Detection of DNA damage in brown bullhead fish from Lake Erie using comet assay

Abstract

Presque Isle Bay is shallow freshwater ecosystem located off the coast of Erie, Pennsylvania. Bounded on the north and west sides by a recurved peninsula which is home to Presque Isle State Park, Presque Isle Bay was listed as an Great Lakes Area of Concern (AOC) in 1991 primarily based on observations of external fish tumors on brown bullhead (Ameiurus nebulosus) collected from the Bay area. Limited findings on the causative agents for these lesions as well as no evidence that these tumors adversely affect survival, growth, or reproduction of this species of fish have left many questions unanswered two decades later. The comet assay determines a qualitative level of DNA damage from cells obtained from blood or tissue samples. This is accomplished by electrophoresis of whole cells fixed to a microscope slide with subsequent analysis using fluorescence microscopy. The extent of DNA damage is directly proportional to the amount of “tail” seen in the dye‐stained DNA comet. In this research project, we have used a comet assay to assess the level of DNA damage within various biological samples isolated from brown bullhead collected within and external to the bay area. While this has not identified the causative agent of DNA damage, it has provided additional information regarding the skin tumors observed on these fish. Research support provided to A.D‐P through a Research Science Consortium Grant from the Tom Ridge Environmental Center and a Mercyhurst University Academic Enrichment Grant.