Impact of ung1Δ in mutants showing increased A3B-induced mutation. A3B-induced CanR rates in yeast that contains genes that limit A3B-induced mutation (yfgΔ; orange bars) or in yeast with genes that limit A3B-induced mutation codeleted with UNG1 (yfgΔ ung1Δ; blue bars). Error bars indicated 95% confidence intervals. Double-deletion strains (yfgΔ ung1Δ) that maintain similar A3B-induced CanR rates to the single-deletion strain and ung1Δ strains (black dashed line) are considered epistatic with ung1Δ and likely contribute to the repair or error-free bypass of A3B-induced lesions. yfgΔ ung1Δ strains with A3B-induced CanR rates higher than ung1Δ strains are either additive or greater than additive with UNG1 deletion and likely increase the amount of ssDNA that A3B acts upon.
