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Determining The Effects Of Mistranslating Transfer Rna Variants On Drosophila Melanogaster, Joshua R. Isaacson

Electronic Thesis and Dissertation Repository

Transfer RNAs (tRNAs) play a central role in translation as adaptor molecules between mRNA and protein. Variant tRNAs can cause the misincorporation of an amino acid into a growing polypeptide. Mistranslating tRNA variants are surprisingly common in humans but the effects of mistranslating tRNA variants on eukaryotic biology are poorly understood. My thesis aimed to create a model of tRNA-induced mistranslation using the fruit fly Drosophila melanogaster and characterize the effects of mistranslating tRNA variants on eukaryotic biology.

I first integrated a gene encoding a serine tRNA variant that induced proline-to-serine (P>S) mistranslation into the fly genome. Proteins isolated …

Development Of An In Vitro Model Of Mitochondrial Dna Copy Number Depletion Via Stable Inducible Expression Of D1135a Mutant Dna Polymerase Gamma, Amanda L. Morin

Electronic Thesis and Dissertation Repository

Mitochondria are responsible for several crucial cellular processes and contain their own DNA (mtDNA) that exists in several copies. Variation of mtDNA copy number (mtDNA-CN) alters energy metabolism and can modify the epigenome and transcriptome. We hypothesized that inducible expression of polymerase-deficient D1135A dominant-negative DNA polymerase gamma (DN-POLG) would result in mtDNA-CN depletion. Here, an in vitro model expressing D1135A POLG was created using the Flp-InTM T-RExTM-293 stable inducible expression system. Stable integration was confirmed with PCR amplification and Sanger sequencing of post-integration genomic sequences. D1135A POLG expression was confirmed with Western blot of the FLAG-tag antibody. Induction of D1135A …

Soybean Arogenate Dehydratases (Gmadts): Involvement In The Cytosolic Isoflavonoid Metabolon Or Trans-Organelle Continuity?, Emily J. Clayton, Nishat S. Islam, Kelsey Pannunzio, Kuflom Kuflu, Ramtin Sirjani, Susanne E. Kohalmi, Sangeeta Dhaubhadel

Biology Publications

Soybean (Glycine max) produces a class of phenylalanine (Phe) derived specialized metabolites, isoflavonoids. Isoflavonoids are unique to legumes and are involved in defense responses in planta, and they are also necessary for nodule formation with nitrogen-fixing bacteria. Since Phe is a precursor of isoflavonoids, it stands to reason that the synthesis of Phe is coordinated with isoflavonoid production. Two putative AROGENATE DEHYDRATASE (ADT) isoforms were previously co-purified with the soybean isoflavonoid metabolon anchor ISOFLAVONE SYNTHASE2 (GmIFS2), however the GmADT family had not been characterized. Here, we present the identification of the nine member GmADT family. We determined that the GmADTs …

Investigating The Soil Mycobiome Of American Ginseng, Rachel Amelia Rajsp

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) is a perennial herbaceous plant cultivated for its medicinal properties. Growers report that when ginseng is replanted in a field previously used to cultivate ginseng, it soon succumbs to disease, known as ginseng replant disease. I examined changes in composition in the ginseng mycobiome throughout cultivation in a newly planted garden and beyond (i.e., 3–14 years post-harvest) with a third-generation metabarcoding approach (Pacific Biosciences, single-molecule real-time sequencing). Amplicons of about 600 nucleotides from the nuclear ribosomal internal transcribed spacer (ITS) region and translation elongation factor 1-α gene were chosen to help discriminate between closely …

Elucidating The Relationships Between Spider Size, Joint Stiffness, And The Mechanical Frequency Response Of The Body, Reese L. Gartly

Electronic Thesis and Dissertation Repository

Spiders use vibrations to sense their surroundings. It has been suggested that the vibration perception in spiders may be altered by the mechanics of the body. I studied the biomechanics of spiders, at the level of leg joints and the whole body. To study joints, I quantified the allometry of leg joint stiffness in spiders. I found that the stiffness of spider joints increased nearly isometrically with increasing body mass, partly by having shorter and thicker leg segments and also by other unknown means. Using these data, I developed empirically validated biomechanical models which predicted the effects of mechanics on …

Short-Term Versus Long-Term Effects Of Nitrogen Addition And Warming On Ecosystem N Dynamics In A Grass-Dominated Temperate Old Field, Benjamin F. A. Souriol

