Biology Commons^™

Screen For Suppressors And Enhancers Of Excitotoxic Neurodegeneration, Anthony Omorodion Edokpolo

Dissertations and Theses

Excitotoxicity is an important and frequently observed neurodegenerative process. Excitotoxicity mediates brain damage in a range of diseases and conditions including stroke, and is triggered by excessive stimulation of glutamatergic synapses. In spite of extensive studies, the molecular mechanisms involved in excitotoxicity following the over-activation of postsynaptic glutamate receptors are not well understood, and clinical trials based on our partial understanding of the process ended with disappointment. Genetic screens in simple animal models offer a powerful alternative approach, since screens are unbiased, analysis is facilitated by strong research tools, and cellular mechanisms are highly conserved through evolution. We produced a …

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …

Dephosphorylation Of Iqg1 By Cdc14 Temporally Regulates Actin Ring Formation, Daniel Patrick Miller

Masters Theses

"Cytokinesis is the final step in cell division when the cell separates the cytoplasm by contracting a ring composed of filamentous actin (F-actin) and type II myosin. Iqg1, an IQGAP family member, is an essential scaffolding protein in budding yeast (S. cerevisiae) required for actin recruitment to, and contraction of, the actomyosin ring. Actin is recruited by the calponin homology domain (CHD) in anaphase after Iqg1 is localized to the bud neck. Consensus sites for the cyclin-dependent kinase (CDK) Cdc28 were identified flanking the CHD. This led us to the hypothesis that phosphorylation of Iqg1 by Cdc28 negatively regulates actin …

Quantification Of Protoporphyrin Ix Accumulation In Glioblastoma Cells – A New Technique, John E Lawrence

Journal Articles

5-Aminolevulinic Acid (5-ALA) is a precursor of heme synthesis. A metabolite, protoporphyrin IX (PpIX), selectively accumulates in neoplastic tissue including glioblastoma. Presurgical administration of 5-ALA forms the basis of fluorescence-guided resection (FGR) of glioblastoma (GBM) tumors. However, not all gliomas accumulate sufficient quantities of PpIX to fluoresce, thus limiting the utility of FGR. We therefore developed an assay to determine cellular and pharmacological factors that impact PpIX fluorescence in GBM. This assay takes advantage of a GBM cell line engineered to express yellow fluorescent protein. Methods. The human GBM cell line U87MG was transfected with a YFP expression vector. After …

The Establishment Of A Fibroblastic Cell Line From Yellow Perch (Perca Flavescens) And Its Potential Applications In Toxicology, Katelin W. Spiteri

Theses and Dissertations (Comprehensive)

This thesis describes the establishment, characterization and potential toxicological applications of YPF5, a yellow perch cell line. YPF5 is a fibroblastic cell line derived from the caudal fin of yellow perch. This cell line has been maintained for over 2 years. Cultures have been passaged over 60 times, and successfully cryopreserved and thawed. YPF5 is grown at room temperature in Leibovitz-15 (L-15) media, supplemented with 10% fetal bovine serum and 3% penicillin-streptomycin. The origin of YPF5 has been confirmed as Perca flavescens through “DNA Barcoding” and reaffirmed through Karyotyping (2n = 48) as per literature reported karyology for percidae including …

A Structure-Function Analysis Of The Arabidopsis Chloroplast Import Protein Attic20, James H. Campbell

Theses and Dissertations (Comprehensive)

Arabidopsis thaliana protein Tic20 (atTic20) is a member of the translocon at the inner envelope membrane of chloroplasts. Evidence to date suggests it is part of the main preprotein conducting aperture in the complex, but its exact role is still debated. To help characterize its role, a protocol optimizing yield and purity of recombinantly expressed atTic20 was developed, and a series of experiments was performed to examine its secondary structure and its ability to interact with chloroplast transit peptides. The attempt to increase protein yield was successful, with growth at 20^oC in the auto-inducing media ZYP-5052 showing the …

Characterizing Dsrna Production In Virus-Infected Fish Cells, Amal Brek Aloufi

Theses and Dissertations (Comprehensive)

