Abstract

Brominated dioxins have recently been detected in Baltic Sea biota. Due to their similarities to the highly toxic chlorinated dioxins, concern has been raised about their potential biological effects. The present study investigated retention and effects of brominated dioxins in adult zebrafish, as well as maternal transfer and effects on offspring. We exposed adult zebrafish for nine weeks via feed to 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) or to a mixture of brominated dioxins (Baltic Sea mixture), which was designed to reflect relative concentrations found in Baltic Sea biota. We studied spawning success, gonad morphology, hepatic vitellogenin gene expression, and offspring early life-stage development to investigate effects on zebrafish reproduction. Hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic expression of a number of aryl hydrocarbon receptor (AHR)-regulated genes were studied to investigate if the brominated dioxins can activate gene transcription through the AHR pathway in zebrafish. In addition, glutathione reductase activity and expression of genes involved in adaptive responses to intracellular stress were studied to investigate potential stress effects of brominated dioxins. After nine weeks of exposure, all brominated dioxins spiked to the feed were detected in female fish and transferred to eggs. Exposure to the Baltic Sea mixture and TBDD clearly induced AHR-regulated genes and EROD activity. Exposure to TBDD reduced spawning success, altered ovarian morphology and reduced hepatic vitellogenin gene expression, which implies that TBDD has a similar effect pattern as the chlorinated analogue. Overall, our results show that dietary exposure to sublethal concentrations of brominated dioxins may impair reproductive physiology in fish and induce AHR-regulated genes. (C) 2011 Elsevier B.V. All rights reserved.

Keywords

Zebrafish; Polybrominated dibenzo-p-dioxins; Dietary exposure; Maternal transfer; CYP1A1 induction; Reproduction

Published in

Aquatic Toxicology
2011, Volume: 102, number: 3-4, pages: 150-161
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Norman Haldén, Anna

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Mattsson, Anna

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Ullerås, Erik

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Norrgren, Leif

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG14 Conserve and sustainably use the oceans, seas and marine resources for sustainable development
SDG3 Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1016/j.aquatox.2011.01.008

Permanent link to this page (URI)

https://res.slu.se/id/publ/46888