Electronic Thesis and Dissertation Repository

Increased atmospheric nitrogen (N) deposition and climate warming are both anticipated to influence the ecosystem N dynamics of northern temperate ecosystems substantially over the next century. Nevertheless, in field experiments with N addition and warming treatments, temporal scale can play an important role in determining the extent of treatment effects on N dynamics, and it is unclear to what extent the results of short-term studies can be extrapolated to responses over longer time scales. I compared the short-term versus long-term effects of N addition and warming on net N mineralization, N leaching, and N retention in a grass-dominated old field. …

The Detectability Of Atlantic Salmon (Salmo Salar) Microsatellite And Mitochondrial Environmental Dna, Simone N. Miklosi

Electronic Thesis and Dissertation Repository

Little is known about what information can be gathered from microsatellite eDNA. It is important to gain a deeper understanding of the detectability and analysis of microsatellite eDNA because it could provide information about population size that mitochondrial eDNA cannot. Water samples were collected from tank and river experiments, and rivers known to contain Atlantic salmon (Salmo salar) and analyzed for Atlantic salmon mitochondrial and microsatellite eDNA. Mitochondrial eDNA was detected from all the tank experiments and 10 out of 15 rivers known to contain Atlantic salmon. Microsatellite eDNA was detected from all the tank experiments and none …

Effect Of Rearing Conditions On The Allocation Of Larval And Adult Acquired Essential And Nonessential Fatty Acids To Flight In Two Adult Lepidoptera: Danaus Plexippus And Mythimna Unipuncta, Libesha Anparasan

Electronic Thesis and Dissertation Repository

Insects which are nectivorous as adults acquire essential fatty acids, which are important for many biological processes, almost exclusively from the larval diet. Thus, adult allocation of this limited resource may result in trade-offs in migrant insects that delay reproduction. I used the true armyworm, Mythimna unipuncta, and monarch butterfly, Danaus plexippus, to test the hypothesis that environmental cues (fall migratory or summer reproductive) would influence the use of fatty acids during flight (0-6h). I used larval and adult diets manipulated isotopically (δ¹³C) and chromatographic analyses to determine fatty acid composition and source in the fat …

Characterization Of Etoxazole Resistance In Tetranychus Urticae Populations Collected From Commercial Greenhouses & Fields In Ontario, Jeremy Spenler

Electronic Thesis and Dissertation Repository

In this investigation, etoxazole resistance was monitored in two spotted spider mite (TSSM) populations collected from commercial greenhouses in Ontario. The frequency of an etoxazole resistant, recessive target-site mutation, I1017F, in chitin synthase I (CHS1) was tracked within populations over the course of the study. Cytochrome P450 (P450) activity emerged as a possible alternative mechanism to resist etoxazole exposure in one population.

Using genetic crossing between highly resistant mite populations and a susceptible lab population, filial (F1) hybrid populations were created. The recessive I1017F target-site mutation was abolished in F1 hybrids highly susceptible to etoxazole, while elevated P450 …

Msspl9 Modulates Nodulation Under Nitrate Sufficiency Condition In Medicago Sativa, Vida Nasrollahi, Gamalat Allam, Susanne E. Kohalmi, Abdelali Hannoufa

Biology Publications

Nodulation in Leguminous spp. is induced by common environmental cues, such as low nitrogen availability conditions, in the presence of the specific Rhizobium spp. in the rhizosphere. Medicago sativa (alfalfa) is an important nitrogen-fixing forage crop that is widely cultivated around the world and relied upon as a staple source of forage in livestock feed. Although alfalfa’s relationship with these bacteria is one of the most efficient between rhizobia and legume plants, breeding for nitrogen-related traits in this crop has received little attention. In this report, we investigate the role of Squamosa-Promoter Binding Protein-Like 9 (SPL9), a target of miR156, …

Development Of Reverse Genetics Tools In The Two-Spotted Spider Mite Tetranychus Urticae, Nivitha Bhaskar

Electronic Thesis and Dissertation Repository

Tetranychus urticae, commonly known as the two-spotted spider mite, poses a significant threat to agriculture due to its ability to feed on a diverse range of plant hosts and its strong detoxification abilities in overcoming xenobiotic response. With global warming projected to increase spider mite infestations, it is vital to study the detoxification genes that enable the mite to adapt and survive. The spider mite genome sequence reveals a unique set of detoxification genes that can be studied using RNAi as a promising reverse genetic tool. However, the current genetic toolkit requires improvement. This study examined the effectiveness of …

Plant Production Of A Virus-Like Particle-Based Vaccine Candidate Against Porcine Reproductive And Respiratory Syndrome, Jordan T. Vanderburgt, Ondre Harper, Christopher P. Garnham, Susanne E. Kohalmi, Rima Menassa

