FIGURE 1: Mutation frequencies induced by different doses in UV and EMS mutagenesis. The S288c haploid yeast strain was submitted to mutagenesis by different doses of UV light (A) or different time periods of incubation with EMS (B). The mutation frequency in surviving colonies was assessed through the presence of different types of mutations: temperature sensitivity (white bars), auxotrophic mutations on eight drop-out media (grey bars) and respiratory deficiency (black bars). No viable colonies were recovered after 420 min of incubation with EMS.