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Elucidation Of The Players And Events Regulating The First Meiotic Division In Mouse Spermatocytes, Amy Lynn Inselman

Doctoral Dissertations

Meiosis is the process that ensures the continued propagation of new organisms and is a source of genetic variability within a population. During meiotic prophase many dynamic rearrangements occur in the nucleus of the cell. These rearrangements include homologous chromosome pairing, recombination, synaptonemal complex breakdown, chromosome condensation and spindle assembly. The regulatory mechanisms behind these complex processes at the G2/MI transition have not been completely elucidated, preventing our complete understanding of the processes. The purpose of this work is to provide new insight to the events and players involved in the regulation of the G2/MI transition in mouse spermatocytes.

Part …

Structural And Kinetic Characterization Of Myoglobins From Eurythermal And Stenothermal Fish Species, Peter William Madden

Electronic Theses and Dissertations

Teleost myoglobin (Mb) proteins from four fish species inhabiting different temperature environments were used to investigate the relationship between protein function and thermal stability. Mb was isolated from yellowfin tuna (homeothermal warm), mackerel (eurythermal warm), and the Antarctic teleost Notothenia coriiceps (stenothermal cold). Zebrafish (stenothermal tropical) myoglobin was expressed from cloned cDNA. N. coriiceps Mb cDNA has also been cloned, expressed at 20°C , and isolated from E. coli, but was not used in any of the functional and kinetic studies. These proteins differed in oxygen affinity, as measured by O₂ dissociation rates and P₅₀ values, and …

Role Of Ionic Interactions In The Catalytic Mechanism Of R67 Dihydrofolate Reductase, Stephanie Nicole Hicks

Masters Theses

The goal of this research is to investigate the role of K32 and K33 in the catalytic mechanism of R67 dihydrofolate reductase (DHFR). K32 is located in the active site pore and is the only charged residue in the active site while K33 is located on the surface of R67 DHFR. Both of the ligands for R67 DHFR, NADPH and dihydrofolate (DHF), have negative charges capable of forming ionic interactions with symmetry related K32 residues. NMR, DELPHI, and docking studies predict that K32 is involved in ionic interactions with the 2’phosphate of NADPH. Docking studies also predict that K32 participates …

K+- Induced Dilation Of Cremasteric Arterioles Involves Na+/K+Atpase And Inward Rectifier K+ Channels, Wendy Burns

Dissertations

The purpose of this study was to evaluate the possible mechanisms involved in cremasteric arteriolar dilation as a result of increased concentrations of ([K⁺]_o) extracellular potassium. Many other studies suggested that Na⁺/K⁺ ATPase or K_IR channels are responsible for potassium-induced vasodilation in other systems (2, 12, 22, 40, 46, 52, 16, 17, 25, 33, 34, 85, 99, 151). However, these studies show only partial inhibition of dilation as a result of independent blockageof each mechanism. The hypothesis of this study was that both mechanisms contribute to potassium-induced dilation seen in cremasteric arterioles. …

Involvement Of Transit Peptide Aromatic Residues In Precursor Interaction(S) With The Chloroplast Import Apparatus, Huixia Zhang

Masters Theses

The import of nuclear-encoded preproteins into chloroplast is mediated by the transit peptide located in the N-terminus of the preproteins. A semi-conserved FGLK motif is identified in most of the transit peptides bioinformatically, despite the lack of homology in the primary sequence. To investigate the role of phenylalanines in the FGLK motifs of SStp in the interaction with outer envelope import apparatus, mutations were made on the two motifs found in prSSU from tobacco: F26TGLK and F35PVSRK. These mutations include F→W, F→S, and F→A in both of the motifs. The WT precursor (prSSU), 6 single prSSU mutants, 9 double prSSU …

Modeling Of The Inverse Heat -Conduction Problem With Application To Laser Chemical Vapor Deposition And Bioheat Transfer, Peng Zhen

Doctoral Dissertations

This dissertation consists of two parts. Part one deals with three-dimensional laser induced chemical vapor deposition (3D-LCVD), whereas part two deals with a Pennes model of a 3D skin structure. LCVD is an important technique in manufacturing complex micro-structures with high aspect ratio. In part one, a numerical model was developed for simulating kinetically-limited growth of an axisymmetric cylindrical rod by pre-specifying the surface temperature distribution required for growing the rod and then by obtaining optimized laser power that gives rise to the pre-specified temperature distribution. The temperature distribution at the surface of the rod was assumed to be at …

Synthesis And Biological Evaluation Of Novel Capacitative Calcium Entry Blockers, Thadigiri Celina Mala

Chemistry & Biochemistry Theses & Dissertations

Studies have shown that 2-aminoethoxydiphenyl borate (2-APB) inhibits thrombin-mediated influx of Ca^{2 +} through store-operated calcium channels in human platelets. Based on this molecule, two sets (boron analogues and the non-boron analogues) were synthesized and characterized by IR, NMR and CHN analysis and evaluated in human platelets to block thrombin-induced [Ca²⁺] elevation.

