Microbiology Commons^™

Hiv Suppresses Cervical Neutrophil Infiltration In Women With Normal Or Abnormal Pap Smears, Mika Caplan, Peter C. Angeletti, Duan Loy, Kandali Samwel, Daniela Gonzalez, Crispin Chisanga, Julius Mwaiselage, Asafu Munema, Brenda Bashekera, Kessy Goodwin, John Dustin Loy, John T. West, Charles Wood

UCARE: Research Products

Human immunodeficiency virus (HIV) infection of CD4+ T cells results in a weakened immune system due to decreased white blood cells, particularly multi-lobed neutrophils (neutropenia) and other granulocytes.¹ The purpose of this study was to determine whether a correlation exists between HPV/HIV status and presence of neutrophils. To test this, we used a computer software program (QuPath) to analyze neutrophil infiltration seen in pap smears of both HIV+ and HIV- patients from samples collected in Tanzania from three different sites: Bagamoyo, Chalinze, and Dar es Salaam. The software was used to quantify neutrophils per image based on the size …

In Vitro Assay Development As An Alternative To The Use Of Laboratory Animals For Measuring Clostridium Perfingens Type C Toxoid, Lauren M. Wilmes

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Clostridium perfringens type C produces beta toxin, which is a primary virulence determinate that can cause necrotic enteritis in neonatal animals. Vaccines directed against C. perfringens toxins have shown to be efficacious in preventing disease. However, the production of a commercial vaccine requires not only an efficacious antigen, but also testing methods for quantifying antigens and potency on final product. This research was undertaken to fulfill a need for the reduction in small animal usage to produce and deliver vaccines. The current testing methods are performed in vivo according to the Code of Federal Regulations number 9 (9CFR) United …

Rapid Identification And Typing Of Mycobacterium Avium Complex Using Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (Maldi-Tof) Library And Biomarker Based Approaches, Claudia Antonika, John Dustin Loy, Raul Barletta, Michael Collins

UCARE: Research Products

Bacteria associated with the Mycobacterium avium complex (MAC) cause significant problems in animal agriculture and cause large economic losses and morbidity of livestock. Two clinically important subspecies of M. avium are M.avium ssp paratuberculosis (MAP) and M. avium ssp hominissuis (MAH). MAP is the etiologic agent of Johne’s disease, a chronic and fatal enteritis in ruminants, that has been linked to Crohn’s disease in humans.1 MAH has zoonotic potential as it is one of the leading causes of secondary infections in AIDS patients. Identification of M. avium in clinical samples is challenging as they have overlapping host ranges and clinical …

Education Institutions Creation Of Partnerships, Iwasan D. Kejawa Ed.D

Department of Educational Administration: Faculty Publications

This issue is embracing the creation of partnerships with establishments worldwide for the provisions of life embodiments to graduates. At moment, there may be lack of friendship or partnership with establishments to create incentives for newly graduates of so many colleges and universities (Hirsh & Weber, 1999). Partnership with external companies will surely bring enormous grants to the colleges and universities and it will also encourage friendly establishments to provide incentives and perks to colleges, universities and alumni. It may be concluded that the advantages of creating rapport with external congruences is the comraderies and also compromises that will be …

Factors Affecting The Parasitism Of Gregarine Species In Grasshoppers In Western Nebraska, Alexandra Creigh, Kristin Mclarty, Scott Lyell Gardner

Honors Program: Senior Projects (Public)

We conducted a survey of the species of parasites found in grasshoppers around the area of Dunwoody’s Pond to investigate whether there were any species specific parasitic relationships occurring there. We collected grasshoppers from several areas around Dunwoody’s Pond totaling 15 species including Melanoplus bivittatus (Say 1825) , Melanoplus sanguinipes (Fabricius, 1798) , Melanoplus differentialis (Thomas 1865), and Melanoplus femurrubrum (De Geer 1773), along with others (Seymour et al., 2009) and compared the parasites found in them. This study is similar to one conducted in South America by Lloyd in 1951, and we hoped to find connections between species to …

Breeding For Resistance In California Strawberry To Verticillium Dahliae, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This article focuses on breeding resistant strawberries to the fungus Verticillium dahliae, common name Verticillium wilt. This is a serious fungal disease that can result in a loss of 50% or more of a strawberry harvest when grown in infested soil. The main goal is to provide an example of how a cultivar can be made more resistant to a plant pathogen with the use of plant breeding methods.