Viral dsRNA is produced by almost all viruses sometime during their replicative cycle. These viral nucleic acids are potent inducers of both innate and adaptive immune responses, and are therefore considered important immuno-modulators. Previous studies have shown that viruses produce dsRNA when replicating in mammalian cells; however, to date no one has demonstrated viral dsRNA production in virus infected fish cells. Therefore, the goal of this study is to investigate dsRNA production by fish viruses in fish cells, verifying production and performing initial characterization of the dsRNA molecules being produced. Three different rainbow trout cell lines were used in this …

Genetic Sex Conditions And Redefining Sex, Jayce O'Shields

Student Scholarship

Western culture has a tendency to value binaries and discreet categories that separate its social structure and provide a sense of order and organization. The value placed on binaries and categories may be advantageous in some aspects, but when it starts to infringe upon the legal and medical rights of individuals not easily placed in either binary category, it can become less advantageous.

A baby is usually classified as either male or female shortly after birth, and all future legal, social, and economic actions and rights of that individual are more or less decided according to this classification. A problem …

Transformation Of Stimulus Correlations By The Retina, Kristina D. Simmons, Jason Prentice, Gašper Tkačik, Jan Homann, Heather K. Yee, Stephanie E. Palmer, Philip C. Nelson, Vijay Balasubramanian

Publications and Research

Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online. Responding to spatio-temporally structured stimuli such as natural movies, pairs of ganglion cells were modestly more correlated than in response to white noise checkerboards, but …

Smokeless Tobacco Use: A Risk Factor For Hyperhomocysteinemia In A Pakistani Population, Mohammad Perwaiz Iqbal, Mohsin Yakub

Department of Biological & Biomedical Sciences

Background

Smokeless tobacco (ST) use is highly prevalent in the South Asian populations. While there have been a number of reports on association of ST consumption with cancer, very few studies have been conducted to investigate its relationship with cardiovascular disease. Hyperhomocysteinemia is a well-recognized risk factor for cardiovascular disease; however, its association with ST use has never been investigated. The objective of this study was to evaluate the relationship of ST use with hyperhomocysteinemia in an urban Pakistani population.

Methodology/Principal Findings

In a cross-sectional study for assessment of risks of hyperhomocysteinemia, 872 healthy adults (355 males and 517 females …

Protective Effects Of Sphingomyelin Against Uv Photodamage In Human Keratinocytes, Kathleen De Guzman

Master's Theses

Ultraviolet (UV) radiation has been demonstrated in numerous studies to be a major risk factor for non-melanoma skin cancer development. Despite the emergence of current UV-preventative strategies, such as sunscreens and skin-protective clothing, the incidence of non-melanoma skin cancer has continued to rise. This has encouraged investigations on alternative methods for UV prevention. In particular, bovine milk sphingomyelin has been studied for its potential in protecting human skin against UV photodamage. While the previous studies have suggested that sphingomyelin exhibits UV-protective properties in a human skin equivalent model, the exact mechanisms behind sphingomyelin’s photoprotective effects are yet unknown.

This thesis …

Investigating Potential Bioactive Compounds From Rhodococcus And Their Effects On Mcf7 Breast Cancer Cells, Megan N. Crabtree

Electronic Theses and Dissertations

Many drugs used in the treatment of various cancers are derived from or influenced by compounds from nature. The soil bacterium Rhodococcus is of interest because of its identified secondary metabolic pathways and the production of novel natural antibiotics from several strains. In this study, a solid agar extraction method was used to collect compounds from strains of Rhodococcus. These bacterial compound extracts were then tested using a MTT assay in order to evaluate their effectiveness in augmenting MCF7 breast cancer cell death. The results of two way ANOVA analyses revealed 18 compound extracts from 15 strains of Rhodococcus that …

Microtubule Severing At Crossover Sites By Katanin Generates Ordered Cortical Microtubule Arrays In Arabidopsis, Quan Zhang, Erica Fishel, Tyler Bertroche, Ram Dixit

Biology Faculty Research

Highlights

• Severing primarily depolymerizes the overlying CMT at crossover sites
• Severing probability increases nonlinearly with crossover time
• Katanin localizes to crossover sites and is required for severing
• Loss of katanin activity prevents the formation of coaligned CMT arrays

