Life Sciences Commons^™

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 …

Effects Of Experimental Malaria Infection On Migration Of Yellow-Rumped Warblers (Setophaga Coronata), Rebecca J. Howe

Electronic Thesis and Dissertation Repository

The potential of migratory animals to spread infectious diseases depends on how infection affects movement. If infection delays or slows the speed of travel, transmission to uninfected individuals may be reduced. Whether and how malaria (Plasmodium spp.) affects bird migration has received little experimental research. I captured 40 actively-migrating Yellow-rumped Warblers (Setophaga coronata) at a migration stopover site and held them in captivity. I inoculated 25 with P. cathemerium while 15 received sham inoculations. After 12 days the birds were released. Six P. cathemerium-inoculated birds (24%) developed P. cathemerium infections after inoculation. I radio-tagged all birds, …

Kindlin-1 Is Involved In Spreading, Migration, And Protein Regulation In Epidermal Scc-13 Cells, Naomi Mishan

Electronic Thesis and Dissertation Repository

Kindlin-1 is a scaffold protein linking the cytoskeleton to the extracellular matrix. Loss of function mutations in the FERMT1 gene (encoding Kindlin-1) cause gastrointestinal and skin defects associated with increased susceptibility to aggressive epidermal squamous cell carcinoma (SCC). This study investigated the consequences of targeted FERMT1 inactivation in the SCC-13 cell line of epidermal SCC. My studies demonstrate Kindlin-1 is not essential for SCC-13 proliferation or clonogenic potential in culture. Kindlin-1 was required for cell spreading on collagen I, but not on laminin-332, and its absence enhanced SCC-13 directional migration. Finally, I identified several proteins involved in tumor formation and …

Tracing Nutrient Sources To Lipid Production In Birds And Insects Using Stable Isotope (Δ13c, Δ2h) Tracers: Implications For Nutritional Physiology Of Migratory Species, Libesha Anparasan

Electronic Thesis and Dissertation Repository

Using stable isotope measurements of inert tissues to determine origins and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been attempted. I explored isotopic links between diet and stored lipids in captive White-throated Sparrows (Zonotrichia albicollis) and true armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Isotopic discrimination between body lipids and diet was established as linear calibration functions. Isotopic uptake following a diet switch in moths was used to trace lipid accumulation over time. Isotopic correlations between breath metabolic …

The Relative Importance Of Larval And Adult Nutrition In The Isotopic Profile Of The Spermatophore Produced By The Male True Armyworm Moth (Mythimna Unipuncta) (Haworth)., Aida Parvizi

Electronic Thesis and Dissertation Repository

The wings of true armyworm (Mythimna unipuncta) are metabolically inactive tissue and as their isotopic profiles are determined by resources obtained during larval development, they provide information on natal origin of immigrants. The majority of female immigrants are mated so could the isotopic profiles of spermatophores dissected from her reproductive tract provide information about the natal origin of her mates? However, as spermatophores are produced by metabolically active male accessory glands and could use resources obtained from larval and adult feeding I conducted experiments to determine the relative importance of these two dietary sources on the isotopic profiles …

Growth Characteristics And Lipid Metabolism Of Cultured Migratory Bird Skeletal Muscle Cells, Kevin G. Young

Electronic Thesis and Dissertation Repository

Diets rich in n-3 polyunsaturated fatty acids (PUFA) may alter the muscle metabolism of migratory birds, improving their endurance performance. I established and validated for the first time in vitro muscle models of a migratory songbird (yellow-rumped warbler, Setophaga coronata coronata) and shorebird (sanderling, Calidris alba). To evaluate the role of n-3 PUFA in improving fatty acid metabolism in migratory bird muscle, I measured metabolic outcomes following n-3 PUFA supplementation in these two avian cell types and a murine (Mus musculus, C₂C₁₂) cell line. PUFA supplementation in C₂C₁₂ cells …

Hitchhiker's Guide To Migration: Effects Of Experimental Parasitic Infection And Other Immune Challenges On Migratory Traits Of Sparrows, Tosha R. Kelly

Electronic Thesis and Dissertation Repository

Seasonal migration exposes animals to a variety of habitats and parasites, and if infected migratory birds migrate successfully there is great potential for birds to transport infectious diseases long distances. Our current understanding of whether birds contribute to the spread of disease relies upon observational field studies that are limited in their ability to discern cause from effect. Using captive and field-based experiments for my doctoral research, I answered three research questions: (1) are nocturnal migratory restlessness (Zugunruhe) and body condition affected by mounting an acute phase immune response during migration; (2) what are the impacts of parasitic …

