Life Sciences Commons^™

Ecological, Molecular, And Electron Microscopical Investigations Of The Distribution Of Shell-Boring Polychaetes Along The Coast Of Maine, Emma Tomasetti

Honors College

Blister worms are polychaete worms that live in various calcareous materials such as dead shells, red algae, limestone, and cinder blocks, along with cultured shellfish, such as oysters or sea scallops. These worms can be considered a pest due to their nature to burrow into their host’s substrate and create blisters that then fill with mud and detritus. In chapter 1, I worked closely with an oyster farm looking at the reproductive status of one species of blister worm, P. websteri, and the efficacy of cold storage as a method of ridding oysters of P. websteri. For chapter 2, I …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …