Life Sciences Commons^™

Characterizing Mab Cluster R Prophage Of Pathogen Mycobacterium Abscessus (Mab), Madeline Kimble

Honors College

Mycobacterium abscessus (Mab) is an emerging pathogen that can cause pulmonary, skin and disseminating infections. It is one of the most drug-resistant pathogens and infections typically result in high morbidity and mortality. Understanding mechanisms of antibiotic resistance is critical for developing more effective treatments. Prophage, integrated viral genomes, are known to contribute to bacterial virulence and antibiotic resistance, yet Mab prophages remain largely uncharacterized.My research aims to characterize the diversity of the novel cluster MabR prophage genomes. The Molloy lab has demonstrated that the prophage McProf increases mycobacterial resistance to antibiotics. Using the McProf prophage genome sequence, we probed the …

Infection And Diet-Induced Gut Dysbiosis: Impact On Sleep Quality In Danio Rerio, Benjamin Williams

Honors College

A known bidirectional relationship between intestinal microflora and the central nervous system, coined the gut-brain-axis, has stimulated work on the association between gut dysbiosis and inflammation, and sleep quality. Previous studies in the Hayes Lab have reported that a high fat (HF) diet was correlated with immobile phases, a marker of low motility during sleep found in some neurological disease and sleep duration[1]. Long sleep duration (>1 S.D. above norms for age) is associated with poor sleep quality or sleep fragmentation in participants who are overweight or obese according to body mass index values[2]. The current work utilizes a …

The Impact Of Natural Rubber As A Toughening Agent On The Strength, Degradability, And Toxicity Of An Algae-Based Bioplastic, Megan Driscoll

Honors College

With the growing attention on widespread plastic usage and its impact on the environment and human health, the need for sustainable alternatives to petroleum-based plastics is more important than ever. One of the most promising solutions is bioplastics; however, current bioplastics struggle to compete with the material properties of petroleum- based plastics. Agar is a sustainable algae-derived hydrocolloid polysaccharide that can be used for bioplastics and biofilms. Despite promising characteristics, bioplastics made from agar are brittle. Common additives, such as the plasticizer glycerol, offset brittleness but sacrifice strength in return. This study looks at the impact of natural rubber as …

Identifying The Link Between Non-Coding Regulatory Rnas And Phenotypic Severity In A Zebrafish Model Of Gmppb Dystroglycanopathy, Grace Smith

Honors College

Muscular Dystrophy (MD) is characterized by varying severity and time-of-onset by individuals afflicted with the same forms of MD, a phenomenon that is not well understood. MD affects 250,000 individuals in the United States and is characterized by mutations in the dystroglycan complex. gmppb encodes an enzyme that glycosylates dystroglycan, making it functionally active; thus, mutations in gmppb cause dystroglycanopathic MD1 . The zebrafish (Danio rerio) is a powerful vertebrate model for musculoskeletal development and disease. Like human patients, gmppb mutant zebrafish present both mild and severe phenotypes. In order to understand the molecular mechanisms involved, we performed high-throughput RNA …

Cpsa Protein-Protein Interactions In Group B Streptococcus, Ben Tero

Honors College

Group B Streptococcal (GBS) infections pose a great threat to mortality in neonates. Neonates are often exposed to GBS both before, during, and after delivery, which can cause a range of health problems including meningitis, sepsis, or stillbirth. One of the major virulence factors that contributes to the infectivity of the pathogen is the bacterial capsule. The capsule is a polysaccharide matrix surrounding the cell which helps in the evasion of host defenses, and penetration into normally sterile sites like the bloodstream. The highly conserved GBS protein CpsA has been shown to regulate expression of the capsule. The objective of …

Genomic And Proteomic Effects Of Red Raspberry (Rubus Idaeus) Consumption On The Perivascular Adipose Tissue Of The Obese Zucker Rat, A Model Of Human Metabolic Syndrome, Jasmine Waite

Honors College

The Metabolic Syndrome (MetS) affects 35% of U.S. adults and is an indicator of early death. While pharmacological treatments have been developed for the majority of MetS risk factors, obesity-induced inflammation remains to be addressed. Dysfunctional adipose tissue is a source of inflammation, and perivascular adipose tissue (PVAT) is critical in its pathogenesis. This study investigates the effects of red raspberry (rubus idaeus) diet-enrichment on inflammation of PVAT. The obese Zucker rat (OZR) model of MetS and the lean Zucker rat (LZR) control (C) model were used. Rats received an eight-week control or whole red raspberry-enriched (WRR) diet …

