SREB, a GATA Transcription Factor That Directs Disparate Fates in Blastomyces dermatitidis Including Morphogenesis and Siderophore Biosynthesis
Figure 3
Phenotype of the SREB null mutant.
(A) When grown on 7H10 medium containing 150 µM FeSO4, the null mutant (SREBΔ) grew as yellow-orange pigmented colonies that discolored the medium (37°C; 15 days incubation). In contrast the wild-type strain (ATCC 26199) grew as white colored yeast and did not pigment the medium. At 37°C, SREBΔ and wild-type isolates grew as budding yeast. Following a shift in temperature from 37°C to 22°C, SREBΔ failed to complete the conversion from yeast to mycelia (17 days; HMM medium). (B) The null mutant (SREBΔ) does not accumulate significant biomass or expand by radial growth when compared to the wild-type isolate. For each strain, 2.5×104 yeast were spotted on HMM medium and incubated at 22°C for 14 days. (C) The null mutant (SREBΔ) and wild-type isolates have a similar growth rate when they are cultured as yeast at 37°C incubation. Culture density was measured in triplicate at A600. Cultures were grown in liquid HMM supplemented with 10 uM FeSO4. The data were from two independent experiments.