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Rhodococcus Opacus Pd630 Genetic Tool Development To Enable The Conversion Of Biomass, Drew Michael Delorenzo

McKelvey School of Engineering Theses & Dissertations

The discovery of fossil fuels facilitated a new era in human history and allowed many firsts, such as the mass production of goods, the ability to travel and communicate long distances, the formation of population dense cities, and unprecedented improvements in quality of life. Alternative sources of energy and chemicals are needed, however, as hydrocarbon reserves continue to deplete and the effects of burning fossils on the planet become better understood. Lignocellulosic biomass is the most abundant raw material in the world and a viable alternative to petroleum-derived products. The pre-treatment of lignocellulose (e.g., thermocatalytic depolymerization, enzymatic hydrolysis, pyrolysis, etc.) …

The Role Of Multidrug Resistance Regulators Mara, Soxs, Rob And Rama In Regulating Virulence Traits In Salmonella Enterica, Srinivas Thota

Dissertations

Enteric pathogens sense numerous signals specific to the anatomical location in the intestine and integrate them with the complex regulatory networks to temporally and spatially regulate their virulence genes. MarA, SoxS, Rob and RamA are homologous transcription factors that belong to AraC family of proteins in Salmonella enterica that primarily were thought to be involved in rendering antibiotic resistance to bacteria by up regulating efflux pumps and down regulating outer membrane porins. The fact that these transcription factors respond to the same intestinal compounds that regulate virulence genes in Salmonella motivated us to look for other roles of these transcription …

Characterization Of Early Biofilm Formation And Physiology In Neisseria Gonorrhoeae, Kelly Eckenrode

Dissertations, Theses, and Capstone Projects

Many bacteria rely on the dynamics of their extracellular appendages to perform important tasks, like motility and biofilm formation. Interestingly, these dynamics have been linked to physiological responses in some pathogenic bacteria; therefore, it is important to understand more about the role of physical forces in bacteria. I used the causative agent of the human disease gonorrhea, Neisseria gonorrhoeae, as a model system to study the role of physical force on early biofilm formation. The advantage of this system is that cell-cell interactions are controlled by extracellular filaments called type IV pili (tfp). Tfp is composed of monomers that give …

Response Of Early Life Stage Homarus Americanus To Ocean Warming And Acidification: An Interpopulation Comparison, Maura K. Niemisto

Electronic Theses and Dissertations

Anthropogenic carbon released into the atmosphere is driving rapid, concurrent increases in temperature and acidity across the world’s oceans, most prominently in northern latitudes. The geographic range of the iconic American lobster (Homarus americanus) spans a steep thermal gradient and one of the most rapidly warming oceanic environments. Understanding the interactive effects of ocean warming and acidification on this species’ most vulnerable early life stages is important to predict its response to climate change on a stage-specific and population level. This study compares the responses of lobster larvae from two sub-populations spanning New England’s north-south temperature gradient (southern …

The Effect Of Metal Composition And Particle Size On Nanostructure-Toxicity In Plants, Natalie Lynn Smith

MSU Graduate Theses

Silver nanoparticles (AgNPs) have consistently been shown to have a detrimental effect on bacteria, fungi, and plants. The interaction of AgNPs with plants has received considerable scientific attention, because it is potentially through plants that these structures can enter the food chain and bioaccumulate in humans and animals. To determine the effects of AgNPs on plants, Arabidopsis thaliana seedlings were chronically exposed to sublethal levels of AgNPs using a standardized method. To gain insight on mechanism of phytotoxicity, the seedlings were exposed to low concentrations of Ag⁺ (in the form of silver nitrate), AgNPs, or gold nanoparticles (AuNPs). To …

Adversarial Deep Neural Networks Effectively Remove Nonlinear Batch Effects From Gene-Expression Data, Jonathan Bryan Dayton

Theses and Dissertations

Gene-expression profiling enables researchers to quantify transcription levels in cells, thus providing insight into functional mechanisms of diseases and other biological processes. However, because of the high dimensionality of these data and the sensitivity of measuring equipment, expression data often contains unwanted confounding effects that can skew analysis. For example, collecting data in multiple runs causes nontrivial differences in the data (known as batch effects), known covariates that are not of interest to the study may have strong effects, and there may be large systemic effects when integrating multiple expression datasets. Additionally, many of these confounding effects represent higher-order interactions …

Investigation Of Even-Skipped, A Developmentally-Regulated Gene Controlling Neural Segmentation In Dragonflies, Kathryn Bangser

Honors Theses

A comprehensive understanding of the genetic mechanisms underlying pattern formation and neurogenesis is necessary in order to trace the evolutionary history of insect embryogenesis.

