Biology Commons^™

Testing Functional Homology Of The Lga2 And Rga2 Genes Of Sporisorium Reilianum In Ustilago Maydis, Joshua Thomas

College of Arts & Sciences Senior Honors Theses

Ustilago maydis, a basidiomycete fungus, infects corn and displays dimorphism, transitioning between nonpathogenic and pathogenic stages. Its life cycle involves mating of haploids with different alleles, resulting in the formation of galls/tumors filled with teliospores. The a1 and a2 alleles regulate pheromone recognition and mating. The lga2 and rga2 genes in the a2 allele are crucial for uniparental mitochondrial inheritance. Sporisorium reilianum, a related fungus, has homologs of lga2 and rga2 with U. maydis. To test the functional homology of the S. reilianum genes, protoplasts of U. maydis strains deleted for lga2 or lga2 and rga2 were transformed …

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald

College of Arts & Sciences Senior Honors Theses

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in Western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …

Impact Of Sodium Benzoate And A High Fat Diet On Kidney Of Mice., Anna Lipinski

College of Arts & Sciences Senior Honors Theses

Sodium Benzoate (SB) is a commonly utilized food preservative with potential therapeutic uses for neurological conditions such as Alzheimer’s disease and hepatic encephalopathy. Consumption of SB is generally regarded as safe (GRAS), by the Food and Drug Administration, at amounts of 0.1% by weight of food. However, previous reports indicate that SB exposure may induce histological alterations in kidney structures and promote oxidative stress. Thus, with increasing obesity rates and fatty diets, the effects of SB coupled to a high fat diet (HFD) remain to be determined. This study addressed the hypothesis that SB with a HFD will increase extracellular …

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Impact Of Lyophilization On Porcine Hemoglobin Properties., Mustafa Almosawi

College of Arts & Sciences Senior Honors Theses

Blood transfusion is the single most often performed lifesaving procedure in hospitals worldwide. Unfortunately, packed red blood cells (RBCs) used for transfusion can only be stored for 42 days at 4 °C before being discarded due to irreversible damage that occurs during storage. Any reduction in available RBCs for an extended period can lead to blood shortages. To increase the shelf-life of RBCs, we investigated freeze-drying (lyophilizing) in the presence of the non-toxic sugar trehalose as a method for long-term preservation. However, the oxidative stress of the lyophilization and storage processes can compromise the functionality of these cells, and the …

The Evolution Of Empathy: Through The Lens Of A Rodent Model., Caroline Driscoll-Braden

Electronic Theses and Dissertations

Empathy is the capacity to be affected by and share the emotions of others, to discern the circumstances prompting another’s emotional state, and to identify with another by adopting their perspective. Research investigating the empathically motivated behavior of rats can help inform the evolutionary history of empathy and provide additional support of the continuity of empathy in animals and humans. In this dissertation, I examine the helping behavior of rats to explore the complexities of rodent empathy. In Chapter I, I review the multiple layers of empathy and describe both historical and contemporary research examining empathy in non-humans. I explain …

The Emerging Oral Pathogen, Filifactor Alocis, Modulates Antimicrobial Responses In Primed Human Neutrophils., Ian J. Snider

College of Arts & Sciences Senior Honors Theses

Periodontitis is an irreversible, chronic inflammatory, infectious disease of the oral cavity that affects approximately half of all adults 30 years or older in the USA. The oral cavity is under high immune surveillance because of its constant exposure to microbes in the environment. The primary immune cell responsible for this surveillance is the neutrophil. Pathogens associated with periodontitis possess virulence factors and have evolved strategies to evade neutrophil antimicrobial responses to survive. One such pathogen is Filifactor alocis, whose presence is associated with the progression of periodontitis. F. alocis manipulates several neutrophil antimicrobial functional responses to avoid killing, an …

Impacts Of Dietary Restriction On A Drosophila Model Of Werner Syndrome, Eileen Sember

