Life Sciences Commons^™

Cis-Acting Determinants Of Coronavirus Genome Translation And Replication, Kortney Michele Gustin

Doctoral Dissertations

Coronaviruses are a family of positive-sense, single-stranded, 5’-capped and 3’- polyadenylated RNA viruses that replicate entirely in the cell cytoplasm. Replication of the viral genome requires translation to produce proteins used for RNA synthesis and virion assembly. The 5’- and 3’- untranslated regions of the coronavirus genome have been found to contain cis-acting elements that are required for replication of the genome and a defective interfering RNA. Presumably, both viral and cellular proteins interact with these elements and serve as trans-acting factors in genome translation and replication. Of interest is the functional significance of a 5’-proximal cis-acting 397-nucleotide …

The Role Of Cytomegalovirus Viral Chemokines In Neutrophil Activation And Viral Dissemination, Mindy L. Miller-Kittrell

Doctoral Dissertations

CMV is the leading cause of both non-hereditary mental retardation and hearing loss and CMV infection following transplantation carries a serious risk for complications. The development of a CMV vaccine or better therapeutic treatment is desired but to develop these a more complete understanding of CMV pathogenesis is necessary. Sequence comparisons between attenuated and virulent strains of HCMV map major differences to a 15kb region (ULb’) containing the chemokine homolog, vCXCL-1. The vCXCL-1 protein of the Toledo (Tol) strain was previously shown to function in vitro as a CXC chemokine. Murine CMV (MCMV) also encodes a viral chemokine, MCK2. Prior …

Distribution Of Mycobacterium Ulcerans In Aquatic Environments In Ghana, Heather Williamson

Doctoral Dissertations

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a necrotizing skin disease prevalent in 30 countries of West Africa and Australia. The disease begins as a painless nodule or papule that, if left untreated, can lead to ulceration that can cover much of the body. Though not usually fatal, morbidity is high, especially in rural areas where the disease is prevalent.

Epidemiological evidence has linked incidence of Buruli ulcer to slow moving or stagnant waters, but despite this, the mode of transmission is not known. Evidence for M. ulcerans in aquatic environments has relied on detection based upon PCR …

Studies Of The Di/Tripeptide Transporter In Saccharomyces Cerevisiae: The N-Terminal Cytoplasmic Domain Of Ptr2p Is Involved In Post-Translational Regulation, Steven Clinton Minkin Jr.

Doctoral Dissertations

Throughout nature cells use peptides as a source of nutrition. For microbes, an ability to utilize peptides is especially important in nitrogen-poor environments, as peptides can be catabolized for their use as a nitrogen source. The yeast Saccharomyces cerevisiae imports di/tripeptides from the environment using the peptide transporter Ptr2p. Cellular levels of Ptr2p are highest under poor-nitrogen conditions. Here we report that the addition of a rich nitrogen source to the growth medium results in a down-regulation of Ptr2p, wherein plasma membrane Ptr2p is ubiquitinated, endocytosed, and delivered to the vacuole for destruction. We report evidence that the N-terminal portion …

Introduction Of Mycobacterium Ulcerans Mycolactone Genes Into A Heterologous Host, Samantha Elizabeth Wirth

Masters Theses

Mycobacterium ulcerans is the causative agent of Buruli ulcer (BU), a necrotizing skin disease endemic to West Africa and Australia. The cytopathicity, cell cycle arrest and immunosuppression characteristic of BU are attributed to the production of a plasmid-encoded, macrolide toxin, mycolactone. The core of mycolactone is a product of two large polyketide synthases (PKS) and is conserved among all mycolactone congeners. Heterogeneity of the toxin is a result of differences in the polyketide side chain, the product of a third PKS. The mycolactone plasmid (MP) was initially thought to be restricted to M. ulcerans. However, other mycolactone producing mycobacteria …

Vertically Aligned Carbon Nanofiber Arrays As A Platform For Gene Delivery And Expression Analysis In Mammalian Cells, David George James Mann

Doctoral Dissertations

Vertically aligned carbon nanofiber (VACNF) arrays have been developed as a novel tool for direct physical introduction and expression of DNA in mammalian cells (termed impalefection). This study describes the optimization of impalefection, the quantification of immobilized DNA on VACNFs, and the application of VACNFs in analysing gene expression in mammalian cells. Mechanical, chemical and biological parameters were optimized for impalefection. Alterations in a majority of the parameters resulted in no significant difference in impalefection efficiency, including nanofiber composition, DNA precipitation, cell confluency, cell concentration and sodium butyrate. The optimal DNA concentration ranged between 100 nanograms and 1 microgram, and …

Development Of A Bacteriophage Based Bioluminescent Bioreporter System For The Detection Of Escherichia Coli K12 And O157:H7, Courtney M. Johnson

Masters Theses

Detection of pathogenic bacteria in the environment and food products is of increasing importance especially in light of recent outbreaks of Escherichia coli O157:H7. I describe here a bacteriophage based bioluminescent bioreporter method for E. coli O157:H7 detection that combines the specificity bacteriophage have for their host, quorum sensing, and lux based bioluminescence from Vibrio fischeri. This new method for detection of E. coli utilizes the luxI/luxR quorum sensing present in V. fischeri which uses N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) as an autoinducer (Miller & Bassler 2001). Once the concentration of OHHL is high enough it binds the LuxR protein …

Characterization Of Motility And Surface Attachment In Thirteen Members Of The Roseobacter Clade, Rachael N. Slightom

Masters Theses

The Roseobacter clade is an abundant and biogeochemically relevant group of marine bacteria. Physiological and ecological traits identified in specific representatives of the clade are often universally attributed to all Roseobacter group members, however, culture-dependent studies utilizing phylogenetically distinct members are rare. Other attributes often associated with this clade include motility, biofilm formation and surface attachment, chemotaxis and quorum sensing. This study compared a collection of 13 diverse Roseobacter strains both pheno- and genotypically on the basis of these traits. Motility was determined for seven previously uncharacterized strains, with five of the strains demonstrating motility. Microscopic analysis using both phase …

The Microscope (2008-2009), Department Of Microbiology

The Microscope

No abstract provided.