Digital Commons Network^™

The Role Of Curved Dna In Promoter Selection By The Major Bacillus Subtilis Rna Polymerase., Carl Feemster Mcallister

LSU Historical Dissertations and Theses

The major RNA polymerases of Bacillus subtilis and Escherichia coli recognize the same conserved sequences at $-$10 and $-$35 of the promoter. The B. subtilis enzyme requires additional DNA sequences for efficient promoter utilization. Deletion mutants were used to demonstrate that the function of two B. subtilis phage SP82 promoters, Ba1129 and Alu156, was dramatically affected by sequence upstream from $-$35. The upstream DNA contained runs of four to six adenines with a 10-11 base pair periodicity. Indicative of DNA curvature, these regions decreased electrophoretic mobility of DNA fragments containing either promoter. The curved upstream DNA increased the affinity of …

The Relationship Between Root Anatomic And Metabolic Responses To Soil Waterlogging In The Coastal Grass Spartina Patens., David Maaloe Burdick

LSU Historical Dissertations and Theses

Spartina patens is a perennial grass that dominates dune, swale and marsh habitats in coastal Louisiana. Plant roots require oxygen for respiration and normal root function, and one of the most serious problems wetland plants encounter is the development of anaerobic conditions in the soil. The remarkable success of S. patens in habitats that occupy distant positions on a soil waterlogging gradient suggests either genetic differentiation or phenotypic adaptation among these populations. Field and greenhouse investigations were conducted to: (1) identify anatomic and metabolic soil waterlogging responses in Spartina patens, (2) examine the relationship between these responses, and finally (3) …

Synthesis, Transport And Assembly Of Wild Type And Mutant Precursors Of The Small Subunit Of The Chloroplast Enzyme Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase., Samuel John Landry

LSU Historical Dissertations and Theses

The small subunits of the chloroplast enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) are synthesized in the cytoplasm as precursors and transported into the organelle. The precursor (pS) of the small subunit (S) of RuBisCO contains an amino-terminal extension, the transit peptide, which is removed during or after transport into the chloroplast. The possible involvement of an RNA-containing component in transport of proteins into chloroplasts was investigated using a reconstituted system of pS translated in vitro and isolated chloroplasts. The post-ribosomal supernatant of the in vitro translation mixture and/or isolated chloroplasts were treated with ribonuclease prior to incubation for transport. Transport of pS …

A Molecular Characterization Of An Escherichia Coli Restriction System Specific For 5-Methylcytosine-Containing Dna., Troy Kevin Ross

LSU Historical Dissertations and Theses

The McrB restriction system in Escherichia coli K-12 is responsible for sequence-specific recognition and inactivation of DNA containing 5-methylcytosine. A derivative of plasmid pUC8 with a 5.5-kilobase pair BglII-EcoRI restriction fragment from the E. coli K-12 chromosome, imparted the wild-type phenotype to the McrB$\sp-$ strain K802. The limits of the McrB region within this DNA fragment were defined by deleting portions of the 5.5-kb insert and assaying for McrB restriction of M.AluI-methylated DNA. Analyses of polypeptides encoded by the McrB region using a maxicell strain revealed that at least three proteins, having molecular weights of approximately 51,000, 39,000, and 33,000, …

An Investigation Of The Fungus, Balansia Cyperi Edg., And Its Effect On Purple Nutsedge, Cyperus Rotundus L., Mary Elizabeth Stovall

LSU Historical Dissertations and Theses

This study was designed to investigate host specificity of the fungus Balansia cyperi Edg. on Cyperus rotundus L. (purple nutsedge) and to determine the effect of fungus presence on the biology and ecology of the sedge. Isolates of epiphytic Balansias from C. rotundus and C. virens had similar cultural characters, conidium morphology, and extracellular enzyme activity in artificial culture. However, B. cyperi from C. rotundus had a faster growth rate, greater conidium production, and higher temperature optimum than did the isolate from C. virens. Artificial infection of C. rotundus by B. cyperi from C. rotundus was far more successful than …

Amino Acid Responses Of Olfactory Bulb Cells In The Channel Catfish., Hilary Winfield Thompson

