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Eliciting The Effect Free Roaming Cats Have On Native Hawaiian Wildlife Using Stable Isotope Analysis, Erin Salano

Theses and Dissertations--Biology

This study measured the concentration of the stable isotopes Carbon and Nitrogen within the tissues of free-roaming and indoor cats on the Hawai’ian islands. This study aimed to determine whether cats are consuming more human provisioned or wild food sources and whether their diet is having a negative impact on endemic species; with a focus on assessing impacts on conserved bird populations. We hypothesized that human provisioned food sources have higher levels of carbon due to the amount of corn fillers within them, while wild food sources are more Nitrogen rich. We found that indoor and feral cats sampled from …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Variation In Behavioral Strategies For Coping With Environmental Uncertainty, Allison Mclaughlin

Theses and Dissertations--Biology

My dissertation investigates how animals behaviorally respond to environmental change, especially when there is limited information about that change. Uncertainty about the environment comes in various forms, including food resources which vary unpredictably and novel cues which present an unknown level of potential risk or benefit. Various behavioral strategies help animals cope with such uncertainty. Tactics to manage unpredictable variation in food include gathering information to reduce uncertainty (sampling) and strategically adjusting preference or aversion to variation in resources (variance-sensitivity). To manage the uncertainty of a novel cue, animals may generalize their previous experience with similar cues, or they may …

Exploring The Molecular Basis Of Touch: A Comparative Analysis Of Gene Expression In Sensory Corpuscle-Rich And Corpuscle-Poor Skin Regions In The Duck, Thomas Hart

Theses and Dissertations--Biology

Cutaneous touch is facilitated by discrete cellular complexes composed of non-neuronal cells associated with mechanoreceptor neuron endings. The non-neuronal cells of these cutaneous end organ complexes (CEOCs) are believed to contribute to touch, but their role in touch sensation remains unclear. To better understand the function of CEOC cells, we sought to characterize the transcriptional profile of CEOC-rich tissue and identify genes expressed in CEOC cells. Bill skin of the tactile foraging Pekin duck (Anas platyrhynchos) is dense with CEOCs, specifically the avian analogs of mammalian Pacinian and Meissner corpuscles, while corpuscles in duck foot skin are scarce. Using RNA …

Examining The Effects Of Hyperglycemia On Retinal Regeneration, Emmanuella Ec Kyllians

Theses and Dissertations--Biology

Diabetes is a disease that affects how the body processes glucose, leading to a cascade of other complications, one of which is diabetic retinopathy (DR). DR is a neurovascular disease that affects the retina and research has revealed the role of retinal neurodegeneration in its development. Animal models like zebrafish have emerged as important tools for studying the molecular and cellular mechanisms underlying DR. On the other hand, retinitis pigmentosa (RP) is a degenerative disease that involves the progressive degeneration of rods and cones, and hyperglycemia has been found to impair regeneration. Therefore, this study aims to examine the effects …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

Parental Effects On Offspring Reaction Norms: Consequences For Complex Phenotypes In Variable Environments, Alexandra G. Cones

Theses and Dissertations--Biology

Organismal traits all exhibit some degree of environmental sensitivity, and both the strength and direction of these phenotypically plastic responses to the environment can evolve in adaptive ways. For example, parents can use information about their own environment to precondition the traits of their offspring so that they thrive in their future environment. This transgenerational plasticity can also alter the plasticity of offspring, but explicit investigations of this specific phenomenon are rare. I begin with a review of the literature and provide a quantitative genetic framework to investigate this phenomenon, which I then explore empirically using avian embryos. The metabolic …

Estrogen Regulation Of Daily Metabolic Rhythms In Female Mice, Oluwabukola Omotola

Theses and Dissertations--Biology

Circadian rhythms are approximately 24-hour cycles of behavior, physiology, and gene expression. In mammals, these circadian rhythms are generated by clocks located in nearly every tissue in the body. The function of circadian clocks is to synchronize physiology and behavior with environmental cycles such as the light-dark cycle. After menopause, when circulating levels of estrogens are very low, women are more susceptible to obesity comorbidities such as metabolic syndrome and cardiovascular disease, suggesting that estrogens regulate these processes. Estrogens could protect females from metabolic dysfunction by regulating circadian rhythms. Consumption of diets that are high in fat contribute to obesity. …

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

The Ecology And Evolution Of Human Reproductive Behavior, Kaylynne Glover

Theses and Dissertations--Biology

The complexity of human reproductive behavior has necessitated its examination through a variety of scientific disciplines, each focusing on specific elements of our biology, behavior, and society. However, this complexity also necessitates that we reintegrate the information learned from each discipline into a single framework, one rooted in the evolutionary principles that have shaped the development of all life on earth. In this dissertation, I use this framework to explore human reproductive behavior, with a particular focus on sexual coercion and fertility-mediated sexual behavior.

