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Open Access. Powered by Scholars. Published by Universities.®

2000

Western Michigan University

Biology

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Identification And Characterization Of Zinc-Responsive Genes In Pseudomonas Fluorescens, Thomas L. Wilson Dec 2000

Identification And Characterization Of Zinc-Responsive Genes In Pseudomonas Fluorescens, Thomas L. Wilson

Masters Theses

Genes responsive to elevated concentrations of zinc were identified via transposon mutagenesis in the common soil bacterium, Pseudomonas fluorescens ATCC13525. Some of these genes were essential to maintain metal homeostasis in the bacterial cell. DNA sequences of the transposon-tagged genes were determined by DNA sequencing of arbitrary PCR products. DNA sequence analysis indicated that one gene was similar to P-type ATPases responsible for transporting metal ions out of the cell. The corresponding mutant was sensitive to zinc, cadmium, and lead indicating that this gene may be responsible for defending Pseudomonas fluorescens against these metal ions. Four zinc-induced genes shared similarity …


Role Of Dopamine D4 Receptor In The Genomic And Behavioral Effects Of Psychostimulants: Relevance To Schizophrenia, Bina Garimella Dec 2000

Role Of Dopamine D4 Receptor In The Genomic And Behavioral Effects Of Psychostimulants: Relevance To Schizophrenia, Bina Garimella

Masters Theses

The role of dopamine D4 receptors in the induction and expression of behavioral sensitization to amphetamine, cocaine and PCP was investigated in this study. Behavioral changes and genomic responses accompanying sensitization were examined using a highly selective D4 receptor antagonist, PNU-101387G. Induction and expression of behavioral sensitization to cocaine was blocked by PNU-101387G. However, the D4 antagonist did not modulate the induction and expression of behavioral sensitization to PCP. Neuroadaptive genomic responses accompanying acute and chronic effects of amphetamine and their modulation by PNU-101387G was examined by looking at alterations in the expression of two immediate-early genes: c-fos and NGFI-A. …


Cadmium Induced Gene Expression And Signal Transduction Pathway, Daisuke Maki Dec 2000

Cadmium Induced Gene Expression And Signal Transduction Pathway, Daisuke Maki

Masters Theses

Cells respond to cadmium (Cd), a common environmental contaminate, by potentially decreasing reduced intracellular glutathione, as well as, increasing the expression of several antioxidant genes. One of these antioxidant genes, glucose-6- phosphate dehydrogenase (G6PDH), is the rate limiting enzyme of the pentose phosphate pathway. This pathway produces NADPH which is used for maintenance of reduced glutathione so, it is hypothesized that Cd should increase G6PDH expression. In this study, we demonstrate that Cd increases the level of G6PDH mRNA in primary rat hepatocytes in culture. In the presence of the antioxidants, N-acetylcysteine (NAC), Trolox, or glutathione monoethyl ester an attenuation …


The Role Of Nf-Кb Activation In Breast Carcinoma And Glioblastoma Cell Lines, Kelly T. Murphy Aug 2000

The Role Of Nf-Кb Activation In Breast Carcinoma And Glioblastoma Cell Lines, Kelly T. Murphy

Masters Theses

The nuclear factor-КB (NF-КB)/Rel family of inducible dimeric transcription factors regulates numerous genes associated with the immune, mitogenic, and apoptotic responses. Investigations were made into the role of NF-КB in breast carcinoma (MCF-7, T47D, MDA-MB-231) and glioblastoma (U87MG, U373MG, Ul 18MG) cell lines. NF-КB binding to DNA was quantified using both gel mobility shift assays and transient transfections of a vector containing a luciferase gene under the control of 4 tandem copies of the NF-КB binding sequence. To determine the correlation between NF-КB activation, cellular proliferation, and foci formation, the tumor cells were cultured and analyzed in the presence of …


Isolation And Characterization Of A Genetic Locus That Confers Tolerance To Cadmium And Zinc In Pseudomonas Fluorescens, Szi Fei Feng Aug 2000

Isolation And Characterization Of A Genetic Locus That Confers Tolerance To Cadmium And Zinc In Pseudomonas Fluorescens, Szi Fei Feng

