PM16 Molecular Indicators for Ecological Exposure
Exhibit Hall
8:00 AM - Monday
(PM263) Development and Field Application of a Molecular Biomarker Approach for Exposure Assessment.
Roberts, A1, Oris, J1, Clements, W2, Burton, Jr., G3, 1 Miami University, Oxford, OH, USA2 Colorado State University, Ft. Collins, CO, USA3 Wright State University, Dayton, OH, USA
ABSTRACT- The development of sensitive, biologically-based indicators of contaminant exposure (i.e. biomarkers) is an ongoing topic of research. These responses have been proposed as a first-tier method of identifying contaminant exposure before population level effects occur. This research sought to implement a biomarker-based method of exposure assessment using caged fish and real time reverse-transcriptase polymerase chain reaction (rtRT-PCR) measurements of gene expression. In order to apply this system to a wide geographic area, methods of analyzing gene expression in a number of fish species were developed. Primers were developed for the CYPIA1, metallothionein, and vitellogenin genes in rainbow trout, cutbow trout, and Atlantic salmon. Each of these genes has been shown to respond specifically to planar aromatic compounds, heavy metals, and environmental estrogens, respectively. Fish were placed in cages and exposed in situ at reference and contaminated sites on the Cache la Poudre River (CO), the Arkansas River (CO), the St. John River (NB), and two urban creeks near Dayton, OH. Quantitative gene expression was determined using rtRT-PCR. Biomarker expression profiles were obtained that demonstrated differences in CYPIA1, metallothionein, and vitellogenin mRNA production unique to each site. These biomarkers indicated that specific types of compounds were bioavailable and present in sufficient concentrations to elicit a response in the organism. These findings support the use of a biomarker-based approach for exposure identification and assessment.
Key words: trout, biomarker, RT-PCR