Deletion of the phosphatidylserine synthase gene CHO1 rescues copper sensitivity of the sur7Δ mutant.

(A) Dilutions of cells were spotted onto minimal synthetic medium in the absence or presence of 3 mM CuSO₄ and incubated for 48 hr at 30°C. (B) The indicated cell types were incubated in water (- Cu) or 10 μM CuSO₄ (+ Cu) for 2 hr at 37°C and then stained with SYTOX Green. The bars represent the average of at least 4 independent assays and error bars indicate SD. * indicates P < 0.02 by t test comparison. Strains used were wild type control DIC185, cho1Δ (YLD222-74 and YLD222-75), sur7Δ (YJA11), and sur7Δ cho1Δ (YLD221-5 and YLD221-6).