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Candida albicans exhibits enhanced alkaline and temperature induction of Efg1-regulated transcripts relative to Candida dubliniensis.

Caplice N, Moran GP - Genom Data (2015)

Bottom Line: Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis.We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis.Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

View Article: PubMed Central - PubMed

Affiliation: Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Dublin 2, Ireland.

ABSTRACT
Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis. In this meta-analysis, we compare the transcriptional response of C. dubliniensis and C. albicans to the individual environmental stimuli that shape the gene expression profiles during filamentation in 10% serum, namely alkaline pH, 37 °C and reduced cell density. We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis. Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

No MeSH data available.


Analysis of fluorescence in C. albicans SC5314 (CaPHWP1-GFP) and C. dubliniensis Wü284 (CdPHWP1-GFP) harbouring a PHWP1-GFP fusion construct. (a) Photomicrographs showing fluorescent intensity in CaPHWP1-GFP and CdPHWP1-GFP during growth in YPD buffered to pH 7.2 at 37 °C and 10% (v/v) YPD pH 7.2 at 37 °C. (b & c) Temporal analysis of fluorescence in (a) CaPHWP1-GFP and CdPHWP1-GFP fusion strains and (b) CaPECE1-GFP and CdPECE1-GFP fusion strains. Fluorescence was measured by flow cytometry and mean fluorescence per 10,000 cells was measured and expressed in arbritrary fluorescent units.
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f0025: Analysis of fluorescence in C. albicans SC5314 (CaPHWP1-GFP) and C. dubliniensis Wü284 (CdPHWP1-GFP) harbouring a PHWP1-GFP fusion construct. (a) Photomicrographs showing fluorescent intensity in CaPHWP1-GFP and CdPHWP1-GFP during growth in YPD buffered to pH 7.2 at 37 °C and 10% (v/v) YPD pH 7.2 at 37 °C. (b & c) Temporal analysis of fluorescence in (a) CaPHWP1-GFP and CdPHWP1-GFP fusion strains and (b) CaPECE1-GFP and CdPECE1-GFP fusion strains. Fluorescence was measured by flow cytometry and mean fluorescence per 10,000 cells was measured and expressed in arbritrary fluorescent units.

Mentions: The data presented here indicate that pH and temperature shifts alone have little effect on the induction of several hypha-specific transcripts in C. dubliniensis. In order to characterise this in more detail, we carried out qualitative and quantitative analysis of an Efg1-regulated promoter in C. albicans and C. dubliniensis using a GFP fusion. Induction of GFP expression from the HWP1 promoter (PHWP1-GFP) was observed in C. albicans in response to a shift in both temperature (37 °C) and pH 7.2 (Fig. 5a). A shift in temperature or pH alone was also sufficient to induce visible fluorescence in C. albicans (data not shown). In C. dubliniensis, temperature or pH shifts in YPD medium induced lower levels of fluorescence from the HWP1 promoter relative to that observed in C. albicans, which concurs with the expression data generated by microarray analysis (Fig. 5a). However, nutrient depletion (10% v/v YPD) increased the fluorescence intensity at pH 7.2 and 37 °C (Fig. 5a). Even in the presence of combined temperature and pH shifts nutrient depletion was required to visualise fluorescence and for the formation of filaments, mainly pseudohyphae.


Candida albicans exhibits enhanced alkaline and temperature induction of Efg1-regulated transcripts relative to Candida dubliniensis.

Caplice N, Moran GP - Genom Data (2015)

Analysis of fluorescence in C. albicans SC5314 (CaPHWP1-GFP) and C. dubliniensis Wü284 (CdPHWP1-GFP) harbouring a PHWP1-GFP fusion construct. (a) Photomicrographs showing fluorescent intensity in CaPHWP1-GFP and CdPHWP1-GFP during growth in YPD buffered to pH 7.2 at 37 °C and 10% (v/v) YPD pH 7.2 at 37 °C. (b & c) Temporal analysis of fluorescence in (a) CaPHWP1-GFP and CdPHWP1-GFP fusion strains and (b) CaPECE1-GFP and CdPECE1-GFP fusion strains. Fluorescence was measured by flow cytometry and mean fluorescence per 10,000 cells was measured and expressed in arbritrary fluorescent units.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664712&req=5

f0025: Analysis of fluorescence in C. albicans SC5314 (CaPHWP1-GFP) and C. dubliniensis Wü284 (CdPHWP1-GFP) harbouring a PHWP1-GFP fusion construct. (a) Photomicrographs showing fluorescent intensity in CaPHWP1-GFP and CdPHWP1-GFP during growth in YPD buffered to pH 7.2 at 37 °C and 10% (v/v) YPD pH 7.2 at 37 °C. (b & c) Temporal analysis of fluorescence in (a) CaPHWP1-GFP and CdPHWP1-GFP fusion strains and (b) CaPECE1-GFP and CdPECE1-GFP fusion strains. Fluorescence was measured by flow cytometry and mean fluorescence per 10,000 cells was measured and expressed in arbritrary fluorescent units.
Mentions: The data presented here indicate that pH and temperature shifts alone have little effect on the induction of several hypha-specific transcripts in C. dubliniensis. In order to characterise this in more detail, we carried out qualitative and quantitative analysis of an Efg1-regulated promoter in C. albicans and C. dubliniensis using a GFP fusion. Induction of GFP expression from the HWP1 promoter (PHWP1-GFP) was observed in C. albicans in response to a shift in both temperature (37 °C) and pH 7.2 (Fig. 5a). A shift in temperature or pH alone was also sufficient to induce visible fluorescence in C. albicans (data not shown). In C. dubliniensis, temperature or pH shifts in YPD medium induced lower levels of fluorescence from the HWP1 promoter relative to that observed in C. albicans, which concurs with the expression data generated by microarray analysis (Fig. 5a). However, nutrient depletion (10% v/v YPD) increased the fluorescence intensity at pH 7.2 and 37 °C (Fig. 5a). Even in the presence of combined temperature and pH shifts nutrient depletion was required to visualise fluorescence and for the formation of filaments, mainly pseudohyphae.

Bottom Line: Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis.We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis.Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

View Article: PubMed Central - PubMed

Affiliation: Microbiology Research Unit, Division of Oral Biosciences, Dublin Dental University Hospital, University of Dublin, Dublin 2, Ireland.

ABSTRACT
Filamentous growth is an important virulence trait of the human pathogenic fungi within the genus Candida, and the greater propensity of C. albicans to form hyphae has been proposed to account for the greater virulence of this species relative to the less pathogenic species C. dubliniensis. In this meta-analysis, we compare the transcriptional response of C. dubliniensis and C. albicans to the individual environmental stimuli that shape the gene expression profiles during filamentation in 10% serum, namely alkaline pH, 37 °C and reduced cell density. We could identify conserved core temperature and pH responses, however many signature Efg1-regulated, hypha-induced transcripts (e.g. ECE1, HWP1) exhibited reduced or lack of induction in C. dubliniensis. Comparison of the activity of the HWP1 and ECE1 promoters in both species using GFP fusions showed a lag in serum induced fluorescence in C. dubliniensis relative to C. albicans and nutrient depletion was required for maximal expression of these Efg1-regulated transcripts in C. dubliniensis.

No MeSH data available.