Cell and Developmental Biology Commons^™

Attempted Cloning Of A Wnt Gene From Botrylloides Violaceus, Manasa Chandra, James Tumulak

Biological Sciences

Botrylloides violaceus is a colonial ascidian with the ability to undergo sexual and asexual reproduction as well as regeneration. The canonical pathway starts with the extracellular protein Wnt and ends with β-catenin, a transcription factor, which also functions in cell adhesion. The Wnt signaling pathway is involved in embryogenesis and regeneration in a variety of other species. In our studies we attempt to isolate and sequence both a Wnt gene and from Botrylloides via degenerate primer design and PCR. Using bioinformatic methods we aligned sequences from other organisms, as the Botrylloides genome has not yet been sequenced. Using mouse, Ciona, …

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan

Graduate Theses and Dissertations

Oligopeptides and low molecular weight polypeptides play central roles as effectors and signal transducers acting as hormones, neurotransmitters, growth factors, toxins, and antimicrobial factors that are important for the survival of the organism. Owing to the ubiquitous involvement of peptides in many key regulatory processes, we have been interested to identify native peptides in different cells and tissues and understand their functions. To conduct our studies, we used avian macrophages and heterophils as models of specialized cells which constitute central components of innate immunity. These studies involved (a) qualitative identification and characterization of the peptides associated with high intensity mass …

Identification Of A Conserved Cluster In The Rh Domain Of Grk Critical For Activation By Gpcrs, Faiza Baameur

Dissertations & Theses (Open Access)

One of the most critical aspects of G Protein Coupled Receptors (GPCRs) regulation is their rapid and acute desensitization following agonist stimulation. Phosphorylation of these receptors by GPCR kinases (GRK) is a major mechanism of desensitization. Considerable evidence from studies of rhodopsin kinase and GRK2 suggests there is an allosteric docking site for the receptor distinct from the GRK catalytic site. While the agonist-activated GPCR appears crucial for GRK activation, the molecular details of this interaction remain unclear. Recent studies suggested an important role for the N- and C-termini and domains in the small lobe of the kinase domain in …

The Role Of Multiple Ccaat-Binding Factors In Candida Albicans Gene Expression, Lashall Lynn Bates

Graduate Theses and Dissertations

The CCAAT-binding factor is a heterooligomeric transcription factor that is evolutionarily conserved in eukaryotes. In yeast, the DNA-binding component that interacts with the CCAAT consensus sequence in promoters consists of the subunits termed Hap2p, Hap3p and Hap5p. In yeast and fungi, a fourth subunit, Hap4p, is required for regulating gene expression. The goal of this research is to understand the function of the Candida albicans CCAAT-binding factor and how it relates to virulence and pathogenicity. C. albicans is a human opportunistic pathogen responsible for a variety of mucosal and systemic infections that result in significant morbidity and mortality, particularly in …

Dissolved Organic Matter Influences The Timing Of Embryonic Development Of The Purple Sea Urchin, Strongylocentrotus Purpuratus., Corbin J. Hodges

Master's Theses

Marine dissolved organic matter (DOM) comprises one of the largest carbon reservoirs on earth and has long been considered a potential energy source for marine invertebrates. The importance of DOM transport has been adequately demonstrated for unicellular organisms, where DOM can meet 100% of an organisms energy needs, but the effects of DOM uptake for marine metazoans are less well understood. In this study, three general areas involving the influence of DOM transport to marine invertebrates were explored. First, we assessed the effects of using seawater exposed to high intensity ultraviolet radiation (UVR) on the study organism; embryos of the …

Inhibition Of Pi 3-Kinase Signaling Contributes To Metronidazole Resistance In The Protozoan Parasite, Entamoeba Histolytica, Rhonda Powell

All Theses

Amoebiasis is defined as an intestinal infection with the human protozoan parasite, Entamoeba histolytica; approximately 100,000 deaths annually can be attributed to amoebiasis. Disease states range from asymptomatic colonization to invasive amoebiasis, characterized by abdominal pain and dysentery. Dissemination to extraintestinal sites, such as the liver and/or brain, can occur. Vesicle trafficking is critical for parasite virulence, and multiple signaling cascades within the pathogen facilitate these events.
One important regulator of signal transduction is the tightly controlled PI 3-kinase (PI3K), which phosphorylates the lipid, phosphatidylinositol bisphosphate (PIP₂), producing phosphatidylinositol trisphosphate (PIP₃). Effector proteins, such as Akt, …

