Molecular Biology Commons^™

Single Molecule Fluorescence Studies Of Protein Structure And Dynamics Underlying The Chloroplast Signal Recognition Particle Targeting Pathway, Dustin R. Baucom

Graduate Theses and Dissertations

The work presented in this dissertation explores the structural dynamics in the chloroplast signal recognition particle pathway. Findings include cpSRP shows scanning functionality similar to that in the cytosolic SRP with the ribosome. The intrinsically disordered C-terminal tail of the Albino3 protein has some transient secondary structure. Upon binding to cpSRP43 in solution, separate secondary structure formation was identified in the C-terminal tail of Albino3. Finally, to increase efficiency of analyzing fluorescence time traces for this work, a modular software was produced.

Natural Variation In Yeast Stress Signaling Reveals Multiple Paths To Similar Phenotypes, Amanda N. Scholes

Graduate Theses and Dissertations

Natural environments are dynamic, and organisms must sense and respond to changing conditions. One common way organisms deal with stressful environments is through gene expression changes, allowing for stress acclimation and resistance. Variation in stress sensing and signaling can potentially play a large role in how individuals with different genetic backgrounds are more or less resilient to stress. However, the mechanisms underlying how gene expression variation affects organismal fitness is often obscure.

To understand connections between gene expression variation and stress defense phenotypes, we have been exploiting natural variation in Saccharomyces cerevisiae stress responses using a unique phenotype called acquired …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …

Analyzing Multigene Stacking And Genome Editing Strategies In Rice, Bhuvan Pathak

Graduate Theses and Dissertations

Crop improvement through biotechnology is an integrated effort, incorporating multiple approaches like integration of genes, editing of native genes, and removal of selection marker genes. Before streamlining the protocols, the efficiency and feasibility of the individual approach and their components must be tested. This study evaluated following approaches: 1) stacking an array of genes into a single locus by site-specific integration via Cre-lox recombination in rice, 2) determining the efficiency of I-SceI and the CCR5-ZFN in the targeted excisions of gene fragments in rice and Arabidopsis, and 3) determining the efficiency of CRISPR/Cas9 in generating targeted mutations for genome editing …

Investigating Growth Performance And Intestinal Barrier Integrity In Heat-Stressed Modern Broilers And Their Ancestor Jungle Fowl, Travis Tabler

Graduate Theses and Dissertations

Heat stress (HS) has a negative effect on poultry production sustainability due to its adverse consequence on bird welfare, health, growth, and mortality. Although modern broilers have greater gut mass and higher energy use efficiency than unselected birds, they are more vulnerable to HS that induces “leaky gut syndrome,” or increased intestinal permeability. The aim of the current study was to determine the effect of HS on growth performance and gut barrier integrity in three modern broiler lines and their ancestor the Jungle Fowl. Four chicken populations including Giant Jungle Fowl (JF), Athens Canadian Random Bred (ACRB), 1995 Arkansas Random …

Global Acetylation Dynamics In The Heat Shock Response Of Saccharomyces Cerevisiae, Rebecca E. Hardman

Graduate Theses and Dissertations

All organisms face a constant barrage of environmental stresses. Single-cell organisms such as Saccharomyces cerevisiae, or common Baker’s yeast, must rely solely on cellular responses in order to survive. This response must occur in a rapid and highly coordinated manner to quickly inhibit all unnecessary processes and shuttle all available resources to those necessary for survival. One method that cells utilize for rapid protein regulation is the use of post-translational modifications. Enzymes within the cell add or remove a variety of chemical modifications, thus altering the local chemical environment of a protein. This creates a conformational change in the protein …

Investigation Of Microbiota In Health And Disease Of Poultry, Bishnu Adhikari

Graduate Theses and Dissertations

The microbiotas play vital roles in health and diseases of both humans and animals. 16S rRNA genes sequence analysis is one of the most popular and commonly used methods in the analysis of microbiotas associated with hosts. In this dissertation, the microbiotas of chickens (broilers, breeders, and layers) and turkeys were evaluated by 16S rRNA gene sequencing. Characterization of the culturable subpopulations of Lactobacillus in the chicken gut can serve as a valuable resource for probiotic development. In Chapter 2, Lactobacillus subpopulations recovered on MRS from chicken gut were defined comprehensively for the first time using 16S rRNA gene profiling, …

Spatial Reorganization Of Histone-Like Nucleoid Structuring Proteins Caused By Silver Nanoparticles, Meaad Alqahtany

Graduate Theses and Dissertations

Silver nanoparticles (AgNPs) and ions (Ag+) can be the new generation of antibiotics due to their antimicrobial effects against bacteria and other microbes. Many studies have shown that AgNPs and suppress the growth of bacteria and damage the cell walls of the microbes; therefore, treating bacterial cells with AgNPs may be a promising method to terminate multi-resistant bacteria. In this work, the effect of AgNPs with two different surface coatings on the spatial reorganization of histone-like nucleoid structuring (H-NS) proteins in Escherichia coli bacteria was investigated using quantitative super-resolution fluorescence microscopy to understand the toxicity and antimicrobial mechanism of AgNPs. …

Hormone Signaling, Gene Expression, And Mitochondrial Hormone Receptor Expression In Avian Muscle (Cells), Kentu Rushadd Lassiter

Graduate Theses and Dissertations

Mitochondria are vital to the proper growth and function of muscle cells since they’re responsible for the majority of ATP production used for cellular energy. Previous studies have investigated how differences in mitochondrial function affects feed efficiency (FE) in broilers phenotyped for High and Low FE. Low FE broilers have been shown to have increased levels of reactive oxygen species (ROS), thus contributing to higher levels of oxidative stress and damage seen in these birds. Global gene and protein expression studies conducted on breast muscle of the High FE and Low FE phenotypes have suggested that differences in mitochondrial function …