Determining The Key Residues For Capsule Production In The Gbs Cpsa Protein, Anna Struba

Honors College

Streptococcus agalactiae (GBS) is a common bacterium found commensally in the vaginal mucosa of healthy adults. GBS also causes severe infection in neonates, often leading to meningitis, which can cause lifelong health consequences including impaired hearing and seizures. Infection of newborns mainly arises from a colonized mother, either before birth through ascending infection or during labor. Ascending infection, where the bacteria travel to the fetus from the vaginal mucosa, is especially concerning as it can lead to loss of pregnancy or premature birth. The most common method of neonatal GBS disease prevention is antibiotic prophylaxis during delivery, though this method …

Finalizing The Genome Annotation Of Model Cluster E Mycobacteriophage Ukulele Via Rna-Seq Analysis, Jackson R. Foley

Honors College

Mycobacteriophage (phage) are viruses that infect bacteria of the genus Mycobacterium, including pathogenic M. tuberculosis and non-pathogenic M. smegmatis. Temperate phages are capable of undergoing both lytic and lysogenic infection. In lytic infections, phage lyse the host cell after replication. In lysogenic infection, the phage integrates its genome into the host genome (prophage) and replicates with the host. All pathogenic strains of Mycobacterium carry prophage that potentially contribute to host virulence and fitness. Formation and maintenance of these prophage is not well understood, particularly for cluster E phage. This project characterizes gene product (gp) 53, a potential Cro-like …

Identification Of Tnfaip8l1 Binding Partners Through Co-Immunoprecipitation And Mass Spectrometry, Audrey Hoyle

Honors College

The expanded understanding of the gene families and mechanisms governing tumorigenesis pathways has enormous potential for improving current cancer therapies and patient prognoses. One such gene family that participates in the regulation of tumorigenesis is the tumor necrosis factor alpha-induced protein 8 (TNFAIP8) gene family, which is comprised of four members: TNFAIP8, TNFAIP8L1, TNFAIP8L2, and TNFAIP8L3. The TNFAIP8L1 gene is thought to function as a tumor suppressor, but the mechanisms by which it exerts this function have yet to be elucidated. We hypothesize that the TNFAIP8L1 protein acts as a tumor suppressor through protein-protein …

Determining The Role Of Saly In Streptococcus Pyogenes Immune Evasion Using Fluorescence Microscopy, Taaniel Kiidli

Honors College

Streptococcus pyogenes, the etiologic agent for several life-threatening invasive diseases, utilizes numerous mechanisms to evade the host immune response and establish a successful infection causing a significant source of morbidity and mortality risks for patients. The bacterium is known to cause necrotizing fasciitis in both humans and zebrafish, with extensive necrotic damage to tissues but surprisingly lacking in an inflammatory response for a systemic infection. This suggests that the recruitment of inflammatory cells to the site of infection is inhibited. To observe this in real-time, we used the zebrafish model of Streptococcal pathogenesis to analyze immune cell recruitment in …

Defining The Role Of Ip3r-Medicated Er Calcium Flux In Jc Polyomavirus Infection, Ashley N. Soucy

Honors College

The human JC polyomavirus (JCPyV) persists as an asymptomatic infection in the kidneys of healthy individuals within the majority of the global population. Viral infection of JCPyV is established through peroral transmission due to poor sanitary practices. In severely immunocompromised individuals, JCPyV migrates to the central nervous system (CNS), resulting in the fatal and incurable demyelinating disease progressive multifocal leukoencephalopathy (PML). Virus-host cell interactions regulate infectious processes and influence viral pathogenesis. JCPyV attachment to host cells is mediated by α2,6-linked LSTc while internalization is mediated by 5-hydroxytryptamine serotonin type 2 receptors (5-HT₂Rs). Activation of 5-HT₂Rs can …

The Effects Of Mercury Exposure On The Cytochrome C Oxidase 1 Gene Of Larval Dragonflies, Megan C. Little

Honors College

Mercury is an environmental pollutant; its most toxic form is methylmercury. Once mercury is converted to methylmercury in a body of water it is able to bioaccumulate in organisms and biomagnify up the food chain. Mercury is able to cause DNA damage through the generation of free radicals and binding to sulfhydryl groups of cysteines in zinc finger DNA binding domains, inhibiting DNA repair machinery. In this study the potential mutagenic effects of mercury were investigated on larval dragonflies (Odonta: Anisoptera) collected from national parks across the United States. Since mercury is a known mutagen it was hypothesized that the …

