A Bacterial Symbiont Is Converted From An Inedible Producer Of Beneficial Molecules Into Food By A Single Mutation In The Gaca Gene,
2013
Harvard University
A Bacterial Symbiont Is Converted From An Inedible Producer Of Beneficial Molecules Into Food By A Single Mutation In The Gaca Gene, Pierre Stallforth, Debra A. Brock, Alexandra M. Cantley, Xiangjun Tian, David C. Queller, Joan E. Strassmann, Jon Clardy
Biology Faculty Research
Stable multipartite mutualistic associations require that all partners benefit. We show that a single mutational step is sufficient to turn a symbiotic bacterium from an inedible but host-beneficial secondary metabolite producer into a host food source. The bacteria's host is a "farmer" clone of the social amoeba Dictyostelium discoideum that carries and disperses bacteria during its spore stage. Associated with the farmer are two strains of Pseudomonas fluorescens, only one of which serves as a food source. The other strain produces diffusible small molecules: pyrrolnitrin, a known antifungal agent, and a chromene that potently enhances the farmer's spore production and …
Genetic Diversity Of Plasmodium Vivax Clinical Isolates From Southern Pakistan Using Pvcsp And Pvmsp1 Genetic Markers,
2013
Aga Khan University
Genetic Diversity Of Plasmodium Vivax Clinical Isolates From Southern Pakistan Using Pvcsp And Pvmsp1 Genetic Markers, Afsheen Raza, Najia K. Ghanchi, Ali M. Thaver, Sana Jafri, Mohammad A. Beg
Department of Pathology and Laboratory Medicine
Background:
Plasmodium vivax is the prevalent malarial species accounting for 70% of malaria burden in Pakistan; however, there is no baseline data on the circulating genotypes. Studies have shown that polymorphic loci of gene encoding antigens pvcsp and pvmsp1 can be used reliably for conducting molecular epidemiological studies. Therefore, this study aimed to bridge the existing knowledge gap on population structure on P. vivax from Pakistan using these two polymorphic genes.
Methods:
During the period January 2008 to May 2009, a total of 250 blood samples were collected from patients tested slide positive for P. vivax, at the Aga Khan …
Presenting Fake Figures: A Tool To Teach Effective Scientific Figure Design,
2013
University of Miami
Presenting Fake Figures: A Tool To Teach Effective Scientific Figure Design, Verónica A. Segarra, Stephanie Pulford, Susan Walsh
Faculty Publications
No abstract provided.
Bacterial Assemblages And Microbial Enzyme Activity In The Major Tributaries Of The Lower Mississippi River,
2013
University of Mississippi
Bacterial Assemblages And Microbial Enzyme Activity In The Major Tributaries Of The Lower Mississippi River, Justin Millar
Electronic Theses and Dissertations
Spatial variation in the structure and function of bacterial communities is far more complex than previously believed. High throughput sequencing techniques have begun to elucidate the dynamic worldwide patterns of bacterial biogeography; however, there are still many ecosystems for which there is little to no representative data. Currently there are no high throughput-based analyses of bacterial assemblages in large rivers. Rivers form important connections between terrestrial land use and marine biogeochemistry and act as conduits for organisms and allochthonous nutrients. Bacteria dominate carbon cycling and nutrient processing in rivers, and therefore can influence regional and global elemental cycles. This study …
The Characterization Of The Interplay Between Sumoylation And Influenza A Virus,
2013
University of Texas at El Paso
The Characterization Of The Interplay Between Sumoylation And Influenza A Virus, Andres Santos
Open Access Theses & Dissertations
Influenza A virus is a negative sense single stranded RNA virus responsible for multiple devastating pandemics in the past. This virus is capable of entering multiple eukaryotic hosts, sequestering, and using their cellular machinery for its own replicative purposes. This plethora of molecular events is all orchestrated through a shockingly limited repertoire of only 11 viral proteins. All of which are all strictly dependent on cellular processes such as post-transcriptional regulation, protein translation, post-translational modifications, etc. This study is focused on the characterization of the interplay between Influenza A virus and the cellular SUMOylation system. The first part of this …
Metagenome Sequence Analysis Of Filamentous Microbial Communities Obtained From Geochemically Distinct Geothermal Channels Reveals Specialization Of Three Aquificales Lineages,
2013
