Cell and Developmental Biology Commons^™

Gene Expression Patterns That Support Novel Developmental Stress Buffering In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Josiah T. Wagner, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Background: The cellular signaling mechanisms and morphogenic movements involved in axis formation and gastrulation are well conserved between vertebrates. In nearly all described fish, gastrulation and the initial patterning of the embryonic axis occur concurrently with epiboly. However, annual killifish may be an exception to this norm. Annual killifish inhabit ephemeral ponds in South America and Africa and permanent populations persist by the production of stress-tolerant eggs. Early development of annual killifish is unique among vertebrates because their embryonic blastomeres disperse randomly across the yolk during epiboly and reaggregate several days later to form the embryo proper. In addition, annual …

A Coxiella-Like Endosymbiont Is A Potential Vitamin Source For The Lone Star Tick, Todd A. Smith, Timothy Driscoll, Joseph J. Gillespie, Rahul Raghavan

Biology Faculty Publications and Presentations

Amblyomma americanum (Lone star tick) is an important disease vector in the United States. It transmits several human pathogens, including the agents of human monocytic ehrlichiosis, tularemia, and southern tick-associated rash illness. Blood-feeding insects (Class Insecta) depend on bacterial endosymbionts to provide vitamins and cofactors that are scarce in blood. It is unclear how this deficiency is compensated in ticks (Class Arachnida) that feed exclusively on mammalian blood. A bacterium related to Coxiella burnetii, the agent of human Q fever, has been observed previously within cells of A. americanum. Eliminating this bacterium (CLEAA, Coxiella-like endosymbiont of A. americanum) with antibiotics …

Mathematical Model For Bone Mineralization, Svetlana V. Komarova, Lee Safranek, Jay Gopalakrishnan, Miao-Jung Yvonne Ou, Marc D. Mckee, Monzur Murshed, Frank Rauch, Erica Zuhr

Mathematics and Statistics Faculty Publications and Presentations

Defective bone mineralization has serious clinical manifestations, including deformities and fractures, but the regulation of this extracellular process is not fully understood. We have developed a mathematical model consisting of ordinary differential equations that describe collagen maturation, production and degradation of inhibitors, and mineral nucleation and growth. We examined the roles of individual processes in generating normal and abnormal mineralization patterns characterized using two outcome measures: mineralization lag time and degree of mineralization. Model parameters describing the formation of hydroxyapatite mineral on the nucleating centers most potently affected the degree of mineralization, while the parameters describing inhibitor homeostasis most effectively …

Identification Of Novel Small Rnas And Characterization Of The 6s Rna Of Coxiella Burnetii, Indu Warrier, Linda D. Hicks, James M. Battisti, Rahul Raghavan, Michael F. Minnick

Biology Faculty Publications and Presentations

Coxiella burnetii, an obligate intracellular bacterial pathogen that causes Q fever, undergoes a biphasic developmental cycle that alternates between a metabolically-active large cell variant (LCV) and a dormant small cell variant (SCV). As such, the bacterium undoubtedly employs complex modes of regulating its lifecycle, metabolism and pathogenesis. Small RNAs (sRNAs) have been shown to play important regulatory roles in controlling metabolism and virulence in several pathogenic bacteria. We hypothesize that sRNAs are involved in regulating growth and development of C. burnetii and its infection of host cells. To address the hypothesis and identify potential sRNAs, we subjected total RNA isolated …

Phenotypic Variation In The Model Organism, Danio Rerio, Rachel D. Champaigne, Kim H. Brown

Student Research Symposium

Model organisms are used to study evolutionary conserved traits. Zebrafish (Danio rerio) are used a model organism because of their highly fecundity, external fertilization, and robust nature, making them highly adaptable to environmental and genetic variation. In an effort to limit data variation that lies outside of topic interest, phenotypic measures of variation must be performed, understood, and taken into consideration for future studies. A common measurement of phenotypic variation in fish is in the maximum (Ucrit) swimming speeds. Inter and intra-strain variation in zebrafish Ucrit swimming speeds will be observed in a swim tunnel. Baseline values will …

Mitochondrial Reactive Oxygen Species (Ros): Which Ros Is Responsible For Cardioprotective Signaling?, Anders Olav Garlid

Dissertations and Theses

Mitochondria are the major effectors of cardioprotection by procedures that open the mitochondrial ATP-sensitive potassium channel (mitoK_ATP), including ischemic and pharmacological preconditioning. MitoK_ATP opening leads to increased reactive oxygen species (ROS), which then activate a mitoK_ATP-associated PKCε, which phosphorylates mitoK_ATP and leaves it in a persistent open state (Costa, ADT and Garlid, KD. Am J Physiol 295, H874-82, 2008). Superoxide (O₂^•-), hydrogen peroxide (H₂O₂), and hydroxyl radical (HO^•) have each been proposed as the signaling ROS but the identity of the ROS responsible for this …

