Organismal Biological Physiology Commons^™

Identifying Determinants Of Target Specificity In Two Related Bacterial Peptide Toxins, Andrew D. Holmes

Honors Thesis

Toxin-antitoxin (TA) systems were originally identified as two-component systems ensuring the stable inheritance of plasmids in bacterial populations. Recently, they have been identified on bacterial chromosomes where their functions remain mostly undefined. The par locus of E. faecalis plasmid pAD1 (par_pAD1) was the first TA system defined in a Gram-positive bacterium and a homolog encoded on the E. faecalis chromosome (par_EF0409) was later described. Related loci numbering in the hundreds have been identified throughout Gram-positive bacteria based on homology to the toxin of the system, Fst, and similarities in genetic organization and regulation. Despite their similar sequences, over-expression ...

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization ...

Characterizing The Requirements For The Matricellular Protein, Dccn, In Nervous System Function, Elizabeth L. Catudio Garrett

Graduate Student Theses, Dissertations, & Professional Papers

The brain is organized as a complex network of specialized neurons that communicate via a combination of electrical and chemical signals. Our brains function to generate movement, control organ function, or direct complex behaviors; all of which requires the ability to regulate the flow of communication between circuits and networks. Work in this thesis addresses two areas of neuron communication: first, how does the release of more than one neurotransmitter from a single neuron impact behavior, and second, are matricellular proteins (MCPs) key contributors to synaptic transmission and neuron function? The conserved CCN family of MCPs have a unique mosaic ...

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and ...

Screening The Cultivable Cave Microbial Mats For The Production Of Antimicrobial Compounds And Antibiotic Resistance, Jerneja Ambrožič Avguštin, Patricia Petrič, Lejla Pašić

International Journal of Speleology

The current work extends the phenotypic characterization of a bacterial culture collection obtained from white, yellow, grey or pink microbial cave wall colonies that are common in the caves of Slovenian Karst. We have determined antibiotic resistance to 22 natural and synthetic antibiotics in 69 isolates from the microbial mats. Thirty-eight isolates (52%) were resistant to 1-5 antibiotics; another 27 isolates (37%) were resistant to 6-10 antibiotics; and 7 isolates (0.1%) were resistant to 11-17 antibiotics. We screened for production of antimicrobial compounds by growing cave isolates on five different media and overlaying individual cultures with ten Gram-positive and ...

Drivers And Consequences Of Carbon Use Efficiency - And Its Measurement In Soil, Grace Pold

Doctoral Dissertations

Soils serve as massive carbon sinks, but their ability to continue this ecological service is contingent on how the resident soil microbial community will respond to the ongoing climate crisis. One key dimension of the microbial response to warming is its carbon use efficiency (CUE), or the fraction of carbon taken up by an organism which is allocated to growth rather than respiration. However, the scientific community is still in the early stages of understanding the drivers, consequences - and even accurate measurements of - CUE. In this dissertation, I first quantified the variability of CUE and its responsiveness to temperature and ...

Anti-Human Cd9 Antibody Fab Fragment Impairs The Internalization Of Extracellular Vesicles And The Nuclear Transfer Of Their Cargo Proteins., Mark F. Santos, Germana Rappa, Jana Karbanová, Cheryl Vanier, Chikao Morimoto, Denis Corbeil, Aurelio Lorico

College of Osteopathic Medicine (TUN) Publications and Research

The intercellular communication mediated by extracellular vesicles (EVs) has gained international interest during the last decade. Interfering with the mechanisms regulating this cellular process might find application particularly in oncology where cancer cell-derived EVs play a role in tumour microenvironment transformation. Although several mechanisms were ascribed to explain the internalization of EVs, little is our knowledge about the fate of their cargos, which are crucial to mediate their function. We recently demonstrated a new intracellular pathway in which a fraction of endocytosed EV-associated proteins is transported into the nucleoplasm of the host cell via a subpopulation of late endosomes penetrating ...

Ultramicrobacteria Genome Database Project, Abdullah A. Salim, Tien Tran, Andrew Putt, Terry C. Hazen

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Ultramicrobacteria (UMB) are a largely uncultured, globally abundant, and metabolically active group of bacteria. UMB have cell diameters ≤0.3μm, cell volumes ≤0.1 μm3, and small streamlined genomes. Recent findings indicate that UMB aid in bioremediation and nutrient cycling, but future investigations and comprehension of current findings are skewed by highly variable nomenclature and a lack of databases for functional, genomic, geochemical, or spatial data specific to candidate UMB. We aim to develop a user-friendly open-access database of various UMB candidates linked to an open-access online map where researchers can gather genomic, spatial, and geochemical data. Our comprehensive review ...