University of New Mexico
Metagenome Sequence Analysis Of Filamentous Microbial Communities Obtained From Geochemically Distinct Geothermal Channels Reveals Specialization Of Three Aquificales Lineages, Cristina Takacs-Vesbach, William P. Inskeep, Zackary J. Jay, Markus J. Herrgard, Douglas B. Rusch, Susannah G. Tringe, Mark A. Kozubal, Natsuko Hamamura, Richard E. Macur, Bruce W. Fouke, Anna-Louise Reysenbach, Timothy R. Mcdermott, Ryan Dem. Jennings, Nicolas W. Hengartner, Gary Xie
Biology Faculty Publications and Presentations
The Aquificales are thermophilic microorganisms that inhabit hydrothermal systems world- wide and are considered one of the earliest lineages of the domain Bacteria. We analyzed metagenome sequence obtained from six thermal “filamentous streamer” communities (∼40 Mbp per site), which targeted three different groups of Aquificales found in Yellow- stone National Park (YNP). Unassembled metagenome sequence and PCR-amplified 16S rRNA gene libraries revealed that acidic, sulfidic sites were dominated by Hydrogenobac- ulum (Aquificaceae) populations, whereas the circum-neutral pH (6.5–7.8) sites containing dissolved sulfide were dominated by Sulfurihydrogenibium spp. (Hydrogenothermaceae). Thermocrinis (Aquificaceae) populations were found primarily in the circum-neutral sites with undetectable …
Exploitation Of The Bacteriophage-Derived Peptidase Chapk,
2013
Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland.
Exploitation Of The Bacteriophage-Derived Peptidase Chapk, Pierre-Mehdi Hadbi
Theses
This project investigated an anti-staphylococcal bacteriophage-derived peptidoglycan hydrolase enzyme, namely a cysteine-histidine amydohydrolase/peptidase (CHAPk). The study focused firstly on optimizing the production of recombinant CHAPk, which was previously cloned in an E. coli expression system, and sets out the resulting optimal Standard Operating Procedures (SOPs) for production, purification and determination of concentration and activity of the resulting protein stock. A typical yield resulting from the investigation was 300pg of CHAPk from one litre of E.coli culture. The activity of the purified enzyme was typically in the region of 190U nmol ’. Secondly, the project investigated …
Hypoxia Inducible Factor 1 Alpha (Hif-1a): A Major Regulator Of Placental Development,
2013
Wright State University - Main Campus
Hypoxia Inducible Factor 1 Alpha (Hif-1a): A Major Regulator Of Placental Development, Renee E. Albers
Browse all Theses and Dissertations
Hypoxia-inducible factor-1 alpha (HIF-1a) is a critical component of the cellular oxygen-sensing machinery and is essential for placental formation and embryonic survival. In this study, we promoted prolonged expression of HIF-1a, by using a form that is insensitive to oxygen, denoted as CA-HIF-1a. In order to have continual placental specific expression of the CA-HIF-1a, lentiviral infection was performed on embryos at the blastocyst stage of development and transferred into pseudo-pregnant mothers. Placental analysis was performed via in situ hybridization on embryonic day 14.5 (E14.5) to determine the effects of CA-HIF-1a prolonged expression. Data indicate that prolonged activity of CA-HIF-1a restricted …
Antilisterial Characteristics Of Volatile Essential Oils,
2013
University of Kentucky
Antilisterial Characteristics Of Volatile Essential Oils, Leeann L. Slaughter
Theses and Dissertations--Animal and Food Sciences
This study explored the in vitro and in situ antilisterial inhibitory activity of 16 essential oils during indirect exposure: Spanish Basil oil (Ocimum basilicum), Bay oil (Pimenta racemosa), Italian Bergamot oil (Citrus bergamia), Roman Chamomile oil (Anthemis nobilis), Sir Lanka Cinnamon oil (Cinnamomum zeylanicum), Citral, Clove Bud oil (Syzygium aromaticum), Cumin Seed oil (cuminum cyminum), Eucalyptus oil (Eucalyptus globulus), Eugenol, Geranium extract (Pelargonium graveolens), Marjoram oil (Origanum majorana), Neroli extract (Citrus aurantium), Peppermint oil (Mentha piperita L.), …
The Relative Contribution Of Methanotrophs To Microbial Communities And Carbon Cycling In Soil Overlying A Coal-Bed Methane Seep,
2013
Old Dominion University
The Relative Contribution Of Methanotrophs To Microbial Communities And Carbon Cycling In Soil Overlying A Coal-Bed Methane Seep, Christopher T. Mills, Gregpry F. Slater, Robert F. Dias, Stephanie A. Carr, Christopher M. Reddy, Raleigh Schmidt, Kevin W. Mandernack
Chemistry & Biochemistry Faculty Publications
Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. 14C-dead) carbon to soil microbial communities. Natural abundance 13C and 14C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison …
The Use Of Metagenomic Approaches To Analyze Changes In Microbial Communities,
2013
Old Dominion University
The Use Of Metagenomic Approaches To Analyze Changes In Microbial Communities, Girish Neelakanta, Hameeda Sultana
Biological Sciences Faculty Publications
Microbes are the most abundant biological entities found in the biosphere. Identification and measurement of microorganisms (including viruses, bacteria, archaea, fungi, and protists) in the biosphere cannot be readily achieved due to limitations in culturing methods. A non-culture based approach, called “metagenomics”, was developed that enabled researchers to comprehensively analyse microbial communities in different ecosystems. In this study, we highlight recent advances in the field of metagenomics for analyzing microbial communities in different ecosystems ranging from oceans to the human microbiome. Developments in several bioinformatics approaches are also discussed in context of microbial metagenomics that include taxonomic systems, sequence databases, …
Thalassiosira Spp. Community Composition Shifts In Response To Chemical And Physical Forcing In The Northeast Pacific Ocean,
2013
Old Dominion University
Thalassiosira Spp. Community Composition Shifts In Response To Chemical And Physical Forcing In The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Traci L. Haddock, Susanne Menden-Deuer, Eric G. Roy, Mark L. Wells, Bethany D. Jenkins
Biological Sciences Faculty Publications
Diatoms are genetically diverse unicellular photosynthetic eukaryotes that are key primary producers in the ocean. Many of the over 100 extant diatom species in the cosmopolitan genus Thalassiosira are difficult to distinguish in mixed populations using light microscopy. Here, we examine shifts in Thalassiosira spp. composition along a coastal to open ocean transect that encountered a 3-month-old Haida eddy in the northeast Pacific Ocean. To quantify shifts in Thalassiosira species composition, we developed a targeted automated ribosomal intergenic spacer analysis (ARISA) method to identify Thalassiosira spp. in environmental samples. As many specific fragment lengths are indicative of individual Thalassiosira spp., …
Expression And Characterization Of The Major Capsid Protein (Mcp) Of A Giant Marine Virus: Cafeteria Roenbergensis Virus,
2013
University of Texas at El Paso
Expression And Characterization Of The Major Capsid Protein (Mcp) Of A Giant Marine Virus: Cafeteria Roenbergensis Virus, Sayan Chakraborty
Open Access Theses & Dissertations
The oceans play significant roles in maintaining the climate on Earth and providing nutrients to the whole biosphere. Oceanic microbes produce approximately half of the Earth's oxygen. It has been shown that the populations of microbial communities in oceans are largely regulated by viral infection and thus affect the marine ecosystem. Cafeteria roenbergensis Virus (CroV) is a giant marine virus with a linear, double stranded, and AT-rich DNA genome. The genome of CroV has a size of 744kb and encodes for 544 predicted genes. CroV derived its name from its host, a unicellular marine zooplankton Cafeteria roenbergensis (Cro) that is …
Sumoylation Exerts Minimal Effects On The Splicing Regulatory Activity Of The Influenza A Virus Non-Structural Protein Ns1,
2013
University of Texas at El Paso
Sumoylation Exerts Minimal Effects On The Splicing Regulatory Activity Of The Influenza A Virus Non-Structural Protein Ns1, Griselda Melendez
Open Access Theses & Dissertations
One of the greatest challenges facing the development of a universal treatment for influenza infection is the virus's ability to mutate rapidly and produce new antigenic properties. Targeting the viral components of one strain does not ensure that the treatment will be effective with a newly developed strain. One alternative would be to develop therapies that target cellular factors the virus depends on for survivability. One of these factors is the cellular SUMOylation system. We have previously demonstrated that the Small Ubiquitin-like MOdifier (SUMO) interacts with the influenza virus by SUMOylating several viral proteins and by affecting the interferon blocking …
Role Of Post-Translational Modifications In The Hiv Cofactor Activity Of Ledgf/P75,
2013
University of Texas at El Paso
Role Of Post-Translational Modifications In The Hiv Cofactor Activity Of Ledgf/P75, Denisse Adriana Gutierrez
Open Access Theses & Dissertations
see document.
