Life Sciences Commons^™

Direct-To-Consumer Genetic Testing In The College Classroom: Knowledge, Attitudes, And Concerns Of Introductory Biology Students, Nicanor Austriaco

Biology Faculty Publications

Pioneered by companies like 23andMe.com, deCODEme.com, and Navigenics.com, direct-to-consumer genetic testing refers to genetic tests that are marketed directly to consumers via television, print media, or the Internet. This kind of testing provides access to a customer’s genetic information without necessarily involving either a medical health care professional or a genetic counselor in the process. In recent years, a course offered to medical and graduate students at Stanford University has included an option for students to undergo personal genotyping, raising the possibility that direct-to-consumer genetic testing could also be incorporated into undergraduate biology courses to enhance student learning. In this …

Deletion Of Aif1 But Not Of Yca1/Mca1 Protects Saccharomyces Cerevisiae And Candida Albicans Cells From Caspofungin-Induced Programmed Cell Death, Nicanor Austriaco, Christopher Chin, Faith Donaghey, Kathrine Helming, Morgan Mccarthy, Stephen Rogers

Biology Faculty Publications

Caspofungin was the first member of a new class of antifungals called echinocandins to be approved by a drug regulatory authority. Like the other echinocandins, caspofungin blocks the synthesis of β(1,3)-D-glucan of the fungal cell wall by inhibiting the enzyme, β(1,3)-D-glucan synthase. Loss of β(1,3)-D-glucan leads to osmotic instability and cell death. However, the precise mechanism of cell death associated with the cytotoxicity of caspofungin was unclear. We now provide evidence that Saccharomyces cerevisiae cells cultured in media containing caspofungin manifest the classical hallmarks of programmed cell death (PCD) in yeast, including the generation of reactive oxygen species (ROS), the …

S-Adenosyl-L-Methionine Protects The Probiotic Yest, Saccharomyces Boulardii, From Acid-Induced Cell Death, Nicanor Austriaco, Vincent Cascio, Daniel Gittings, Kristen Merloni, David Laprade

Biology Faculty Publications

Background

Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract.

Results

We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we …

Endoplasmic Reticulum Involvement In Yeast Cell Death, Nicanor Austriaco

Biology Faculty Publications

Yeast cells undergo programed cell death (PCD) with characteristic markers associated with apoptosis in mammalian cells including chromatin breakage, nuclear fragmentation, reactive oxygen species generation, and metacaspase activation. Though significant research has focused on mitochondrial involvement in this phenomenon, more recent work with both Saccharomyces cerevisiae and Schizosaccharomyces pombe has also implicated the endoplasmic reticulum (ER) in yeast PCD. This minireview provides an overview of ER stress-associated cell death (ER-SAD) in yeast. It begins with a description of ER structure and function in yeast before moving to a discussion of ER-SAD in both mammalian and yeast cells. Three examples of …

Yeast Bax Inhibitor, Bxi1p, Is An Er-Localized Protein That Links The Unfolded Protein Response And Programmed Cell Death In Saccharomyces Cerevisiae, Nicanor Austriaco, James Cebulski, Joshua Malouin, Nathan Pinches, Vincent Cascio

Biology Faculty Publications

Bax inhibitor-1 (BI-1) is an anti-apoptotic gene whose expression is upregulated in a wide range of human cancers. Studies in both mammalian and plant cells suggest that the BI-1 protein resides in the endoplasmic reticulum and is involved in the unfolded protein response (UPR) that is triggered by ER stress. It is thought to act via a mechanism involving altered calcium dynamics. In this paper, we provide evidence that the Saccharomyces cerevisiae protein encoded by the open reading frame, YNL305C, is a bona fide homolog for BI-1. First, we confirm that yeast cells from two different strain backgrounds lacking YNL305C, …

Common-Path Multimodal Optical Microscopy, Marla Tipping, Chandra S. Yelleswarapu, Sri-Rajasekhar Kothapalli, Alexey Veraksa, D.V.G.L.N. Rao

Biology Faculty Publications

We have developed a common-path multimodal optical microscopy system that is capable of using a single optical source and a single camera to image amplitude, phase, and fluorescence features of a biological specimen. This is achieved by varying either contrast enhancement filters at the Fourier plane and/or neutral density/fluorescence filters in front of the CCD camera. The feasibility of the technique is demonstrated by obtaining brightfield, fluorescence, phase-contrast, spatially filtered, brightfield + fluorescence, phase +fluorescence, and edge-enhanced+fluorescence images of the same Drosophila embryo without the need for image registration and fusion. This comprehensive microscope has the capability of providing both …

Daughter Cells Of Saccharomyces Cerevisiae From Old Mothers Display A Reduced Life Span, Nicanor Austriaco, Brian K. Kennedy, Leonard Guarente

Biology Faculty Publications

The yeast Saccharomyces cerevisiae typically divides asymmetrically to give a large mother cell and a smaller daughter cell. As mother cells become old, they enlarge and produce daughter cells that are larger than daughters derived from young mother cells. We found that occasional daughter cells were indistinguishable in size from their mothers, giving rise to a symmetric division. The frequency of symmetric divisions became greater as mother cells aged and reached a maximum occurrence of 30% in mothers undergoing their last cell division. Symmetric divisions occurred similarly in rad9 and ste12 mutants. Strikingly, daughters from old mothers, whether they arose …