FIGURE 2: Schematic representation of functional assays based on DNA damage sensitivity. (A) Sensitivity to chemical or physical agents is determined by the spot assay. An overnight culture of yeast cells is serially diluted (10-fold dilution) and spotted onto plates containing the specific DNA damaging agent or are treated with UV. The effect of variants is determined by comparing growth of yeast expressing the variants vs WT. (B) The sensitivity to DNA damaging agents is evaluated by OD₆₀₀ measurement of cell growth in liquid medium. Yeast cells are grown in medium containing the chemical agents or exposed to UV irradiation. The sensitivity of yeast cells carrying the gene variants is compared to yeast cells carrying the WT gene. MMS: methyl methane sulfonate; HU: hydroxyurea.