Fig. 4. More tot phenotypes. (A) Calcofluor White sensitivity. Serial dilutions of strains were replica spotted on YPD plates containing no or 50 µg of Calcofluor White (CW). All totΔ strains show hypersensitivity against Calcofluor White, whereas the positive reference, chs3Δ, displays resistance towards the drug. (B) Caffeine sensitivity. Strains were spotted on YPD plates containing up to 10 mM caffeine and grown for 3 days at 30°C. All totΔ strains show more or less hypersensitivity towards caffeine. (C) 6-AU phenotype. Strains were spotted on SD plates containing no 6-AU, 50 µg/ml 6-AU or50 µg/ml 6-AU plus uracil. Except for the tot2Δ mutant, which is mildly affected by the drug, all other totΔ strains show hypersensi tivity towards 6-AU. The dst1Δ mutant served as a positive 6-AU-hypersensitive control strain.