Unknown,Transcriptomics,Genomics,Proteomics

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Identification of Candida albicans genes differentially expressed in the presence of arachidonic acid

ABSTRACT: Although Candida species, more specifically C. albicans, are the most common pathogenic yeasts, little is known about the mechanism involved in eicosanoid production, a virulence factor in these organisms. This is an important area of research which may aid in the understanding of the complex interactions between host and pathogen and may possibly lead to the identification of novel antifungals or drug targets. In this study, genomic hybridization studies using C. albicans DNA microarrays were used to evaluate the regulation of C. albicans biofilm genes during incubation in the presence of arachidonic acid, the major precursor for prostaglandin E2 production. The results obtained indicated that the genes differentially expressed had diverse functions not normally required for cell growth. Two-condition experiment, Control biofilms vs. Arachidonic acid treated biofilms at different time intervals. Biological replicates: 3 Control, 3 Arachidonic acid treated, independently grown and harvested. Technical replicate: dye swap included. Triplicate per array.

ORGANISM(S): Candida albicans

SUBMITTER: Carolina Pohl-Albertyn

PROVIDER: E-GEOD-36436 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:The interaction between fungal pathogen and host during infection is a complex and dynamic process. To resolve this, we chose the zebrafish model organism as the host to study C. albicans infection via systems biology approach. Transcriptome microarray data and histological analysis of surviving fish were sampled at different post-infection time points. The dynamic variations of significant genes expression profiles in C. albicans and zebrafish were concurrently analyzed by principal component analysis (PCA). The PCA results clearly indicated that the infection of C. albicans can be divided into three phases that include adhesion, invasion and damage phases. The results were highly consistent with subsequent histological analysis. Furthermore, we found the primary ontology function of genes with significant variations in both C. albicans and zebrafish is iron related. Most of the iron related genes in C. albicans were over-expressed in late stage, while most of the iron related genes in zebrafish were suppressed at the same phase of infection. It suggested that the iron homeostasis function of the host was shut-down when massive hemorrhage in zebrafish occurred during later stages of infection. At the same time, the iron scavenging function of C. albicans was activated. This implied the competition for iron is an important issue between the host and the fungal pathogen during infection. When we administered excess iron into the microenvironment of infection site, the infection process was significantly delayed. That indicated the virulence of C. albicans is correlated with its protein-bond iron scavenging strategies. Our finings not only provided dynamic mechanistic views of the iron competition but also highlighted the potential regulatory schemes in fungal pathogenesis. Each fish was intraperitoneally injected with C. albicans cells and these infected fish were collected at 0.5, 1, 2, 4, 6, 8, 12, 16, 18 hpi. 0.625M-NM-<g of Cy3 cRNA for C. albicans array and 1.65 M-NM-<g of Cy3 cRNA for zebrafish array was fragmented to an average size of about 50-100 nucleotides by incubation with fragmentation buffer at 60M-BM-0C for 30 minutes. Each time points contain three biological repeat. For C. albicans array, each biological repeat has two technical replicates.

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Identification of Candida albicans genes differentially expressed in the presence of arachidonic acid

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