FIG 10.

Dependence of C. albicans and C. dubliniensis farnesol sensitivity on CDR1 expression. (A) Colony formation analysis comparing cell viability between wild-type and cdr1 null strains after 1 to 6 h of FOH or vehicle (methanol) exposure. Wild-type (yLM660), cdr1 null (yLM708), cdr1 cdr2 double deletion (yLM710), and tac1 znc1 mrr2 triple deletion (yLM702) strains were each diluted from overnight YPD cultures and treated with 200 μM FOH in YPD medium. Aliquots, after an appropriate dilution (if needed), were spread on YPD plates at the indicated time points. Fold change in CFU was calculated by setting the CFU before treatment (not shown) to 1 and is presented in a logarithmic form (base 2). (B) Representative plate scans showing a high FOH concentration in agar medium reduces colony growth of a tac1Δ/Δ znc1Δ/Δ mrr2Δ/Δ strain. Dilutions of a wild-type strain (yLM660) and a tac1 znc1 mrr2 triple deletion mutant (yLM702) from overnight cultures were plated on YPD agar supplemented with 200 μM FOH or the same volume of vehicle (methanol). Plates were imaged after incubation for the indicated amounts of time at 30°C. (C) Colony formation analysis comparing cell viability between three C. dubliniensis strains (CD36, Wü284, and CD57) after 1 to 6 h of FOH or vehicle (methanol) exposure. Wild-type (yLM660) and cdr1 cdr2 double deletion (yLM710) C. albicans strains were tested in parallel as a control. The strains were each diluted from overnight YPD cultures and treated with 200 μM FOH in YPD medium. Aliquots, after an appropriate dilution (if needed), were spread on YPD plates at the indicated time points. Fold change in CFU was calculated by setting the CFU before treatment (not shown) to 1 and is presented in a logarithmic form (base 2).