LSU Historical Dissertations and Theses

Amino acid (AA) responses of olfactory bulb (OB) mitral cells (MC) in the catfish, Ictalurus punctatus, were studied electrophysiologically. A total of 63 cells were recorded in 28 fish in two separate experiments. For the first study, 27 cells in 22 fish were studied with olfactory tract (OT) intact during stimulation with 10$\sp{-6}$ M to 10$\sp{-2}$ M concentrations of 11 AA. MC responses were quantified by interspike interval (ISI) variables sensitive to inhibition (maximum ISI) and excitation (number of action potentials (AP), minimum ISI). APs were also counted in subdivisions to produce a measure sensitive to MC response temporal patterning. …

Floral Ontogeny And Histogenesis In Leguminosae., Kittie Sue Derstine

LSU Historical Dissertations and Theses

Inflorescence organogeny and floral initiation are investigated topographically (using scanning electron microscopy) and histogenetically in Acacia baileyana (Mimosoideae) and Lupinus havardii (Papilionoideae). Floral ontogeny is investigated topographically in Parkinsonia aculeata (Caesalpinioideae). The paniculate racemes of A. baileyana are constructed of first- and second-order inflorescence meristems. Each produces first-order and second-order bracts, respectively, in acropetal order. Each of the former bracts subtends one second-order inflorescence meristem while the latter bract type subtends a single flower. The radially symmetrical floral meristem of A. baileyana produces calyx members in helical order and corolla members simultaneously with a precocious terminal carpel. Common stamen primordia …

Diseases And Plant Population Biology, Nancy J. Huntly, R Inouye

Biology Faculty Publications

No abstract provided.

Characterization Of The Cellular Immune Defect In Chronic Bovine Paratuberculosis., John Michael Kreeger

LSU Historical Dissertations and Theses

Cattle, naturally infected with Mycobacterium paratuberculosis, were evaluated with respect to immune status. Their ability to express cell mediated immune responses to homologous and heterologous antigens was also evaluated. Lymphocyte and macrophage augmentation was attempted to localize the immune defect in cattle with paratuberculosis. Infected cattle had varying responses to johnin skin test antigen. Lymphocyte blastogenic responses and migration inhibition were, however, consistently positive in infected cattle. Non-infected cattle had positive skin test reactions, blastogenic responses, and migration inhibition after sensitization with M. bovis BCG, M. paratuberculosis, and keyhole limpet hemocyanin. No changes were seen in lymphocyte blastogenic response, migration …

Response Of Soybean Growth And Dinitrogen-Fixing Ability To Insect-Induced Defoliation., Maurice Blake Layton Jr

LSU Historical Dissertations and Theses

A series of greenhouse experiments was conducted to investigate the effects of insect-induced defoliation on growth and N$\sb2$-fixing ability of soybean. This research had three major objectives: (1) to examine the effects of different levels of defoliation, (2) to determine the impact of progressive defoliation, and (3) to study the ability of soybeans to recover following defoliation. All experiments were conducted in a similar manner. Larvae of the soybean looper, Pseudoplusia includens (Walker), were used to defoliate soybeans in the vegetative stage of development and the acetylene-ethylene reduction assay was used to provide an indirect measure of N$\sb2$-fixing ability of …

Compatibility Of Biological Control With Host Plant Resistance And Insecticidal Control In Soybeans., David Boyd Orr

LSU Historical Dissertations and Theses

Studies were conducted to investigate the influence of both plant resistance and insecticidal controls used in soybean on several natural enemies of pest insects. There were two major objectives to this research: (1) to examine the effects of an insect herbivore-resistant soybean genotype on relationships between four levels of a trophic system; (2) to determine the influence of the primary insecticides applied to control Louisiana soybean insect pests on survival of a major biological control agent of stink bugs. In the first study, pre-imaginal development of the predatory pentatomid, Podisus maculiventris (Say), was affected by soybean antibiosis in a manner …

Ultrastructural Studies Of Cell Membrane-Associated Events In Early And Late Stages Of Bovine Coronavirus Replication., Harold Ross Payne