A Comparison Of Different Treatments For Mesothelioma, Samira Rezaei

Anthós

The goal of this research was to survey the literature of studies on mesothelioma treatments and compare their rates of success. The focus was on radiation therapy which is used with chemotherapy or surgery treatment for this specific type of cancer. The research is based on the chosen treatments of thirteen patients who shared their stories on different websites. The number of survived years for these patients was compared. The results show that the average number of years survived in patients who used mind-body therapy is greater than other patients who use radiation therapy as palliation with chemotherapy, surgery treatment …

Partitioning The Fitness Components Of Rna Populations Evolving In Vitro, Carolina Diaz Arenas, Niles Lehman

Chemistry Faculty Publications and Presentations

All individuals in an evolving population compete for resources, and their performance is measured by a fitness metric. The performance of the individuals is relative to their abilities and to the biotic surroundings – the conditions under which they are competing – and involves many components. Molecules evolving in a test tube can also face complex environments and dynamics, and their fitnessmeasurements should reflect the complexity of various contributing factors as well. Here, the fitnesses of a set of ligase ribozymes evolved by the continuous in vitroevolution system were measured. During these evolution cycles there are three different catalytic …

Exploring Tissue Engineering: Vitamin D3 Influences On The Proliferation And Differentiation Of An Engineered Osteoblast Precursor Cell Line During Early Bone Tissue Development, Shelley S. Mason

Dissertations and Theses

Most of the load-bearing demand placed on the human body is transduced by skeletal tissue, and the capacity of the skeleton to articulate in various opposing directions is essential for body movement and locomotion. Consequently, cartilage and bone defects due to trauma, disease, and developmental abnormalities result in disabling pain and immobility for millions of people worldwide. A novel way of promoting cartilage and bone regeneration is through the incorporation of either primary cells or multipotent progenitor cells in a three-dimensional (3D) biomaterial scaffold, and/or the addition of exogenous growth and differentiation factors. The first part of this study reports …

Expression Of Growth Arrest And Dna Damage Protein 45-Alpha (Gadd45-Alpha) And The Ccaat/Enhancer Binding Protein-Delta (C/Ebp-Delta) In Fishes Exposed To Heat And Hypoxia, Daniel Omar Hassumani

Dissertations and Theses

The cellular stress response (CSR) is one of the most highly conserved mechanisms among all organisms. Cellular stress can be defined as damage or the threat of damage to proteins, macromolecules and/or DNA. The response to damage can involve cell cycle regulation, protein chaperoning, DNA repair or, if macromolecular damage is too severe, apoptotic mechanisms can be initiated. This thesis details experiments that were designed to examine the cellular response to non-lethal environmental stressors at the protein level, using two fish species as study models. Two proteins that can cause cell cycle arrest and apoptosis mechanisms were examined. Expression of …

Microbial Biomineralization Of Iron, Wen Fang

Dissertations and Theses

Iron is a common cation in biomineral sand; it is present for example in magnetite produced by magnetotactic bacteria and in iron sulfides produced by sulfate reducing microorganisms. The work presented in this thesis focused on two types of microorganisms capable of forming iron biominerals. In the first project I have studied the effect of O2 on the respiratory physiology and the formation of magnetosomes by Magnetospirillum magneticum AMB-1. In the second project I have studied the relationship between olivine and the activity of dissimilatory sulfate reducing (DSR) microorganisms. For the first project, I grew cells of AMB-1 in cultures …

Extrahepatic 25-Hydroxylation Of Vitamin D3 In An Engineered Osteoblast Precursor Cell Line Exploring The Influence On Cellular Proliferation And Matrix Maturation During Bone Development, Shelley S. Mason, Sean S. Kohles, Shelley R. Winn, Randy D. Zelick

Biology Faculty Publications and Presentations

Osteoblastic precursors experience distinct stages during differentiation and bone development, which include proliferation, extracellular matrix (ECM) maturation, and ECM mineralization. It is well known that vitamin D plays a large role in the regulation of bone mineralization and homeostasis via the endocrine system. The activation of vitamin D requires two sequential hydroxylation steps, first in the kidney and then in the liver, in order to carry out its role in calcium homeostasis. Recent research has demonstrated that human-derived mesenchymal stem cells (MSCs) and osteoblasts can metabolize the immediate vitamin D precursor 25- dihydroxyvitamin D₃(25OH₂D₃) to the active steroid 1α,25-dihydroxyvitamin D₃ …

