Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Giardia intestinalis is a parasitic protozoan that possesses a flavohemoglobin (gFlHb), an enzyme that plays a role in the detoxification of reactive nitrogen species (RNS) and reactive oxygen species (ROS) via its nitric oxide dioxygenase (NOD) activity as well as its NADH-oxidase activity. This enzyme is a potential target for imidazole-based antigiardial drugs that act as ligands of… more Year: 2023, 2023
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Fungal pathogens adapt to environmental changes faster than their hosts, due in part to their adaptive mechanisms exhibited in response to stress. Ustilago maydis was used to investigate potential natural antisense transcript (NAT) RNA-mediated mechanisms that enhance fungal adaptation to stress. Of the 349 NATs conserved amongst U. maydis and two related smut fungi, five NATs were… more Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Giardia intestinalis possesses four isotypes of cytochrome b5 (gCYTB-I-IV) that differ from their mammalian counterparts, suggesting different functions in this protozoan parasite. Although the recently discovered Giardia flavoenzyme, GiOR-1, reduces these cytochromes, its properties have not been thoroughly studied, owing to the difficulty in its expression. Here I describe successful… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This thesis investigated the role of the neuronal ceroid lipofuscinosis protein, Cln5, during autophagy. This was accomplished by performing well-established assays in a Dictyostelium cln5 knockout model (cln5-). In this study, cln5- cells displayed a reduced maximum cell density during growth and impaired cell proliferation in autophagy-stimulating media. cln5- cells had an increased… more Year: 2019, 2019
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The parasitic protist Giardia intestinalis does not synthesize heme and lacks many common eukaryotic heme proteins, yet it expresses four cytochrome b5 (gCYTB5) isotypes of unknown function. These have low reduction potentials and distinct subcellular locations that are consistent with structural features and biological functions that differ from their mammalian counterparts. Isotype III… more Year: 2019, 2019
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Sajer, Bayan, Thesis advisor (ths): Yee, Janet, Degree committee member (dgc): Rafferty, Steven, Degree committee member (dgc): Bates, Holly, Degree committee member (dgc): Brunetti, Craig, Degree granting institution (dgg): Trent University Abstract: <p>The parasitic protist Giardia intestinalis has five heme proteins: a flavohemoglobin and several isotypes of cytochrome b5. While the flavohemoglobin has a role in counteracting nitric oxide, the functions of the cytochromes (gCYTb5s) are unknown. In this study, the protein level and cellular localization of three gCYTB5 isotypes (gCYTb5-I, II and III) and flavohemoglobin were examined… more Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Ustilago maydis is a biotrophic fungal plant pathogen that causes 'common smut of corn' disease. During infection, U. maydis develops a metabolic dependency on its host, relying on uptake of the carbon molecules provided within Zea mays tissues. The research presented indicated a requirement for metabolism of the pentose sugar D-xylose through functional investigation of a U.… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Exposure of pre-metamorphic amphibians to neonicotinoid insecticides may be contributing to the global decline in amphibian populations. In this study, anuran embryos and tadpoles of the African clawed frog (Xenopus laevis) and the North American leopard frog (Lithobates pipiens) were used to determine the effects of embryonic exposure to neonicotinoids. In addition, Xenopus was used to… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The parasitic protist Giardia intestinalis lacks most heme proteins yet encodes a flavohemoglobin (gFlHb) that converts nitric oxide to nitrate and likely protects the cell from nitrosative stress. In this work an antibody raised against gFlHb was used to examine both changes in gFlHb expression levels and intracellular localization in Giardia in response to nitrosative stress. Giardia… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>To study the Giardia intestinalis cell cycle, counterflow centrifugal elutriation (CCE) was used to separate an asynchronous trophozoite culture into fractions enriched for cells at the different stages of the cell cycle. For my first objective, I characterized the appearance of a third peak (Peak iii) in our flow cytometry analysis of the CCE fractions that initially suggested the… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Stressors are often an inescapable part of an organism's life. While the effects of many stressors have been well studied individually, potential interactions between stressors exist that may result in greater than additive negative effects. Stressors may be linked by conflicting demands on energy budgets, interfering with important physiological pathways, or necessitating… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Dayer, Guillem Sébastien, Thesis advisor (ths): Yee, Janet, Thesis advisor (ths): Rafferty, Steven, Degree committee member (dgc): Brunetti, Craig, Degree committee member (dgc): Saville, Barry, Degree granting institution (dgg): Trent University Abstract: <p>Giardia intestinalis is an anaerobic protozoan that lacks common eukaryotic heme-dependent respiratory complexes and does not encode any proteins involved in heme biosynthesis. Nevertheless, the parasite encodes several hemeproteins, including three members of the Type II cytochrome b5 sub-group of electron transport proteins found in anaerobic protist and amitochondriate organisms.… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Aquatic consumers frequently face nutritional limitation, caused in part, by imbalances between the nutrients supplied by primary producers and the metabolic demands of the consumers. These nutritional imbalances alter many ecological processes including consumer life-history traits, population dynamics, and food web properties. Given the important ecological role of organismal nutrition… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Ustilago maydis is a basidiomycete smut fungus and the causal agent of common smut of corn. Disease progression and fungal development in this pathogen occur in planta, terminating in the production of dormant teliospores. Dormant spores of many fungi are characterized by reduced metabolic activity, which is restored during spore germination. The transition out of dormancy requires the… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study investigated the role of the JNK signaling pathway in cadmium-treated mouse embryo forelimb bud cells in vitro. Primary cultures of forelimb bud cells harvested at day 11 of gestation were pre-treated with JNK inhibitor SP600125, and incubated with or without CdCl2 for 15, 30, 60, 120 minutes and 24, 48 hours or 5 days. Endpoints of toxicity were measured through cell… more