Biology Publications

Porcine reproductive and respiratory syndrome (PRRS) is a disease leading to spontaneous abortions and stillbirths in sows and lowered life quality and expectancy in growing pigs. PRRS is prevalent worldwide and has significant economic impacts to swine industries around the globe. Co-expression of the two most abundant proteins in the viral envelope, the matrix protein (M) and glycosylated protein 5 (GP5), can produce a neutralizing immune response for the virus providing a potentially effective subunit vaccine against the disease, but these proteins are difficult to express. The goal of this research was to display antigenic portions of the M and …

Localization Of Arabidopsis Glucan Synthase-Like 5, 8, And 12 To Plasmodesmata Andthe Gsl8-Dependent Role Of Pdlp5 In Regulating Plasmodesmal Permeability, Behnaz Saatian, Susanne Kohalmi, Yuhai Cui

Biology Publications

Cell-to-cell communication via membranous channels called plasmodesmata (PD) plays critical rolesduring plant development and in response to biotic and abiotic stresses. Several enzymes and receptor-like proteins (RLPs), including Arabidopsis thaliana glucan synthase-likes (GSLs), also known as callosesynthases (CALSs), and PD-located proteins (PDLPs), have been implicated in plasmodesmal permeabilityregulation and intercellular communication. Localization of PDLPs to punctate structures at the cellperiphery and their receptor-like identity have raised the hypothesis that PDLPs are involved in theregulation of symplastic trafficking during plant development and in response to endogenous andexogenous signals. Indeed, it was shown that PDLP5 could limit plasmodesmal permeability throughinducing an increase …

A Kin-Selection Model Of Fairness In Heterogeneous Populations, Geoff Wild, Veronica J. Flear, Graham J. Thompson

Biology Publications

Humans and other primates exhibit pro-social preferences for fairness. These preferences are thought to be reinforced by strong reciprocity, a policy that rewards fair actors and punishes unfair ones. Theories of fairness based on strong reciprocity have been criticized for overlooking the importance of individual differences in socially heterogeneous populations. Here, we explore the evolution of fairness in a heterogeneous population. We analyse the Ultimatum Game in cases where players’ roles in the game are determined by their status. Importantly, our model allows for non-random pairing of players, and so we also explore the role played by kin selection in …

Characterizing The Function Of B Cells That Accumulate In The Inflamed Central Nervous System In Anti-Myelin Autoimmunity, Lika Chowdhury

Electronic Thesis and Dissertation Repository

While the role of autoimmune T cells has been extensively studied in anti-myelin

autoimmunity, little is known about the function of B cells in multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS). B cells form clusters with T cells in the meninges directly adjacent to demyelinating lesions. Previous studies have shown that disease progression is dependent on the depletion of specific populations of B cells, but it is not clear which contributes to pathology or how. The purpose of this thesis is to characterize the population of meningeal B cells to determine how they differ …

Deciphering The Role Of Spl12 And Agl6 From A Genetic Module That Functions In Nodulation And Root Regeneration In Medicago Sativa., Vida Nasrollahi, Ze-Chun Yuan, Qing Shi Mimmie Lu, Tim Mcdowell, Susanne Kohalmi, Abdelali Hannoufa

Biology Publications

Our results show that SPL12 plays a crucial role in regulating nodule development in Medicago sativa L. (alfalfa), and that AGL6 is targeted and downregulated by SPL12. Root architecture in plants is critical because of its role in controlling nutrient cycling, water use efficiency and response to biotic and abiotic stress factors. The small RNA, microRNA156 (miR156), is highly conserved in plants, where it functions by silencing a group of SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors. We previously showed that transgenic Medicago sativa (alfalfa) plants overexpressing miR156 display increased nodulation, improved nitrogen fixation and enhanced root regenerative capacity during vegetative …

Root-Inhabiting And Rhizosphere Mycobiomes And Crop Yield Of Corn And Wheat, Marianna E. Wallace

Electronic Thesis and Dissertation Repository

The root mycobiome plays a direct role in plant productivity, and the study of its community composition allows for identification of organisms that influence plant health. To better understand the role of fungal community composition in crop productivity, the root-associated mycobiomes of historically high and low yield sites of corn and wheat planted in rotation were characterized and analyzed along with soil physicochemical variables and crop yield. In each field studied, root and rhizosphere mycobiomes reflected significant differences in fungal species composition. Several soil variables were found to be predictors of differences in composition of sample types including soil texture …

The Brain-Gut Axis Of Honeybees: Testing How Microbiota Affect Individual And Social Behaviour, Julia F. Lacika, Shenella George

Undergraduate Student Research Internships Conference

No abstract provided.