The Role Of Human Endogenous Retroviruses In Renal Cell Carcinoma, Michele D. Tisdale

Biological Sciences Theses & Dissertations

Human endogenous retroviruses make up approximately 8-9% of the human genome. A number of expressed HERVs, those that are actively transcribing, have been associated with various cancers. Suppression mechanisms that control HERV expression often fail or become more permissive in tissues where expression should be restricted. Previous studies have identified HERV expression in breast cancer tissues, whereas normal tissue HERV expression remained suppressed. In addition, studies of DNA hypermethylation have correlated with the ability to contribute to cancer development. Hypermethylation of several tumor suppressor genes occurs frequently in cancers and alterations in promoter regions could contribute to the development of …

Molecular And Cellular Mechanisms Whereby The Apical Ectodermal Ridge (Aer), Via Wnt5a, Mediates Directional Migration Of The Adjacent Mesenchyme During Vertebrate Limb Development, Kate E. Kmetzsch

Theses and Dissertations

The vertebrate embryonic limb is a key model in elucidating the genetic basis underlying the three dimensional morphogenesis of structures. Despite the wealth of insights that have been generated from this model, many long-standing questions remain. For example, it has been known for over 70 years that the apical ectodermal ridge (AER) of the embryonic limb is essential for distal outgrowth and patterning of the adjacent limb mesenchyme. The mechanisms whereby the AER does accomplish outgrowth and patterning are still poorly understood. We propose that secreted FGFs from the AER activate Wnt5a expression in gradient fashion, which in turn provides …

Zyxin Regulates Epithelial-Mesenchymal Transition By Mediating Actin-Membrane Linkages At Cell-Cell Junctions, Liv Rebecca Sperry

Theses and Dissertations

Development is punctuated by morphogenetic rearrangements of epithelial tissues, including complete detachment of individual motile cells during epithelial-mesenchymal transition (EMT). Dramatic actin rearrangements occur as cell-cell junctions are dismantled and cells become independently motile during EMT. Characterizing dynamic actin rearrangements and identifying actin machinery driving these rearrangements is essential for understanding basic mechanisms of cell-cell junction remodeling; yet, neither the precise series of actin rearrangements at cell-cell junctions that accompany EMT, nor the machinery that controls actin rearrangement during EMT, have been identified. This work represents a detailed study of junctional actin reorganization in cells undergoing EMT, identifies actin regulatory …

Exposure To Ultraviolet Radiation Causes Proteomic Changes In Embryos Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Joseph Paul Campanale

Master's Theses

The amount of solar ultraviolet radiation (UVR, 290-400 nm) reaching Earth’s surface is increasing due to ozone depletion and global climate change. Embryos of the purple sea urchin, Strongylocentrotus purpuratus, provide an ideal system for examining how UVR affects developing marine organisms and cells in general. To model the protein-mediated cell cycle response to UV-irradiation, six batches of S. purpuratus embryos were exposed to UVR, monitored for delays in the first mitotic division and examined for global proteomic changes. Embryos from each batch were exposed to or protected from artificial UVR for 25 or 60 min. Embryos treated with …

Function Of The Notch/Delta Pathway In Ophthalmic Trigeminal Placode Development, Matthew K. Ball

Theses and Dissertations

The ophthalmic trigeminal placode (opV) is the birth place of one cell type of sensory neurons contributing to the trigeminal ganglion. Signals from the neural tube induce placodal identity within the surface ectoderm. Specified opV placode cells then up-regulate neuron differentiation markers and migrate to the ganglion. Several molecular pathways have been shown to act in opV placode cell development. Despite this, signals that specify individual neurons from within the opV placode remain unknown. However, it is known that components of the Notch signaling pathway are expressed in the opV placode. I tested the role of Notch signaling in opV …

Prostate Cancer Biomarker Identification: A Comparative Study, Wenjuan Jiang

Computational Modeling & Simulation Engineering Theses & Dissertations

With the current development of proteomics techniques, the discovery of potential molecular biomarkers for early detection of prostate cancer has been greatly improved. In this thesis, we implemented five classifiers including the support vector machine (SVM), Bayesian Classifier, Decision Tree, Random Forest and the Multilayer perceptron (MLP) to test their effectiveness in prostate cancer biomarker identification using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) tissue imaging data. The classifiers were utilized to discriminate cancer mass spectra from normal ones for the data collected at the Eastern Virginia Medical School (EVMS). There are 94 7 spectra from normal tissues and 27 from …