Determining The Role Of Cdr20291_0493 Sporulation Initiation In Clostridium Difficile, Carolina Bueno

Kansas State University Undergraduate Research Conference

Our lab focuses on the gene regulatory networks of Clostridium difficilesporulation and toxins virulence factors. Spores are the major reason of the disease transmission; this is why it is important to understand how this spores are formed so drugs can be targeted to formation. Our objective is to identify the gene regulatory networks that control sporulation. The candidate target gene we are studying is CDR20291_0493 in C. difficileR20291 strain. We want to understand the role of this gene in sporulation initiation of C.difficile. We first created a mutant of CDR20291_0493 mutant R20291Dto look for sporulation phenotype and ...

Diversity And Shifts Of The Bacterial Community Associated With Baikal Sponge Mass Mortalities, Sergei Belikov, Natalia Belkova, Tatiana Butina, Lubov Chernogor, Alexandra Martynova-Van Kley, Armen Nalian, Colin Rorex, Igor Khanaev, Olga Maikova, Sergey Feranchuk

Faculty Publications

The disease of freshwater sponges was first discovered in 2011, when pink samples were found in the Central Basin of Lake Baikal. Subsequently, the visible signs of the disease have changed, and now sponges appear with various symptoms of damage to the body, such as discoloration, tissue necrosis, the formation of brown patches and dirty-purple biofilms on some branches. These signs of the disease are accompanied by the mass death of sponges. We identified differences in microbiomes by sequencing 16S rRNA genes and found changes in the consortium of microorganisms of freshwater Baikal sponges. We found that the observed imbalance ...

Illumination Of The Golgi Apparatus Of Pathogenic And Nonpathogenic Naegleria Species, Tyler M. Poe

Theses and Dissertations

In this study, Naegleria fowleri, a pathogenic amoeba and the causative agent of Primary Amebic Meningoencephalitis (PAM), was utilized to determine the presence or absence of classically conserved Golgi molecules featured in the expression of a Golgi apparatus. Previous studies concluded no Golgi expression via light microscopy and transmission electron microscopy, but a recent report on Naegleria gruberi indicated the presence of dispersed Golgi tubules. Non-pathogenic species of the Naegleria genus such as Naegleria gruberi 30540 and Naegleria lovaniensis 30569 were utilized in Western immunoblot analysis compared to reduced whole-cell lysate proteins of two strains of N. fowleri and Vero ...

Gut Symbiont Viability In Honey Bees Exposed To Agrochemical Stressors, Bryant Justin Gabriel

Dissertations and Student Research in Entomology

The honey bee gut microbiome is essential for protecting this pollinator against abiotic and biotic stressors, including the prevention of harmful gut parasites and pathogens. Previous studies have not only demonstrated a linkage of bee gut dysbiosis to increased immunodeficiencies and pathogen sensitivities, but also report the maladaptation of the gut microbiome in bees exposed to agricultural and apicultural chemistries. There are few techniques available that allow for a simple and reliable analysis of the relative proportions of live and dead gut microbes in bees exposed to these chemistries. Previous techniques for measuring gut symbiont dysbiosis are temporally limited by ...

The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld

School of Osteopathic Medicine Faculty Scholarship

Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding ...

Regulation Of The Tubulin Homolog Ftsz In Escherichia Coli, Monika S. Buczek

All Dissertations, Theses, and Capstone Projects

Escherichia coli is a well-known pathogen, and importantly, a widely used model organism in all fields of biological sciences for cloning, protein purification, and as a model for Gram-negative bacterial species. And yet, researchers do not fully understand how this bacterium replicates and divides. Every year additional division proteins are discovered, which adds complexity to how we understand E. coli undergoes cell division. Due to their specific roles in cytokinesis, some of these proteins may be potential targets for development of antibacterials or bacteriostatics, which are much needed for fighting the current global antibacterial deficit. My thesis work focuses on ...

