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Articles 1 - 16 of 16

Full-Text Articles in Molecular Biology

Sigma Factor N (Σn): A Novel Regulator Of Extreme Acid Resistance In Enterohemorrhagic E. Coli O157:H7, Pamela Ann Fay Jan 2012

Sigma Factor N (Σn): A Novel Regulator Of Extreme Acid Resistance In Enterohemorrhagic E. Coli O157:H7, Pamela Ann Fay

Graduate Theses and Dissertations

Extreme acid resistance contributes to the successful transmission of enterohemorrhagic E. coli (EHEC) through acidic food matrices and the stomach, allowing it to gain access to the intestine and elicit disease in humans. Alternative sigma factor N (σN, encoded by rpoN) was previously identified as a novel regulator of extreme acid resistance in EHEC. This study investigated the role for σN and co-expressed products of the rpoN operon in the acid resistance phenotype of EHEC. The results revealed that σN primarily controls acid resistance through repression of the glutamate-dependent acid resistance (GDAR) system through control of the ...


Systematics Of Harrisia (Cactaceae), Alan R. Franck Jan 2012

Systematics Of Harrisia (Cactaceae), Alan R. Franck

Graduate Theses and Dissertations

The genus Harrisia Britton (Cactaceae) comprises species of columnar cacti that are united by a unique seed morphology. The species range in form from prostrate shrubs to large trees and are native to South America and the Caribbean region. Harrisia is placed in an unresolved position within subtribe Trichocereinae of tribe Cereeae of subfamily Cactoideae. Relationships among the species within Harrisia are also poorly understood. In this study, several species of Harrisia were sequenced for as many as seven different regions of nuclear and plastid DNA. Species in the Caribbean were also examined with amplified fragment length polymorphisms. The morphology ...


Development And Application Of An F/M Based Anaerobic Digestion Model And The Rt-Ribosyn Molecular Biology Method, Matthew Raymond Cutter Jan 2012

Development And Application Of An F/M Based Anaerobic Digestion Model And The Rt-Ribosyn Molecular Biology Method, Matthew Raymond Cutter

Graduate Theses and Dissertations

A simple anaerobic digestion model has been developed for a continuously-stirred tank reactor (CSTR), which links the specific biogas production rate to the food/microorganism ratio (F/M). The model treats the various microbial populations involved in the sequential biological processes involved in anaerobic digestion as a composite and links the entire biomass specific growth rate directly to the specific biogas production rate. The model was calibrated by determining the specific gas production rate for a range of F/M values using a municipal wastewater seed sludge. The model predictions for steady-state biogas production rates were compared to observed biogas ...


Investigation Into The Mechanism Of Salicylate-Associated Genotypic Antibiotic Resistance In Staphylococcus Aureus, Nada Salah Helal Jan 2012

Investigation Into The Mechanism Of Salicylate-Associated Genotypic Antibiotic Resistance In Staphylococcus Aureus, Nada Salah Helal

Graduate Theses and Dissertations

Growth of Staphylococcus aureus with the NSAID salicylate increases phenotypic resistance (SAPAR), and the frequency at which heritable resistance occurs to various antibiotics (SAGAR). This study describes the effect of salicylate on heritable and phenotypic resistance to a set of antibiotics for laboratory and multi-drug resistant strains of S. aureus and investigates the link between resistance and SAGAR. Drug gradient plates were used to determine phenotypic resistance to antibiotics targeting DNA replication, transcription, translation and the cell wall in the presence or absence of salicylate. To measure heritable resistance, mutation frequencies were determined for each antibiotic in the presence and ...


Matrix Metalloproteinase Genes Are Transcriptionally Regulated By E2f Transcription Factors: A Link Between Cell Cycle Control And Metastatic Progression, Jacqueline Lea Johnson Jan 2012

Matrix Metalloproteinase Genes Are Transcriptionally Regulated By E2f Transcription Factors: A Link Between Cell Cycle Control And Metastatic Progression, Jacqueline Lea Johnson

Graduate Theses and Dissertations

The RbµE2F transcriptional regulatory pathway plays a critical role in the cell cycle. Rb is inactivated through multiple waves of phosphorylation, mediated mainly by cyclin D and cyclin E associated kinases. Once Rb is inactivated, cells can enter Sµphase. Collectively, three Rb family members and ten E2F proteins coordinate every additional stage of the cell cycle, from quiescence to mitosis. However the RbµE2F pathway is frequently altered in cancer. Aside from cell proliferation, the RbµE2F pathway regulates other essential cellular processes including apoptosis, cell differentiation, angiogenesis and DNA damage repair pathways, but its role in invasion and cancer progression is ...