Summary
The noncentrosomal cortical microtubules (CMTs) of land plants form highly ordered parallel arrays that mediate cell morphogenesis by orienting cellulose deposition [1, 2 and 3]. Since new CMTs initiate from dispersed cortical sites at random orientations [4], parallel array organization is hypothesized to require selective pruning of CMTs that are not in the dominant orientation. Severing of CMTs at crossover sites …

Reflections On The Cost Of "Low-Cost" Whole Genome Sequencing: Framing The Health Policy Debate, Timothy Caulfield, Jim Evans, Amy Mcguire, Christopher Mccabe, Tania M. Bubela, Robert Cook-Deegan, Jennifer Fishman, Stuart Hogarth, Fiona A. Miller, Vardit Ravitsky

Office of the Provost

The cost of whole genome sequencing is dropping rapidly. There has been a great deal of enthusiasm about the potential for this technological advance to transform clinical care. Given the interest and significant investment in genomics, this seems an ideal time to consider what the evidence tells us about potential benefits and harms, particularly in the context of health care policy. The scale and pace of adoption of this powerful new technology should be driven by clinical need, clinical evidence, and a commitment to put patients at the centre of health care policy.

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, …

Identification Of Set1 Target Genes, William Beyer, Scott D. Briggs

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Set1 complex, a histone methyltransferase complex found in S. cerevisiae (budding yeast), is the only histone methyltransferase responsible for catalyzing methylation of histone H3 at Lysine 4. It possesses homologues in other species, humans included. While yeast only have the Set1 complex, the human homologues of the yeast Set1 complex include mixed-lineage leukemia family (MLL1-4), Set1 A, Set1 B, among others. MLL1-4 has been shown to play a role in transcription, cell type specification, and the development of leukemia. One application of characterizing the role of a protein is that the information gained can provide insight into the function …

Barrier To Autointegration Factor (Baf) Inhibits Vaccinia Virus Intermediate Transcription In The Absence Of The Viral B1 Kinase, Nouhou Ibrahim, April Wicklund, Augusta Jamin, Matthew S. Wiebe

Nebraska Center for Virology: Faculty Publications

Barrier to autointegration factor (BAF/BANF1) is a cellular DNA-binding protein found in the nucleus and cytoplasm. Cytoplasmic BAF binds to foreign DNA and can act as a defense against vaccinia DNA replication. To evade BAF, vaccinia expresses the B1 kinase, which phosphorylates BAF and blocks its ability to bind DNA. Interestingly, B1 is also needed for viral intermediate gene expression via an unknown mechanism. Therefore, we evaluated the impact of B1-BAF signaling on vaccinia transcription. Strikingly, the decrease in vaccinia transcription caused by loss of B1 can be rescued by depletion of BAF. The repressive action of BAF is greatest …

Female Rats Display Enhanced Rewarding Effects Of Ethanol That Are Hormone Dependent, Laura O'Dell

Selected Works Temporary Series

Background: Ethanol (EtOH) abuse is a major health and economic concern, particularly for females who appear to be more sensitive to the rewarding effects of EtOH. This study compared sex differences to the rewarding and aversive effects of EtOH using place-conditioning procedures in rats. Methods: Separate groups of adult (male, female, ovariectomized [OVX] female) and adolescent (male and female) rats received EtOH (0, 0.5, 1.0, 2.0 or 2.5 g/kg; i.p.) and were confined to their initially nonpreferred side of our conditioning apparatus for 30 minutes. On alternate days, they received saline and were confined to the other side. Following 5 …

Female Rats Display Enhanced Rewarding Effects Of Ethanol That Are Hormone Dependent, Laura O'Dell

Departmental Papers (Psych)

