Aaron P Mitchell

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Disruption of newly identified genes in the pathogen Candida albicans is a vital step in determination of gene function. Several gene disruption methods described previously employ long regions of homology flanking a selectable marker. Here, we describe disruption of C. albicans genes with PCR products that have 50 to 60 bp of homology to a genomic sequence(More)
The fungal pathogen Candida albicans is frequently associated with catheter-based infections because of its ability to form resilient biofilms. Prior studies have shown that the transcription factor Bcr1 governs biofilm formation in an in vitro catheter model. However, the mechanistic role of the Bcr1 pathway and its relationship to biofilm formation in(More)
The impact of many microorganisms on their environment depends upon their ability to form surface bound communities called biofilms [1]. Biofilm formation on implanted medical devices has severe consequences for human health by providing both a portal of entry and a sanctuary for invasive bacterial and fungal pathogens [1 and 2]. Biofilm regulators and(More)
Sporulation of the yeast Saccharomyces cerevisiae is restricted to one type of cell, the a/alpha cell, and is initiated after starvation for nitrogen in the absence of a fermentable carbon source. More than 25 characterized genes are expressed only during sporulation and are referred to as meiotic genes or sporulation-specific genes. These genes are in the(More)
The fungal pathogen Candida albicans is naturally diploid, and current gene disruption strategies require two successive transformations. We describe here a genetic construct (UAU1) for which two copies may be selected. Insertion of UAU1 into one genomic site, after a single transformation, allows selection for segregants with two copies of the insertion.(More)
For some time, gene disruptions in Candida albicans have been made with the hisG-URA3-hisG ('Ura-blaster') cassette, which can be re-used in successive transformations of a single strain after homologous excision of URA3. However, the hisG repeats are too large for efficient PCR amplification of the entire cassette, so it cannot be used for PCR(More)
Environmental pH exerts broad control over growth and differentiation, but the molecular responses to external pH changes are poorly understood. Here we have used open reading frame macroarray hybridization to identify alkaline response genes in Saccharomyces cerevisiae. Northern or lacZ fusion assays confirmed the alkaline induction of two ion pump genes(More)
Environmental pH changes have broad consequences for growth and differentiation. The best-understood eukaryotic pH response pathway acts through the zinc-finger transcription factor PacC of Aspergillus nidulans, which activates alkaline pH-induced genes directly. We show here that Saccharomyces cerevisiae Rim101p, the pH response regulator homologous to(More)
Candida species cause frequent infections owing to their ability to form biofilms - surface-associated microbial communities - primarily on implanted medical devices. Increasingly, mechanistic studies have identified the gene products that participate directly in the development of Candida albicans biofilms, as well as the regulatory circuitry and networks(More)
Growth and differentiation of Candida albicans over a broad pH range underlie its ability to infect an array of tissues in susceptible hosts. We identified C. albicans RIM101, RIM20, and RIM8 based on their homology to components of the one known fungal pH response pathway. PCR product-disruption mutations in each gene cause defects in three responses to(More)