Since 1930 the University of California, Davis, has been developing strawberry cultivars that are adapted to the agricultural industry and regional farms. Developing cultivars that require fewer inputs are of …

Altered Ratio Of T Follicular Helper Cells To T Follicular Regulatory Cells Correlates With Autoreactive Antibody Response In Simian Immunodeficiency Virus–Infected Rhesus Macaques, Wenjin Fan, Andrew James Demers, Yanmin Wan, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

Individuals with chronic HIV-1 infection have an increased prevalence of autoreactive Abs. Many of the isolated HIV broadly neutralizing Abs from these individuals are also autoreactive. However, the underlying mechanism(s) that produce these autoreactive broadly neutralizing Abs remains largely unknown. The highly regulated coordination among B cells, T follicular helper (T_FH) cells, and T follicular regulatory (T_FR) cells in germinal centers (GCs) of peripheral lymphatic tissues (LTs) is essential for defense against pathogens while also restricting autoreactive responses. We hypothesized that an altered ratio of T_FH/T_FR cells in the GC contributes to the …

Mucosal Antibody Responses To Vaccines Targeting Siv Protease Cleavage Sites Or Fulllength Gag And Env Proteins In Mauritian Cynomolgus Macaques, Hongzhao Li, Yan Hai, So-Yon Lim, Nikki Toledo, Jose Crecente-Campo, Dane Schalk, Lin Li, Robert W. Omange, Tamara G. Dacoba, Lewis R. Liu, Mohammad Abul Kashem, Yanmin Wan, Binhua Liang, Qingsheng Li, Eva Rakasz, Nancy Schultz-Darken, Maria J. Alonso, Francis A. Plummer, James B. Whitney, Ma Luo

Nebraska Center for Virology: Faculty Publications

HIV mutates rapidly and infects CD4⁺ T cells, especially when they are activated. A vaccine targeting conserved, essential viral elements while limiting CD4⁺ T cell activation could be effective. Learning from natural immunity observed in a group of highly HIV-1 exposed seronegative Kenyan female sex workers, we are testing a novel candidate HIV vaccine targeting the 12 viral protease cleavage sites (PCSs) (the PCS vaccine), in comparison with a vaccine targeting full-length Gag and Env (the Gag/Env vaccine) in a Mauritian cynomolgus macaque/SIV model. In this study we evaluated these vaccines for induction of mucosal antibodies to SIV …

Sivcpz Closely Related To The Ancestral Hiv-1 Is Less Or Non-Pathogenic To Humans In A Hu-Blt Mouse Model, Zhe Yuan, Guobin Kang, Lance Daharsh, Wenjin Fan, Qingsheng Li

Nebraska Center for Virology: Faculty Publications

The HIV-1 pandemic is a consequence of the cross-species transmission of simian immunodeficiency virus in wild chimpanzees (SIVcpz) to humans. Our previous study demonstrated SIVcpz strains that are closely related to the ancestral viruses of HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505) and two SIVcpz lineages that are not associated with any known HIV-1 infections in humans (SIVcpzMT145 and SIVcpzBF1167), all can readily infect and robustly replicate in the humanized-BLT mouse model of humans. However, the comparative pathogenicity of different SIVcpz strains remains unknown. Herein, we compared the pathogenicity of the above four SIVcpz strains with HIV-1 using humanized-BLT mice. …

Identification Of Unequally Represented Founder Viruses Among Tissues In Very Early Siv Rectal Transmission, Jian Chen, Yanqin Ren, Lance Daharsh, Lu Liu, Guobin Kang, Qingsheng Li, Qiang Wei, Yanmin Wu, Jianqing Xu

Nebraska Center for Virology: Faculty Publications

Characterizing the transmitted/founder (T/F) viruses of multi-variant SIV infection may shed new light on the understanding of mucosal transmission.We intrarectally inoculated six Chinese rhesus macaques with a single high dose of SIVmac251 (3.1 × 10⁴ TCID₅₀) and obtained 985 full-length env sequences from multiple tissues at 6 and 10 days post-infection by single genome amplification (SGA). All 6 monkeys were infected with a range of 2 to 8 T/F viruses and the dominant variants from the inoculum were still dominant in different tissues from each monkey. Interestingly, our data showed that a cluster of rare T/F viruses …