LSU Historical Dissertations and Theses

The early events in the infection of human rectal tumor cells by bovine coronavirus were investigated by immunoelectron microscopy and by studies with lysosomotropic weak bases. Virus particles labeled with colloidal gold were endocytosed by synchronously infected cells and accumulated in vacuoles that resembled secondary lysosomes. Sites of fusion between the virus envelope and the plasmalemma were observed but fusion events along intracellular membranes were not found. Exposure of cells to ammonium chloride or to mythylamine during the first hour of infection had little inhibitory effect on the production of infectious virus. Chloroquine treatments were inhibitory but this effect was …

Molecular Analysis Of Mutant And Wild Type Alcohol Dehydrogenase Alleles From Drosophila., Mark Andrew Batzer

LSU Historical Dissertations and Theses

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. These data indicate that ADH from Hawaiian drosophilids was similar in molecular weight to Drosophila melanogaster ADH, but that the isoelectric points of the Hawaiian electromorphs were distinct. Therefore it was evident that western blots could be used to characterize ADH from different species of Drosophila. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots …

Pseudomonas Sp. Strain Pg2982: Uptake Of Glyphosate And Cloning Of A Gene Which Confers Increased Resistance To Glyphosate., Joseph E. Fitzgibbon

LSU Historical Dissertations and Theses

Chapter 1. Pseudomonas sp. strain PG2982 has the ability to use the phosphonate herbicide, glyphosate, as a sole phosphorus source. Glyphosate uptake occurs at a maximum in the late log phase of growth and is induced by phosphate starvation. Uptake is inhibited by phosphate and arsenate, but not by the amino acids glycine and sarcosine. The K$\sb{\rm m}$ and V$\sb{\rm max}$ for glyphosate uptake were calculated to be 23uM and 0.97nmoles/mg dry wt/min, respectively. A phosphate transport system with a broad substrate specificity seems to be responsible for glyphosate uptake. Chapter 2. Pseudomonas sp. strain PG 2982 is highly resistant …

Reproductive And Life History Characteristics Of A North American Prairie Orchid Spiranthescernua Cernua (Linnaeus) L.C. Richard., John Maclay Schmidt

Student Work

Introduction: Reproductive systems have a profound effect on the genetic structure of plant populations. How genes are passed from one generation to the next influences the amount and structure of genetic variation in succeeding generations (Clegg, 1980; Bell, 1982). Sexual reproduction increases the genetic variation within a population through recombination while asexual reproduction duplicates the maternal genome (Williams, 1975). A variety of systems have evolved in plants which combine both sexual and asexual reproduction (Lloyd, 1984 ).

An Experimental Study Utilizing Integrated / Right Brain Processes In Teaching Biology, Rebecca M. Aulenbacher

Theses

The purpose of this study was to determine any measurable differences in student academic outcomes when they participated in activities designed to involve both hemispheres as compared to when they participated in activities designed to involve the left hemisphere . It was predicted that students who participated in more integrated/right brain activities would show higher academic achievement . It was further predicted that students who were right hemisphere preferenced would do better than those who were left hemisphere preferenced.

Two intact groups of Biology I students were taught the same four - chapter unit on cells , utilizing the same …

Sociobiology And The Law: The Biology Of Altruism In The Courtroom Of The Future, Charles F. Weiss

Michigan Law Review

A Review of Sociobiology and the Law: The Biology of Altruism in the Courtroom of the Future by John H. Beckstrom

Adaptation Of Striped Bass To Sea Water Following Direct Transfer From Freshwater: Morphological, Biochemical, And Physiological Parameters, Judy A. King

Electronic Theses and Dissertations

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by …

G87-838 Management Of Greenbugs In Sorghum (Revised May 1994), Robert J. Wright, Stephen D. Danielson, Zb Mayo

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide describes the identification, biology and management options for greenbugs in Nebraska sorghum.

The greenbug is the most important insect pest of grain and forage sorghums in Nebraska. Although numbers fluctuate from year to year, greenbugs are a limiting factor to sorghum yield in most years. Their management is complicated by the fact that greenbugs have been able to evolve populations capable of overcoming plant resistance and organophosphate insecticides, so best management practices continue to change over time.