Synthesis And Kinetic Studies Of High-Valent Metal-Oxo Species Generated By Photochemical And Chemical Methods, Haiyan Liu

Masters Theses & Specialist Projects

Highly reactive iron-oxo intermediates play important roles as active oxidants in enzymatic and synthetic catalytic oxidation. Many transition metal catalysts are designed for biomimetic studies of the predominant oxidation catalysts in Nature, namely cytochrome P450 enzymes. In this work, a series of iron(IV)-oxo porphyrins [Fe^IV(Por)O] and manganese(IV)-oxo porphyrins [Mn^IV(Por)O] have been successfully produced in two electron-deficient ligands by photochemical and chemical methods, and spectroscopically characterized by UV-vis, and ¹H-NMR.

With iodobenzene diacetate [PhI(OAc)₂] as the oxygen source, iron(III) porphyrin and manganese(III) porphyrin complexes converted to ...

Identifying Mechanisms Of Host Plant Specialization In Aphis Craccivora And Its Bacterial Symbionts, Thorsten Hansen

Theses and Dissertations--Entomology

Many insects form close relationships with microbial symbionts. Insect symbionts can provide novel phenotypes to their hosts, including influencing dietary breadth. In the polyphagous cowpea aphid, Aphis craccivora, the facultative symbiont Arsenophonus improves aphid performance on one host plant (locust), but decreases performance on other plants. The goal of my thesis was to investigate the mechanism by which Arsenophonus facilitates use of locust. First, I assembled an Aphis craccivora-Arsenophonus-Buchnera reference transcriptome to conduct RNAseq analysis, comparing gene expression in aphids feeding on locust and fava, with and without Arsenophonus infection. Overall, few transcripts were differentially expressed. However, genes ...

The Bi-Directional Relationship Between Gut Microbiota And Autoimmunity, Trevor O. Kirby

EWU Masters Thesis Collection

Humans serve as a major reservoir for a vast number of microbiota. These microbes have evolved symbiotic relationships with humans due to their close proximity with their host. As a result, the immune system adapts to the microbiota thus modulating immunological function. Autoimmunity is a state in which there are aberrant immune responses produced against host tissue. Intestinal bacteria are directly impacted by instances of inflammation brought on by autoimmunity. The complicated nature between autoimmunity and bacterial modulation demonstrates a bi-directional relationship. Here, we utilize experimental autoimmune encephalomyelitis, a model for multiple sclerosis, to explore the bi-directional relationship that disease ...

Distiphallus Morphology And Its Role In Copulation Dynamics In Anastrepha Suspensa (Loew), Taylor J. Inboden

Masters Theses

Anastrepha suspensa (Diptera; Tephritidae) is an agricultural pest species

causing severe economic damage and is controlled, in part, by applying knowledge

of this species' reproduction (e.g., disrupting fertile copulations by SIT). During

copulation, males transfer sperm as well as protein rich fluids through an aedeagus

and distiphallus, which females then store in three spermathecae and one ventral

receptacle. Within the female reproductive tract, the ventral receptacle and the

three spermathecae are strategically separated from each other. I hypothesized

males' ability to direct sperm transfer within the female reproductive tract is

through the structures found in the distiphallus. Utilizing scanning ...

Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Through their transformation of naturally occurring organic matter, coastal marine bacteria play an essential role in carbon cycling. A phenomenon termed the priming effect (PE) occurs when microbial communities remineralize recalcitrant organic matter faster in the presence of labile organic matter and may be prevalent in coastal systems. To understand how microbial community members interact to induce PE, it is essential to first understand the mechanisms underlying PE in single strains and simplified bacterial communities. The effect to which different concentrations and sources of labile carbon stimulated the production of bacterial biomass from riverine organic matter by two marine bacteria ...

The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen

Electronic Thesis and Dissertation Repository

The cabbage looper, Trichoplusia ni, a global generalist lepidopteran pest, has developed resistance to many synthetic and biological insecticides, requiring effective and environmentally acceptable alternatives. One possibility is the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). This baculovirus is highly infectious for T. ni, with potential as a biocontrol agent, however, its effectiveness is strongly influenced by dietary context. In this study, microscopy and transcriptomics were used to examine how the efficacy of this virus was affected when T. ni larvae were raised on different diets. Larvae raised on potato host plants had lower chitinase and chitin deacetylase transcript levels and thickened ...