Thyroid disruption in walleye (Sander vitreus) exposed to environmental contaminants: Cloning and use of iodothyronine deiodinases as molecular biomarkers

Thyroid hormones play a role in the initiation of ovarian maturation in fish

Michelle Picard-Aitken; Henri Fournier; Richard Pariseau; David J. Marcogliese; Daniel G. Cyr

2007

Scholarcy highlights

  • Thyroid hormones play a role in the initiation of ovarian maturation in fish
  • The objectives of this study were to assess the effects of environmental contaminants in the Ottawa River on thyroid hormones of immature walleye and to develop a molecular biomarker of thyroid status
  • Walleye at Plaisance had two-fold elevated levels of thyroxine and 1.5-fold elevated levels triiodothyronine, whereas the molar ratio of T3:T4 was reduced by over 50% compared to Deep River
  • A real-time PCR assay of deiodinase expression indicated that hepatic mRNA levels of type I and type III deiodinase were not modified between sites, whereas they were increased for type II deiodinase at Rivière Blanche as compared to the other sites
  • The response of this novel molecular transcript indicates a divergence with that expected based on the effects of experimentally induced hyperthyroidism on fish deiodinase expression; additional endpoints are necessary to interpret changes in thyroid hormones levels in fish exposed to environmental contaminants

Need more features? Save interactive summary cards to your Scholarcy Library.