College of Arts & Sciences Senior Honors Theses

Werner syndrome (WS) is an autosomal recessive disorder that results in premature aging and occurs in 1 in 1,000,0000 to 1 in 10,000,000 people. In humans, WS is the result of mutations that render the WRN gene, that contains a helicase and an exonuclease domain, non-functional. Currently, there is no cure for WS in humans, making dietary and lifestyle interventions attractive for increasing the quality and longevity of lives. Diet restriction (DR) has been shown to extend the lifespan of several model organisms, including Drosophila melanogaster, making it a strong candidate for WS treatment. In this thesis, mutant flies …

Transmission And The Evolution Of Diseases Caused By Chlamydia Trachomatis, Sars-Cov-2, And Plasmodium Species., Nathan Steffens

Electronic Theses and Dissertations

Principles of natural selection have proven valuable for explaining why pathogens cause the diseases that they do. In theory, the evolved level of host exploitation should reflect how dependent a pathogen is on host health for transmission. This dependency is shaped by transmission mode and transmission opportunity, which should therefore be predictors of disease manifestations. In this dissertation, I apply these principles to investigations of depression in Chlamydia trachomatis and virulence of SARS-COV-2 and Plasmodium species. This dissertation has five chapters. In chapter I, I describe the theoretical foundation of my dissertation research. I also briefly introduce each study system. …

Characterization Of Microbotryum Lychnidis-Dioicae Secreted Effector Proteins That Manipulate Its Host Plant, Silene Latifolia., Ming-Chang Tsai

Electronic Theses and Dissertations

The smut fungal species Microbotryum lychnidis-dioicae is an obligate phytopathogen colonizing the plant host, Silene latifolia. A significant feature of M. lychnidis-dioicae infection is that the fungus can replace pollen on the anthers of susceptible host plants with fungal teliospores, thus earning the fungus the name: anther smut disease of flowers. The fungus synthesizes and secretes effector proteins into the cells of the plant host during infection, and the protein-protein interactions may interfere with and modify metabolism, plant development, and gene expression of the host to allow fungal colonization. Two potential fungal effector proteins, MVLG_06175 and MVLG_05122, were identified …

Functional Role Of Ppal And Potential For Moss In Industrial Applications., Susana Perez Martinez

Electronic Theses and Dissertations

This dissertation is an examination and characterization of the functional roles of PPAL. PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) is a recently discovered gene. PPAL homologs are present in all plants and many animals, where its function is largely unknown. It is possible that PPAL could participate in prenylation processes since it shares similarity to the α subunits of known prenylation enzymes. Prenylation is a post-translational modification of proteins that involves the addition of a lipid moiety to proteins to facilitate membrane targeting and association and promote protein-protein interactions. Prenylation has important roles in plant growth and development, including …

Computational And Biochemical Characterizations Of Anhydrobiosis-Related Intrinsically Disordered Proteins., Brett R. Janis

Electronic Theses and Dissertations

Anhydrobiosis is the remarkable phenomenon of “life without water”. It is a common technique found in plant seeds, and a rare technique utilized by some animals to temporarily stop the clock of life and enter a stasis for up to several millennia by removing all of their cellular water. If this phenomenon can be replicated, then biological and medical materials could be stored at ambient temperatures for centuries, which would address research challenges as well as enhance the availability of medicine in areas of the world where refrigeration, freezing, and cold-chain infrastructure are not developed or infeasible. Furthermore, modifying crop …

Harmful Algal Blooms In The Ohio River: Spatial And Temporal Differences., Bevin Hardy

Electronic Theses and Dissertations

The frequency of harmful algal blooms (HABs) has been increasing across the globe, especially in river ecosystems. Although more common in lakes, more HABs have been reported in rivers in the past decade, particularly in the Ohio River. In 2019, a HAB stretched 200 to 300 miles throughout the Ohio River from September to October. Samples were collected for the duration of the 2019 bloom (August-October) in the McAlpine Pool in Louisville, KY to compare microcystis toxin (microcystin) concentrations on a temporal and spatial scale. Different habitats (bay, creek, river) were sampled throughout the bloom, and two additional sampling days, …