My Summer Working With Two-Spotted Spider Mites, Renée A. Smith

Undergraduate Student Research Internships Conference

Two-spotted spider mites are a polyphagous pest, capable of eating a magnitude of food crops which causes a large problem for Canadian agriculture. Their ability to consume various crops stems from their ability to adapt to various chemical defence mechanisms. This ability allows them to acquire resistance to many commonly used pesticides. This has resulted in large infections in Canadian farms with few options to prevent the pests from affecting crop yields. Take a look at my project if you'd like to see how the Grbic lab is working to combat this issue using genetic engineering techniques!

A Bacterial Microbiome Analysis Of Solarized Ginseng Garden Soils, Anka Colo

Undergraduate Student Research Internships Conference

American ginseng (Panax quinquefolius) is a highly valued perennial crop grown for its roots during a four-year cultivation cycle. American ginseng is subject to ginseng replant disease (GRD) in which severe root rot develops in newly planted ginseng grown in a former ginseng garden. A common strategy to mitigating GRD is not available and techniques such as fumigation, fungicides, and biocontrol are ineffective, banned, or are slowly being phased out. Alternatively, soil solarization is a pre-plant technique used to treat soil to reduce disease inoculum and alter soil microbiomes. In summer 2019, a six-week soil solarization experiment was …

Inside Insects - Climate Change And Metamorphosis, Cailyn R. Mckay

Undergraduate Student Research Internships Conference

Climate change is causing extreme environmental conditions including an increase in the frequency of heat waves which have the potential to seriously impact insect species, particularly during the sedentary pupal stage. The true armyworm is used here as a model species to evaluate the effects of simulated heat waves on reproductive activity and output later in life. Heat waves had a negative impact on moth reproduction and could be impacting the ecology of the species today and in the future.

Screening For The Effects Of Signalling Types In Fruitless Containing Neuron Affecting Social Space And Climbing, Khadijat Oluwakemi Mosuro

Undergraduate Student Research Internships Conference

Knockdown of neurotransmitter signalling types in the Fruitless neuron to see how they affect social space and climbing in the Drosophila melanogaster

Manipulating The Root Mycobiome To Improve Plant Performance And Reduce Pathogen Pressure In Corn (Zea Mays), Noor F. Saeed Cheema

Electronic Thesis and Dissertation Repository

Crop yield often varies within a field of a single genetically uniform crop plant, with the causes presumed to be a mix of both biotic and abiotic factors. Manipulating crop root mycobiomes could potentially increase yield by reducing pathogen impacts and improving access to soil water and nutrients. This study aimed to identify different fungal inoculation treatments that could increase the growth of corn seedlings sown in low productivity soils to that in high productivity soils and shift the root mycobiome composition. Fungal inoculation treatments did not have significantly different root mycobiome composition than seedlings grown in low yield control …

Characterization Of Galectin-16 Expression And Function In Placental Cells, Jennifer Kaminker

Electronic Thesis and Dissertation Repository

The processes of cellular differentiation and apoptosis are critical for placental development. The galectin-16 gene (LGALS16) is associated with these processes in the placenta, but the mechanism by which it acts is poorly characterized. My bioinformatics analysis revealed that LGALS16 expression was limited to specific tissues including the placenta and identified multiple regulatory molecules (transcription factors and miRNAs), which could potentially control relevant transcriptional and post-transcriptional mechanisms. Considering the predominant expression of LGALS16 in placenta, I examined the expression, regulation, and function of LGALS16 in BeWo and JEG-3 cell lines representing in vitro models of trophoblast differentiation. In …

Long-Term Winter-Site Fidelity In Song Sparrows (Melospiza Melodia), Tosha R. Kelly, Keith A. Hobson, Garth @. Casbourn, Elizabeth A. Macdougall-Shackleton, Scott A. Macdougall-Shackleton

Biology Publications

In migratory animals, the degree to which individuals return to the same wintering sites across multiple years can affect fitness and population dynamics, and thus has important implications for conservation. Despite this, long-term evaluations of wintering-site fidelity are rare for migratory birds: many populations are intensively studied on their breeding grounds but tracking the migratory movements of small birds once they leave the breeding grounds is challenging. To evaluate patterns of overwintering location and fidelity, we collected winter-grown claw tissue from 301 Song Sparrows (Melospiza melodia; 449 samples) captured in spring at their breeding grounds over six consecutive …

