Table 1.
C. albicans and C. dubliniensis strains used in this study.
Figure 1.
Differential chlamydospore development by the analyzed Candida strains in Staib liquid medium.
C. dubliniensis wild type Wü284 and the C. albicans nrg1Δ mutant MMC3 form chlamydospores, in contrast to the C. albicans wild type SC5314. The fungal strains were grown for 28 h in Staib medium at 25°C and inspected by microscopy (scale bar: 10 µm).
Figure 2.
Identification of chlamydospore specific genes in Candida.
Venn diagram of genes which were ≥ two fold up- (A) and downregulated (B) in both the C. albicans nrg1Δ mutant and the C. dubliniensis wild type during growth in Staib medium.
Table 2.
Strongly differentially expressed genes in C. albicans nrg1Δ and C. dubliniensis vs. C. albicans in Staib medium.
Table 3.
Protein sequence identity/similarity among gene products encoded by the four genes most strongly upregulated during chlamydospore formation.
Figure 3.
Induced expression levels of genes CSP1 and CSP2 during chlamydospore formation.
C. dubliniensis Wü284, C. albicans SC5314 and the C. albicans nrg1Δ mutant were grown for 28 h in Staib medium and YPD medium, respectively, before total RNA was isolated. (A) qRT-PCR measurements detected a strong upregulation of cdCSP1 and cdCSP2 gene expression levels in C. dubliniensis during growth in Staib versus YPD medium. (B) Similarly, the C. albicans homologues caCSP1 and caCSP2 were found to be upregulated in the chlamydospore producing C. albicans nrg1Δ mutant stronger than in C. albicans wild-type yeast cells. The results are the means ±SD from three biological replicates, ‘*’ indicates that the detected differences were significant (P<0.05).
Figure 4.
Proteins encoded by cdCSP1 and cdCSP2 are specifically expressed and located in chlamydospores.
C. dubliniensis wild type Wü284 (A) and the C. dubliniensis GFP reporter strains Cd30750G1A/B (cdCsp1-GFP) (B) and Cd40770G1A/B (cdCsp2-GFP) (C) were grown in YPD and Staib liquid medium for 28 h at 25°C, and on rice-extract agar for 3 d at 25°C, respectively, and inspected by phase contrast and fluorescence microscopy. Fluorescence microscopy demonstrated that the genes of interest are specifically induced during growth in Staib medium and that the encoded proteins exclusively localize to chlamydospores. The two independently constructed A/B-GFP reporter strains behaved identically and only one of them is shown (scale bar: 10 µm).
Figure 5.
Proteins encoded by C. albicans caCSP1 and caCSP2 are specifically expressed and located in chlamydospores.
C. albicans wild type SC5314 (A) and the C. albicans GFP reporter strains Ca3512G1A/B (caCsp1-GFP) (B) and Ca4170G1A/B (caCsp2-GFP) (C) were grown in YPD medium for 28 h at 25°C and on rice-extract agar for 3 d at 25°C, respectively, before the fungal cells were inspected by phase contrast and fluorescence microscopy. Note that the monitored proteins exclusively localize to chlamydospores. The two independently constructed A/B-GFP reporter strains behaved identically and only one of them is shown (scale bar: 10 µm).