HA5 Genomics and Proteomics
Room 17A/B, Level 4
8:00 AM - 12:00 PM, Thursday, 13 November 2003
Chair: Ferguson, Lee ,
(519) Thyroid hormone disruption prediction using genetic endpoints in amphibian species.
Helbing, C1, Degitz, Sigmund2, Van Aggelen, Graham3, Bailey, Carmen1, Veldhoen, Nik1, Zhang, Fang1, Tietge, Joseph2, 1 University of Victoria, Victoria, British Columbia, Canada2 U.S. EPA - Mid-Continent Ecology Division, Duluth, Minnesota, USA3 Environment Canada - Pacific Environmental Science Centre, North Vancouver, British Columbia, Canada
ABSTRACT- The promise of genomics rests on the ability to identify patterns of gene expression that are perturbed upon exposure to a toxic (lethal or sublethal) substance in a rapid, high throughput screening methodology. Since changes in gene expression often precede overt morphological and physiological endpoints, choosing genetic endpoints that are predictive of downstream events can simplify and shorten the entire exposure regime. We have been developing several molecular tools that can be used in laboratory and field settings and on different species. The core approach focuses on frog DNA array and quantitative real-time polymerase chain reaction (QPCR) analyses combined with tissue-specific analyses, a novel biopsy technique and morphological, physiological and chemical validation. Thyroid hormones (THs) trigger the rapid metamorphosis of the tadpole into a juvenile frog. Using premetamorphic tadpoles, we have systematically examined the effect of TH agonists and antagonists on different tissues and have developed genetic response profiles in an effort to generate a genetic profile suite that would serve as the basis of a high throughput screening method.
Key words: amphibian metamorphosis, DNA array, endocrine disruption, thyroid hormone