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The Thiol Specific Antioxidant (Tsa1) Gene Is Required For Survival In Macrophages And Oxidative Stress Resistance In Histoplasma Capsulatum, Lauren Kennedy

Master's Theses

Histoplasma capsulatum(Hc) is a pathogenic fungus that causes one of the most common invasive fungal respiratory diseases, Histoplasmosis. Histoplasmaundergoes a dimorphic shift from mold to yeast which is crucial to pathogenesis of the organism.

The thiol specific antioxidant gene, Tsa1,is strongly upregulated in the yeast (pathogenic) morphotype. This data led to the hypothesis that this gene plays a role in protecting Hcfrom host mediated oxidative attack. To characterize Tsa1 function, a knockdown strain (tsa1-RNAi) was created by RNAi gene silencing. Expression of Tsa1in the tsa1-RNAistrain was reduced to 10% that …

The Effect Of Alcohol And Bitterness Levels On Brewing Yeast Viability, Nichole Elizabeth Bryant

Master's Theses

Two of the most popular beer styles within the craft brewing industry are India Pale Ales (IPA’s) and those with high alcohol by volume (ABV). Production of these styles requires high gravity fermentation and high amounts of bittering hops in order to reach the required values for ABV and International Bitterness units (IBU) respectively. The aim of this study was to determine the impact of high gravity fermentation and high IBU levels on yeast viability and repitching cycles.

An initial experiment on high gravity fermentations was done in order to assess the effects this variable had alone. Successive five day …

Investigation Of Chromosome Size Effect On The Rate Of Crossovers In The Meiotic Yeast Saccharomyces Cerevisiae, Lanie Maria Galland

Master's Theses

Meiosis is a specialized type of cell division characterized by a single round of DNA replication and two rounds of chromosome segregation, ultimately resulting in four haploid cells. During meiosis I, chromosomes align and reciprocal recombination results in the formation of a crossover, creating the tension required to properly segregate homologs during the first round of meiosis.

Two mechanisms involved in regulating the occurrence of crossing over are assurance and interference. Crossover assurance describes the phenomenon that at least one crossover will form between each pair of homologous chromosomes during prophase I. Crossover interference, on the other hand, describes the …

Investigating The Roles Of Ndj1 And Tid1 In Crossover Assurance In Saccharomyces Cerevisiae, Rianna Knowles

Master's Theses

Meiosis is the specialized process of cell division utilized during gametogenesis in all sexually reproducing eukaryotes, which consists of one round of DNA replication followed by two rounds of chromosome segregation and results in four haploid cells. Crossovers between homologous chromosomes promote proper alignment and segregation of chromosomes during meiosis.

Crossover interference is a genetic phenomenon in which crossovers are non-randomly placed along chromosomes. Crossover assurance ensures that every homologous chromosome pair obtains at least one crossover during Prophase I. Crossovers physically connect homologous pairs, allowing spindle fibers to attach and separate homologs properly. However, some organisms have shown an …

Investigating The Roles Of Ndj1 And Tid1 In Distributive Segregation Using Non-Exchange Chromosomes, Jonathan V. Henzel

Master's Theses

Meiosis is a specialized cell division that leads to a reduction of ploidy in sexually reproducing organisms through segregation of homologous chromosomes at the first meiotic division. Improper segregation of chromosomes during meiosis results in anueploidy, which is usually fatal during embryonic development. The meiotic process is therefore tightly regulated. Typically, proper segregation of homologs at meiosis I requires pairing of homologous chromosomes, followed by crossover recombination between homologs. Crossovers enable proper chromosomal segregation during the first meiotic division in part by establishing tension in the meiotic spindle. However, in the absence of crossovers, some cells maintain the ability to …

A Reverse Genetics Approach For Studying Histone H4 Structure-Function Relationships In Yeast, Michael J. Bonaduce

Master's Theses

A previously constructed mutation of the histone H4 gene has been the subject of a detailed analysis. The mutation involves an H4 gene encoding two amino acid changes which substitute aspartic acid for glycine at positions 13 and 42 of the polypeptide. These substitutions result in a nonfunctional H4 protein when assayed in Saccharomyces cerevisiae. In contrast, an analysis of an amino terminal deletion of amino acids 3-26 results in a functional H4 protein. Physical biochemistry studies identify the sites of histone-histone interactions between residues 38-102 of histone H4, the same area in which position 42 resides. The question being …