Masters Theses

This thesis describes the isolation and characterization of a region containing several genes involved in metal tolerance in the common soil bacterium, Pseudomonas fluorescens ATCC 13525. The DNA region was identified in a cadmium and zinc sensitive mutant, 45-B10, which contains a lacZ-based reporter gene transposon Tn5-B20 inserted in the chromosome. The DNA surrounding the transposon was cloned from this mutant strain and DNA sequencing of this region revealed seven genes that share similarity with genes whose products are involved in the cation-proton antiporter efflux system of other Gram-negative bacteria. Complete DNA sequence was obtained from four of these …


Effects Of Elevated Carbon Dioxide And Nitrogen Fixation On A Legume-Based System: A Test With Soybean And The Soybean Looper, Pseudoplusia Includens, Angela M. Spickard Jun 2000

Effects Of Elevated Carbon Dioxide And Nitrogen Fixation On A Legume-Based System: A Test With Soybean And The Soybean Looper, Pseudoplusia Includens, Angela M. Spickard

Masters Theses

Wild-type and non-nodulated soybean were grown at 367 ± 10 ppm [ambient] and 756 ± 10 ppm [elevated] CO2 to determine whether nitrogen fixation could minimize the effects of elevated CO2 on plant nutritional and defensive chemistry. Relative to non-nodulated soybean, wild-type soybean had higher concentrations of leaf nitrogen and proteinase inhibitors, as well as lower C:N ratios and lower phenolics. Elevated CO2 resulted in decreased leaf nitrogen and proteinase inhibitor contents, and increased C:N ratios and phenolics in both soybean strains. Constitutive levels of phenolics and proteinase inhibitors occurred as predicted by the Carbon/Nutrient Balance hypothesis …


Identification And Classification Of Coryneform Bacteria Isolated From Bovine Mammary Glands, Jeffrey L. Watts Apr 2000

Identification And Classification Of Coryneform Bacteria Isolated From Bovine Mammary Glands, Jeffrey L. Watts

Dissertations

Coryneform bacteria are frequently isolated from bovine mastitis and these infections are associated with economic losses. Corynehacterium bovis, a lipid requiring species, has been the most frequently isolated coryneform from the milk of infected bovine mammary glands. However, the taxonomic status of this organism is uncertain. In the current study, a polyphasic approach was used to identify coryneform bacteria isolated from bovine mastitis and determ ine the phylogenetic relationships among the identified species. A total of 212 coryneform bacteria isolated from bovine mastitis was obtained from mastitis reference laboratories in the United States and Canada. Presumptive identification based upon …


Target-And Stage-Dependent Influences On Axonal Outgrowth Of An Identified Motorneuron In Leech Cns Explants, April Crowley Apr 2000

Target-And Stage-Dependent Influences On Axonal Outgrowth Of An Identified Motorneuron In Leech Cns Explants, April Crowley

Masters Theses

The neural circuit that controls rhythmic contraction of the hearts in the medicinal leech, Hirudo medicinalis, provides an amenable model to investigate pathfinding and target selection. The bilaterally paired heart tubes (HT) in leech are eventually innervated by the heart excitor motomeuron (HE) following a period of remodeling that requires the presence of the HT. To begin characterizing possible HT-derived cues, co-cultures of CNS with innervated HT have been used. Previous work demonstrated that young, but not adult, HT was able to support profuse general outgrowth, but the HE extended few projections onto HT of any age. Current studies …


Molecular And Biological Characterization Of A Tanapox Virus Tnf-Binding Protein And The Complete Nucleotide Sequence Of The Psti-J Genomic Fragment, Mini Paulose-Murphy Apr 2000

Molecular And Biological Characterization Of A Tanapox Virus Tnf-Binding Protein And The Complete Nucleotide Sequence Of The Psti-J Genomic Fragment, Mini Paulose-Murphy

Dissertations

Most of the poxvirus encoded virulence factors have been identified as proteins that are secreted from infected host cells. Some of these secretory proteins impede host immune defenses. We have previously demonstrated that tanapox virus (TPV) infected cells secrete a 38 kDa glycopeptide that binds to human (h) interferon-γ, h-interleukin (IL)-2, and hIL-5. We now show an additional activity in the supernatant from TPV infected cells that down-regulates the expression of tumor necrosis factor-a (TNF-α) induced cell adhesion molecule gene expression. This activity was not detected in mock infected cells. Enzyme linked immunosorbent assays (ELISA) on primary human endothelial cells, …