Another common aphid found in sorghum is the corn leaf aphid. Corn leaf aphids are often mistaken for greenbugs; however, they …

Differentiation And Other Factors Influencing The Replication Of Murine Hepatitis Viruses In Cells From The Rat Central Nervous System, Sven Andre Beushausen

Digitized Theses

An in vitro system employing primary neural cell cultures derived from the cerebral cortices of neonatal rat brains was developed to examine, with greater fidelity, parameters influencing coronavirus (CV) induced demyelination in the rat.;Studies regarding the specificities of the viscerotropic mouse hepatitis virus MHV3 and the sero-related neurotropic JHM virus (JHMV) for neural cell types demonstrated an unambiguous tropism of {dollar}{lcub}\rm MHV\sb3{rcub}{dollar} for astrocytes and JHMV for oligodendrocytes. Relatively small changes in spatial density of oligodendrocytes profoundly influenced JHMV replication. Furthermore, repression of JHMV in oligodendrocytes was shown to be concomitant with differentiation, occurring naturally in vitro according to a …

Molecular And Genetic Analysis Of The Phi X174 A* Gene And The Escherichia Coli Rep Gene, Joseph James Colasanti

Digitized Theses

This work involves the molecular cloning the {dollar}{lcub}\rm A\sp\ast{rcub}{dollar} gene of {dollar}\Phi{lcub}\rm X174{rcub}{dollar} and the rep gene of E. coli into plasmid vehicles that allow their expression to be regulated. These special plasmids contain controlling elements of phage {dollar}\lambda{dollar} that enable expression of cloned genes to be switched "on" by altering the temperature at which they are propagated.;The presence of the {dollar}{lcub}\rm A\sp\ast{rcub}{dollar} gene product is extremely toxic to E. coli. Therefore, to isolate and stably maintain a recombinant plasmid carrying this gene, its expression must be repressed. The use of an inducible expression vector allowed gene {dollar}{lcub}\rm A\sp\ast{rcub}{dollar} to …

A Kinematic And Electromyographic Study Of The Mechanisms Contributing To Cerebellar Intention Tremor And Dysmetria, Didier A. Flament

Digitized Theses

The kinematic and electromyographic (EMG) characteristics of cerebellar tremor and dysmetria were investigated in six Cebus monkeys. Cerebellar dysfunction was produced by reversible cooling lesions of the dentate and interposed nuclei. The aims of the study were (1) to compare the characteristics of the cerebellar intention tremor that occurs after the end of a voluntary movement (static or terminal tremor) with the tremor that occurs after the limb has been perturbed, (2) to determine the role played by stretch-evoked activity in generating this tremor, (3) to investigate the nature of the tremor that occurs during a voluntary movement (kinetic tremor) …

Electrochemical And Photochemical Properties Of Metallophthalocyanines, Tebello Nyokong

Digitized Theses

The absorption and magnetic circular dichroism (MCD) spectra of a series of phthalocyanine (Pc) complexes (CoPc, ZnPc, FePc, RuPc, MnPc and MgPc) have been recorded. Axial ligation to CoPc, ZnPc, FePc and RuPc complexes results in the species that are soluble in methylene chloride, and hence, for the first time, allows for the observation of the high energy bands in the solution spectra of the MPc complexes.;Although, the Q band is well separated from the rest of the bands, configuration interaction results in a considerable overlap of bands in the Soret region. Band deconvolution calculations are thus, used to provide …

Progesterone And Estrogens In Intrauterine Tissues During Pregnancy And Labour, Stephen George Power

Digitized Theses

A decline in progesterone and a rise in estrogen levels in the maternal and fetal plasmas occur prior to parturition. I examined the hypothesis that similar changes in the ovine intrauterine tissues are associated with labour. I also determined whether the intrauterine tissues could produce progesterone and estrogens and whether these activities change in association with labour.;Samples of maternal and fetal bloods, fetal fluids, myometrium, endometrium, chorion, amnion and allantois were obtained from pregnant sheep of different gestational ages and in labour occurring either at term or induced prematurely by administration of ACTH to the fetus. Steroids were measured using …

Population Characteristics Of The Crayfish, Cambarus Bartoni, In Lakes With And Lakes Without Introduced Populations Of Smallmouth Bass, Micropterus Dolomieui, In Algonquin Provincial Park, Ontario, Keith Marquis Somers