Analytical Performance Of A Low‐Cost Multiplex Polymerase Chain Reaction Human Papillomavirus Genotyping Assay For Use In Sub‐Saharan Africa, Kandali Samwel, Crispin Kahesa, Julius Mwaiselage, Daniela Gonzalez, John T. West, Charles Wood, Joel Palefsky, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

We have tested a multiplex polymerase chain reaction (PCR) human papillomavirus (HPV) genotyping assay to fill the need for rapid and low‐cost HPV detection in Sub‐ Saharan Africa. This method allows high throughput genotyping and simultaneous detection of 14 high‐risk and two low‐risk HPV types, by PCR amplification of HPV DNAs in a single reaction tube. In this study, we describe stepwise experiments to validate the multiplex HPV PCR assay for determination of HPV genotypes from 104 cervical brush samples from Tanzanian women. Assay performance was evaluated by determination of intra‐laboratory reproducibility, sensitivity, and specificity. Further performance was assessed by …

Discovery Of A Non-Nucleoside Rna Polymerase Inhibitor For Blocking Zika Virus Replication Through In Silico Screening, Aryamav Pattnaik, Nicholas Palermo, Bikash R. Sahoo, Zhe Yuan, Duoyi Hu, Arun S. Annamalai, Hiep L. X. Vu, Ignacio Correas, Pavan Kumar Prathipati, Christopher J. Destache, Qingsheng Li, Fernando A. Osorio, Asit K. Pattnaik, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

Zika virus (ZIKV), an emerging arbovirus, has become a major human health concern globally due to its association with congenital abnormalities and neurological diseases. Licensed vaccines or antivirals against ZIKV are currently unavailable. Here, by employing a structure-based approach targeting the ZIKV RNA-dependent RNA polymerase (RdRp), we conducted in silico screening of a library of 100,000 small molecules and tested the top ten lead compounds for their ability to inhibit the virus replication in cell-based in vitro assays. One compound, 3-chloro-N-[({4-[4-(2-thienylcarbonyl)-1-piperazinyl]phenyl}amino)carbonothioyl]-1-benzothiophene-2-carboxamide (TPB), potently inhibited ZIKV replication at submicromolar concentrations. Molecular docking analysis suggests that …

Non-Naturally Occurring Porcine Reproductive And Respiratory Syndrome Virus (Prrsv) And Methods Of Using, Hiep Lai Xuan Vu, Fernando Osorio, William W. Laegreid, Asit K. Pattnaik, Fangrui Ma

Nebraska Center for Virology: Faculty Publications

A non-naturally occurring porcine reproductive and respiratory syndrome virus (PRRSV) is provided herein, and methods of making and using the non-naturally occurring PRRSV also are provided.

Metatranscriptome Of Human Faecal Microbial Communities In A Cohort Of Adult Men, Galeb S. Abu-Ali, Raaj S. Mehta, Jason Lloyd-Price, Himel Mallick, Tobyn Branck, Kerry L. Ivey, David A. Drew, Casey Dulong, Eric Rimm, Jacques Izard, Andrew T. Chan, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

The gut microbiome is intimately related to human health, but it is not yet known which functional activities are driven by specific microorganisms' ecological configurations or transcription. We report a large-scale investigation of 372 human fecal metatranscriptomes and 929 metagenomes from a subset of 308 men in the Health Professionals Follow-Up Study. We identified a metatranscriptomic 'core' universally transcribed over time and across participants, often by different microorganisms. In contrast to the housekeeping functions enriched in this core, a 'variable' metatranscriptome included specialized pathways that were differentially expressed both across participants and among microorganisms. Finally, longitudinal metagenomic profiles allowed ecological …

Brain Is A Potential Sanctuary For Subtype C Hiv-1 Irrespective Of Art Treatment Outcome, For Yue Tso, Guobin Kang, Eun Hee Kwon, Peter Julius, Qingsheng Li, John T. West, Charles Wood

Nebraska Center for Virology: Faculty Publications

Subtype C HIV-1 is responsible for the largest proportion of people living with HIV-1 infection. However, there is limited information about the roles of the brain and its cell types as a potential sanctuary for this subtype and how the sanctuary may be affected by the administration of anti-retroviral therapy (ART). To address this issue, we collected postmortem brain tissues from ART treated HIV-1 infected Zambian individuals who experienced complete viral suppression and those who did not. Tissues from various brain compartments were collected from each individual as frozen and formalin-fixed paraffin embedded brain specimens, for detection and quantification of …