Validation Of N-Myristoyltransferase As Potential Chemotherapeutic Target In Chagas Disease,
2013
University of Texas at El Paso
Validation Of N-Myristoyltransferase As Potential Chemotherapeutic Target In Chagas Disease, Linda Herrera
Open Access Theses & Dissertations
The protozoan parasite Trypanosoma cruzi is the etiological agent of Chagas disease, a problem endemic to Central and South America. In recent years, this neglected infectious disease has become a global health concern. The only clinically available drugs for the chemotherapy of Chagas disease have important disadvantages such as, high toxicity, strain resistance and variable efficacy. Therefore, there is an urgent need for the development of new antichagasic agents. The enzyme N-myristoyltransferase (NMT) has been characterized in a range of eukaryotes, from Saccharomyces cerevisae to Homo sapiens. Moreover, NMT has been shown to be essential in protozoan parasites, including Leishmania …
The Threat Of Domestic Bioterrorism: Fact Or Fiction,
2013
University of Texas at El Paso
The Threat Of Domestic Bioterrorism: Fact Or Fiction, Stacy M. Langston
Open Access Theses & Dissertations
The threat of a domestic bioterrorist attack can be a daunting issue to cover. Using the analytic technique What If? Analysis a scenario was created for a domestic bioterrorism attack in Houston, TX. Indicators were developed to determine how to mitigate and respond to the attack. Recommendations were provided following the attack that can be used to prevent future attacks that were conducted in the scenario. Having a hindsight view of an attack is the best way to prevent and respond to the attack.
Managing Soil Microbial Communities With Organic Amendments To Promote Soil Aggregate Formation And Plant Health,
2013
University of Kentucky
Managing Soil Microbial Communities With Organic Amendments To Promote Soil Aggregate Formation And Plant Health, Shawn T. Lucas
Theses and Dissertations--Plant and Soil Sciences
The effects of managing soil with organic amendments were examined with respect to soil microbial community dynamics, macroaggregate formation, and plant physio-genetic responses. The objective was to examine the possibility of managing soil microbial communities via soil management, such that the microbial community would provide agronomic benefits. In part one of this research, effects of three amendments (hairy vetch residue, manure, compost) on soil chemical and microbial properties were examined relative to formation of large macroaggregates in three different soils. Vetch and manure promoted fungal proliferation (measured via two biomarkers: fatty acid methyl ester 18:2ω6c and ergosterol) and also stimulated …
Type I Interferon Activation Of Natural Killer (Nk) Cells By Cytomegalovirus (Cmv) And Their Interaction With Dendritic (Dc) And Nkt Cells,
2013
Wright State University
Type I Interferon Activation Of Natural Killer (Nk) Cells By Cytomegalovirus (Cmv) And Their Interaction With Dendritic (Dc) And Nkt Cells, Howaida A. Oulad Abdelati
Browse all Theses and Dissertations
In our current study the roles of natural killer (NK) cells in regulation of the acute phase of murine cytomegalovirus (MCMV) infection were demonstrated. NK cells utilize perforin and gamma interferon to kill MCMV infected cells. Activation of NK cells is controlled by the balance between inhibitory and activation receptors and modulated by cytokines produced from the infected cells. Type I interferons are produced mainly by plasmacytoid dendritic cells (PDCs). Type I interferons have a substantial role in enhancing NK cells cytotoxic activity and NK cells proliferation and maintain cell survival through STAT mediated signaling pathway. IL-12 produced by dendritic …
Characterization Of Brer Interaction With The Bile Response Promoters Breab And Brer In Vibrio Cholerae,
2013
Dartmouth College
Characterization Of Brer Interaction With The Bile Response Promoters Breab And Brer In Vibrio Cholerae, Francisca A. Cerda-Maira, Gabriela Kovacikova, Brooke A. Jude, Karen Skorupski, Ronald Taylor
Dartmouth Scholarship
The Vibrio cholerae BreR protein is a transcriptional repressor of the breAB efflux system operon, which encodes proteins involved in bile resistance. In a previous study (F. A. Cerda-Maira, C. S. Ringelberg, and R. K. Taylor, J. Bacteriol. 190:7441-7452, 2008), we used gel mobility shift assays to determine that BreR binds at two independent binding sites at the breAB promoter and a single site at its own promoter. Here it is shown, by DNase I footprinting and site-directed mutagenesis, that BreR is able to bind at a distal and a proximal site in the breAB promoter. However, only one of …