Investigating The Mechanism Of Jc Polyomavirus Endocytosis, Conner Robert Lajoie

Honors College

The majority of the human population is infected with JC polyomavirus (JCPyV), which establishes an asymptomatic infection in the kidney of healthy individuals. In immunosuppressed individuals, the virus spreads to the brain and attacks glial cells, causing progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease. With limited treatments available, an improved understanding of the virus-host cell interactions during JCPyV infection is crucial for developing effective PML therapies. JCPyV internalization into host cells requires the serotonin 5- hydroxytryptamine type 2 (5-HT2) receptors. The mechanism by which the 5-HT2Rs mediate viral entry has not yet been characterized, yet it is thought to …

How Does 2,4-Dinitrophenol Compare To Triclosan As A Mitochondrial Uncoupler?, Erik Gerson

Honors College

2,4-Dinitrophenol (DNP) is a well-documented mitochondrial uncoupler that was widely used as a dieting drug in the 1930’s. It was later banned in 1938 due its negative side effects which included extreme weight loss, the formation of cataracts, skin rashes, and death. Triclosan (TCS) is a common antimicrobial agent that is a component in soaps, toothpastes, and other household products. In addition to its antimicrobial role, TCS has been found to alleviate skin inflammation and dermatitis. However, TCS has also been linked to several health issues including increased cases of asthma and allergy, developmental problems, and decreased fertility. Previous studies …

Towards A Molecular Method For The Detection Of Leaf Rust In Lowbush Blueberry, Steven Valentino

Honors College

Thekopsora minima, or leaf rust, is a fungal pathogen that infects Vaccinium angustifolium (lowbush blueberry), an economically important crop to the state of Maine. T. minima undergoes a complicated life cycle that contains five unique spore stages. It causes abscissions in the leaves of plants that may consequently lower yields in the next growing cycle if leaf drop is severe. Currently, growers are instructed to apply fungicides in late July to prevent further infection. However, this is often not effective due to poor timing. Data on spore release patterns would be beneficial to elucidate the infection period. However, microscopic identification …

Regulation Of Microrna-199 Upon Pseudomonas Aeruginosa Infection In Zebrafish, Eliot Rivers Gagné

Honors College

The innate immune response is vital in an organism’s ability to fight infection. Aspects of the innate immune response including inflammation, phagocyte populations, and the production of reactive oxygen species (ROS) must be closely regulated in order to effectively eliminate pathogenic entities. Dysregulation of the innate immune response can cause various pathologies, including chronic infection, autoimmunity, and cancer. Recent studies have shown that microRNAs (miRs) play a regulatory and “fine-tuning” role in the innate immune system of the Zebrafish.⁹⁹ We have found that the expression of miR-199 is significantly upregulated upon stimulation of the Zebrafish innate immune system with …

Characterization Of Transcriptional Control Elements In Cluster E Mycobacteriophage Ukulele, Campbell Belisle Haley

Honors College

Mycobacteriophage (phage) are a diverse group of viruses that infect Mycobacterium. Their study allows further understanding of viral evolution and genetics. Phage tightly control gene expression and transcribe their genes using host RNA polymerases. This project identifies potential transcriptional control elements in the genome of mycobacteriophage Ukulele. Promoters are sequences of the genome that allow binding of RNA polymerase and initiation of transcription. 21 putative promoters were identified in the Ukulele genome. To confirm transcriptional activity from putative promoters, a GFP reporter system was developed in mycobacterial cells. Intrinsic terminators are mRNA sequences that form secondary structure during transcription …

Preliminary Analysis Of Β-Methylamino-L-Alanine Interactions With Cu/Zn Superoxide Dismutase In Amyotrophic Lateral Sclerosis Zebrafish Models, Elizabeth Pflugradt

Honors College

Amyotrophic Lateral Sclerosis (ALS) is a terminal neurodegenerative disease

with symptoms including limb-onset muscle wasting, difficulties swallowing and breathing, leading to death. Sporadic ALS occurs in 90% of patients, while 10% of cases are familial (FALS). Twenty percent of FALS cases are a result of mutation in the copper-zinc superoxide dismutase (SOD1) gene, leading to the activation of the mitochondrial apoptosis pathway. Meanwhile, a prominent cause of sporadic ALS is exposure to neurotoxins, such as β-methylamino-L-alanine (BMAA). BMAA has been suggested to induce selective motor neuron death, which is observed in ALS patients. While research has been done to how …

Characterization Of The Mycobacteriophage Ukulele Integration System; Identification Of Integration Site Attp And The Role Of The Integrase In Lysogeny Regulation, Emily E. Whitaker

Honors College

Mycobacteriophage (phage) are a group of viruses that infect bacteria in the genus Mycobacterium. Two phage lifestyles are lytic and temperate. Lytic phage only carry out the lytic life cycle, resulting in host cell lysis. Temperate phage are capable of completing both lytic and lysogenic life cycles. During the lysogenic life cycle, a phage-encoded integrase facilitates integration at sites attP in the phage genome and attB in the host to form a lysogen. The cluster E mycobacteriophage integration system is poorly understood. Ukulele, a lysogenic cluster E phage, is being used to identify the Cluster E attP and characterize lysogeny …

Complete Annotations Of The Cluster E Mycobacteriophage Ukulele Genome And Characterization Of Cluster E Lysogeny Regulation, Gwendolyn M. Beacham

Honors College

Mycobacteriophages (phages) are diverse and abundant viruses that infect species of the genus Mycobacterium. Mycobacteriophages are categorized into clusters based primarily on nucleotide similarity (18). Some clusters are well-characterized, while others, such as Cluster E, are poorly characterized (20). There are 54 members of Cluster E (39) including the phage Ukulele that was isolated at the University of Maine in 2011. This thesis is aimed towards characterizing Cluster E phages using Ukulele as a model. Cluster E phages have long tails of approximately 300 nm and they produce slightly turbid plaques on a lawn of Mycobacterium smegmatis. Putative …

The Role Of Morphology Transitions In Tissue-To-Blood Spread Of Infestation, Joshua M. Jones

Honors College

The fungal organism Candida albicans is a nearly ubiquitous commensal inhabitant of the human body. However, in susceptible individuals it can establish mucosal infections as well as life-threatening systemic infection. We are investigating a key contributor to C. albicans’ pathogenesis: its ability to switch among multiple growth forms in response to an array of environmental signals. We hypothesize that this ability to undergo morphological transitions mediates its ability to disseminate from localized infections to system-wide bloodstream infection. Using a transparent zebrafish embryo model of infection, we have directly assessed specific contributions of C. albicans’ morphologies in the process of tissue-to-bloodstream …

A Novel Mechanism For Mechanosensing By Endothelial Cells, Jennifer Macdowell

Honors College

The formation of new vasculature is an essential process, but can also be utilized by cancerous cells. Angiogenesis requires the directed migration of the endothelial cells lining the nascent blood vessels. This process is largely mediated by integrin, which plays a key role in the interplay between sensing a force in the extracellular matrix (ECM) and transducing this signal, a process termed mechanotransduction. Through cell-ECM focal adhesions, integrin mediates the signaling both into and out of the cell, promoting growth of focal adhesions and subsequent cell spreading and migration. In order to study focal adhesion dynamics related to force, we …

Investigation Of The Mechanism Underlying Arsenic Disruption Of Mast Cell Degranulation, Alejandro Velez

Honors College

Exposure to arsenic (As) is a global health concern, according to the World Health Organization and Agency for Toxic Substances and Disease Registry. Prolonged exposure to this naturally occurring chemical has been linked to hyperkeratosis, type II diabetes, developmental abnormalities, and cancer. Some of the adverse health effects of As may be linked to its ability to alter cellular signal transduction. Recently, published work from the Gosse laboratory has shown that inorganic arsenite inhibits the signaling cascade leading to mast cell degranulation, a vital immune function, through an as-yet unknown mechanism.
Further work in the Gosse lab has suggested that …

Evolutionary And Molecular Analysis Of Conserved Vertebrate Immunity To Fungi, Erin Carter

Honors College

The innate immune system is highly conserved amongst all multicellular organisms. Yet a constant battle exists between host cells and pathogens due to the rapid evolution of immune system components. Functional genomics and in silico methods can be employed to elucidate the evolutionary patterns of vertebrate immunity to pathogenic fungi such as Candida albicans, an opportunistic fungal pathogen that can cause lethal candidiasis in the immunocompromised. Mammals such as humans and mice possess conserved C-type lectin receptors that recognize the C. albicans cell wall. However, these receptors have not been identified in fish. Here I describe how we identified potential …

