Figure 6: Phenotypes of the C. neoformans ira1 mutant are not associated with light sensing.
(A) Light represses mating in crosses between wild type or ira1 mutant parents, but does not on the bwc1 parents. Yeast cells were mixed on Murashige-Skoog medium and incubated in the dark or light. Mating is represented by the filaments emerging from the edges of the yeast colonies. (B) The ira1 mutants have a wild type level of UV sensitivity in contrast to bwc1 mutants. 10-fold serial dilutions of yeast cells were plated onto media, one plate was irradiated with 120 J/m2 UV, and strains grown 2 days to form colonies. (C) The ira1 mutant has a reduction in virulence, with an additive effect when combined with the bwc1 mutation. Wax moth larvae were inoculated for each strain, as indicated, in two independent experiments and survival monitored over time. Left graph n = 17; the wild type is more virulent than the two other strains (P < 0.001). Right graph n = 12; the differences between ira1Δ and ira1Δ + IRA1 (P < 0.05) or ira1Δ and bwc1Δ ira1Δ (P < 0.05) are statistically significant.
