TABLE 3.

Minimal inhibitory concentrations of drugs in the yeast mutant strains

Strains	CYH (μg/ml)	CHL (mg/ml)	RHO (μg/ml)
PDR1	<0.2	5	10
pdr1-3 pdr5Δ	<0.2	3	<2.5
pdr1-3	>1.0	7.5	>20
pdr1-3 elm1Δ	<0.2	<2	<2.5
pdr1-3 cla4Δ	0.2	2	<2.5
pdr1-3 gin4Δ	0.4	5	>20
pdr1-3 nap1Δ	0.8	5	>20

Agar plate drug resistance assays were performed with various concentrations of cycloheximide (0.2, 0.4, 0.6, 0.8, and 1.0 μg/ml), chloramphenicol (1, 2, 3, 5, 6, and 7.5 mg/ml), and rhodamine (2.5, 5.0, 7.5, 8, 10, 15, and 20 μg/ml). The PDR5 gene has been shown to be involved in the regulation of resistance to these three drugs (Rogers et al. 2001). Each experiment was repeated at least twice. CHL, chloramphenicol; RHO, rhodamine.