Research Paper Volume 2, Issue 8 pp 475—486

Figure 1. K6001-B7 carries a monogenic and dominant allele that confers resistance to cumene hydroperoxide (CHP). (A) K6001-B7 is resistant to CHP. Overnight cultures of the parent (K6001, MATa), K6001-B7 and an isogenic MATα (K6001-α32) strain were spotted as serial dilution on SC agar with and without CHP and grown at 28°C (upper panel). K6001-B7 grows on 0.1 mM CHP, a concentration lethal for K6001 and K6001-α32. (lower panel) Similar test were performed with oxidants tert-butyl hydroperoxide (t-BTH) (left) and H₂O₂ (right). (B) K6001-B7 transmits with a monogenic Mendelian trait. K6001-B7 was mated with K6001-α32, tetrads gained by sporulation and tested for CHP and t-BTH resistance. Shown is the 2:2 segregation of a representative tetrade. (C) B7 is a dominant mutation. (upper panel) K6001 and K6001-B7 were mated with K6001-α32, resultant diploids assayed for CHP resistance. +/B7 diploids retained the stress resistance of the B7 haploid. (lower panel) B7 is dominant across backgrounds. K6001 and K6001-B7 were mated with the distant S. cerevisiae strain BY4742. Similar to the pure K6001 background situation, BY/K6001-B7 diploids were more resistant to CHP (left) and sensitive to H₂O₂ (right) compared to the BY/K6001 diploids.