Resource Selection, Survival, And Departure Of Adult Female Mallards From The Lake St. Clair Region During Autumn And Winter, Matthew Palumbo

Electronic Thesis and Dissertation Repository

During autumn and winter, mallards (Anas platyrhynchos) maximize fitness through their spatiotemporal distribution to avoid mortality risks while balancing trade-offs to access foods to undergo migration and maintain homeostasis. Thousands of mallards use Lake St. Clair as it is an important, but threatened, migratory staging area in the Great Lakes. My goal was to understand how mallards were selecting resources in the region and potential relationships of selection strategies. My objectives were to estimate resource selection of adult female mallards, in relation to perceived risk of hunting mortality, and determine if selection strategies were related to survival and …

Regulation Of Liver Mitochondrial Metabolism During Hibernation By Post-Translational Modification, Katherine E. Mathers

Electronic Thesis and Dissertation Repository

Hibernation, characterized by a seasonal reduction in metabolism and body temperature, allows animals to conserve energy when environmental conditions (e.g. temperature, food availability) are unfavourable. During hibernation, small mammals such as the 13-lined ground squirrel (Ictidomys tridecemlineatus) cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5 °C, and interbout euthermia (IBE), where metabolic rate and body temperature rapidly increase and are maintained at euthermic levels several hours. Suppression of metabolism during entrance into torpor is paralleled by rapid suppression of liver mitochondrial metabolism. In my thesis, I …

Chromatin Accessibility Dynamics In The Arabidopsis Root Epidermis And Endodermis During Cold Acclimation, Shawn Hoogstra

Electronic Thesis and Dissertation Repository

Understanding cell-type specific transcriptional responses to environmental conditions is limited by a lack of knowledge of transcriptional control due to epigenetic dynamics. Additionally, cell-type analyses are limited by difficulties in applying current technologies to single cell-types. A novel DNase-seq protocol and analysis procedure, deemed DNase-DTS, was developed to identify DHSs in the Arabidopsis epidermis and endodermis under control and cold acclimation conditions. Results identified thousands of DHSs within each cell-type and experimental condition. DHSs showed strong association to gene expression, DNA methylation, and histone modifications. A priori mapping of existing DNA binding motifs within accessible genes and the cold C-repeat/dehydration …

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner

Electronic Thesis and Dissertation Repository

Behavioural isolation can occur due to divergence in aspects of courtship and mating, and can contribute to reproductive isolation. The purpose of this study is to determine how a gene, Mekk1, contributes to female rejection behaviour between D. melanogaster and D. simulans. Unique polymorphisms were identified within D. simulans Mekk1 that could contribute to behaviour, most of which are non-coding. Both transcripts of Mekk1 appear to be expressed at similar levels in D. simulans and D. melanogaster. These data also indicate that Mekk1 may be expressed in a specific region of the brain called the mushroom body, …

Exploiting Fission Yeast Genetic Interaction Data To Identify Disease-Specific Drug Targets For Tuberous Sclerosis Complex, Ashyad Rayhan

Electronic Thesis and Dissertation Repository

Tuberous sclerosis complex (TSC) is an inherited genetic disorder caused by loss-of-function mutations in either TSC1 or TSC2. Their respective gene products regulate the mechanistic target of rapamycin (mTOR) signaling pathway, which serves as an activator of cellular proliferation, metabolism, and cell survival. Orthologs of the TSC1 and TSC2 genes exist in a wide range of organisms, including the commonly used and genetically tractable model eukaryote, Schizosaccharomyces pombe. To better understand the functional roles of S. pombe tsc1 and tsc2, I exploited recent advances in genetic interaction biology to identify and characterize genes that modulate the phenotypic …

Characterization Of Six Arabidopsis Arogenate Dehydratase Promoters, Emily J. Cornelius

Electronic Thesis and Dissertation Repository

Phenylalanine is an important aromatic amino acid synthesized by higher plants, and is a major component of numerous specialized metabolites including structural components, pigments, and defense compounds. The last step in the synthesis of phenylalanine is catalyzed by an enzyme called AROGENATE DEHYDRATASE, of which there are six different isoenzymes encoded by the Arabidopsis genome. All six have specialized roles within the plant, and are differentially expressed during development and under stressful conditions. To deduce the specialized role of each ADT, unique patterns of regulatory motifs were identified for all six ADT promoters, as well as corresponding transcription factors with …