Background: Ethanol (EtOH) abuse is a major health and economic concern, particularly for females who appear to be more sensitive to the rewarding effects of EtOH. This study compared sex differences to the rewarding and aversive effects of EtOH using place-conditioning procedures in rats. Methods: Separate groups of adult (male, female, ovariectomized [OVX] female) and adolescent (male and female) rats received EtOH (0, 0.5, 1.0, 2.0 or 2.5 g/kg; i.p.) and were confined to their initially nonpreferred side of our conditioning apparatus for 30 minutes. On alternate days, they received saline and were confined to the other side. Following 5 …

Recurrent Modification Of A Conserved Cis-Regulatory Element Underlies Fruit Fly Pigmentation Diversity, William A. Rogers, Joseph R. Salomone, David J. Tacy, Eric M. Camino, Kristen A. Davis, Mark Rebeiz, Thomas M. Williams

Biology Faculty Publications

The development of morphological traits occurs through the collective action of networks of genes connected at the level of gene expression. As any node in a network may be a target of evolutionary change, the recurrent targeting of the same node would indicate that the path of evolution is biased for the relevant trait and network. Although examples of parallel evolution have implicated recurrent modification of the same gene and cis-regulatory element (CRE), little is known about the mutational and molecular paths of parallel CRE evolution. InDrosophila melanogaster fruit flies, the Bric-à-brac (Bab) transcription factors control the development …

The Importance Of Epigenetic Phenomena In Regulating Activity Of The Genetic Material, Sin Chan

Senior Honors Projects

Genetics has taught us that genes are represented as discrete sequences within a larger DNA molecule found embedded within the chromosomes of a living cell. Collectively these chromosomes and their associated genes carry all of the instructions for life. Until recently, the prevailing thought has been that genes are destiny in the life of an individual since the genes carry the information that determines the general traits and characteristics associated with that individual. The relatively recent understanding of mechanisms that underlie epigenetic phenomena has led to a rethinking of this concept. Epigenetics describes cellular mechanisms that explain how two individuals …

A Force Of Nature: Molecular Mechanisms Of Mechanoperception In Plants, Gabriele B. Monshausen, Elizabeth S. Haswell

Biology Faculty Research

The ability to sense and respond to a wide variety of mechanical stimuli-gravity, touch, osmotic pressure, or the resistance of the cell wall-is a critical feature of every plant cell, whether or not it is specialized for mechanotransduction. Mechanoperceptive events are an essential part of plant life, required for normal growth and development at the cell, tissue, and whole-plant level and for the proper response to an array of biotic and abiotic stresses. One current challenge for plant mechanobiologists is to link these physiological responses to specific mechanoreceptors and signal transduction pathways. Here, we describe recent progress in the identification …

Characterization Of Jak, Stat, And Src Interactions In Head And Neck Squamous Cell Carcinoma, Reshma Jaseja, Reshma Jaseja

Dissertations and Theses (Open Access)

Recurrence of Head and Neck Squamous Cell Carcinoma (HNSCC) is common; thus, it is essential to improve the effectiveness and reduce toxicity of current treatments. Proteins in the Src/Jak/STAT pathway represent potential therapeutic targets, as this pathway is hyperactive in HNSCC and it has roles in cell migration, metastasis, proliferation, survival, and angiogenesis. During short-term Src inhibition, Janus kinase (Jak) 2, and signal transducer and activator of transcription (STAT) 3 and STAT5 are dephosphorylated and inactivated. Following sustained Src inhibition, STAT5 remains inactive, but Jak2 and STAT3 are reactivated following their early inhibition. To further characterize the mechanism of this …

Developmental Expression Profile Of Bric Á Brac 2, Midline And H15 In The Developing Eye And Central Nervous System Of Drosophila Melanogaster, Petra Visic

Honors Theses

Aberrant activity of a single gene can lead towards development of cancerous cells. Drosophila melanogaster is a useful model system to study cancer because there is high degree of evolutionary conservation in signaling pathways between humans and flies that play major roles in regulating cell proliferation and growth (Miles et al., 2011). At The University of Southern Mississippi (USM), Dr. Leal’s lab has gathered evidence suggesting that bab1 and bab2 interact with the T-box gene midline (mid) and its paralog H15, while the early developmental function of bab1 and bab2 remains unknown. That is why elucidating the early …