Fast Pyrolysis Of Muconic Acid And Formic Acid Salts, Laura Duran

Honors College

Lignocellulosic biomass is emerging as a sustainable resource for the production of alternative liquid fuels. As the need to lessen dependence on petroleum sources grows, lignocellulosic feedstocks are being investigated as a renewable, abundant source of energy. Chemical pulping processes include a high-lignin by-product, black liquor, which is already used for fuel in industry. Black liquor is burned to generate steam and electricity and to recover pulping chemicals. Currently, the thermochemical conversion of black liquor to liquid fuel is being researched at The University of Maine. In this black liquor research, an intermediate lignin-derived acid, muconic acid, and formic acid …

Reverse Genetic Analysis Of A Cysteine Protease-Encoding Gene (Rd19a) Of Arabidopsis Thaliana In Relation To The Mechanism Of Resistance To The Piercing/Sucking Insect Myzus Persicae, Siobhan A. Cusack

Honors College

A recent study in Solanum bulbocastanum (a wild relative of the cultivated potato) aiming to identify potential genes involved in aphid and pathogen resistance mechanisms found that a homolog of the Arabidopsis thaliana cysteine protease gene RD19a is upregulated during aphid infestation. RD19a is upregulated in response to abiotic stresses such as drought and high salinity, and rd19a mutants show increased susceptibility to bacterial infection. In this study, Arabidopsis rd19a mutants and wild-type plants were subjected to aphid feeding to observe and compare the molecular, physiological and phenotypic responses. The aim was to further establish the proof of concept regarding …

The Role Of Traf2 In Zebrafish, Bradie N. Manion

Honors College

Tumor necrosis factor (TNF) receptor associated factor 2 (Traf2) is suspected to be involved in the anti-apoptotic pathways of the innate immune system in the zebrafish. The expression of three different forms of Traf2, 2a1, 2a2, and 2b, was knocked down in pairs using antisense morpholino oligonucleotides in zebrafish embryos. A rescue was attempted by knocking down a potential receptor for the Traf2 to pathway. After infection with snakehead rhabdovirus (SHRV), mortality was quantified and the apoptotic effects of each of the Traf2 genes was assessed. Cell death was quantified using the TUNEL technique. The findings indicated that at least …

Optimization Of A Fluorescent In Situ Hybridization Protocol In The Chloroplast Hosting Mollusc Elysia Chlorotica, Geoffry Austin Davis

Honors College

The symbiosis between the mollusc Elysia chlorotica and chloroplasts of its algal prey, Vaucheria litorea, has challenged the understanding of chloroplast biology. E. chlorotica feeds on and retains the algal chloroplasts within its digestive cells. The chloroplasts remain photosynthetically active for months in the animal’s cells devoid of the algal nucleus which encodes approximately 90% of the proteins required for the chloroplasts. To help explain the ability of E. chlorotica to maintain functionally active chloroplasts, horizontal gene transfer (HGT) of V. litorea nuclear genes to the E. chlorotica genome has been hypothesized. However, the extent of HGT, as well as …

Characterization Of Genes In The Cftr-Mediated Innate Immune Response, Eric Peterman

Honors College

Recently, the Kim Lab has shown that the cystic fibrosis transmembrane conductance regulator (cftr) gene is responsible for mediating resistance to Pseudomonas aeruginosa in a zebrafish infection model. Using the Gene Expression Omnibus, an NCBI functional genomics data repository, it was determined that Smad3, a transcription factor in the TGF-β signaling pathway, is upregulated in the presence of P. aeruginosa. It was found that in our zebrafish model, the Smad3 paralogs Smad3a and Smad3b are upregulated following microinjection of a cftr antisense morpholino oligomer. It was also found that microinjection of Smad3a and Smad3b morpholinos, along with …

The Haptotactic Motility Of Angiogenic Endothelial Cells, Breana E. Bennett

Honors College

Angiogenesis, an essential but often pathological biological process, requires complex cellular coordination. This coordination is achieved through numerous extracellular signals. We investigated the role of the extracellular matrix (ECM) protein fibronectin in the support of angiogenesis and endothelial cell motility. The directed migration in response to increasing concentration of ECM proteins is termed haptotaxis. We created a preliminary, two-dimensional model of the haptotactic motility of endothelial cells using a step change in fibronectin density as a substrate. Bovine aortic endothelial cells (BAECs) exhibited directional motility towards the higher fibronectin concentration side. In addition, the physical and mechanical properties of BAECs …