Assessing Landscape Effects On Genetics And Dispersal Of The Rocky Mountain Apollo Butterfly Parnassius Smintheus Using A Resistance Mapping Approach, Ning Chen

Electronic Thesis and Dissertation Repository

Landscape variables that best explain genetic differentiation may not also best explain dispersal patterns, but many studies use genetic differentiation as a proxy for dispersal. I tested the effects of landscape on both genetic differentiation and dispersal in parallel, to explore whether landscape effects on genetic differentiation between populations and landscape effects on dispersal would be comparable in such contexts. I used circuit theory (Circuitscape) and least cost transect analysis to evaluate the effects of landscape on both movement and genetic differentiation of the butterfly, Parnassius smintheus, in the Jumpingpound Ridge study system. Circuit theory and least cost transect …

Induction Of Alternative Pathway Respiration By Nitrate In Chlamydomonas, Shanmugasundaram Pakkiriswami

Electronic Thesis and Dissertation Repository

Abstract

Besides the ubiquitous cytochrome pathway of mitochondrial respiration, the green algae Chlamydomonas reinhardtii possesses an alternative pathway of respiration, which is comprised of a single protein, alternative oxidase (AOX). AOX is induced when C. reinhardtii cells are shifted from a growth medium containing ammonium as the nitrogen source to one with nitrate. The primary aim of this thesis was to understand the metabolic connections between nitrate assimilation and the induction of the alternative pathway. That these two metabolic processes are closely linked is supported by the fact that a gene encoding AOX (AOX1) is clustered with the …

Characterization Of Acaricide Resistance, Plant-Mediated Rnai Against Two-Spotted Spider Mites (Tetranychus Urticae Koch), And Assessing Off- And Non-Target Effects, Hooman Hosseinzadeh Namin

Electronic Thesis and Dissertation Repository

The two-spotted spider mite (TSSM), Tetranychus urticae (Koch), is one of the most damaging agricultural pests in the world. It feeds on over 150 crops, causing considerable yield losses in greenhouses and agricultural fields. Currently, using synthetic acaricides is the main method to control TSSM. However, it can develop resistance to acaricides with repeated exposure, and typically resistance can occur within two to four years. To understand the underlying mechanisms of spider mite adaptation to acaricides is an essential part of resistance management strategy. The resistance ratio of the pyridaben-selected strain compared with the pre-selection strain was estimated at greater …

The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen

Electronic Thesis and Dissertation Repository

The cabbage looper, Trichoplusia ni, a global generalist lepidopteran pest, has developed resistance to many synthetic and biological insecticides, requiring effective and environmentally acceptable alternatives. One possibility is the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). This baculovirus is highly infectious for T. ni, with potential as a biocontrol agent, however, its effectiveness is strongly influenced by dietary context. In this study, microscopy and transcriptomics were used to examine how the efficacy of this virus was affected when T. ni larvae were raised on different diets. Larvae raised on potato host plants had lower chitinase and chitin deacetylase transcript levels …

The Lasting Effects Of Perceived Predation Risk On The Avian Brain And Behaviour, Lauren E. Witterick

Electronic Thesis and Dissertation Repository

Predators affect prey populations not only through direct killing, but also through perceived predation risk – the ‘fear’ of predators. Responding to predation risk is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to population level effects. I manipulated perceived predation risk using auditory playbacks of predators or non-predators in wild caught black-capped chickadees (Poecile atricapillus) in acoustic isolation and wild caught brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. I found changes in dendritic morphology and inhibited neurogenesis in response to increased perceived predation risk lasting at …

The Genetic And Environmental Basis For Chc Biosynthesis In Drosophila, Heather Ke Ward

Electronic Thesis and Dissertation Repository

Cuticular hydrocarbons (CHCs) are produced by insects and primarily used to prevent desiccation. In Drosophila, certain compounds have secondary roles as infochemicals that may act during courtship to influence mate choice. Certain CHCs may stimulate courtship with heterospecifics or act to repel conspecifics. The CHC profile produced by an individual is the result of the interaction between its genetic background and the environment, though the genes that underlie species differences in CHC production and how the environment can modulate the abundance of individual compounds within a species is not well known. Here, candidate gene CG5946 was found to be …

Elevated Temperature And Co2 Concentrations Affect Carbon Flux In Two Boreal Conifers, Sasha Madhavji

Electronic Thesis and Dissertation Repository

Elevated temperatures and CO₂ will alter carbon flux in two dominant boreal tree species Picea mariana (black spruce) and Larix laricina (tamarack). Trees were grown in three temperature treatments (ambient, ambient +4 °C, and ambient +8 °C) at either 400 ppm or 750 ppm CO₂, to simulate climate conditions between now and the year 2100. Spruce acclimated to increasing temperature detractively; warming scenarios reduced spruce net carbon gain. Tamarack maintained comparable levels of net photosynthesis (A_net) across warming treatments and both species acclimated respiration (R_dark) with increasing growth temperature. Elevated CO₂-grown …

Expression And Characterization Of A Putative Βeta-Glycosidase From The Ginseng Pathogen Pythium Irregulare, Scarlett Puebla Barragan

Electronic Thesis and Dissertation Repository

A putative ginsenosidase (PiGH1-x) from the oomycete pathogen of American Ginseng, Pythium irregulare, was expressed in E. coli DH5α to assess its capability to partially deglycosylate ginsenosides. The recombinant protein was extracted using non-denaturing and denaturing conditions and purified using gel filtration chromatography and nickel affinity purification. Glycosidase activity was tested using p-nitrophenyl β-D-glucopyranoside (pNPG) as the substrate and measured through spectrophotometry. Ginsenosidase activity was tested using ginsenoside Rb1 as the substrate, reaction products were identified using LC-MS. Recombinant PiGH1-x cleaved glucose from pNPG, and converted ginsenoside Rb1 into Rd and Gypenoside XVII, demonstrating both (12) and (16) glycosidase activity. …

Transcriptional Regulation Of Cell-Type Specific Expression In The Arabidopsis Root, Keegan M. Leckie

Electronic Thesis and Dissertation Repository

Characterizing transcription factor interactions with their corresponding binding sites is crucial for understanding how gene expression is regulated by DNA sequence. A more comprehensive understanding of this process could have benefits in synthetic promoter design and creation of genetically modified organisms. Herein, the promoters of genes exhibiting cell-type specific expression within a single layer of the Arabidopsis root are analyzed to identify cis-regulatory motifs implicated in cell-type specific expression. De novo motif prediction identifies multiple motif candidates overly represented in the promoter sequences of co-expressed genes specific for epidermal, cortex, and endodermal expression. Several endodermal specific putative motifs are …

Winter Warming Affects The Onset Of Reproduction But Not Cognition Or The Hippocampus In Black-Capped Chickadees (Poecile Atricapillus), Robert J. Martin

Electronic Thesis and Dissertation Repository

The effects of overwinter temperature on behaviour and cognition, hippocampal volume, and reproductive timing were studied in Black-capped chickadees (Poecile atricapillus). I hypothesized that overwinter temperature would have varied effects for Black-capped chickadees that overwinter in northern climates. I found that temperature had no effect on behaviour and cognition, or hippocampal volume, but temperature did influence reproductive timing. Birds that experienced warmer winter conditions had significantly more developed gonads than birds that experienced colder conditions. These results suggest that while birds are clearly sensitive to ambient winter temperature, temperature only modulates some processes and not all. These studies …

Regulation Of Learning And Memory By The Drosophila Melanogaster Swi/Snf Complex, Max H. Stone

Electronic Thesis and Dissertation Repository

The SWI/SNF complex is a highly-conserved ATP-dependent chromatin remodelling complex that is important in the etiology of intellectual disability (ID). I systematically investigated the overall and adult-specific roles of each of the 15 Drosophila melanogaster SWI/SNF complex components in memory. Flies with RNAi-mediated knockdown of individual SWI/SNF genes in the mushroom body (MB) were tested for short- and long-term memory impairment using courtship conditioning. Knockdown of several SWI/SNF genes through development, including brahma, Bap60, Snr1, and e(y)3, caused loss of memory. Adult-specific knockdown of SWI/SNF genes caused some loss of memory phenotypes, indicating an acute role in adult MB activity. …

Energetics Of Migratory Bats During Stopover: A Test Of The Torpor-Assisted Migration Hypothesis, Dylan E. Baloun

Electronic Thesis and Dissertation Repository

The torpor-assisted migration hypothesis posits that during stopover bats regulate time in torpor facultatively so that daily energy expenditure is independent of ambient roosting temperature. However, direct measurements of total roosting energy expenditure in relation to ambient and body temperature are lacking. I captured migratory silver-haired bats (Lasionycteris noctivagans) at Long Point, Ontario in spring and fall 2016. I used quantitative magnetic resonance analysis to measure full-day energy expenditure of bats roosting at 10, 17 and 25°C and assessed the effects of migration season, body mass, sex and age on energy use. I found that daily energy expenditure …