No Evidence That Songbirds Use Odour Cues To Avoid Malaria-Infected Conspecifics, Leanne A. Grieves, Elizabeth A. Macdougall-Shackleton

Biology Publications

Many animals have evolved mechanisms to detect and avoid parasitized conspecifics, primarily through odour cues, but whether birds are capable of odour-mediated parasite avoidance is unknown. Recently, we showed that exposing song sparrows (Melospiza melodia) to avian malaria parasites (Plasmodium sp.) alters the chemical composition of their preen oil, which is the major source of body odour in birds. Here, we presented song sparrows with preen oil from uninfected (sham-inoculated) and malaria-infected conspecifics, predicting that birds would spend more time with odour cues from uninfected than infected birds. Birds without detectable malarial infections spent about 50% more …

The Effect Of Breathing Patterns Common To Competitive Swimming On Gas Exchange And Muscle Deoxygenation During Heavy-Intensity Fartlek Exercise, Kevin J. Grossman

Electronic Thesis and Dissertation Repository

The purpose of this study was to compare the respiratory and muscle deoxygenation (HHb) responses of regulated breathing versus free-breathing, during continuous exercise (CONLD) and intermittent 5s breath holds (BH) (CONLD-BH), intermittent 5s sprint (FLK) and combined 5s BH and sprint (FLK-BH) followed by 25s of free-breathing. Oxygen uptake(V̇O₂)was unchanged between CONLD (2.12±0.35L/min) and CONLD-BH (2.15±0.42L/min; p=0.116), and FLK (2.24±0.40L/min) and FLK-BH (2.20±0.45L/min; p=0.861). Δ[Hb_tot]: CONLD (3.3±1.6µM) > CONLD-BH (-2.5±1.2µM; ∆177%; p<0.001), but unchanged between FLK (2.0±1.6µM) and FLK-BH (0.82±1.4µM; p=0.979). Δ[HHb]: CONLD (7.3±1.8µM) > CONLD-BH (7.0±2.0µM; ∆4%; p=0.011), and FLK (6.7±1.8µM) < FLK-BH (8.7±2.4µM; p<0.001). It is suggested that the unchanged V̇O₂ between CONLD and CONLD-BH was supported by increased deoxygenation, reflected by decreased ∆[Hb_tot] and blunted …

Seasonal Migration Distance Varies With Natal Dispersal And Predicts Parasitic Infection In Song Sparrows, Tosha R. Kelly, Heather L. Macgillivray, Yanina Sarquis-Adamson, Matthew J. Watson, Keith A. Hobson, Elizabeth A. Macdougall-Shackleton

Biology Publications

Seasonal migration and natal dispersal represent the major large-scale movements in the lives of animals. Individuals that are relatively prone to movement and exploration might thus be more likely to disperse and also to migrate farther. Such movement might be either negatively associated with parasitic infection (if infection prevents hosts from successful long-distance migration) or positively associated (e.g. if longer-distance migrants encounter more abundant or more diverse parasites). We examined whether natal dispersal tendency predicts seasonal migration distance in song sparrows (Melospiza melodia) and whether migration distance predicts infection with bloodborne parasites upon arrival at the breeding grounds. …

From Individuals To Communities: The Effect Of Climate Change On Ectothermic Predators, Matthew Lawrence Meehan

Electronic Thesis and Dissertation Repository

The living components of ecological systems exist within a nested hierarchy, consisting of individuals, populations, and communities. Because of this nestedness, climate change can greatly impact ecological systems, as whole-organism metabolic and physiological demands change for ectotherms under warming, the effects of which may compound with every succeeding level. Therefore, a multi-level approach can better isolate how climate change will reshape ecological systems. In my doctoral research, I used feeding and mesocosm experiments to examine how climate change affects ectothermic predators at the individual-, population-, and community-level, using mesostigmatic mites (Arachnida: Parasitiformes) as my model predator. My research objectives were …

Effects Of Spatial And Temporal Heterogeneity On The Genetic Diversity Of The Alpine Butterfly Parnassius Smintheus, Mel Lucas

Electronic Thesis and Dissertation Repository

Genetic diversity represents a population’s evolutionary potential, as well as its demographic and evolutionary history. Advances in DNA sequencing have allowed the development of new and potentially powerful methods to quantify this diversity. However, when using these methods best practices for sampling populations and analyzing data are still being developed. Furthermore, while effects of the landscape on spatial patterns of genetic variation have received considerable attention, we have a poorer understanding of how genetic diversity changes as a result of temporal variation in environmental and demographic variables. Here, I take advantage of advances in DNA sequencing to investigate genetic diversity …