DNA damage and repair in yeast (Saccharomyces cerevisiae) cells exposed to lead

The DNA damage and repair effects of yeast (Saccharomyces cerevisiae) cells induced by lead ( Pb) were tested in this study. Yeast cells were cultured for 72 h at the following Pb concentrations : 0 (controls), 1 ppm (11.6 mu g/dl) and 8 ppm (92.6 mu g/dl), and 0.1 g kappa-selenocarrageenan (10000 mu g Se/g) used as repair reagent was added directly to the yeast culture medium (100 ml) for the repair assays. The percentage of damaged cells was observed from fluorescence microscope. Statistical analysis showed that the two lead doses damaged DNA structure of yeast cells significantly, and the higher concentration made more serious damage than that of the lower concentration. With the addition of kappa-selenocarrageenan, DNA damage was repaired to some degree. Furthermore, the accumulation effects of DNA damage from the parent generation to the filial generation yeast cells was also investigated. At the lower lead concentration, the accumulation effects were more significant than that at the higher concentration.