Delayed Anesthetic Preconditioning And Metallothioneins I+Ii: Novel Mediators Of Anesthetic-Induced Protection, Scott David Edmands

Open Access Dissertations

Ischemic injury is a common and debilitating outcome of natural illness and as a complication of commonly performed medical procedures. Whereas naturally occurring ischemic insults are often the result of unpredictable events, such as in the case of stroke or heart attack, the risk of operative and perioperative ischemia is somewhat better characterized in the clinical setting. Given the prevalence and severity of outcomes in ischemic injury, there is significant interest in developing better pharmacological and procedural approaches to improve patient outcomes. One approach that has shown significant promise in the laboratory setting, particularly in the context of planned medical …

Modulation Of Macrophage Responses To Borrelia Burgdorferi In Acute Murine Lyme Carditis, Chris Martin Olson

Open Access Dissertations

The Lyme disease spirochete Borrelia burgdorferi is the only known human pathogen that directly activates invariant natural killer T (iNKT) cells. The number and activation kinetics of iNKT cells vary greatly among different strains of mice. Here, we report the role of the iNKT cell response in the pathogenesis of Lyme disease using C57BL/6 (B6) mice, a strain with optimal iNKT cell activation that is resistant to the development of spirochetal-induced inflammation. During experimental infection of B6 mice with B. burgdorferi , iNKT cells localize to the inflamed heart where they are activated by CD1d-expressing macrophages. Activation of iNKT cells …

The Conformational Gymnastics Of The Escherichia Coli Seca Molecular Machine And Its Interactions With Signal Sequences, Jenny Lynn Maki

Open Access Dissertations

Protein secretion is a selective and regulated process that is essential in all organisms. In bacteria the preprotein translocase SecA, either free in the cytosol or associated with the SecYEG translocon, recognizes and binds most post-translational secretory proteins containing an N-terminal signal sequence. In Gram-negative bacteria, the molecular chaperone SecB binds many of the preproteins to keep them in a translocation-competent state. Subsequently, SecB delivers the preproteins to the translocon-associated SecA, which binds the signal sequence and also interacts with mature regions of the preprotein. After the preprotein/SecA/SecYEG complex has formed, the energy derived from ATP hydrolysis by SecA coupled …

Preparation, Separation, Purification, Characterization And Human Cell Line Anti-Cancer Evaluation Of Rice Bran Peptides, Arvind Kannan

Graduate Theses and Dissertations

Bioactive compounds are revolutionizing the nutritional and medicinal world with their inherent disease-fighting properties. A wide range of functional groups fall under the category of imparting health benefits. Compounds from both animal and plant origins have been generated as bioactive agents that have opened up new vistas for alternative medicine and natural healing. For example, in a debilitating disease like cancer, these compounds can act to suppress or delay the underlying pathology over and above the conventional treatment strategies involving drugs or chemotherapy. In other words conventional and invasive therapy, although still considered appropriate at certain stages of cancer, their …

The Membrane Interface Of Chloroplast Signal Recognition Particle-Dependent Protein Targeting, Naomi Jane Marty

Graduate Theses and Dissertations

A novel signal recognition particle (SRP) found in the chloroplast (cpSRP) works in combination with the cpSRP receptor, cpFtsY, to facilitate the post-translational targeting of a family of nuclear-encoded thylakoid proteins to the Alb3 translocase in thylakoid membranes. Work here focused on understanding events at the membrane that take place to ensure targeting of the cpSRP-dependent substrate to Alb3. Specifically, we sought to understand the structural and functional role of membrane binding by cpFtsY, a protein that exhibits the ability to partition between the membrane (thylakoid) and soluble (stroma) phase during protein targeting. We also sought to understand whether a …

Spermiogenesis And In Vitro Culture Of Spermatogenic Cysts In Drosophila Pseudoobscura, Monicah Njogu

Seton Hall University Dissertations and Theses (ETDs)

Spennatogenesis is a complex process that involves differentiation and morphological changes of diploid stem cells into highly specialized, haploid, motile germ cells. Many of the transformative processes involved in mammalian spermatogenesis are conserved in flies, and their study would be facilitated by the availability of a reliable in vitro culture system. Culture of Drosophila melanogaster spermatogenic cysts is limited in usefulness because of early degeneration of cysts, low yield of elongated spermatozoa, and rare occurrences of motile sperm. We have developed a culture system for studying fly spermatogenesis using isolated spermatogenic cysts from the testes of Drosophila pseudoobscura. This species …

Functional Interaction Of Racf2 And The Wasp Family Protein, Scar, In The Rab8 Signaling Pathway Of The Social Amoeba, Dictyostelium Discoideum, Terri Bruce

All Dissertations

The small GTPase, Rab8, has been shown to play a role in cell-cell adhesion and restructuring of the actin cytoskeleton in both mammalian cells and the lower eukaryote, Dictyostelium discoideum. In D. discoideum, cells expressing constitutively activated Rab8 (Rab8CA) display reduced cell-cell adhesion and increased actin-rich protrusions as well as delayed aggregation. Rab8 has been implicated in the restructuring of the actin cytoskeleton, but no specific pathway for this action has been identified. In other systems, actin-rich membrane extension formation is regulated by WASp family proteins, including SCAR. Here we provide evidence of a functional relationship between the WASp family …

Construction And Characterization Of A Novel Fusion Protein From The Extracellular Domain Of Mult1 And Transmembrane And Intracellular Domains Of Fas And Its Therapeutic Evaluation For Cancer Treatment Using An Adenoviral Delivery System, Hari Shankar Kotturi Rajeshwar

All Dissertations

One of the strategies that tumor cells adopt to evade immunosurveillance mounted by elements of the innate immune system, such as NK cells, is to down-regulate certain cell surface molecules through a process also called shedding. Mouse UL16-binding protein-like transcript 1 (MULT1), which can activate NK cells through NK cell receptor NKG2D, is one of such molecules. Tumor cells can also avoid Fas mediated apoptosis by down-regulating its expression, secreting antagonistic `decoy' receptors, or expressing anti-apoptotic molecules. In this study, we report the design and evaluation of the antitumor activity of a novel fusion protein MULT1E/FasTI, consisting of the extracellular …

Modeling Brain Injury: Expression Of Glial Fibrillary Acidic Protein In Stretch-Injured Astrocytes, Lindsey Cooke

Undergraduate Theses and Capstone Projects

Traumatic brain injury (TBI) is the leading cause of death and disability in individuals under 45. Individuals who survive TBI may be disabled for the rest of their lives and suffer from cognitive, physical, social and financial problems. Following TBI it has been shown that astrocytic gene expression of many proteins, including glial fibrillary acidic protein (GFAP), increases. These “reactive” astrocytes are thought to have both beneficial and detrimental effects on neuronal survival and function. The current study uses an in vitro model of injury which grows astrocytes on deformable silastic membranes to allow for dynamic stretch of cultured cells …

Study Of The Dna Damage Complexes Within The Htlv-1 Tax Oncoprotein Interactome, Sidi Mehdi Belgnaoui

Theses and Dissertations in Biomedical Sciences

Human T-cell leukemia virus type 1 (HTLV-1) is a transforming retrovirus that can give rise to adult T-cell leukemia (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). Tax is a virally encoded oncoprotein that is involved in HTLV-1 mediated cellular transformation. It has been hypothesized that Tax induces genomic instability via repression of the cellular DNA damage repair response. Our laboratory has previously shown that the interaction between Tax and various proteins involved in the DNA-damage response pathway impairs the ability of these proteins to mount an efficient repair response. As part of these observations, we proposed that Tax induces …

Food Entrainment Of Circadian Gene Expression Altered In Pparα-/- Brown Fat And Heart, Brian Chun Kim Goh

Honors Theses

No abstract provided.

