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Elucidating The Evolution And Function Of Srnas That Facilitate Bacterial Stress Tolerance, Madeline Claire Krieger
Elucidating The Evolution And Function Of Srnas That Facilitate Bacterial Stress Tolerance, Madeline Claire Krieger
Dissertations and Theses
Non-coding small RNAs (sRNAs) are ubiquitous post-transcriptional regulators found in both gram-negative and gram-positive bacteria. Despite their integral role in many regulatory pathways, including those that facilitate stress-tolerance, little is known about the evolutionary forces that drive the emergence of novel sRNAs, how prevalent sRNAs are within bacterial species, or the functions of a majority of these transcripts. In this work, I first describe the evolution of OxyS, a well-characterized sRNA in gram-negative Enterobacteriaceae that is involved in coordinating the bacterial response to oxidative stress. Next, I identify novel sRNAs differentially produced by the gram-positive oral pathogen Streptococcus mutans in …
Small Rna Mgrr Regulates Sensitivity Of Escherichia Fergusonii To Oxidative Stress, Austin Paul Wright
Small Rna Mgrr Regulates Sensitivity Of Escherichia Fergusonii To Oxidative Stress, Austin Paul Wright
Dissertations and Theses
Non-coding small RNAs (sRNAs) are integral to post-transcriptional gene regulation in bacteria. The function of an sRNA is dependent on both secondary structure and the sequence of its unstructured seed region. The sRNA seed region typically base-pairs with target mRNAs to down-regulate the expression of target genes by blocking the ribosome-binding site or by promoting RNase-mediated degradation of the sRNA-mRNA complex. sRNAs have also been shown to increase expression of target genes by releasing RNA secondary structures that block ribosome-binding sites. Selective pressure to maintain sRNA function conserves the sequence of the sRNA seed region, but mutations in mRNA sequences …
Phenotypic And Mutational Consequences Of Mitochondrial Etc Genetic Damage, Michael James Lue
Phenotypic And Mutational Consequences Of Mitochondrial Etc Genetic Damage, Michael James Lue
Dissertations and Theses
Genetic mutation is the ultimate source of new phenotypic variation in populations. The importance of mutation cannot be understated, and constitutes a significant evolutionary force. Although single mutations may have little to no impact on organismal performance or fitness, when multiplied across the total number of potential sites within the genome, mutation can have a large impact. Accurate measurement of the rates, molecular mechanisms, and distributions of effects of mutations are critical for many applications of evolutionary theory. Despite the importance of both deleterious and beneficial mutations, their genome-wide patterns and phenotypic consequences are poorly understood when considering the mitochondrial …
Increased Glutathione Metabolic Defense Capabilities In Cultured Alzheimer's Diseased Lymphoblast Cell Lines, Collin M. Shaw
Increased Glutathione Metabolic Defense Capabilities In Cultured Alzheimer's Diseased Lymphoblast Cell Lines, Collin M. Shaw
Dissertations and Theses
The hypothesis to be tested states that the pathology of Alzheimer's disease (AD) involves elevated levels of oxidative stress, resulting in elevated levels of cellular oxidative defense mechanisms. If the premise is true, than AD pathologically afflicted cells should have a higher demand for glutathione (GSH) as an innate oxidative defense mechanism hence; greater GSH concentrations, increased GSH resynthesis capabilities, and increased levels of cystathionine gamma-lyase (CNase). Alzheimer diseased and age matched control lymphoblast cells, obtained from OHSU's Oregon Brain Aging Study, were cultured, and GSH biochemistry was subsequently evaluated. GSH was depleted by exposing cells to the GSH depleting …