The synthesis of the non-boron compounds was performed in a simple one step process. According to the literature, some of these compounds were synthesized previously by a complicated two-step process.

All the compounds synthesized were tested for biological activity and the results showed that they …

Prediction Of Fetal Sheep Brain Metabolic Rate During Hypoxia And Cord Occlusion, Adam D. Hickerson

Loma Linda University Electronic Theses, Dissertations & Projects

Many investigators have observed that fetal and neonatal animals are remarkably tolerant to hypoxia compared to the adult. The precise mechanisms however are still unclear. In order to better characterize the hemodynamic and metabolic responses of the fetal brain to hypoxic stress, we have designed a mathematical model to predict tissue oxygenation and metabolic rate of the fetal brain during both moderate hypoxia and severe asphyxia.

The model is based on the Krogh cylinder concept and is similar to one previously published by our lab. Several new concepts were added including the ability to run the model over time using …

K+-Induced Smooth Muscle Calcium Sensitization Requires Rhoa Kinase (Rok) Translocation To Caveolae Which Is Inhibited In Non-Neuronal Cell Memory, Nicole Hairrell Urban

Theses and Dissertations in Biomedical Sciences

KC1 causes smooth muscle contraction by elevating intracellular free calcium ([Ca²⁺]i₎, while receptor stimulation activates an additional mechanism termed Ca²⁺- sensitization that can involve activation of ROK and PKC. However, recent studies support the hypothesis that KC1 may also increase Ca²⁺-sensitivity (36). Our data showed that the PKC inhibitor, GF-109203X, did not, while the ROK inhibitor, Y-27632, did inhibit KCl-induced tonic (5’) force and myosin light chain (MLC) phosphorylation in rabbit artery. Y-27632 also inhibited Bay K-8644- and ionomycin-induced MLC phosphorylation and force, but did not inhibit KCl-induced calcium entry or peak …

Identifying The Catalytic And Ligand Binding Roles Of Active Site Residues In Homotetrameric R67 Dihydrofolate Reductase, Michael Brad Strader

Doctoral Dissertations

R67 dihydrofolate reductase (DHFR) is a novel protein that confers clinical resistance to trimethoprim (TMP). Surprisingly, this R-plasmid encoded enzyme does not share homology with chromosomal DHFR. Recently a high resolution crystal structure of R67 DHFR has been solved. From this structure, R67 DHFR is a homotetramer that possesses exact 222 symmetry and a single active site pore that traverses the length of the protein (Narayana et al., 1995). Although this symmetry implies that four symmetry related binding sites must exist for each substrate, isothermal titration calorimetry studies indicate only two molecules bind. Three possible combinations of bound ligands have …

The Identification And Isolation Of A Full Length Beta Carbonic Anhydrase Cdna In Arabidopsis Thaliana, Lisa Michelle Ballard

Honors Theses

No abstract provided.

Vaccines For Infection Salmon Anemia Virus, Nathan Edward Charles Brown

Electronic Theses and Dissertations

Infectious salmon anemia (ISA) virus is an emerging pathogen of fanned Atlantic salmon. Due to the massive economic losses inflicted by the ISA virus, effective measures to control future outbreaks are necessary. An attractive method for preventing ISA virus from infecting stocks of Atlantic salmon is vaccination. DNA vaccination is a proven cheap, effective means of protecting fish from aquatic viruses. In this thesis DNA vaccination of Atlantic salmon was investigated. Three different strains of ISA virus were cultured and purified by density gradient ultracentrifugation. ISA virus RNA was isolated and used to amplify full-length cDNAs of five ISA virus …

The Quantitative Assessment Of Osteoinductivity Of Human Demineralized Bone Matrix And Cdna Array Analysis Of Osteogenic Differentiation In Human Periosteal Cells, Sittisak Honsawek

Theses and Dissertations in Biomedical Sciences

Demineralized bone matrix (DBM) has been extensively utilized in orthopeadic, periodontal, and maxillofacial applications. DBM comprises bone morphogenetic proteins (BMPs) that are essential regulators for endochondral bone formation. The current study was undertaken to establish the quantitative in vitro assays for determining the osteoinductive potential of human DBM and the use of cDNA gene expression array technology for examining gene expression profiles during osteoblast differentiation in human periosteal cells.

BMP-4 is one of the most osteoinductive factors and has been investigated for clinical applications. For this reason, BMP-4 was designated as the osteoinductive protein for use in the quantitative in …

Real-Time Study Of Multidrug Resistance Mechanism In Pseudomonas Aeruginosa Using Nanoparticle Optics And Single Live Cell Imaging, Sophia Vasou Kyriacou

Chemistry & Biochemistry Theses & Dissertations

This thesis centers on the study of the xenobiotic efflux system in Pseudomonas aeruginosa, which is a ubiquitous bacterium. It resists many structurally and functionally diverse substrates due to expression of Mex-extrusion pumps, including MexAB-OprM, MexCD-OprJ, MexEF-OprN and MexXY-OprM systems. Despite extensive research, the structure and mechanism of multidrug resistance is unclear (1-9). For example, (i) how do MexA, MexB and OprM proteins assemble to extrude antibiotics? (ii) What is the antibiotic susceptibility of MexA, MexB, and OprM proteins? (iii) How do substrates cross the outer membrane of P. aeruginosa? (iv) Where are antibiotics accumulated inside the cell? This thesis …

Hybridization Between The Watersnakes Nerodia Sipedon And Nerodia Fasciata, In The Carolinas: A Morphological And Molecular Approach, Konrad Mebert

Biological Sciences Theses & Dissertations

A few traditionally applied diagnostic characters of color pattern were compared with an additional set of morphological and genetic characters to evaluate differences between Nerodia sipedon and N. fasciata and to study the dynamics across their hybrid zone in the Carolinas. Many of the morphological characters exhibited significant interspecific differences, although only the number of dorsally complete crossbands (CBa) was diagnostic by itself. A discriminant function analysis of morphological characters was successful in separating both taxa. Species-specific nuclear markers, identified by the AFLP (Amplified Fragment Length Polymorphism) technique were nearly fixed and served as diagnostic markers. They revealed extensive introgression …

Hyaluronate Lyase Gene Of Streptococcus Pyogenes: Molecular Characterization And Regulation, Sheryl Lynne Walton

Theses and Dissertations in Biomedical Sciences

Streptococcus pyogenes causes an assortment of diseases ranging from pharyngitis to necrotizing fasciitis. This bacterium has the ability to elaborate several extracellular products capable of causing tissue damage; one of which is a hyaluronate lyase. Little information is available regarding the regulation of streptococcal hyaluronidase. As such, the expression of hylA in the hyaluronate lyase-producing strain ATCC 10403 and in strains that do not produce detectable enzyme was analyzed by RT-PCR and quantitative PCR. Hyaluronate lyase transcript was detected throughout growth for all strains; however, expression of hylA in the enzymatically inactive strains, 71698 and SF370, was determined …

Phosphoproteomic Studies Of Smooth Muscle Contraction: Investigation Of Differential Phosphorylation In Relaxed/Contracted Rat Aortic Smooth Muscle Tissue Using Maldi-Tof Ms, Tonya M. Pekar

Theses, Dissertations and Capstones

Many human disorders are associated with the malfunction of smooth muscle tissue, or are related to the capabilities of its proper function—asthma, glaucoma, renal inefficiency, hypertension, and cardiovascular disease. Dysfunctional proteins are frequently implicated as the source of such disorders. As the second highest cause of death in the United States, the epidemic of cardiovascular disease makes the study of smooth muscle of utmost concern.

The capabilities of proteomics and mass spectrometry allow the entire proteome complement of a cell or tissue type to be analyzed at once. This investigation employs such techniques in an effort to better understand the …

Identification And Partial Characterization Of A Family Of Putative Palmitoyltransferases In Dictyostelium Discoideum, Brent Elliot Wells

Electronic Theses and Dissertations

Heterotrimeric guanine nucleotide binding proteins (G-proteins) are essential components of a wide variety of eukaryotic cellular signaling pathways. Heterotrimeric G proteins consist of a 40 kDa α-subunit, a 36 kDa β-subunit and a small 8-10 kDa γ- subunit. Acting as molecular switches, G proteins relay molecular information fiom membrane bound receptors to downstream intracellular effectors. Most G-proteins require lipid modification by myristic acid and palmitic acid for proper localization and function. Protein palmitoylation is a post-translational, reversible thioester linkage of palmitic acid (C16:O) to an N- terminal cysteine residue of a substrate protein. Palmitoylation of G-proteins occurs specifically on the …

Evolution And Analysis Of A Catalytically Effective Model Enzyme: The Importance Of Active Site Orientation And Tuned Conformational Fluctuations, G. S. Blair Williams

Dissertations, Theses, and Masters Projects

No abstract provided.

Genetic Variation Within And Among The Suminoe Oyster (Crassostrea Ariakensis) Populations And Stocks As Assessed By Molecular Markers, Qian Zhang

Dissertations, Theses, and Masters Projects

No abstract provided.

Synalpheus Shrimp From Carrie Bow Cay, Belize. Systematics, Phylogenetics And Biological Observations (Crustacea: Decapoda: ; Alpheidae), Ruben Rios Gonzalez

Dissertations, Theses, and Masters Projects

Snapping shrimp in the family Alpheidae are remarkably abundant in coral reef ecosystems worldwide. The second most speciose genus, Synalpheus , includes species usually small and reclusive, and their general morphology is notably uniform, yet the number of species is staggeringly high, as is the intraspecific variability. These features have contributed to a poorly resolved taxonomic status, as evidenced both by recurring lumping and splitting of species and by lack of proper definition of several common species. I examined western Atlantic species of Synalpheus in the large and regionally dominant "Gambarelloides group of species", an informal but widely used guild …

Characterization Of The Xgat-1 Gene In Xenopus Laevis, Lisa Layne August

Dissertations, Theses, and Masters Projects

No abstract provided.

Cloning Of Bovine Placental Lactogen And Production In Vitro, Stephanie A. Doucette

Electronic Theses and Dissertations

Bovine placental lactogen (bPL) is a hormone produced by the fetal portion of the placenta during gestation. Although there is little known about the structure and function of the protein, it is thought to play a role in the growth of the fetus and in mammary growth and differentiation. Attempts have been made to heighten the understanding of bPL through the use of recombinant DNA technology. Thus far, researchers have been able to produce the recombinant molecule in bacteria cells. Bacteria, however, are incapable of carrying out some of the post-translational modifications characteristic of mammalian proteins. For example, unlike native …

A Mycobacterium-Inducible Nramp In Striped Bass Morone Saxatilis, Erin Jeffrey Burge

Dissertations, Theses, and Masters Projects

In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay (USA) striped bass, Morone saxatilis, are currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. This dissertation characterizes an Nramp gene in this species (MsNramp ) and provide evidence for induction following Mycobacterium exposure. The striped bass MsNramp gene and 554 amino acid sequence contain all the signal features of the Nramp family, including a topology of 12 transmembrane domains (TM), the transport protein specific 'binding-protein-dependent transport system inner membrane component …

Cloning And Functional Characterization Of Hypoxia-Inducible Factor 1alpha Upstream Regions In Xenopus Laevis, Conor W. Sipe

Dissertations, Theses, and Masters Projects

No abstract provided.

Comparative Serological And Molecular Analysis Of Group Viii Spiroplasma From Australia And North America, April Carmita Murphy

Legacy ETDs

Spiroplasma bacteria (Mollicutes: Spiroplasmataceae) are characterized by motility, helical morphology and are most frequently found in insect guts and phloem tubes of plants. Traditionally, Spiroplasma have been classified by serology. Recent work has generated 16S rDNA sequences that generally correlate with the serological findings. Although the serology and the 16S rDNA sequence analysis clearly classifies strains to the group level, they do not distinguish between strains within the same group. The goal of this project was to investigate the utility of the 16S-23S rDNA intergenic spacer region sequence as a means to distinguish these closely related strains.

We chose Group …

Mosquitoes, West Nile Virus, Attractants, Competition, Environmental Conditions, And Insecticide Resistance, Alan Bradley Wells

Legacy ETDs

The six main objectives of this project were: 1) test for levels of West Nile Virus in mosquitoes collected at a Fulton County Recreational Facility, 2) assay various mosquito oviposition attractants on West Nile virus positive female mosquitoes, 3) test effects of distance between mosquito infusion attractants, 4) determine effects of study site location, treatment, and competition distances on mosquito collections, 5) test for any correlation between environmental factors and mosquito abundance, and 6) measure levels of enzymatic insecticide resistance present in species of female mosquitoes that tested positive for the presence of West Nile Virus. Ofthe two species that …