Article Figures & Data
Figures
- FIG. 1.
Hyphal triggering by dilution of stationary cells. Cells were grown overnight at 37°C in buffered YPD, pH 7.5, in order to obtain stationary cells (OD600 ≥ 20). This culture was diluted to an OD600 of 0.5 in the same medium, same temperature, and same pH. At each hour following the initiation, the cell forms were counted (⧫, hyphae; ▪, pseudohyphae; •, yeast cells), and the OD600 was measured (▴). The figure represents the average of two independent experiments, and the standard deviations of the hyphal points only are shown for clarity.
- FIG. 2.
Serum induction of stationary cells with increased time of growth resumption at 30°C. Cells were grown overnight at 30°C in YPD in order to obtain stationary cells (OD600 ≥ 20). These cultures were diluted to an OD600 of 0.01 in the same medium, same temperature, and same pH. At each hour from 0 to 6 at 30°C, 10% of final serum was added to a sample, and the tube was transferred at 37°C for 3 h. The 24-h time point corresponds to an overnight exponentially growing culture at 30°C with a final OD600 of 0.01 treated the same way. Then, the cell forms were counted (⧫, hyphae; ▪, pseudohyphae; •, yeast cells). These results are from three independent experiments.
- FIG. 3.
Influence of the growth phase on hyphal formation after dilution in fresh medium. Cells were grown overnight in serial dilution at 37°C in buffered YPD, pH 7.5, in order to obtain a range of concentrations. These cultures were diluted to an OD600 of 0.01 in fresh medium at the same temperature and same pH. At 3 h following the initiation, the cell forms were counted. The data are the results from three independent experiments, and the standard deviations of the hyphae percentages only are shown for the clarity of the graph. ⧫, hyphae; ▪, pseudohyphae; •, yeast cells.
- FIG. 4.
Dilution of stationary-phase cells at different final concentrations. Cells were grown overnight at 37°C in buffered YPD, pH 7.5, in order to obtain stationary cells (OD600 = 20). The cells were centrifuged and resuspended in fresh medium at the same temperature and same pH at an OD600 of 1 (1), an OD600 of 5 (2), an OD600 of 10 (3), an OD600 of 15 (4), or an OD600 of 20 (5) or in water at an OD600 of 0.5 (6). After 3 h, a sample of cells was photographed (a). Hyphal lengths were measured, and the averages and standard deviations are reported in the graph (b).
- FIG. 5.
Release from quorum-sensing molecules triggers hyphal formation. Cells were grown overnight at 37°C in buffered YPD, pH 7.5, in serial dilution in order to obtain a range of cultures from early-exponential- to stationary-phase cells (OD600 ≥ 20). All of the samples but the more grown were centrifuged, and their medium was sterilized by filtration. Then, the more grown culture was used to inoculate the range of spent media to an OD600 of 0.5 at the same temperature (a) or diluted to an OD600 of 0.5 in fresh medium at the same temperature plus a range of farnesol concentrations (b). After 3 h, the cell forms were counted. The data are the results from at least three independent experiments, and the standard deviations of the hyphal percentages only are shown for the clarity of the graph. ⧫, hyphae; ▪, pseudohyphae; •, yeast cells.
- FIG. 6.
Classification of the functional groups with divergent responses. For each time point ratio (time 10, 30, 60, or 180 min/time zero), the log2 value at 37°C was subtracted from the log2 at 37°C plus farnesol. Genes with a score greater than 0.8 or lower than −0.8 were selected (both with about 150 genes). The list was refined to keep only genes with an S. cerevisiae homologue in order to use the GO resources (http://www.yeastgenome.org/GOContents.shtml ). The lists of function were simplified to remove redundant categories and weak probability groups with no clear significance in the C. albicans response. The upper part of the table indicates the functional categories overexpressed at 37°C without farnesol, while the lower part indicates the functional categories with an increased expression in the presence of farnesol. The finding of functional categories at a time point is represented by a square. The same analysis has been done with the 37°C experiment versus the 30°C study in order to distinguish between the consequences of hyphal growth and the consequences of continued farnesol treatment. Functional categories found in both analyses are represented by a gray square (▦), while functional categories specific to the presence of farnesol are represented by black squares (▪). The best probability for each group occurrence for the 37°C plus farnesol versus 37°C analysis is presented on the right. Illustrations of the predominant growth forms for each time point of the 37°C and 37°C plus farnesol experiment are displayed on top of the figure.
- FIG. 7.
A selection of genes with different profiles due to farnesol. Genes from some of the functional categories described in Fig. 6 at time 10 min were selected, and their profiles in response to the 37°C plus farnesol, 30°C, and 37°C experiments are presented. The data correspond to the ratio between the times 10, 30, 60, or 180 min after the dilution versus time zero. A, cell wall/hyphal genes; B, cell cycle genes; C, chromatin/histone genes; D, β-oxidation/glyoxylate cycle genes; and E, drug response genes.