Brain Is A Potential Sanctuary For Subtype C Hiv-1 Irrespective Of Art Treatment Outcome, For Yue Tso, Guobin Kang, Peter Julius, Qingsheng Li, John T. West, Charles Wood

Nebraska Center for Virology: Faculty Publications

Subtype C HIV-1 is responsible for the largest proportion of people living with HIV-1 infection. However, there is limited information about the roles of the brain and its cell types as a potential sanctuary for this subtype and how the sanctuary may be affected by the administration of anti-retroviral therapy (ART). To address this issue, we collected postmortem brain tissues from ART treated HIV-1 infected Zambian individuals who experienced complete viral suppression and those who did not. Tissues from various brain compartments were collected from each individual as frozen and formalin-fixed paraffin embedded brain specimens, for detection and quantification of …

Contribution Of The Gp120 V3 Loop To Envelope Glycoprotein Trimer Stability In Primate Immunodeficiency Viruses, Dane Bowder, Haley Hollingsead, Kate Durst, Duoyi Hu, Wenzhong Wei, Joshua Wiggins, Halima Medjahed, Andrés Finzi, Joseph Sodroski, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

The V3 loop of the human immunodeficiency virus type 1 (HIV-1) gp120 exterior envelope glycoprotein (Env) becomes exposed after CD4 binding and contacts the coreceptor to mediate viral entry. Prior to CD4 engagement, a hydrophobic patch located at the tip of the V3 loop stabilizes the non-covalent association of gp120 with the Env trimer of HIV-1 subtype B strains. Here, we show that this conserved hydrophobic patch (amino acid residues 307, 309 and 317) contributes to gp120-trimer association in HIV-1 subtype C, HIV-2 and SIV. Changes that reduced the hydrophobicity of these V3 residues resulted in increased gp120 shedding and …

Ultrastructure Of Meelsvirus: A Nuclear Virus Of Arrow Worms (Phylum Chaetognatha) Producing Giant "Tailed" Virions, George L. Shinn, Brianna L. Bullard

Nebraska Center for Virology: Faculty Publications

Most known giant viruses, i.e., viruses producing giant virions, parasitize amoebae and other unicellular eukaryotes. Although they vary in the level of dependence on host nuclear functions, their virions self-assemble in the host cell's cytoplasm. Here we report the discovery of a new prototype of giant virus infecting epidermal cells of the marine arrow worm Adhesisagitta hispida. Its 1.25 μm-long virions self-assemble and accumulate in the host cell's nucleus. Conventional transmission electron microscopy reveals that the virions have a unique bipartite structure. An ovoid nucleocapsid, situated in a broad "head" end of the virion is surrounded by a thin …

Synthesis, Secretion, And Perception Of Abscisic Acid Regulates Stress Responses In Chlorella Sorokiniana, Maya Khasin, Rebecca E. Cahoon, Sophie Alvarez, Richard Beckeris, Seong-Il Eyun, Qidong Jia, Jean-Jack Riethoven, Kenneth Nickerson, Wayne R. Riekhof

Kenneth Nickerson Papers

Abscisic acid (ABA) is a phytohormone that has been extensively characterized in higher plants for its roles in seed and bud dormancy, leaf abscission, and stress responses. Genomic studies have identified orthologs for ABA-related genes throughout the Viridiplantae, including in unicellular algae; however, the role of ABA in algal physiology has not been characterized, and the existence of such a role has been a matter of dispute. In this study, we demonstrate that ABA is involved in regulating algal stress responses. Chlorella sorokiniana strain UTEX 1230 contains genes orthologous to those of higher plants which are essential for ABA …

Development Of A Broadly Protective Modified-Live Virus Vaccine Candidate Against Porcine Reproductive And Respiratory Syndrome Virus, Haiyan Sun, Aspen Workman, Fernando A. Osorio, David J. Steffen, Hiep L.X. Vu

Nebraska Center for Virology: Faculty Publications

Modified-live virus (MLV) vaccines are widely used to protect pigs against porcine reproductive and respiratory syndrome virus (PRRSV). However, current MLV vaccines do not confer adequate levels of heterologous protection, presumably due to the substantial genetic diversity of PRRSV isolates circulating in the field. To overcome this genetic variation challenge, we recently generated a synthetic PRRSV strain containing a consensus genomic sequence of PRRSV-2. We demonstrated that our synthetic PRRSV strain confers unprecedented levels of heterologous protection. However, the synthetic PRRSV strain at passage 1 (hereafter designated CON-P1) is highly virulent and therefore, is not suitable to be used as …