Consequences Of Environmental Mercury Exposure For Migratory Fitness And Survival Of Passerine Birds, Yanju Ma

Electronic Thesis and Dissertation Repository

Mercury (Hg) is a global contaminant that persists in the environment. The organic form, methylmercury (MeHg) has been shown to adversely affect bird immune function, foraging behavior, navigation, and flight ability. Many songbirds migrate seasonally, a process that consists of multiple endurance flights and refueling at stopovers. Current knowledge of the effects of MeHg on songbird migration and survival is mostly speculative. In this thesis, I present three studies of MeHg in migratory songbirds. In Chapter 2, I assessed the breeding ground MeHg exposure (inferred from feather Hg) of 15 songbird species captured during fall migration at bird banding stations …

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 …

Weather And Photoperiod Indices Of Autumn And Winter Dabbling Duck Abundance In The Mississippi And Atlantic Flyways Of North America, Lena M. Van Den Elsen

Electronic Thesis and Dissertation Repository

Climate change may influence autumn and winter distributions of dabbling ducks throughout the Atlantic and Mississippi Flyways of North America. To determine how weather and photoperiod influenced autumn-winter abundances of dabbling ducks at staging areas in eastern North America, I modeled weather and photoperiod variables with rate of change in relative abundance of various dabbling duck species over space and time. Latitude was incorporated into models to determine if changes in duck abundance in relation to weather severity were influenced by locale. Changes in abundance were best described by weather models incorporating temperature and snowfall variables for all species except …

Energetics And Digestive Physiology Of Age Classes Of Songbirds During Fall Migration, Brendan J. Mccabe

Electronic Thesis and Dissertation Repository

Among vertebrates, performance of juveniles is typically poor compared to adults. During fall, North American passerine birds migrate south ahead of deteriorating conditions on northern breeding areas. During this migration, juvenile passerines are typically three or four months old and have predictably poor performances. Differential performance could be due to lack of experience, selection against poor-performing cohort members, or physiological constraints of juveniles. Limited evidence suggests that physiology of juveniles may differ from adults during fall migration. I investigated how body composition, metabolic rate, and digestive physiology of juvenile and adult passerines differ during fall migration. In Chapter Two, I …

Cardiomyocyte Polarity And Embryonic Heart Development: Role Of Rac1, Carmen Leung

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) are the most common human birth defect and the leading cause of death from a birth defect in the first year of life. Thus, a further understanding of the mechanisms underlying CHDs, which could lead to improved diagnosis and treatment, is crucial. The small GTPase, Rac1, acts as a pleiotropic effector of numerous cellular processes; however, little is known about its role in embryonic heart development. The aim of this thesis was to investigate the role of Rac1 signaling in cardiac development. Using the Cre/loxP system, mouse models with an anterior second heart field (SHF) or …

Natural Variation In Malarial Infection And Immune Investment In A Migratory Songbird, And The Effects Of Infection On Flight Performance, Laura Rooney

Electronic Thesis and Dissertation Repository

Endurance flight and immune defense are energetically costly activities for birds, and there may be a trade-off between migration and immune investment. Avian blood parasites consume host resources, which may decrease a bird’s resource pool so that endurance flight and immune defense may not be possible simultaneously. I developed a molecular method to detect and quantify blood parasite infection in migrating yellow-rumped warblers (Setophaga coronata), and measured immune activity. I assessed the impact of infection on endurance flight performance and refueling in captive birds. Infection status was not related to age or sex, or timing of migration, and …

The Role Of Islands In The Migration Of Bats Across Lake Erie And Lake Ontario: Lasiurus Borealis, Lasiurus Cinereus And Perimyotis Subflavus, Toby J. Thorne

Electronic Thesis and Dissertation Repository

Large bodies of water, such as the Great Lakes in North America, are potential barriers to migrating bats. Islands may be used as stopover sites by bats crossing the Great Lakes as stopover sites, or included in crossing routes to reduce the distance flown over open water. I predicted that stopover use by migrating bats would result in higher activity on Great Lakes islands during late-season migration than at mainland sites. I monitored acoustic activity at 11 sites across four locations in Ontario: Amherst and Pelee islands, Kingston and Pinery Provincial Park during the summer (June and July), and during …

Immune Function And Infection Status Is Related To Migration Distance And Phases Of The Annual Cycle In Song Sparrows (Melospiza Melodia), Tosha R. Kelly