Too Important To Tamper With: Predation Risk Affects Body Mass And Escape Behaviour But Not Escape Ability, Benjamin T. Walters, Tin Nok Natalie Cheng, Justin Doyle, Chistopher G. Guglielmo, Michael Clinchy, Liana Y. Zanette

Biology Publications

Escaping from a predator is a matter of life or death, and prey are expected to adaptively alter their physiology under chronic predation risk in ways that may affect escape. Theoretical models assume that escape performance is mass dependent, whereby scared prey strategically maintain an optimal body mass to enhance escape. Experiments testing the mass-dependent predation risk hypothesis have demonstrated that prior experience of predation risk can affect body mass, and the behavioural decisions about evasive actions to take. Other studies on natural changes in body mass indicate that mass can affect escape. No single experiment has tested if all …

Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor

Electronic Thesis and Dissertation Repository

Over time, genetic differences can accumulate between populations that are geographically separated. This genetic divergence can lead to the evolution of reproductive isolating mechanisms that reduce gene flow between the populations and, upon secondary contact, result in distinct species. The process of speciation is, thus, what accounts for the multitude of species that contribute to the rich biodiversity on Earth. Interspecies hybrid sterility is a postzygotic isolating mechanism that affects the development of hybrids, rendering them sterile. A notable trend, known as Haldane's Rule, describes that heterogametic individual (e.g. males in Drosophila) are more susceptible to sterility than homogametic …

Insect Immunity Varies Idiosyncratically During Overwintering., Laura V Ferguson, Brent J Sinclair

Biology Publications

Overwintering insects face multiple stressors, including pathogen and parasite pressures that shift with seasons. However, we know little of how the insect immune system fluctuates with season, particularly in the overwintering period. To understand how immune activity changes across autumn, winter, and spring, we tracked immune activity of three temperate insects that overwinter as larvae: a weevil (Curculio sp., Coleoptera), gallfly (Eurosta solidaginis, Diptera), and larvae of the lepidopteran Pyrrharctia isabella. We measured baseline circulating hemocyte numbers, phenoloxidase activity, and humoral antimicrobial activity, as well as survival of fungal infection and melanization response at 12°C and 25°C to capture any …

Transcriptomic Correlates Of Caste Differentiation And Invasiveness In A Subterranean Termite, Tian Wu

Electronic Thesis and Dissertation Repository

Termite colonies are characterized by a division of labour into reproductive and helper castes (soldiers and workers). Caste differentiation is associated with differences in gene expression that reflect developmental and evolutionary origins. I used RNA-seq to investigate genome-wide expression patterns of reproductive nymph, soldier, and worker castes of Reticulitermes flavipes from three populations. I found 93 genes differentially expressed as a function of caste, with the majority of genes being uniquely up-regulated in soldiers. My findings suggest that soldiers evolved genes that are distinct from nymphs and workers, and are signs of possible genomic novelty. I also analyzed this transcriptome …

Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun

Electronic Thesis and Dissertation Repository

Speciation can occur when accumulated differences in mating behavior force diverging species to remain reproductively isolated from one another. A key determinant of behavioural isolation is the evolution of female mating preferences that prevent interspecific males from mating. However, no individual genes involved in species-specific preferences of females have yet been identified. Using various genetic mapping techniques available for studying strains and species of Drosophila, I identify candidate genes involved in D. simulans female discrimination against D. melanogaster males. One candidate gene in particular, Katanin-60, was selected for further characterization. Katanin-60 is a gene encoding a microtubule severing …

The Influence Of Adjacent Forest And Agriculture On Restored Grassland Diversity And Composition, Rachel A. Chambers

Electronic Thesis and Dissertation Repository

Little native grassland remains in North America due to land-use changes. Conversion to agriculture is a common means of loss. This fragmentation creates edges in the landscape and associated edge effects. Grassland plant communities are susceptible to edge effects, directly via dispersal and indirectly through environment. This study took place in Norfolk County, Ontario, Canada, in a landscape of agriculture, forest, rural development, and patches of grassland restored by Nature Conservancy Canada. I examined restored grassland edges bordering forest and crops. An intensive study at a single site identified spatial and soil environmental influences on plant diversity and composition. I …

