FIG 3 .

The oxidative response system is required for gamma radiation resistance. (A) Fold increase in expression of genes involved in oxidative stress response after radiation exposure. The expression patterns of target genes were quantitatively determined using qRT analysis with the gene-specific primers listed in Table S2. To determine the expression levels of target genes, the cDNA was synthesized with total RNAs extracted from cells recovered 30 and 60 min after exposure to gamma radiation (3 kGy) or not exposed to gamma radiation. Duplicate technical experiments with three biological samples were performed. Representative images from independent experiments for each target gene are shown. Error bars indicate standard deviations. Asterisks indicate the statistical significance of differences in expression levels of each gene (***, P < 0.001). (B and C) Each Cryptococcus strain was cultured in the liquid YPD medium at 30°C overnight. Serially diluted (1 to 10⁴) cells were spotted onto the YPD medium and then exposed to the indicated dose of gamma radiation. The cells were further incubated at 30°C for 2 days and photographed daily. The two images split by a horizontal white line in each spot assay were obtained from the same plate (C).