Artículo
en Inglés
| IBECS (España) | ID: ibc-185060
The aim of this study was to evaluate the level of Zeocin-induced double-strand breaks (DSBs) in Saccharomyces cerevisiaecells in a different growth phase, using constant-field gel electrophoresis (CFGE). Saccharomyces cerevisiaediploidstrain D7ts1 with enhanced cellular permeability was used. The effects of growth phase and treatmenttime were evaluated based on Zeocin-induced DSBs, measured by CFGE. Survival assay was also applied. No protoplast isolation was necessary for the detection of DSBs in strain D7ts1. Differences in the response of cells depending on the growth phase were obtained. Cells in exponential growth phase had increased DSB levels only after Zeocin treatment with concentrations equal or higher than 200 μgml−1. Increasing treatmenttime did not result in higher DSB levels. Oppositely, treatment of cells at the beginning of stationary phase with Zeocin concentrations resulted in more than 1.5-fold increase in DSB levels in comparison with those in untreated cells. Increased DSB levels were measured for all the treatment times. A dose-dependent decrease in cell survival was observed after Zeocin treatment with concentrations in the range of lethality LD20-LD50. A strong negative correlation was calculated between the levels of DSBs and cell survival. New information is provided concerning DNA susceptibility depending on the growth phase. DNA susceptibility is higher in cells at the beginning of stationary phase than those in exponential phase. Data presented here illustrate that the optimized by us CFGE protocol is sensitive and could be used successfully for DSB measurement in Saccharomyces cerevisiaestrains with enhanced cellular permeability