Flow cytometric analysis of the effects of low-level radiation exposure on natural populations of slider turtles (Pseudemys scripta).

Abstract

Aquatic turtles inhabiting seepage basins containing low concentrations of radioactive and non-radioactive contaminants possess significantly greater variation in DNA content in blood cells than turtles from a control population. This variation, measured on a flow cytometer as the coefficient of variation of the cells in Gl of the cell cycle, is positively correlated with plastron length and estimated age of the turtles. Multiple peaks indicative of aneuploid mosaicism also were observed. We conclude that radiation or some unidentified chemical in the seepage basins likely acts as a clastogenic agent that causes chromosomal rearrangements leading to deletions and duplications that have the effect of increasing DNA content variation in blood cells. The proliferation of a mutant cell line leads to aneuploid mosaicism and the observation of multiple peaks in the DNA histograms.