Efficacy Of An Adenoviral Vectored Multivalent Centralized Influenza Vaccine, Amy Lingel, Brianna L. Bullard, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Mice were immunized with Adenovirus expressing the H1-con, H2-con, H3-con and H5-con HA consensus genes in combination (multivalent) and compared to mice immunized with the traditional 2010–2011 FluZone and FluMist seasonal vaccines. Immunized mice were challenged with 10–100 MLD50 of H1N1, H3N1, H3N2 and H5N1 influenza viruses. The traditional vaccines induced robust levels of HA inhibition (HI) titers, but failed to protect against five different heterologous lethal influenza challenges. Conversely, the multivalent consensus vaccine (1 × 1010 virus particles (vp)/mouse) induced protective HI titers of ≥40 against 8 of 10 influenza viruses that represent a wide degree of divergence within …

Prevalence Of Kaposi’S Sarcoma-Associated Herpesvirus In Uygur And Han Populations From The Urumqi And Kashgar Regions Of Xinjiang, China, Jun Zheng, Yang Yang, Meng Cui, Zhan-Jun Shu, Li-Li Han, Zhen-Qiu Liu, Charles Wood, Tiejun Zhang, Yan Zeng

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious etiologic agent associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease. It has been shown that high KSHV prevalence and high incidence of both classic KS and AIDSassociated KS are found mostly among people of Uygur ethnicity in Xinjiang, while people of Han ethnicity in Xinjiang have a higher KSHV seroprevalence than those of other Han populations in mainland China. However, it is still unclear why there is such geographical and population variation in KSHV distribution in China. In this work, we focused on the populations in the Kashgar region …

Cross-Reactive Immunity To Porcine Reproductive And Respiratory Syndrome Virus And Its Contribution To Protection, Ignacio Correas

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Due to the vast geographical distribution and significant economic losses generated, porcine reproductive and respiratory syndrome virus (PRRSV) can be considered the most important swine pathogen of contemporary times. Current control and eradication strategies against PRRSV have difficulty succeeding because of their complex nature and the absence of an effective vaccine. A major obstacle for PRRSV vaccine development is the broad heterogeneity of the virus, both at the genetic and antigenic level, its rapid evolution, and an incomplete knowledge of the immune responses responsible for clearing the virus from the host. Specifically, how known correlates of protection against PRRSV—neutralizing antibodies …

Relative Contribution Of Porcine Reproductive And Respiratory Syndrome Virus Open Reading Frames 2–4 To The Induction Of Protective Immunity, Katherine Kimpston-Burkgren, Ignacio Correas, Fernando A. Osorio, David Steffen, Asit K. Pattnaik, Ying Fang, Hiep L. X. Vu

Nebraska Center for Virology: Faculty Publications

The minor glycoproteins (GPs) of PRRSV, GP2, GP3, and GP4, form a heterotrimer that is required for viral infectivity, presumably due to its interaction with the key cellular receptor CD163. These 3 GPs are encoded by open reading frames (ORFs) 2a, 3, and 4 (herein referred to as ORFs 2–4), respectively. The goal of this study was to investigate the immunogenicity of the PRRSV-2 minor GPs. Through the use of reverse genetics, a chimeric virus (designated SDFL24) was constructed by replacing ORFs 2–4 of the PRRSV-1 strain SD01-08 with the corresponding genes of the PRRSV-2 strain FL12. While the parental …

Examination Of Contribution Of Pentose Catabolism To Molecular Hydrogen Formation By Targeted Disruption Of Arabinose Isomerase (Araa) In The Hyperthermophilic Bacterium, Thermotoga Maritima, Derrick White

School of Biological Sciences: Dissertations, Theses, and Student Research

Thermotoga maritima ferments a broad range of sugars to form acetate, carbon dioxide, traces of lactate and near theoretic yields of molecular hydrogen (H₂). In this organism, the catabolism of pentose sugars such as arabinose depends on the interaction between the pentose phosphate, Embden Myerhoff and Entner Doudoroff pathways. While values for H₂ yield have been determined using pentose supplemented complex media (CM) and predicted by metabolic pathway reconstruction, quantitative in vivo measurements derived from pathway elimination have not been reported reflecting the lack of a genetic method for the creation of targeted mutations. Here, a spontaneous …