Gatekeepers Of Nitrogen-Fixing Symbiosis: Cytokinin-Ethylene Crosstalk Regulates Symbiotic Interaction In Lotus Japonicus, Seyedehmandana Miri

Electronic Thesis and Dissertation Repository

Leguminous plants thrive under nitrogen-limited soil conditions because of their ability to symbiotically interact with nitrogen-fixing bacteria, known as rhizobia. In the presence of compatible strains of rhizobia, they develop specialized symbiotic organs, called root nodules, which host the bacteria and provide the appropriate conditions for symbiotic nitrogen fixation to occur. The plant hormone cytokinin is the key endogenous trigger for the inception of root nodule organogenesis. In the model legume Lotus japonicus, analysis of the cytokinin receptor gene Lotus histidine kinase 1 (Lhk1) showed that it is required and also sufficient for the initiation of nodule …

Thermal Preference And Performance In A Sub-Antarctic Caterpillar: A Test Of The Coadaptation Hypothesis And Its Alternatives., Tanya M Haupt, Brent J Sinclair, Steven L Chown

Biology Publications

Physiological ecologists have long assumed that thermoregulatory behaviour will evolve to optimise physiological performance. The coadaptation hypothesis predicts that an animal's preferred body temperature will correspond to the temperature at which its performance is optimal. Here we use a strong inference approach to examine the relationship between thermal preference and locomotor performance in the caterpillars of a wingless sub-Antarctic moth, Pringleophaga marioni Viette (Tineidae). The coadaptation hypothesis and its alternatives (suboptimal is optimal, thermodynamic effect, trait variation) are tested. Compared to the optimal movement temperature (22.5°C for field-fresh caterpillars and 25, 20, 22.5, 25 and 20°C following seven day acclimations …

P31. Assessing The Long Term Effects Of Perceived Predation Risk On The Avian Brain, Lauren E. Witterick

Western Research Forum

Predators affect prey populations not only through direct killing, but also through the perception of predation risk. Responding to predator threats is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to the population level. My research focuses on the lasting effects of predator ‘fear’ on the avian brain. I will be using auditory playbacks to manipulate predation risk in black-capped chickadees (Poecile atricapillus) in acoustic isolation and brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. Lasting behavioural changes have been found in black-capped chickadees one week after …

P02. Production Of A Protein Subunit Vaccine For Mannheimia Haemolytica In Lettuce Chloroplasts, Coby K. Martin

Western Research Forum

The cattle industry worldwide is ravaged by bovine respiratory disease (BRD), a bacterial disease caused by Mannheimia haemolytica. We have designed a chimeric protein subunit vaccine against M. haemolytica based on recent evidence demonstrating the protective potential of antigens against a virulence factor, leukotoxin, in addition to a surface lipoprotein. Plant-based production of this protein vaccine provides a safe and inexpensive alternative to traditional production methods. Plant-base production also supports the use of an edible vaccine that will deliver antigens to pharyngeal tissues to provide local immunization against M. haemolytica to prior to its progression into the lungs. Chloroplasts …

The Effects Of Sex, Energy, And Environmental Conditions On The Movement Ecology Of Migratory Bats, Kristin A. Jonasson

Electronic Thesis and Dissertation Repository

Lack of knowledge about the behaviour of migratory species during the migratory period is a major barrier to conservation efforts. In this thesis I focus primarily on differences between the sexes of the bat Lasionycteris noctivagans, during spring migration. Females are pregnant during spring migration and this overlap between migration and reproduction may affect the time and energy management of females as compared to males. In Chapter 2 I examine spring migration phenology of bats at a stopover site. Females arrived earlier than males, likely to give their pups a long growing season. Fat stores appeared to reflect a …

Thermal Biology Of Insect Immunity And Host-Microbe Interactions, Laura V. Ferguson

Electronic Thesis and Dissertation Repository

The influence of temperature on interactions with pathogenic or symbiotic microbes is a driving force behind the survival of insects under climate change. However, we know little of how insects physiologically respond to these pressures. In temperate climates, winter dominates the thermal landscape; thus, I am particularly interested in how cold interacts with insect responses to microbes. Here I explore the thermal biology of the insect immune system and the impacts of cold on host-microbe interactions. First, I demonstrate that acute exposure to cold activates selective components of immunity in Drosophila melanogaster, as a compensatory response to trade-offs or …