VARIATION IN DNA CONTENT OF BLOOD-CELLS OF LARGEMOUTH BASS FROM CONTAMINATED AND UNCONTAMINATED WATERS

Largemouth bass (Micropterus salmoides) were collected from locations with and without documented histories of pollution in Georgia and Sout h Carolina. Whole blood samples were collected from over 3,000 bass an d analyzed by flow cytometry to measure changes in cellular DNA conten t and cell cycle distribution. The coefficient of variation (CV) of th e cell cycle phase G(0)/G(1) peak was used as a measure of variation i n DNA content within an individual. The mean CV varied significantly a mong locations, and some locations with known chemical or radioactive contaminants had higher CVs. Plotting the frequency distribution of CV values for each site revealed greater skewness and kurtosis in most l ocations with known contaminants. In each case, a right skewness indic ated higher proportions of bass with unusually high CV in these locati ons. Aneuploid-like patterns were detected in the DNA histograms of fi ve fish, all from locations with histories of contamination. The perce ntage of cells distributed among phases of the cell cycle (G(0)/G(1), S, and G(2)/M) varied significantly among locations, but there was no apparent relationship to contaminant distribution. Differences in CV a nd frequency of aneuploids among sites with and without histories of p ollution were generally small, but increased variation in DNA content may be associated with contaminant exposure at some locations.