In Chapter 1, I introduce the approach taken in this document, identify several key limitations, and …

Impact Of Short Meditation On Attentional Performance, Lauren E. Guerriero

Theses and Dissertations--Biology

Meditation describes a large variety of traditions that all include the conscious focus of attention. By maintaining attention, meditators experience both acute and long-term changes in physiology, anatomy, and cognitive performance. The type of performance benefit is believed to depend, at least in part, on the specific type of mental training. What is much less clear in the literature is the impact of a single session of meditation on the brain and how the acute changes could impact performance. Studies in advanced meditators show an increase in neuronal coordination and slowing of neuronal firing across many regions in the brain, …

The Social Behavior Of Pine Sawflies In The Genus Neodiprion, John W. Terbot Ii

Theses and Dissertations--Biology

Group living is found across the animal kingdom ranging from temporary mating aggregations to complex, eusocial lifestyles. A particularly common form of group living found among insects are larval or nymphal herds. This lifestyle consists of immature insects living together and results in several proposed costs and benefits. Benefits of this lifestyle include improved ability to regulate a group’s microenvironment, more efficient use of their host, and the ability to engage in collective predator defenses. Offsetting these benefits are costs resulting from living in close proximity to conspecifics which include increased competition, greater visibility to predators, and heightened disease risks. …

Characterization Of Spontaneous Preeclampsia In The African Green Monkey (Chlorocebus Aethiops Sabaeus), Chelsea Christina Weaver

Theses and Dissertations--Biology

Hypertensive pregnancy disorders are a major contribution to maternal and neonatal mortality worldwide. Two of these disorders, preeclampsia and chronic hypertension in pregnancy, affect up to 10% of all pregnancies. These hypertensive disorders of pregnancy are associated with long-term, postnatal risk factors for both mother and offspring. Despite numerous recent advances in preeclampsia research, the underlying mechanisms are still not understood. This could be due to lack of a spontaneous animal model. This dissertation presents the African Green Monkey (AGM; Chlorocebus aethiops sabaeus) as the first known spontaneous animal model of preeclampsia and a highly translational model of chronic …

Spontaneous Postpartum Hypertension In The African Green Monkey, Patrick Rivera

Theses and Dissertations--Biology

Postpartum hypertension (PPHT) is a hypertensive disorder of the puerperium that occurs in women at a rate between 0.8-28% although the exact incidence is unknown due primarily to its transient presentation during a time of reduced medical supervision. The etiology of PPHT is currently unknown with no present experimental animal model. We present the African green monkey (Chlorocebus aethiops sabaeus; AGM) as a potentially translational NHP model of PPHT in humans. AGMs were identified as PPHT using Doppler sphygmomanometry and American Heart Association standards of hypertension for systolic blood pressure (systolic blood pressure > 140 mmHg). Disease characteristics were …

Periocular Mesenchyme Heterogeneity During Morphogenesis Of The Vertebrate Ocular Anterior Segment, Kristyn L. Van Der Meulen

Theses and Dissertations--Biology

The vertebrate eye is a complex organ, responsible for the primary sense with which we interact with our environment: vision. Development of the eye is a tightly regulated process, controlled by a vast network of genes. This process begins with eye morphogenesis, when the eye structure is formed through a series of morphogenetic movements and culminates in the creation of the optic cup, lens, and presumptive optic stalk. Next, retinal differentiation creates the critical cell layers of the retina needed to process light waves that enter the eye, including rod and cone photoreceptors, interneurons, and support cells. Failure in either …

Leveraging Transcriptomic Approaches To Identify Differences In Genetic Programming Driving Two Distinct Wound Healing Mechanisms, Regeneration And Fibrosis, In Acomys And Mus, Shishir K. Biswas

Theses and Dissertations--Biology

Why can some animals and others cannot? This fundamental question has fueled scientists studying regeneration for hundreds of years since early observations in crayfish, salamanders and many other organisms. While most contemporary work in regeneration is done in a handful of species including salamanders, zebrafish and flatforms, these organisms lack a closely-related, non-regenerating sister species from which unique genetic differences can be identified. Additionally, while much has been learned from these organisms, they do not share fundamental biological traits with mammals (endothermy, metabolism and immune system) which limits the ability to translate this research for clinical medicine. To this end, …

Molecular Mechanisms Regulating Optic Fissure Fusion During Zebrafish Eye Development, Megan Weaver

