Sensitivity of Y763, whi2Δ, and siw mutants to various conditions

% heat-shock
(relative to
wild type)
0.05 mm
5 mm caffeineMM at 37°1.0 m NaCl6.6 mm
0.7 m
Y7639.0 (1.0)+++++++++++--++++
whi2Δ0.4 (0.04)+a-+b-++b+b++2-+--+++b+b
alg9Δ11.7 (1.3)+++c-++-++-+--+-++
zds1Δ6.9 (0.77)+----+-++-+--+++-
siw14Δ0.4 (0.044)++-d-+++e++++++++--
prs3Δ10 (1.1)++--++-fND+-gND++++++
  • Five-microliter aliquots of serial dilutions were plated as described in materials and methods. Growth is recorded at the highest cell densities (H)—̃2 × 105 cells/drop—and at the lowest cell density (L)—̃20 cells/drop. MM, minimal medium. +S, 1.0 m sorbitol was added to the medium and growth was recorded at the lowest plating density. +Ca2+, 5 mm CaCl2 was added to the medium.

  • a Sensitivity of whi2 mutants to Calcofluor white is strain dependent; the most sensitive strain is Iso34, which harbors the original whi2 mutation (Saul and Sudbery 1985).

  • b Sensitivity of whi2 mutants to these treatments is dependent on the allelic status of the SSD1 locus. In strain W303a (ssd1-d), growth of a whi2Δ mutant is completely blocked even at the highest cell densities. This increased sensitivity is rescued by SSD1-1V on a multicopy plasmid. Growth of Y763 whi2Δ strains is prevented at high cell densities by 7 mm caffeine.

  • c Growth is blocked by 6 mm caffeine.

  • d Inhibition of growth of the original mutant and an siw14Δ allele in the W303a background requires 7 mm caffeine.

  • e Growth of the original siw14 mutant was temperature sensitive, but the deletion allele was not, regardless of strain background.

  • f Growth of the original mutant was not temperature sensitive.

  • g Growth of the original mutant was not inhibited by 1.0 m NaCl.