Cross-comparison with other stressors. (a) Hierarchical clustering of cadmium and/or nickel sensitivity-conferring mutations with the mutant sensitivity profiles of other stressors [41-45]. The x-axis corresponds to gene deletions and the y-axis indicates the various stressors; mutant strains exhibiting either an enhanced sensitivity or no phenotype are shown in green and black, respectively. Nonmetal stressors were selected from previous genomic phenotyping screens conducted on the deletion mutant collections: methyl methane sulfonate (MMS), γ-radiation (γ-rays), bleomycin (Bleo), alkaline pH (pH), menadione (Men), hydrogen peroxide (H2O2), cumene hydroperoxide (CHP), linoleic acid 13-hydroperoxide (LoaOOH), and diamide (Diam). Mutant strains were hierarchically clustered with EPCLUST (average linkage, uncentered correlation ); only mutants sensitive to at least two different stressors were taken into account for this analysis. (b) Serial dilution assays (tenfold increments from left to right, starting from an optical density at 600 nm [OD600] of 1.0) of wild-type cells grown in the absence (upper row) or in the presence of cadmium or nickel, on either standard yeast extract-peptone-dextrose (YPD) medium or on the same medium buffered at the indicated pH values (see 'Materials and methods' for details).