Theses and Dissertations--Biology

Vertebrate retinal development requires timely and precise fusion of the optic fissure. Failure of this event leads to congenital vision impairment in the form of coloboma. Recent studies have suggested hyaloid vasculature to be involved in OF fusion. In order to examine this link, we analyzed optic fissure fusion and hyaloid vasculogenesis in the zebrafish pax2a noi mutant line. We first determined that pax2a^-/- embryos fail to accumulate F-actin in the optic fissure prior to basement membrane (BM) degradation. Furthermore, using 3D and live imaging we observed reduced OF hyaloid vascularization in pax2a^-/- embryos. When examining the connection …

The Role Of Melatonin In Biological Rhythms Of Songbirds, Clifford E. Harpole

Theses and Dissertations--Biology

In vertebrates, melatonin is a hormone that is produced and secreted at night and inhibited by light. This unique “darkness-only” expression profile makes it an intellectually appealing candidate for a means of transmitting temporal information to an individual, both time of day and time of year.

In passerine birds, “time of day” information is certainly transmitted via melatonin secretion. The primary producer of systemic melatonin in this family of birds is the pineal gland, and surgical removal of it causes a bird to become arrhythmic in constant conditions. I find that as pinealectomized house sparrows (Passer domesticus) become …

The Effect Of Ph On Synaptic Transmission At The Neuromuscular Junction In Drosophila Melanogaster, Catherine Elizabeth Stanley

Theses and Dissertations--Biology

Synaptic transmission is the main avenue of neuronal communication and can be affected by a multitude of factors, both intracellularly and extracellularly. The effects of pH changes on synaptic transmission have been studied for many years across many different models. Intracellular acidification at the presynaptic terminal is known to occur with increased neuronal activity and can also occur in pathological conditions. The effects of these pH alterations are therefore an important area of study. Here, intracellular acidification using either propionic acid or the ammonium chloride pre-pulse technique was examined for the effects on both spontaneous and evoked synaptic transmission at …

From Organisms To Ecosystems: Impacts Of Limb Loss And Regeneration On Crayfish Behavior, Luc Arnaud Dunoyer

Theses and Dissertations--Biology

The ability of some organisms to regenerate tissues and organs has fascinated naturalists since antiquity, dating back to the earliest accounts of scientific inquiry with Aristotle in Ancient Greece. Then, Darwin’s theory invigorated some scientists’ dream of stimulating (or reactivating) regenerative capacities in human beings by showing that we are related to highly regenerative organisms. More recently, a renewed interest in discovering the molecular and genetic basis for organ and tissue regeneration has led biologists to focus more specifically on a restrictive set of model organisms.

Although the process of limb regeneration is different between invertebrate and vertebrate organisms, it …

Investigation Into The Roles Of Her9 And Capn5 During Retinal Development And Regeneration, Cagney Coomer

Theses and Dissertations--Biology

The formation of a healthy and functioning eye requires coordinated interactions between numerous signaling pathways and gene regulatory networks within the developing neural retina. Tight regulation of gene expression is required for cell specification and differentiation in this multilayered, light sensitive tissue. The photoreceptors are the light detecting cells of the retina, capable of functioning in both intense sunlight and dim light at night. When pigment cells of the photoreceptor outer segment are activated by light, a complex chain of events called phototransduction leads to the electrical signal cascade that is transmitted through the retina and ultimately to the brain …

From Genes To Species: Ecological Speciation With Gene Flow In Neodiprion Pinetum And N. Lecontei, Emily E. Bendall

Theses and Dissertations--Biology

My dissertation focuses on how differences accumulate across the genome during ecological speciation with geneflow. To do this I used two species of Neodiprionpine sawflies, which are plant-feeding hymenopterans with high host specificity. I used experimental crosses to measure both intrinsic and extrinsic postzygotic isolation and to understand the contribution of specific traits to reproductive isolation. Despite substantial genetic divergence and haploid males in which all recessive incompatibilities should be expressed, I found surprisingly little evidence of intrinsic postzygotic isolation. Recombination in hybrid males may reconstitute viable genotypes and counteract the effects of haploidy in males. Nevertheless, hybrids have …

Elucidating The Role Of Light-Induced Circadian Disruption On Atherosclerosis In Apolipoproteine-Deficient Mice, Jeffrey Chalfant

Theses and Dissertations--Biology

Circadian rhythms are approximately 24-hour oscillations of nearly every biological process in the body. The circadian system coordinates these rhythms of physiology and behavior with environmental cycles such as the light-dark cycle. Shift workers, who experience irregular exposure to the light-dark cycle, have chronically disrupted circadian rhythms and increased risk of developing cardiovascular disease, but the mechanisms are unknown. Our studies investigated the effects of light-induced circadian disruption on atherosclerosis in ApolipoproteinE-deficient (ApoE^-/-) mice. We found that male ApoE^-/- mice housed in constant light for 12 weeks, which results in severe disruption of circadian rhythms …

