Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom
Figure 5
The BWC2 Gene also Mediates UV/Blue Light Responses in C. neoformans
(A) A self-filamentous haploid strain (MATa +SXI1α) exhibits light-repressed filamentation. This strain was mutated by Agrobacterium-mediated T-DNA insertion, and insertional mutant strain 25F8 filaments equally well in the light and the dark.
(B) Comparison of the structures of Bwc1 and Bwc2. The Bwc1 predicted protein (1,097 amino acids) has a LOV domain, two additional PAS domains and a nuclear localization signal. The Bwc2 predicted protein (392 amino acids) has a PAS domain and zinc finger DNA binding domain.
(C) Bilateral mating between wild-type (WT), bwcl, bwc2, or bwc1 bwc2 double (bwc1,2) mutant strains on V8 medium in the dark and the light (48 h). Filamentation is repressed in wild-type crosses in the light, but not in crosses between mutants or in the dark.
(D) Fusion efficiency of strains under different wavelengths of light. Matings were between wild-type (+) partners, bwc2 mutant (Δ) partners, or one wild-type and one mutant partner (bwc2 α × WT a, or WT α × bwc2 a). Mutation of bwc2 in either or both mating partners relieves inhibition of fusion by white or blue light. Bars indicate the standard error of the mean of three replicates.
(E) Filament formation in wild-type or bwc2/bwc2 mutant diploid strains (24 h). Light does not repress filament formation in bwc2/bwc2 diploids.
(F) The bwc2 and double bwc1 bwc2 (bwc1,2) mutants are as hypersensitive to UV light as bwc1 mutants. Ten-fold serial dilutions of yeast cells were plated in duplicate onto YPD medium, and one set was UV irradiated (~48 mJ/cm2).