PUBLICATION

Oral exposure of adult zebrafish (Danio rerio) to 2,4,6-tribromophenol affects reproduction

Authors
Haldén, A.N., Nyholm, J.R., Andersson, P.L., Holbech, H., and Norrgren, L.
ID
ZDB-PUB-100820-31
Date
2010
Source
Aquatic toxicology (Amsterdam, Netherlands)   100(1): 30-37 (Journal)
Registered Authors
Holbech, Henrik, Norrgren, Leif
Keywords
2,4,6-Tribromophenol, Fish, Reproduction, Vitellogenin, Histopathology, 2,4,6-Tribromoanisole
MeSH Terms
  • Administration, Oral
  • Animals
  • Anisoles/metabolism
  • Embryonic Development/drug effects
  • Endocrine Disruptors/toxicity*
  • Female
  • Fertilization/drug effects
  • Gonads/drug effects
  • Male
  • Ovum/drug effects
  • Ovum/metabolism
  • Phenols/toxicity*
  • Reproduction/drug effects*
  • Vitellogenins/metabolism
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/metabolism
  • Zebrafish/physiology*
PubMed
20719397 Full text @ Aquat. Toxicol.
Abstract
The bromophenol 2,4,6-tribromophenol (TBP) is widely used as an industrial chemical, formed by degradation of tetrabromobisphenol-A, and it occurs naturally in marine organisms. Concentrations of TBP in fish have been related to intake via feed, but little is known about effects on fish health after oral exposure. In this study, we exposed adult male and female zebrafish (Danio rerio) to TBP via feed in nominal concentrations of 33, 330, and 3300mug/g feed (or control feed) for 6 weeks to assess the effects of TBP on reproductive output, gonad morphology, circulatory vitellogenin levels, and early embryo development. The aim was also to investigate the extent to which TBP was metabolised to 2,4,6-tribromoanisole (TBA) in dietary exposed zebrafish, and the amounts of TBP and TBA found in offspring. After 6 weeks of exposure, we found about 3% of the daily dose of TBP in adult fish and the mean concentration of TBA was 25-30% of the TBP concentration. TBP and TBA were detected in offspring with wet weight-based egg/fish concentration ratios well below one. Exposure to TBP significantly reduced the fertilization success and disturbed the gonad morphology, i.e. fewer spermatid cysts in males and increased presence of atretic follicles and oocytes with decreased vitellogenesis in females. In females, the disturbed gonad morphology was accompanied by increased levels of circulating vitellogenin. Significant effects were observed at 3300mug/g feed. Offspring early development was not significantly affected, but yolk-sac oedema tended to increase in frequency in exposed groups with time. Our results show that dietary exposure to TBP, at concentrations found in marine organisms that are part of the natural diet of wild fish, can interfere with reproduction in zebrafish. We also observed low accumulation from feed of TBP in zebrafish and biotransformation of TBP to TBA. This is the first paper showing gonadal histopathological changes and effects on fertility in TBP exposed fish.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
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