Cloning Of The Gene, Purification As Recombinant Protein And Functional Characterization Of Leishmania Mexicana Cytochrome B5 Reductase, Ala Azhari Jan 2012

Cloning Of The Gene, Purification As Recombinant Protein And Functional Characterization Of Leishmania Mexicana Cytochrome B5 Reductase, Ala Azhari

Graduate Theses and Dissertations

Leishmania are protozoan parasites that are transmitted by a sand fly vector. These parasites affect not only humans but also wild animals including domestic dogs and rodents, which form an additional challenge and public health problem to control the disease. Leishmaniasis is an important disease with worldwide distribution, including Saudi Arabia, the Middle East, and other tropical and subtropical areas around the world. Due to the expansion of irrigation and agricultural activities, more exposure to sand fly occurs, which leads to the expansion of leishmaniasis infections as newly emerging disease.

Emerging drug resistance in leishmaniasis is an additional problem, contributed ...


The Role Of Tumor Suppressors, Ship And Rb, In Immune Suppressive Cells, Michelle Marie Collazo Ruiz Jan 2012

The Role Of Tumor Suppressors, Ship And Rb, In Immune Suppressive Cells, Michelle Marie Collazo Ruiz

Graduate Theses and Dissertations

Regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC) have been extensively studied in the past 30-40 years. Their potent suppressive capacity shown in several pathological and clinical settings, such as cancer and transplantation, has made it evident that better understanding their development and function is critical.

Specifically, Tregs play a pivotal role in preventing autoimmunity, graft-versus-host disease (GvHD), and organ graft rejection. We previously demonstrated that germline or induced SH2 domain-containing inositol 5-phosphatase (SHIP) deficiency in the host abrogates GvHD. Here we show that SHIP-deficiency promotes an increase of FoxP3+ cells in both the CD4+CD25+ and the CD4 ...


Microrna Expression And Function During Porcine Oocyte Maturation And Early Embryonic Development, Elane Courtney Wright Jan 2012

Microrna Expression And Function During Porcine Oocyte Maturation And Early Embryonic Development, Elane Courtney Wright

Graduate Theses and Dissertations

Understanding oocyte maturation and embryo development in the pig is essential to improving farm animal reproduction efficiency. Many reproductive tissues are associated with a high degree of transcriptional and translational turnover that may be in part regulated by non-coding RNA such as microRNA (miRNA). The oocyte consists of a storage of maternal RNA and nutrients that are utilized to support oocyte maturation and early embryo development. MiRNA have been identified in the oocyte and throughout early embryo development in many species including the pig. MiRNA exert their biological impact on the cell through post transcriptional gene regulation (PTGR) by interacting ...


Optimizing Molecular Detection And Sequencing Of Porcine Reproductive And Respiratory Syndrome Virus In Clinical Oral Fluid Specimens, Wayne Alan Chittick Jan 2012

Optimizing Molecular Detection And Sequencing Of Porcine Reproductive And Respiratory Syndrome Virus In Clinical Oral Fluid Specimens, Wayne Alan Chittick

Graduate Theses and Dissertations

This thesis begins with discussion of molecular diagnostics used in diagnosis of the Porcine Reproductive and Respiratory (PRRS) virus with specific emphasis on swine oral fluids are discussed through a review of literature. Risks contributing to missed detection are discussed including: virus mutation, viral degradation in clinical samples, and polymerase chain reaction (PCR) inhibition.

Chapter two reports optimization of RNA extraction and PCR protocols for swine oral fluids. The results showed marked differences among extraction protocols, PCR protocols, and combinations thereof in detecting PRRSV in the oral fluid matrix. An important finding was that PCR reactions were partially inhibited and ...


Strategies For Recombinant Protein Production In Maize, Xing Xu Jan 2012

Strategies For Recombinant Protein Production In Maize, Xing Xu

Graduate Theses and Dissertations

Maize is not only one of the world's most important crops, but it is also the first field-grown plant-based recombinant expression system developed for commercial purposes. With advantages of low cost, high yield, high protein stability, and well-developed transformation technology over other plant systems, maize is considered to be an ideal recombinant production system. However, there are three major challenges limiting the use of maize for producing recombinant proteins: 1) maize lacks mammalian-like post-translational modification ability that may be required for pharmaceutical and industrial proteins; 2) transgenic pollen containment in open-field production; and 3) low expression of recombinant products ...


Structure-Function Analyses Of The Tre1 G Protein-Coupled Receptor, Margaret Marie Pruitt Jan 2012

Structure-Function Analyses Of The Tre1 G Protein-Coupled Receptor, Margaret Marie Pruitt

Graduate Theses and Dissertations

Cell migration is a process that is essential to animals during their entire lifetime and improper cell migration is implicated in diseased states such as cancer. Primordial germ cell migration in Drosophila melanogaster is an excellent model to study cell migration. The movements of Drosophila primordial germ cells are well documented and some of the molecules involved have been identified. The G protein-coupled receptor (GPCR) trapped in endoderm-1 (tre1) is one of the first genes involved in primordial germ cell migration. The work in this dissertation focuses on the GPCR Tre1, the roles of Tre1 in Drosophila germ cell migration ...