Ecology, Monogamy, And The Evolution Of Animal Families, Jacqueline Rae Dillard

Theses and Dissertations--Biology

Family-living has been recognized as a necessary prerequisite for the evolution of advanced cooperative societies, yet the evolutionary and ecological processes that drive the coupling of different forms of cooperation in family-based societies are still poorly understood. In my dissertation, I investigate the correlated evolution of parental care, monogamy, and cooperative breeding in a variety of family-based taxa. I explore the mating and social behavior of family-living beetles with incipient cooperation to better understand the factors driving these social traits. Specifically, I evaluate different causes of extra-pair mating in socially monogamous beetles, the potential benefits that young adult offspring may …

Intraspecific Variation In Dehydration Tolerance: Insights From The Tropical Plant Marchantia Inflexa, Rose A. Marks

Theses and Dissertations--Biology

Plants are threatened by global change, increasing variability in weather patterns, and associated abiotic stress. Consequently, there is an urgent need to enhance our ability to predict plant community dynamics, shifts in species distributions, and physiological responses to environmental challenges. By building a fundamental understanding of plant stress tolerance, it may be possibly to protect the ecological services, economic industries, and communities that depend on plants. Dehydration tolerance (DhT) is an important mechanism of water stress tolerance with promising translational applications. Here, I take advantage natural variation in DhT to gain a deeper insight into this complex trait. In addition, …

Bioinformatic And Experimental Analyses Of Axolotl Regeneration, Nour W. Al Haj Baddar

Theses and Dissertations--Biology

Salamanders have an extraordinary ability to regenerate appendages after loss or amputation, irrespective of age. My dissertation research explored the possibility that regenerative ability is associated with the evolution of novel, salamander-specific genes. I utilized transcriptional and genomic databases for the axolotl to discover previously unidentified genes, to the exclusion of other vertebrate taxa. Among the genes identified were multiple mmps (Matrix metalloproteases) and a jnk1/mapk8 (c-jun-N-terminal kinase) paralog. MMPs function in extracellular matrix remodeling (ECM) and tissue histolysis, processes that are essential for successful regeneration. Jjnk1/mapk8 plays a pivotal role in regulating transcription in response to cellular stress stimuli, …

The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback

Theses and Dissertations--Biology

The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet …

A Comparative Study Of Sleep, Diurnal Patterns, And Eye Closure Between The House Mouse (Mus Musculus) And African Spiny Mouse (Acomys Cahirinus), Chanung Wang

Theses and Dissertations--Biology

To understand the function and origins of sleep, sleep needs to be studied across many different species. Although it is well conserved throughout mammals, 95% of papers are restricted to just three species, Homo sapiens, Mus musculus, and Rattus norvegicus. We aimed to characterize sleep and wake in a Murid rodent Acomys cahirinus in greater detail alongside the well-studied laboratory house mouse (Mus musculus) and wild M. musculus using a well validated, non-invasive, piezoelectric system for sleep and activity monitoring. We confirmed A. cahirinus, M. musculus, and wild M. musculus to be primarily …

Characterization Of A Large Vertebrate Genome And Homomorphic Sex Chromosomes In The Axolotl, Ambystoma Mexicanum, Melissa Keinath

Theses and Dissertations--Biology

Changes in the structure, content and morphology of chromosomes accumulate over evolutionary time and contribute to cell, developmental and organismal biology. The axolotl (Ambystoma mexicanum) is an important model for studying these changes because: 1) it provides important phylogenetic perspective for reconstructing the evolution of vertebrate genomes and amphibian karyotypes, 2) its genome has evolved to a large size (~10X larger than human) but has maintained gene orders, and 3) it possesses potentially young sex chromosomes that have not undergone extensive differentiation in the structure that is typical of many other vertebrate sex chromosomes (e.g. mammalian XY chromosomes …

Mitochondrial And Nuclear Patterns Of Conflict And Concordance At The Gene, Genome, And Behavioral Scales In Desmognathus Salamanders, Justin D. Kratovil

Theses and Dissertations--Biology

Advancements in molecular sequencing have revealed unexpected cryptic genetic diversity and contrasting evolutionary histories within genes and between genomes of many organisms; often in disagreement with recognized taxonomy. Incongruent patterns between the mitochondrial and nuclear evolutionary history can have several plausible explanations, but widespread systematic conflict inevitably challenges our conceptions of species boundaries when there is discordance between coevolving and coinherited genomes. It is unknown to what degree mitonuclear conflict drives the process of divergence, or how ubiquitous these patterns are across the tree of life. To understand the evolutionary relevance of intergenomic discordance we must identify the conflicting patterns …