PARENT SESSION
SA3 - Molecular/Cellular Toxicology
Chair: Schlenk, Dan1, 1 University of California-Riverside, Riverside, CA
8:00 AM to 12:00 PM - Sunday, 17 November 2002
Room Ballroom H
(030) Quantification of genotoxicity by examining the expression of apoptotic genes and TUNEL in brown bullheads (Ameiurus nebulous) from the Detroit River.
Busch, Chris*,1,2, Heath, Daniel1,2, Hubberstey, Andrew2, 1 Great Lakes Institute for Environmental Research, Windsor, Ontario, Canada2 Department of Biological Sciences; University of Windsor, Windsor, Ontario, Canada
ABSTRACT- Numerous species of bottom dwelling fish from tributaries of high industrial presence on the Great Lakes have shown both external and internal (liver) tumors (Baumann et al., 1990) (Smith et al., 1994). The presence of liver cancer in bottom dwelling fish is suspected to be caused by elevated levels of polynuclear aromatic hydrocarbons (PAHs) in the surrounding environment (Baumann et al., 1996). Specifically, it is the metabolic formation, through CYP1A induction, of phenolic PAH metabolites that is thought to be the direct cause of observed liver neoplasms (Baumann and Harshbarger, 1998;Krahn et al., 1986;Yuan et al., 1997). We have examined the presence of cells undergoing apoptosis at time of sampling and the expression of apoptotic genes in the brown bullhead. Tumor formation is linked directly with a reduction in the ability of cells to undergo apoptosis once DNA damage has occurred. This survey was designed to determine the molecular mechanisms involved in the increased tumor prevalence in fish exposed to xenobiotic compounds in natural environments. Brown bullheads (Ameiurus nebulosus) were collected from several locations of varying levels of PAH contamination on the Detroit River system. Liver tissue was surveyed for DNA fragmentation, an early stage of apoptosis, by using a terminal deoxynucleotidyl transferase (TUNEL) assay. In addition, levels of expression of specific apoptotic genes, both promoters and inhibitors, were examined. We will present the results of our 2001 survey of the Detroit River including both gene expression data and the TUNEL findings.
Key words: Apoptosis, Brown bullhead, Detroit River, TUNEL