Project description:While Candida dubliniensis and Candida albicans are very close related species, the later is a far more successful yeast pathogen. Several explanations have been pointed out such as discrepancies in fitness, morphogenesis, adherence, or stress resistance. In this study, we investigate the transcriptional reshuffling of C. albicans and C. dubliniensis under conditions that highlight the difference of stress resistances between these strains.
Project description:Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. ÎÎsfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the ÎÎsfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, ÎÎsfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues. Global gene expression in Candida albicans SC5314 or Candida dubliniensis CD36 on reconstituted human oral epithelium (RHE) 30 min postinoculation. Gene expression on RHE was compared to gene expression in cells used as inoculum (0 min). Performed in three biological replicates with dye swaps across the biological replicates. Gene expression of Candida cells on RHE was normalized to gene expression in reference control (0 min); log2 ratios were calculated by dividing spot intensity of experimental by that of the reference control.
Project description:Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. ÎÎsfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the ÎÎsfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, ÎÎsfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues. Global gene expression in Candida albicans SC5314 or Candida dubliniensis CD36 on reconstituted human oral epithelium (RHE) 90 min postinoculation. Gene expression on RHE was compared to gene expression on polycarbonate filter (PCF; used as RHE support matrix) 90 min postinoculation. Performed in two biological replicates with reciprocal dye swaps for each biological replicate. Gene expression of Candida cells on RHE was normalized to gene expression in reference control (PCF); log2 ratios were calculated by dividing spot intensity of experimental by that of the reference control.
Project description:Transcriptional response of Candida dubliniensis during hypha formation and environmental change (temperature, pH, density and nutrients). Transcript profiling of C. dubliniensis identified a core shared transcriptional response with C. albicans during hypha formation and growth at alkaline pH. However, C. albicans expresses several unique hypha-specific genes, including ALS3, HYR1 and SAP4 and 5. Transcript profiling also revealed a novel role for NRG1 in regulating ferric reductases in C. dubliniensis.
Project description:Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. ΔΔsfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the ΔΔsfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, ΔΔsfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues.
Project description:Candida albicans and Candida dubliniensis are closely related species displaying differences in virulence and genome content, therefore providing potential opportunities to identify novel C. albicans virulence genes. C. albicans gene arrays were used for comparative analysis of global gene expression in the two species in reconstituted human oral epithelium (RHE). C. albicans (SC5314) showed upregulation of hypha-specific and virulence genes within 30 min postinoculation, coinciding with rapid induction of filamentation and increased RHE damage. C. dubliniensis (CD36) showed no detectable upregulation of hypha-specific genes, grew as yeast, and caused limited RHE damage. Several genes absent or highly divergent in C. dubliniensis were upregulated in C. albicans. One such gene, SFL2 (orf19.3969), encoding a putative heat shock factor, was deleted in C. albicans. ΔΔsfl2 cells failed to filament under a range of hypha-inducing conditions and exhibited greatly reduced RHE damage, reversed by reintroduction of SFL2 into the ΔΔsfl2 strain. Moreover, SFL2 overexpression in C. albicans triggered hyphal morphogenesis. Although SFL2 deletion had no apparent effect on host survival in the murine model of systemic infection, ΔΔsfl2 strain-infected kidney tissues contained only yeast cells. These results suggest a role for SFL2 in morphogenesis and an indirect role in C. albicans pathogenesis in epithelial tissues.
Project description:The opportunistic human pathogens, Candida albicans and Candida dubliniensis, are closely related species displaying large differences in virulence, but the reasons for these differences are elusive. Microarray-based comparative analysis of global gene expression in the two species incubated on reconstituted human oral epithelium (RHE) was used to identify specific and common changes in gene expression and find novel C. albicans virulence genes Comparative analysis of global gene expression in Candida albicans SC5314 and Candida dubliniensis CD36 in reconstituted human oral epithelium (RHE), polycarbonate filter (PCF; used as RHE support matrix) 30 and 90 min postinoculation, and in cultures used as inocula (0 min). Gene expression in C. albicans and C. dubliniensis was assessed by co-hybridizations matched by treatments. Performed in two or three biological replicates with reciprocal dye swaps for each biological replicate. Gene expression of Candida cells on RHE was normalized to gene expression in reference control (PCF); log2 ratios were calculated by dividing spot intensity of experimental (C. albicans) by that of the reference control (C. dubliniensis).
Project description:Although Candida albicans and Candida dubliniensis are most closely related, both species significantly behave differently with respect to morphogenesis and virulence. In order to gain further insight into the divergent routes for morphogenetic adaptation in both species, we investigated qualitative along with quantitative differences in the transcriptomes of both organisms by cDNA deep sequencing. Following genome-associated assembly of sequence reads we were able to generate experimentally verified databases containing 6016 and 5972 genes for C. albicans and C. dubliniensis, respectively. About 95% of the transcriptionally active regions (TARs) contain open reading frames while the remaining TARs most likely represent non-coding RNAs. Comparison of our annotations with publically available gene models for C. albicans and C. dubliniensis confirmed approximately 95% of already predicted genes, but also revealed so far unknown novel TARs in both species. Qualitative cross-species analysis of these databases revealed in addition to 5802 orthologs also 399 and 49 species-specific protein coding genes for C. albicans and C. dubliniensis, respectively. Furthermore, quantitative transcriptional profiling using RNA-Seq revealed significant differences in the expression of orthologs across both species. We defined a core subset of 84 hyphal-specific genes required for both species, as well as a set of 42 genes that seem to be specifically induced during hyphal morphogenesis in C. albicans. Species specific adaptation in C. albicans and C. dubliniensis is governed by individual genetic repertoires but also by altered regulation of conserved orthologs on the transcriptional level.