One of the most important processes of embryogenesis is the organized pattern formation that allows for proper body segmentation and neural development. Proper segmentation, which relies on a series of specific gene expressions, is necessary for the development of an operational nervous system. Even-skipped (eve), one such regulatory gene, has been studied extensively in certain model organisms, and theories regarding the evolution of its functional role could be further elucidated by visualizing its expression …

Decrypting Female Attractivity In Garter Snakes, Holly Rucker

Senior Honors Projects, 2010-2019

Pheromones are utilized by many species as sexual signals driving mate choice, and pheromone production in vertebrates hinges on sex hormone action. Female red-sided garter snakes (Thamnophis sirtalis parietalis) produce a skin-based sex pheromone used by males for mate detection and selection. Estradiol is necessary for pheromone production, yet the specific mechanisms within the skin are unknown. Central to this is the metabolism of testosterone to estradiol via the enzyme aromatase. It is hypothesized that female garter snakes synthesize estradiol locally in the skin and maintain pheromone production via tissue-specific regulation of aromatase. Further, I hypothesize that female …

Proximate And Ultimate Consequences Of Stressed-Induced Maternal, Paternal, And Joint Parental Effects In A Changing World, Whitley Rayen Lehto

Electronic Theses and Dissertations

Parental experience can alter the developmental and rearing environments of offspring, resulting in parental effects on offspring traits. I addressed the consequences of stress-induced maternal, paternal, and joint parental effects from both ultimate (ecological/evolutionary) and proximate (physiological/epigenetic) perspectives. I used a full-factorial design in which threespine stickleback (Gasterosteus aculeatus) mothers, fathers, both, or neither were exposed to a model predator at developmentally appropriate times to test for predator-induced maternal, paternal, and joint parental effects on daughters’ mating behavior and egg glucocorticoids (stress hormones) and on offspring gene expression. Maternal and paternal predator exposure independently yielded daughters who preferred …

Post-Translational Modifications And Functional Studies Of Dksa In Escherichia Coli, Andrew Charles Isidoridy

Legacy Theses & Dissertations (2009 - 2024)

DksA is a bacterial gene regulator that functions synergistically with the stress alarmone ppGpp to mediate the stringent response. DksA also functions independently of ppGpp to regulate transcription of a number of genes. DksA function is dependent on its binding affinity to RNA polymerase and requires specific interactions between RNAP and catalytic amino acids located on the coiled coil tip, D74 and A76. While much of the previous work on DksA has focused on understanding the mechanisms of action and the numerous gene targets for transcriptional regulation, little is known about the mechanisms by which DksA expression and function may …

Transcriptional Regulation Of Dksa In E. Coli, Daniel Thomas Woods

Legacy Theses & Dissertations (2009 - 2024)

DksA is a global transcription factor that binds RNAP directly to regulate the expression of many genes and operons, including ribosomal RNA, in a ppGpp-dependent or ppGpp–independent manner. It is also involved in facilitating the process of DNA replication by removing stalled transcription elongation complexes that could block the progress of the replication fork. In addition, DksA is important for colonization, establishment of biofilms, and pathogenesis. In order to sustain these various functions, an adequate level of cellular DksA is required. This work tested the hypothesis that the E. coli dksA is substantially regulated at the level of transcription. Using …

Endotoxin Increases Oxidative Stress And Oxygen Tension While Reducing Milk Protein Gene Expression In The Mammary Gland, Alexander Jonathan Spitzer

Graduate College Dissertations and Theses

Mastitis, the inflammation of the mammary gland by bacterial infection, is one of the costliest diseases to the dairy industry primarily due to a loss in milk production. The aim of this study was to investigate the mechanisms underlying reduced milk production during mastitis. We hypothesized that bacterial endotoxin induces cell apoptosis, oxidative stress and increases hypoxia while inhibiting milk gene expression in the mammary gland. To test this hypothesis, mice were bred to pregnancy, and 3 days post-partum the left and right sides of the 4th pair of mammary glands were alternately injected with either the endotoxin liposaccharide (LPS, …

Novel Approaches To Evaluate And Enhance Neonatal Calf Gastrointestinal Health And Development, Fernanda Trindade Da Rosa

Electronic Theses and Dissertations

Physiological adaptations of the gastrointestinal tract (GIT) epithelial cells as well as methods to manipulate early life GIT microbiota colonization during the neonatal stage, is of great importance to the dairy industry. The first objective of this research was to optimize a method based on evaluation of bovine transcripts in fecal RNA via RTqPCR using L-selectin (SELL) as a marker for polymorphonuclear leukocytes (PMNL), keratin 8 (KRT8) and fatty acid binding protein 2 (FABP2) for GIT enterocytes, and tight junctions in fecal RNA and GIT sections in dairy calves. To test the reliability of the fecal RNA method, fecal and …