Electronic Thesis and Dissertation Repository

Life history theory predicts animals adjust immune investment based on their risk of encountering familiar and unfamiliar parasites. Although long-distance migrants may encounter a greater diversity of parasites than short-distance migrants, the energetic costs of migration may constrain immune investment. However, few studies have investigated the relationship between migration distance and immunity. I used stable isotope analysis to estimate the wintering latitude, and thus migration distance, of song sparrows (Melospiza melodia). I assessed whether migration distance was related to the incidence of infection with a blood-borne parasite, parasite load, and immune function. The incidence of infection increased with …

The Effect Of Testosterone On The Spring Migratory Phenotype Of A North American Songbird (Zonotrichia Albicollis), Caitlin L. Vandermeer

Electronic Thesis and Dissertation Repository

In passerines, the endocrine modulators responsible for seasonal changes in migratory behaviour and physiology are unclear. Spring photoperiods alter androgen levels, influencing muscle mass and fat deposition rates to power migration, as well as enhance nocturnal migratory restlessness activity (Zugunruhe). My study compared physiological indicators and migratory restlessness in castrated and intact white-throated sparrows (Zonotrichia albicollis) following photoperiod and hormone manipulation. Nocturnal restlessness activity was highest in migratory intact males or migratory castrated males that received testosterone replacement. Liver mass decreased in all photostimulated migratory groups regardless of testosterone treatment. Likewise, oxidative enzyme activity was unrelated to testosterone, …

Tundra Swan (Cygnus Columbianus Columbianus) Habitat Selection During The Nonbreeding Period, Katelyn H. A. Weaver

Electronic Thesis and Dissertation Repository

Changes in availability and foraging profitability of agricultural and aquatic habitats have the potential to greatly influence population dynamics of waterfowl. Therefore, the purpose of my research was to understand habitat selection by Tundra Swans during the nonbreeding period and to explore the scale-dependency of these relationships. Habitat selection was influenced by seasonal changes in nutritional requirements and food availability; Tundra Swans selected open water and agriculture in winter, wetlands were weakly selected during migration when open water was strongly selected (especially during autumn), and there was a 2-fold increase in use of agriculture from autumn to spring. It appears …

Functional Significance Of Ilk-Elmo2 Interactions In Epidermal Keratinocytes, Ernest Ho

Electronic Thesis and Dissertation Repository

The epidermis consists of a basal layer of undifferentiated keratinocytes and multiple suprabasal layers of differentiated keratinocytes. Undifferentiated keratinocytes are adherent and highly motile, whereas differentiated keratinocytes are comparatively less motile and downregulate cell attachments to the extracellular matrix. Integrin-linked kinase (ILK) is a scaffold protein implicated in the regulation of many cellular functions in keratinocytes, including cell attachment, migration, phagocytosis, and protein trafficking. To determine the mechanisms by which ILK is involved in these processes, I sought to identify other proteins which may interact with ILK in keratinocytes. I identified Engulfment and Cell Motility 2 (ELMO2) to interact with …

Dynamics Of Fat And Lean Mass In Refuelling Migrant Passerines Measured Using Quantitative Magnetic Resonance, Lisa V. Kennedy

Electronic Thesis and Dissertation Repository

Although fat deposition during stopover in migrating passerine birds has been extensively studied, changes in lean mass during refuelling are not well understood. I used quantitative magnetic resonance (QMR) analysis to measure the deposition of fat and lean mass for both recaptured and single capture migrant passerines in spring and fall at Long Point, Ontario. Both the recapture analysis and single capture regression analysis indicated a substantial contribution of lean mass to overall increases in total body mass. Some of the variation in the relative deposition of fat and lean mass was explained by sex, age and season. I then …

Stable Isotope Analyses Of Bat Fur: Applications For Investigating North American Bat Migration, Erin E. Fraser

Electronic Thesis and Dissertation Repository

Many aspects of North American bat migration are not well documented. Stable isotope analyses of animal tissues can elucidate migratory origin, but this technique has not been widely applied to bats. This dissertation i) uses fur stable isotope analyses to investigate North American bat migration and ii) highlights some of the strengths and weaknesses of this analytical technique when applied to bat systems. I conducted stable hydrogen, carbon, and nitrogen isotope analyses on fur from five bat species.

I documented δD_fur heterogeneity in summer resident populations of Myotis lucifugus, Lasiurus borealis, Lasiurus cinereus, and Lasionycteris noctivagans. Stable …