How Science Makes America Great, Kenneth Nickerson

Kenneth Nickerson Papers

The proposed Federal Budget cuts funding for NIH, NSF, and CDC by 16% each and for the EPA by a whopping 31%. Ouch! The situation seems ironic because of President Trump’s slogan “Make America great again!”, which I agree with wholeheartedly. In addition to being a scientist, I also love history (especially military history) and science is at the top of my list of what has made the United States great. ... Why do we do it? I’m in science because it is rewarding. It is invigorating to discover how nature works. Scientists may act individually and in relative obscurity, …

Seroprevalence Of Antibodies Against Kaposi's Sarcoma-Associated Herpesvirus Among Hiv-Negative People In China, Tiejun Zhang, Zhenqiu Liu, Jun Wang, Veenu Minhas, Charles Wood, Gary M. Clifford, Na He, Silvia Franceschi

Nebraska Center for Virology: Faculty Publications

Background: Little information on the prevalence of Kaposi’s sarcoma associated herpesvirus (KSHV) among HIV-negative individuals is available from Asia.

Methods: In the present study, we report findings from a new survey of KSHV in 983 HIV-negative male migrants from Shanghai and their combination with previous similar surveys of 600 female migrants, 600 female sex-workers (FSW), 1336 sexually transmitted infection (STI) clinic male patients, 439 intravenous drug-users (IVDU), and 226 men having sex with men (MSM) from China. KSHV-specific antibodies against latent and lytic antigens were assessed using Sf9 and BC3 monoclonal immunofluorescence assay. Age-adjusted prevalence ratios (PR) and 95% confidence …

Lysine Residues Of Interferon Regulatory Factor 7 Affect The Replication And Transcription Activatormediated Lytic Replication Of Kaposi’S Sarcomaassociated Herpesvirus/Human Herpesvirus 8, Tianzheng Zhang, Ying Wang, Li Zhang, Bin Liu, Jinhui Xie, Charles Wood, Jinzhong Wang

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) infection goes through latent and lytic phases, which are controlled by the viral replication and transcription activator (RTA). Upon KSHV infection, the host responds by suppressing RTA-activated lytic gene expression through interferon regulatory factor 7 (IRF-7), a key regulator of host innate immune response. Lysine residues are potential sites for post-translational modification of IRF-7, and were suggested to be critical for its activity. In this study, we analysed the 15 lysine residues for their effects on IRF-7 function by site-directed mutagenesis. We found that some mutations affect the ability of IRF-7 to activate interferon (IFN)-a1 and …

Detecting, Cloning, And Screening For Suppressors Of Rna Silencing In Maize Chlorotic Mottle Virus And Sugarcane Mosaic Virus, Nicole E. Bacheller

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Maize lethal necrosis disease (MLND) is one of the most important viral diseases of maize. MLND occurs when Maize chlorotic mottle virus (MCMV) co-infects the same plant with one of several potyviruses, including Sugarcane mosaic virus, Wheat streak mosaic virus or Maize dwarf mosaic virus. Originally prevalent in the Midwest and Peru in the 1970s, the disease was called corn lethal necrosis (CLN) and was controlled through breeding and sanitation. Recently, the disease has re-emerged in East Africa and is rapidly spreading and threatening the food sources of subsistence-farming populations. This re-emergence has raised several questions about the unknown …

Phytohormone Signaling In Chlorella Sorokiniana: Perspectives On The Evolution Of Plant Cell-To-Cell Signaling, Maya Khasin

School of Biological Sciences: Dissertations, Theses, and Student Research

Cell-to-cell communication is a key aspect of microbial physiology and population dynamics, and a cornerstone in understanding the evolution of multicellularity. Quorum sensing in bacteria is a canonical example of microbial cell-to-cell signaling, in which bacteria use small molecule signals in order to monitor their population size and modulate their physiology accordingly. We propose that the evolution of plant hormone signaling arose in unicellular green algae, analogously to quorum sensing in bacteria, and that the complexity of these pathways required the recruitment of increasingly specific enzymes to increasingly sophisticated gene networks throughout the course of phytohormone signaling evolution. Using Chlorella …