Characterization And Differentiation Of Peripheral Blood Derived Multipotent Adult Progenitor Cells, Hari Satya Shankar Addagarla

Theses, Dissertations and Capstones

Stem cells are populations of undifferentiated cells that are found in most tissues and act as precursors for regeneration and maintenance. In the future, they could provide promising therapies for diseases which are to date incurable. Our lab developed a novel cell line from the peripheral blood of adult transgenic green fluorescent protein swine and designated them as Peripheral Blood Derived Multipotent Adult Progenitor Cells (PBD-MAPCs). In this study we characterized the mRNA and protein expression profiles of PBD-MAPCs before and after neural differentiation and investigated the potential of PBD-MAPCs to differentiate into myocardial or neural lineages in vitro. We …

Loss Of Ski Expression In Testicular Cancer Leads To An Enhanced Invasive Phenotype Through Both Bmp-Dependent And Bmp-Independent Pathways, Amy N. Nash

Theses, Dissertations and Capstones

The proto-oncogene SKI is a transcription factor and a co-repressor of the TGFβ superfamily, including TGF

β and BMP. However, additional data suggests that SKI may function as a tumor suppressor in some cell types. The TGFβ superfamily has been implicated in cancer progression and germ cell migration. Testicular cancer afflicts men during their peak reproductive years and is the most common cancer among men of this age group. Cisplatin-based chemotherapy is the standard treatment for testicular cancer. This treatment can lead to undesirable side effects, including infertility. We have shown that SKI expression is decreased in testicular germ cell …

Enumeration Of Endothelial Progenitor Cells In Hind Limb Suspended Rats And The Mechanics Of Endothelial Wound Healing, Jarrod Matthew Pennington

Theses, Dissertations and Capstones

The endothelium repairs itself through two methods. One is by the activity of circulating endothelial progenitor cells (EPCs). EPCs are immature endothelial cells that circulate the bloodstream that are capable of proliferation and differentiation into mature endothelium. It is thought that EPCs contribute to the repair and replacement of damaged endothelial cells in the process of reendothelialization. Physical inactivity and bed rest are known to be deleterious to the endothelium. It is possible that this inactivity is also deleterious to the number of viable EPCs, which would reduce the ability of the endothelium to repair itself. We used hind limb …

Effects Of Aging On Regulators Of Muscle Apoptosis In The Female F344bn Rat, Murali K. Gadde

Theses, Dissertations and Capstones

Age-related muscle atrophy is a consequence of normal aging characterized by decreases in muscle mass and strength. The mechanism(s) underlying the loss of muscle mass with increasing age is not fully understood, however recent data has suggested that muscle cell apoptosis may be involved. Here we investigate how aging affects the regulation of muscle apoptosis in the extensor digitorum longus (EDL) and soleus muscles of young (6-month), aged (26-month), and very aged (30-month) female Fischer 344/NNiaHSD X Brown Norway / BiNia (F344BN) rats. EDL and soleus muscle mass/body weight ratios were lower in aged animals but not different between 26- …

Tidal Influences On Bacterial And Phytoplankton Abundances And The Resulting Effects On Patterns Of Dissolved Oxygen In The Skidaway River Estuary, Casey Colleen Brazell

Electronic Theses and Dissertations

Two studies were conducted to investigate the physical and biological processes contributing to the dissolved oxygen (DO) availability in the Skidaway River Estuary (SRE), Savannah, GA during the summer of 2005. A temporal study looked at changes in DO concentrations, Chlorophyll a concentrations, bacterial abundance, water depth, and salinity, every hour, for 26 hours, over both a neap and a spring tide. A spatial study looked at changes in the above variables at 5 sites along the SRE while following the tide inland during a neap high and low tide, and a spring high and low tide. DO concentrations varied …

Evolutionary Analysis Of The Glutamic Acid Decarboxylase 67 Immediate Upstream Region In African Clawed Frogs, Jonathan Lomax Boyd

Dissertations, Theses, and Masters Projects

No abstract provided.

The Distribution Of Unpaired During Drosophila Oogenesis, Travis Sexton

University of Kentucky Doctoral Dissertations

Janus Kinase (JAK) activity specifies the cell fates of the follicular epithelium during Drosophila oogenesis by establishing a gradient of JAK activity with highest levels at the A/P poles. Unpaired (Upd), a ligand for the pathway, is expressed and secreted exclusively from the polar cells potentially establishing the JAK activity gradient. This project proposed that Upd acts as a morphogen to directly establish the JAK activity gradient, specifying the fates of the follicular epithelium. The aims of this work were to investigate the extracellular distribution of Upd and, in addition, factors that may be involved. Furthermore, upd3, a gene …