Evaluating Itpr-Dependence Of Apoptotic Signaling From The Endoplasmic Reticulum, Agustin Vargas, Jay L. Brewster

Featured Research

Stress within the endoplasmic reticulum (ER) can be induced by misfolded proteins accumulating in the lumen of this organelle. Signaling of ER stress to other parts of the cell results in altered gene expression, physiological adaptation, and with sustained stress, apoptosis (cell suicide). ER stress is often studied with highly toxic compounds that create severe ER stress rapidly, and a condition that is likely not physiologically relevant within an organism. In this study, we examine the apoptotic signaling induced by moderate ER stress, and in particular the inositol 1,4,5-trisphosphate receptor (ITPR). The ITPR regulates Ca2+ release from the ER lumen, …

Lysophosphatidic Acid Stimulates Lymphangiogenesis In Human Lymphatic Endothelial Cells, John Macbeth, Donna Nofziger-Plank

Featured Research

Lymphangiogenesis is the process by which new lymphatic vessels sprout and grow from existing vessels whether under developmental, immunological, or cancerous conditions. Proper lymphatic vessel formation is important in working alongside normal angiogenesis in order to help regulate the body’s tissue fluid as well as aid in immunosurveillance. Various factors regulate lymphangiogenesis such as members of the vascular endothelial growth factor family (VEGF). Another factor that has recently been identified to play a role in lymphangiogenesis is the bio-active phospholipid lysophosphatidic acid (LPA) however the molecular mechanism by which LPA regulates lymphangiogenesis has not been well characterized. In this study, …

Carbon Black And Titanium Dioxide Nanoparticles Differentially Activate Oxidative Stress And Apoptosis In A549 Human Alveolar Epithelial Cells, Sarah Alvarado, Brianna Manes, Jay L. Brewster

Featured Research

Recent studies have demonstrated that variation between particulate matter compositions have universally adverse effects on cells and living tissues. Carbon black and titanium dioxide are two such particulates that we are continuously exposed to, yet there is limited research to examine the potential deleterious effects on living tissue. The objective of this study is to characterize the effect of carbon black (CB) and titanium dioxide (TiO2) particulates on A549 human alveolar epithelial lung cells. CB and TiO2 powders were dispersed throughout a solution of water and bovine serum albumin by high-powered sonication. The effects of these particulates on A549 cells …

The Survivin And Ciap1 Anti-Apoptotic Proteins Are Differentially Downregulated In Response To Endoplasmic Reticulum Stress, Vicki Mercado, Jay L. Brewster

Featured Research

The endoplasmic reticulum (ER) is an organelle tasked with synthesis and transport of 50% of new cellular proteins. Dysfunction within this organelle creates signals for repair, adaptation, and in severe cases, cellular apoptosis. Multiple human diseases have been associated with ER dysfunction, and the activation of apoptosis in important populations of cells. Inhibitor of Apoptosis (IAP) proteins are cytosolic proteins that play an anti-apoptotic role in the cytosol. The relationship between endoplasmic reticulum (ER) stress and the expression/stability of IAPs is not well characterized. The objective of this study was to characterize the affect of ER stress on the expression/stability …

The Regulatory Effect Of Semaphorin 7a On Proliferation And Migration In Human Umbilical Vein Endothelial Cells, Steven R. Flemming, Donna Nofziger-Plank

Featured Research

Semaphorin 7A (SEMA 7A), a factor originally identified as regulating axon growth, has recently been implicated as a pro-angiogenic factor. The molecular mechanisms for this ability to stimulate angiogenesis have not been identified. This study examines if SEMA 7A can have a direct effect on vascular endothelial cells or whether it indirectly induces angiogenesis through stimulation and recruitment of macrophages as has been suggested. Using a human umbilical vein endothelial cells (HUVECs), the ability of SEMA 7A to affect proliferation and migration was examined. HUVECs were exposed to SEMA 7A directly or to conditioned media collected from macrophages exposed to …

Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori L. Haigo, Tatiana Sandoval-Guzmán, Kristyna Hradlikova, Annett Duemmler, Ryan R. Kerney, Elly M. Tanaka

Biology Faculty Publications

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum(axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly …