PARENT SESSION
Organized Oral Session 2: At the Crossroads of Genomics and Ecology: The Potential for a Canary on a Chip
Organized by: RD Klaper
Tuesday, August 5. 1:30 PM to 5:00 PM, SITCC Meeting Room 106.
Gene Expression Patterns as Indicators of Health Effects Induced by Exposure to Environmental Contaminants.
Jelaso, Anna*,1, Ide, Charles1, 1 Western Michigan University, Kalamazoo, MI
ABSTRACT- Environmental contaminants disrupt ecosystem homeostasis and produce numerous health effects in wildlife and humans. Decisions regarding the clean-up of contaminated sites are complicated by economic, political and scientific considerations and are often met with much dissent, as it is difficult to establish direct cause and effect relationships between exposure to specific contaminants and specific health effects for ecosystems and for humans at a particular site. New genomics based technologies, such as real-time PCR and DNA microarrays that measure changes in gene expression provide sensitive, molecular tools for improving eco-risk assessment. These technologies can rapidly and accurately determine not only whether an exposure to a specific contaminant has occurred, but also the qualitative and quantitative biological effects related to that exposure. We have developed genomics based technologies to define molecular bioindicators of exposure to environmental contaminants, such as polychlorinated biphenyls (PCBs). Studies using laboratory surrogates of aquatic species demonstrate that gene expression signatures are useful bioindicators of exposure and are predictors of impending or overt health effects. In studies with developing Xenopus laevis frogs, expression levels of physiologically relevant genes were measured using real-time PCR (Taqman). Specific gene expression signatures correlated with exposure and/or the appearance of overt health effects and decreased survivorship. Due to the highly conserved nature of many genes, genes that serve as health effects bioindicators in lower vertebrates, such as frogs may also be relevant for predicting potential health effects in humans and other aquatic organisms. We are extending this work to include mammalian models. Studies using rat C6 neural cells showed that pre-exposure to PCBs causes neuroimmune suppression. Gene expression profiles were analyzed using Affymetrix microarrays, followed by quantitative analysis of specific genes with Taqman PCR. Exposure to PCBs suppressed expression of genes that regulate the neural-immune response, for example, GFAP, SOCS-3, IL-6 and PAI-1.
Key words: real-time PCR, Aroclor 1254, gene expression, microarray