The Evolution Of The Mitochondrial Genomes Of Calcareous Sponges And Cnidarians, Ehsan Kayal Jan 2012

The Evolution Of The Mitochondrial Genomes Of Calcareous Sponges And Cnidarians, Ehsan Kayal

Graduate Theses and Dissertations

The mitochondrial DNA (mtDNA) in animals (Metazoa) is a favorite molecule for phylogenetic studies given its relative uniformity in both size and organization. Yet, as the depth coverage of representative animal groups increases sharply thanks to recent advances in sequencing technology, some clades remain stubbornly under sampled, if even represented at all. Difficulties associated with data collection from problematic taxa can arise from highly derived sequences, fragmented genomes, unusual structure, or any combination of these. Particularly illustrative examples are found in non-bilaterian animals (placozoans, sponges, cnidarians, comb jellies) where the mtDNA is more variable in size and structure. The present ...


Mucopolysaccharidosis Type Iiib And Galnac Transferase Double Knockout Mice And Additional Studies In Gene Therapy And Animal Models To Assess Pathogenesis And Therapy, Eman Elsayed Abass Mohammed Jan 2012

Mucopolysaccharidosis Type Iiib And Galnac Transferase Double Knockout Mice And Additional Studies In Gene Therapy And Animal Models To Assess Pathogenesis And Therapy, Eman Elsayed Abass Mohammed

Graduate Theses and Dissertations

The Mucopolysaccharidoses (MPSs) are a class of lysosomal storage diseases characterized by lysosomal accumulation of glycosaminoglycan (GAG). Understanding the pathogenesis of the neuropathic forms of MPS and improving treatment options for these disorders are major areas of research in the laboratory of Dr. Ellinwood. The neuropathic MPSs include MPS I, II, III (A-D), and VII, all of which have primary storage of heparan sulfate (HS), and a secondary accumulation of GM2 and GM3 gangliosides. Clinically patients with the severe forms of these disorders have central nervous system defects. Mucopolysaccharidosis III, also known as Sanfilippo syndrome, has four subtypes designated as ...


Evaluation Of Polypyrimidine Tract-Binding Protein Gene Promoters In Potato (Solanum Tuberosum Cv. Désirée), Nathaniel Martin Butler Jan 2012

Evaluation Of Polypyrimidine Tract-Binding Protein Gene Promoters In Potato (Solanum Tuberosum Cv. Désirée), Nathaniel Martin Butler

Graduate Theses and Dissertations

Polypyrimidine tract-binding (PTB) proteins are RNA-binding proteins that target specific RNAs for post-transcriptional processing by binding CU-rich motifs. PTBs have established functions in a range of RNA processes including splicing, translation, stability, and long-distance transport. Six PTB-like genes identified in potato have been grouped into two clades based on homology to other known plant PTBs. StPTB1 and StPTB6 are closely related to a PTB protein discovered in pumpkin, designated CmRBP50, and contain four canonical RNA-recognition motifs. CmRBP50 is expressed in phloem tissues and functions as the core protein of a phloem-mobile RNA/protein complex. Sequence from the potato genome database ...


Gene Mapping Of Monogenic Disorders And Complex Diseases Via Genome Wide Association Studies, Xia Zhao Jan 2012

Gene Mapping Of Monogenic Disorders And Complex Diseases Via Genome Wide Association Studies, Xia Zhao

Graduate Theses and Dissertations

Inherited rickets, lower motor neuron disease and chondrodysplasia were recently reported genetic disorders that had been identified on sheep farms in New Zealand. Animals with rickets showed softening and weakening bone, and were characterized by decreased growth rate, thoracic lordosis and angular limb deformities. Sheep diagnosed with lower motor neuron disease were characterized by poor muscle tone and progressive weakness from about one week of age, leading to severe tetraparesis, recumbency and muscle atrophy. Chondrodysplasia in Texel sheep was characterized by dwarfism and angular deformities of the forelimbs. These three disorders were determined likely simple autosomal recessive by backcross breeding ...


New Tools For Studying Mal Gene Regulation In Yersinia Pestis, Carrie Jo Oster Jan 2012

New Tools For Studying Mal Gene Regulation In Yersinia Pestis, Carrie Jo Oster

Graduate Theses and Dissertations

Y. pestis, the etiologic agent of plague, is a significant human pathogen because of its historic role as the cause of three major pandemics and its current role as a potential bioterrorism agent. Gene regulation in this organism is complex and multiple microarray studies have shown that the expression of several genes is affected by quorum sensing as well as temperature. Maltose utilization genes are of particular interest because they are regulated by both of these systems. In order to perform genetic studies on mal genes, and to better understand gene expression in general in Y. pestis, we developed a ...