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: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Kennedy , Victoria, Thesis advisor (ths): Saville, Barry, Degree committee member (dgc): Emery, Neil, Degree committee member (dgc): Donaldson, Michael, Degree committee member (dgc): Farrow, Scott, Degree granting institution (dgg): Trent University Abstract: <p>Heavy metal pollution threatens human and ecosystem health. E. gracilis was investigated for its potential use in bioremediation due to its tolerance for heavy metals and ability to sequester them from the environment. E. gracilis can remove metals by producing metal binding compounds enriched in sulfur and nitrogen. In this thesis, E. gracilis cultures that were pretreated with elevated… more
Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Abstract: <p>During the COVID-19 pandemic, nucleic acid and antibody-based testing methods were heavily relied upon, but can be costly, time-consuming and exhibit high false -negative and -positive rates. Thus, alternative strategies are needed. Viral antigens such as the SARS-CoV-2 spike (S) glycoprotein are critical in the function of the virus and useful as diagnostic biomarkers for viral… more
Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Giardia intestinalis is a waterborne enteric parasite that lacks mitochondria and the capacity for heme biosynthesis. Despite this, Giardia encodes several heme proteins, including four cytochrome b5 isotypes (gCYTB5-I – IV) of unknown function. The aim of this thesis is to gain insight into the function of the Giardia cytochrome b5 isotype III (gCYTB5-III) that is found in the nucleus,… more
Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Phytohormones, Cytokinin (CK) and Abscisic acid (ABA), are best known for controlling plant growth and stress responses; but they also mediate various developmental perspectives in alga. Yet, their mode of action in algal adaptive strategies to heavy metal responses, their involvement in orchestration of phytohormone crosstalk remain largely unknown and a molecular framework of… more
Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Many emerging infectious diseases are caused by pathogens that possess free-living life stages, in which they interact with the environment directly rather than through the mediation of a host. These diseases represent major impediments to wildlife conservation; however, the dynamics of their interaction with the environment are poorly studied, often due to the difficulty of detecting… more
Year: 2021, 2021
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The emergence of fungal hybrid pathogens threatens sustainable crop production worldwide. To investigate hybridization, the related smut fungi, Ustilago maydis and Sporisorium reilianum, were selected because they infect a common host (Zea mays), can hybridize, and tools are available for their analysis. Hybrid dikaryons exhibited filamentous growth on plates but reduced virulence and… more
Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The waterborne protozoan Giardia intestinalis cycles between the environmentally-resistant and infectious cyst and the metabolically-active trophozoite that adheres to the epithelial lining of the small intestine. Adhesion can trigger the innate immune response in epithelial cells, including the synthesis of the free radical nitric oxide (NO) that inhibits cell proliferation and… more
Year: 2019, 2019
Member of: Trent University Graduate Thesis Collection
Abstract: <p>To investigate cytokinins (CKs) in nematodes, CK profiles of a free-living Caenorhabditis elegans and a plant parasitic Heterodera glycines (soybean cyst nematode, SCN) were determined at the egg and larval stages. SCN had higher total CK level than C. elegans; however, CKs in SCN were mostly inactive precursors, whereas C. elegans had more bioactive forms. This is the first study to… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Cytokinins (CKs) are hormones that promote cell division. During the formation of tumors in the Ustilago maydis-Zea mays pathosystem, the levels of CKs are elevated. Although CK levels are increased, the origins of these CKs have not been determined and it is unclear as to whether they promote the formation of tumors. To determine this, we measured the CK levels, identified CK… more
Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Paleczny, Andrea Rose, Thesis advisor (ths): Emery, Neil, Degree committee member (dgc): Yee, Janet, Degree committee member (dgc): Saville, Barry, Degree committee member (dgc): Olechowski, Henry, Degree granting institution (dgg): Trent University Abstract: <p>Cytokinins (CKs) are a family of plant phytohormones responsible for many areas of plant growth and development. There are four free base types of CKs found in higher plants, trans-zeatin (tZ), N6-(∆2-isopentenyl)adenine (iP), cis-Zeatin (cZ) and dihydrozeatin (DZ). CK biosynthesis is regulated by adenosine phosphate-isopentenyltransferase (IPT), which is encoded by a multi-gene family… 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
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: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Moose are an iconic species, known for their large size and impressive antlers. Eight subspecies are classified in circumpolar regions of the planet - four in North America. Two subspecies are similar in shape and size, the north-western moose (Alces alces andersoni) and the eastern moose (Alces alces americana). It was previously believed that these two subspecies meet in northern… more
Year: 2016, 2016
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Interseeding legume cover crops in grain corn may improve the environmental sustainability of corn production system in Southern Ontario. This study aimed to assess the effects of legume species, nitrogen (N) fertilizer rate and arbuscular mycorrhizal fungi (AMF) inoculation on biomass and N requirement in a corn-legume system. Corn was grown with red clover (RCl), microclover (MCl),… more
Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Trinucleotide repeats (TNRs) are a class of highly polymorphic microsatellites which occur in neutral and non-neutral loci and may provide utility for individual- and population-identification. Exonic trinucleotide motifs, in particular, offer additional advantages for non-human species that typically utilize dinucleotide microsatellite loci. Specifically, the reduction of technical… more
Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Iridoviruses are large (120-200nm) double stranded DNA viruses that contain an icosahedral capsid. The iridoviridae family is composed of five genera that infect a wide range of poikilothermic vertebrates (Lymphocystivirus, Ranavirus and Megalocyivirus) and invertebrate hosts (Iridovirus, Chloriridovirus). Frog virus 3 (FV3) is a member of the Ranavirus genus, and is commonly used as a… more
Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Using rodent models, it is possible to study the behavioural and physiological outcomes of early life stress and the influences on normal mammary gland development and carcinogenic risk. Results demonstrate that the experience of three weeks of prolonged maternal separation (LMS; 4 hrs/day) increased the susceptibility of adult, but not pubertal, female BALB/c mice to engage in higher… more