Inefficient Replication Reduces Reca-Mediated Repair Of Uvdamaged Plasmids Introduced Into Competent Escherichia Coli, Harout Arthur Jeiranian, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Transformation of Escherichia coli with purified plasmids containing DNA damage is frequently used as a tool to characterize repair pathways that operate on chromosomes. In this study, we used an assay that allowed us to quantify plasmid survival and to compare how efficiently various repair pathways operate on plasmid DNA introduced into cells relative to their efficiency on chromosomal DNA. We observed distinct differences between the mechanisms operating on the transforming plasmid DNA and the chromosome. An average of one UV-induced lesion was sufficient to inactivate ColE1-based plasmids introduced into nucleotide excision repair mutants, suggesting an essential role for repair …

Uvrd Participation In Nucleotide Excision Repair Is Required For The Recovery Of Dna Synthesis Following Uv-Induced Damage In Escherichia Coli, Kelley Nicole Newton, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

UvrD is a DNA helicase that participates in nucleotide excision repair and several replication-associated processes, including methyl-directed mismatch repair and recombination. UvrD is capable of displacing oligonucleotides from synthetic forked DNA structures in vitro and is essential for viability in the absence of Rep, a helicase associated with processing replication forks. These observations have led others to propose that UvrD may promote fork regression and facilitate resetting of the replication fork following arrest. However, the molecular activity of UvrD at replication forks in vivo has not been directly examined. In this study, we characterized the role UvrD has in processing …

Use Of Two-Dimensional Agarose-Gel Analysis To Characterize Processing Of Uv-Irradiated Plasmids And The Composition Of The Replisome Following Uv-Induced Arrest, Harout Arthur Jeiranian

Dissertations and Theses

In this thesis, I address two fundamental questions related to our understanding of how DNA damage is processed and repaired during replication. Using Two-dimensional (2-D) agarose gel analysis, I first examine whether DNA damage on plasmids introduced by transformation is processed in a manner similar to that observed on endogenously replicating plasmids and the chromosome. The original intent for using this approach was to develop a technique that could examine how different DNA adducts would be repaired in various sequence contexts. However, I found that distinct differences exist between the processing of DNA damage on transforming plasmids and the chromosome. …

Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken

Dissertations and Theses

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations …

The Effects Of Hypoxia And Temperature On Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus, Skye N. Anderson

Dissertations and Theses

Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to …

The Role Of Nucleotide Excision Repair In Restoring Replication Following Uv-Induced Damage In Escherichia Coli, Kelley Nicole Newton

Dissertations and Theses

Following low levels of UV exposure, Escherichia coli cells deficient in nucleotide excision repair recover and synthesize DNA at near wild type levels, an observation that formed the basis of the post replication recombination repair model. In this study, we characterized the DNA synthesis that occurs following UV-irradiation in the absence of nucleotide excision repair and show that although this synthesis resumes at near wild type levels, it is coincident with a high degree of cell death. We confirm that the replication occurring under these conditions involves extensive levels of strand exchange. However, cells undergoing this form of replication accumulate …

Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Endonuclease (Endo) III and formamidopyrimidine-N-glycosylase (Fpg) are two of the predominant DNA glycosylases in Escherichia coli that remove oxidative base damage. In cell extracts and purified form, Endo III is generally more active toward oxidized pyrimidines, while Fpg is more active towards oxidized purines. However, the substrate specificities of these enzymes partially overlap in vitro. Less is known about the relative contribution of these enzymes in restoring the genomic template following oxidative damage. In this study, we examined how efficiently Endo III and Fpg repair their oxidative substrates in vivo following treatment with hydrogen peroxide. We found …

Mitochondrial Physiology Of Diapausing And Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus: Implications For Extreme Anoxia Tolerance, Jeffrey M. Duerr, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Diapausing embryos of the annual killifish Austrofundulus limnaeus have the highest reported anoxia tolerance of any vertebrate and previous studies indicate modified mitochondrial physiology likely supports anoxic metabolism. Functional mitochondria isolated from diapausing and developing embryos of the annual killifish exhibited VO2, respiratory control ratios (RCR), and P:O ratios consistent with those obtained from other ectothermic vertebrate species. Reduced oxygen consumption associated with dormancy in whole animal respiration rates are correlated with maximal respiration rates of mitochondria isolated from diapausing versus developing embryos. P:O ratios for developing embryos were similar to those obtained from adult liver, but were diminished in …

Increased Glutathione Metabolic Defense Capabilities In Cultured Alzheimer's Diseased Lymphoblast Cell Lines, Collin M. Shaw

Dissertations and Theses

The hypothesis to be tested states that the pathology of Alzheimer's disease (AD) involves elevated levels of oxidative stress, resulting in elevated levels of cellular oxidative defense mechanisms. If the premise is true, than AD pathologically afflicted cells should have a higher demand for glutathione (GSH) as an innate oxidative defense mechanism hence; greater GSH concentrations, increased GSH resynthesis capabilities, and increased levels of cystathionine gamma-lyase (CNase). Alzheimer diseased and age matched control lymphoblast cells, obtained from OHSU's Oregon Brain Aging Study, were cultured, and GSH biochemistry was subsequently evaluated. GSH was depleted by exposing cells to the GSH depleting …

Inquiry Into The Causes And Significance Of Cytoplasmic Vacuolation Of Neutrophils In The Peripheral Circulation, Gary Xavier Haight

Dissertations and Theses

One-half million cases of septicemia are reported annually with a mortality of around 35%. Diagnosis depends in part on blood cultures which require one to two weeks. It would be advantageous if an early sign of septicemia were available.

Cytoplasmic vacuolation of polymorphonuclear neutropnils is occasionally seen in the peripheral blood smears of patients who have infections. The object of this work was to determine the cause and significance of cytoplasmic vacuolation with the goal of using the occurrence of vacuolation as an early indicator of infection.

Origin Of Human Trisomy 21 Mosaicism, Diane Dusenbery Waggoner

Dissertations and Theses

Down Syndrome is a human condition caused by an extra copy of a #21 chromosome. At least one to two percent of free (not translocated) trisomy 21 cases are mosaics, i.e., they have two or more distinct cell lines. Usually, one cell line is 47 ,XX or XY ,+21 while the other cell line is normal 46,XX or 46,XY.

The purpose of the study was to establish the etiologies of the separate cell lines by determining whether the zygote was trisomic or normal. Meiotic non-disjunction in the formation of a gamete could lead to a trisomic zygote; loss of a …

Factors Affecting Thyrotropin Secretion In Superfused Rat Anterior Pituitary Cells, Frederick Scott Bartlow

Dissertations and Theses

The use of static in vitro pituitary cultures has been indispensible for examining the regulation of anterior pituitary hormone secretion. While the static cultures have shown the effects of various chemical stimulators of hormone secretion, the dynamics of such secretion has not been assessed before in vitro. The in vitro superfusion method, which partially stimulates in vivo physiologic conditions, allows for the observation of the dynamics of pituitary hormone secretion.

The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh

Dissertations and Theses

After vasectomy, the passage of sperm antigen through the epithelium of the efferent duct in the rhesus macaque probably results in immune complex deposition. Immune complexes can be visualized in the thickened basement by fluorescence microscopy. Subsequent electron microscopic evaluation, with the appearance of electron-dense deposits in the basement membrane of the efferent ducts, substantiates these findings.

Storage And Use Of Glycogen By Juvenile Carcinonemertes Errans, D. Mitchell Wolgamott

Dissertations and Theses

Juvenile C. errans do not feed on particulate matter and yet they can survive, apparently unchanged, for several months before maturing into the adult stage which feeds on the eggs of Cancer magister. The significance of glycogen as an energy source for maintenance of the juvenile form was investigated.

"The Story Of Tumor Immunity", Peter Brian Medawar

Special Collections: Oregon Public Speakers

No abstract provided.

Localization Of Neurosecretory Cells Within The Cerebral Ganglia Of Amphiphorus Imparispinosus Griffin, 1898 (Hoplonemertea) And Their Possible Regulatory Role In The Annual Reproductive Cycle, Gail H. Jacobson

Dissertations and Theses

Nemerteans are common invertebrates along coastlines in both temperate and arctic climates throughout the world. Amphiphorus imparispinosus is a carnivorous member of this phylum that is found abundantly in the intertidal areas of the Oregon coast. As in many other invertebrate phyla, endocrine integration within the nemerteans is thought to be accomplished by neurosecretory mechanisms. In Amphiphorus the presence of these neurosecretory systems has not been previously shown. This project was undertaken to determine if neurosecretory cells are present within the central nervous system of this species and. further, to examine seasonal changes in the number and appearance of these …

The Dispersal And Dispersion Patterns Of Hydra Fusca In A Limited Environment, Faith E. Ruffing

Dissertations and Theses

The dispersal and dispersion patterns of Hydra fusca were examined. Hydra were placed in petri dishes at various densities. The water in the dishes was swirled forcing the animals to the center. The location of each animal was marked at time intervals thereafter. Analyses of the dispersal rates and dispersion patterns were made. Hydra dispersed from a central release point at a non-random rate. There was rapid movement from the center followed by a minimal daily movement. This eventually resulted in a uniform dispersion pattern at high densities in a limited environment. There was a relationship between the ratio of …