Transcription Profiling ofCandida albicansCells Undergoing the Yeast-to-Hyphal Transition

Abstract

The ability of the pathogenic fungus Candida albicans to switch from a yeast to a hyphal morphology in response to external signals is implicated in its pathogenicity. We used glass DNA microarrays to investigate the transcription profiles of 6333 predicted ORFs in cells undergoing this transition and their responses to changes in temperature and culture medium. We have identified several genes whose transcriptional profiles are similar to those of known virulence factors that are modulated by the switch to hyphal growth caused by addition of serum and a 37 degrees C growth temperature. Time course analysis of this transition identified transcripts that are induced before germ tube initiation and shut off later in the developmental process. A strain deleted for the Efg1p and Cph1p transcription factors is defective in hyphae formation, and its response to serum and increased temperature is almost identical to the response of a wild-type strain grown at 37 degrees C in the absence of serum. Thus Efg1p and Cph1p are needed for the activation of the transcriptional program that is induced by the presence of serum.

The Flo8 Transcription Factor Is Essential for Hyphal Development and Virulence inCandida albicans

“…These include all known hypha-specific genes on the microarray ( Figure 5A). IHD1, identified in a genome-wide transcriptional profiling of genes induced or repressed during hyphal development by Nantel et al (2002), was also found in this cluster, and further confirmed by Northern analysis ( Figure 5B). The gene was independently found by Murad et al (2001) as one of the genes regulated by the Nrg1 and Tup1 repressors.…”

Superoxide dismutases and glutaredoxins have a distinct role in the response of Candida albicans to oxidative stress generated by the chemical compounds menadione and diamide

“…Therefore, the lack of Grx (due to GRX2 disruption) and GSSH accumulation may partially explain the inability to form hyphae in the double mutant, i.e., due to ROS accumulation. SOD5 has been demonstrated to relate to hyphae formation by transcript profiling; i.e., this gene is up-regulated during the process of hyphae formation (Nantel et al 2002) Furthermore, Martchenko et al (2004 demonstrated with Northern analysis that SOD5 expression during hyphae formation is due to the presence of serum. SOD1 is also transcribed in the presence of serum (Lamarre et al 2001), which could explain why a double mutant for two oxidative stress genes (GRX2 and SOD1) is defective in hyphae formation.…”

“…SOD5 expression is increased in C. albicans yeast cells exposed to PMNs (Fradin et al 2005) and during morphological change from yeasts to hyphae (Nantel et al 2002). However, while sod1Δ is hypersensitive to killing by a macrophage cell line in vitro (Hwang et al 2002), the same was not observed for sod5Δ (Martchenko et al 2004), indicating that the virulence role of Sod5 may be due to a resistance to different phagocytic cells.…”

“…Some genes related to oxidative stress are also regulated during hyphae formation and appear to be somehow related to C. albicans morphogenesis (Hwang et al 2002, Nantel et al 2002, Martchenko et al 2004, Chaves et al 2007). In addition, Schroter et al (2000) analysed the amount of ROS produced when cells were incubated in 10% serum.…”

Transcript Profiles of Candida albicans Cortical Actin Patch Mutants Reflect Their Cellular Defects: Contribution of the Hog1p and Mkc1p Signaling Pathways

“…Probes, chip hybridization, and quantification. Most of the transcript profiling in this study used Cy3-and Cy5-labeled cDNA probes that were produced from approximately 3 to 5 g of poly(A)(ϩ) RNA and hybridized, as described previously, to microarrays spotted with amplicons from 6,002 putative open reading frames (39). For each condition, at least three independent experiments with reciprocal labeling were done, for a total of six individual hybridizations, unless otherwise stated.…”