The final outcome for our research is to develop a reliable and sensitive suite of genetic biomarkers for the rapid assessment of contaminant exposure in the Grand Calumet River and at the Lake Michigan interface.  Contaminant related genetic damage and damage related disease outcomes may provide information on potential human health risks associated with direct (environmental) or indirect (fish consumption) contaminant exposures.  The research results produced from this work will be useful for those agencies involved in the remediation process of the river and any future remediations that may occur in the lake.  Currently Ron Gregg, a student under my supervision is quantifying a new agarose gel based procedure for the quantification of single and double stranded DNA breaks in brown bullhead catfish. He has worked through as series of experiments which have successfully validated the DNA strand break analysis method in populations held for a short time period held at the Baker Aquaculture Facility and at experimental sites located in the Grand Calumet Lagoons.  We have analyzed data from a collaborative project with Dr. R. Gillespie and have presented the results at two scientific meetings.  R. Gregg is currently working on the protocol for alkaline DNA unwinding procedures for the brown bullhead catfish. 

Objectives:

1. Quantify differences in molecular level genetic damage in bullhead catfish using alkaline DNA unwinding method.

2. Determine utility of using bullhead catfish as a sentinel species for assessment of toxicological risks to indigenous fish species.

Methodology: Numerous toxicants are known to interact to produce free radicals of oxygen and peroxides. The strong oxidative nature of these free radicals create single-strand breaks in DNA. Molecular level mechanisms that repair such DNA breaks vary in efficiency from species to species and in many cases are inhibited by the presence of toxic substances such as heavy metals that may also be present in a contaminated environment. The alkaline unwinding technique is a rapid method of assessing DNA strand breaks and numerous recent studies have shown that the   number of strand breaks, as determined by alkaline unwinding, can be associated with a variety of toxic agents. Thus, assessment of DNA strand breaks by means of the alkaline unwinding technique provides a means of quantifying the molecular level impacts that species living in toxic environments are experiencing. Genetic damage at the molecular level is a precursor to toxicant damage at the cellular, tissue, individual, and population levels.

Rationale: The research described herein will provide a fundamental piece of a broader study that is currently being conducted through collaborative efforts with the USFWS. In a basic sense the information we gather concerning genetic damage at the molecular level will provide the foundation for interpretation of biomarkers at higher levels of biological organization.

Benefits: The benefits of the research are numerous and include applications at the local, regional, and national levels. Locally the results of this research will provide consumers of Lake George fisheries resources an indication of the health and toxicological status of the fish in the lake. In terms of regional benefits this study will serve as a pilot to future research efforts in contaminated portions of the Great Lakes and the Great Lakes Basin and it will serve as a first step toward the quantification of molecular level genetic damage in aquatic resources of this region. Furthermore, our findings will provide baseline information as to the utility of bullhead catfish as a sentinel or indicator species for the contamination of water resources in the Great Lakes Basin. At the National level our published research findings will add to a growing body of literature concerning genetic damage to organisms living in contaminated environments.