethinyl estradiol, amphibian, calling behavior, endocrine disrupting compounds, estrogen, Xenopus laevis Conference: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology, Ann Arbor, United States, 13 Jul - 16 Jul, 2011. Presentation Type: Oral Presentation Topic: Endocrine disruption Citation: Hoffmann F and Kloas W (2011). Calling behaviour of male South African clawed frogs (Xenopus laevis) is affected by 17α-ethinyl estradiol. Front. Endocrinol. Conference Abstract: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology. doi: 10.3389/conf.fendo.2011.04.00018 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Ms. Frauke Hoffmann, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Department of Ecophysiology and Aquaculture, Berlin, 12587, Germany, f.hoffmann@igb-berlin.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Frauke Hoffmann Werner Kloas Google Frauke Hoffmann Werner Kloas Google Scholar Frauke Hoffmann Werner Kloas PubMed Frauke Hoffmann Werner Kloas Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.