Digitized Theses

Populations of the crayfish Cambarus bartoni from six lakes in Algonquin Provincial Park, Ontario were compared to evaluate the influence of an introduced predator, the smallmouth bass Micropterus dolomieui. Bass were introduced into lakes in the southern portion of the park in the late 1800's and early 1900's. Crayfish populations from three lakes containing bass were contrasted with populations from three lakes without bass.;Comparisons of relative abundances, patterns of habitat use and length-frequency distributions were compromised by seasonal changes in crayfish trappability and differences in crayfish species composition. Catches of C. bartoni in baited traps were lower in lakes containing …

Life History Strategies Of A North Temperate Salmonid, Salvelinus Fontinalis, In Polar Bear Provincial Park, Ontario, Peter Owen Steele

Digitized Theses

A northern anadromous population of brook trout (Salvelinus fontinalis), from the Sutton river, in the Ontario Hudson Bay Lowlands, was examined to determine if its life history differed from that reported for the species elsewhere. The Sutton River population was similar to historical anadromous populations native to North America 200 years ago. Only minor differences were discernible between the life histories of brook trout from Sutton River, Ontario, Nelson-Hayes River, Manitoba, and Richmond Gulf, Quebec. All of these populations differed from populations in Canadian Maritime Provinces, in that the northern trout migrated to saline water earlier, matured later and at …

Dopamine D-2 Receptor Mechanisms In The Nucleus Accumbens Involved In Signal Transmission From The Hippocampus To The Mesencephalic Locomotor Region, Charles Renkin Yang

Digitized Theses

The purpose of this study was to investigate, using electrophysiological and behavioural techniques, a mesolimbic dopaminergic mechanism in the accumbens that may regulate the hippocampal output signal transmission to the subpallidal area, and the pedunculopontine nucleus (PPN), an integral part of the mesencephalic locomotor region (MLR).;Electrical stimulation of the hippocampus activated accumbens neurones in urethane-anaesthetized rats. This excitation was attenuated by iontophoretic application of dopamine and by conditioning stimulation (10Hz) of the VTA. This attenuating effect was blocked by iontophoretic applied or intraperitoneally injected dopamine antagonists, as well as by 6-hydroxydopamine lesion of the VTA.;The excitability of the axonal terminals …

The Paraventricular Nucleus Of The Hypothalamus: An Investigation Of The Afferent And Efferent Pathways Involved In The Control Of The Circulation, Monica Mary Caverson

Digitized Theses

Experiments were done in cats to determine the anatomical and functional organization of neural circuits in the hypothalamus involved in mediating afferent renal nerve information to the neurohypophysis and to spinal autonomic centers. In the first series of experiments immunohistochemical staining with antibodies directed against arginine vasopressin and oxytocin provided a comprehensive analysis of the topographical distribution and morphological characteristics of vasopressin and oxytocin immunoreactive perikarya in the paraventricular nucleus of the hypothalamus. In the second series of experiments, to determine the location of paraventriculo-neurohypophysial and paraventriculo-spinal projecting neurons injections of retrograde tracers (horseradish peroxidase or True Blue) were made …

Variation In The Shell Morphology And Growth Rate Of Lampsilis Radiata, A Freshwater Mussel, Robert Charles Bailey

Digitized Theses

I measured a correlation between the habitat of a freshwater mussel, Lampsilis radiata siliquoidea (Barnes 1823), and its shell morphology and growth rate. I then tried to determine the source of morphological and growth rate variation (environmental or genetic), and whether or not the phenotype/habitat correlation was due to differential adaptation.;Morphometric and annual ring analysis of mussels from Inner Long Point Bay, Lake Erie indicated that L. radiata from more exposed, sandier areas of the bay were faster growing and had thicker shells than those from less exposed, muddy areas. Variation among exposure areas in allozyme phenotypes of two gene …

Gene Expression During Embryogenesis In Maize (Zea Mays L), Joseph Gerard Boothe

Digitized Theses

The development of maize embryos from 15 DAP until maturation, at approximately 50 DAP, has been examined at the level of gene expression. Three subsets of embryonic polypeptides have been identified. Subset 1 exhibits little or no variation during the period of study. Subset 2 is prominent in the earlier stages of development but shows reduced relative levels of synthesis as the embryo matures. Subset 3 exhibits novel and/or enhanced synthesis during the later stages of development. Some polypeptides among subsets 1 and 2 appear to show tissue specificity in the seedling and maturing plant indicating that molecular differentiation has …