Undergraduate Students Use Moral Reasoning And Belief In Genetic Determinism In Response To A Crispr/Cas9 Socioscientific Issue., Katie M. Seiter

Electronic Theses and Dissertations

This dissertation explores how students reason about genetic engineering socioscientific issues (SSIs) related to a recently developed, powerful genome editing technology called CRISPR/Cas9. It is divided into three chapters. Chapter One describes an exploratory study that characterized students’ moral reasoning using a sociocultural theoretical framework. I used content analysis and logistic regression to investigate how academic and social factors influenced moral reasoning. Students generally opposed the use of CRISPR/Cas9 technology for non-medical enhancements, and the moral considerations used were influenced by genetics knowledge level and demographic variables such as gender and socio-economic status. Further investigation of moral perspectives for students …

On The Straight And Narrow: How Cultural Beliefs About Sex/Gender Manifest In College Biology Learning Environments., Katherine Ray Kng

Electronic Theses and Dissertations

This dissertation focused on the ways that social beliefs about sex/gender and sexuality manifest in biology classrooms. Especially for health science students, classes include topics like sex, sexuality, sexual behaviors, or sex determination that forms the foundation of their understanding of human forms and behaviors. If the information they receive does not include the LGBTQIA+ community, their education will fail to adequately prepare them for the reality of healthcare practice where they will be expected to treat all patients with dignity and respect. There are three chapters in this dissertation. In chapter one, I asked what beliefs about and conceptions …

The Effects Of Ppal-1 In Arabidopsis Gamete Development., Amanda White

College of Arts & Sciences Senior Honors Theses

Prenylation is a type of post-translational modification in which a 15- or 20-carbon lipid is added to the carboxyl (C) terminus of the protein. Arabidopsis thaliana contains the PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) gene, which encodes a protein with homology to the α-subunits of the three known prenylation enzymes, PFT, PGGT, and Rab-GGT. We previously identified two mutations in PPAL, one of which is ppal-1, which contains a T-DNA insertion in the fourth intron. We have previously observed that self-fertilizing heterozygous ppal-1 plants produce progeny in which homozygous ppal-1 is underrepresented. This project attempts to ascertain …

Phytochemical Content And Anti-Breast Cancer Activity Of Kentucky Native Plants., Nicole A. Mcgrath

College of Arts & Sciences Senior Honors Theses

Plants are a proven and rich source of chemical diversity for the development of pharmaceuticals. Plants that are native to Kentucky are an underexplored resource that could lead to advances in treating human diseases such as cancer. Kentucky native plants, especially those with highly diverse or enriched chemical compositions are possible leads for therapeutic drug development. To explore the potential of native Kentucky plants for treatment of breast cancer, a list of prospective target plants was developed based on literature reports. This list was narrowed to 10 tissues for further in-depth chemical analysis including estimation of alkaloids, terpenes, and phenolics, …

Aboveground-Belowground Interactions: Roles Of Soil Biotic And Abiotic Factors On Switchgrass's (Panicum Virgatum) Growth, Defense Against Herbivory And Cell Wall Chemistry., Binod Basyal

Electronic Theses and Dissertations

Plants constantly interact with their biotic and abiotic soil environments. Most terrestrial plants form beneficial associations with soil microbes such as arbuscular mycorrhizal (AM) fungi, which are widely known for their ability to transfer soil phosphorus and nitrogen to the host plants. They help plants tolerate drought stress and improve plant defense against herbivores such as plant-parasitic nematodes (PPNs). This dissertation investigates the role of AM fungi on switchgrass’s (Panicum virgatum) growth, cell wall chemistry, and defense against PPNs using a combination of growth chamber and field studies. Switchgrass is a native warm-season species which is gaining traction as candidate …

Efficient Conditional Inactivation Of Rdh10 Reveals Important Role Of Retinoic Acid During Lung Branching Morphogenesis., Nhut Quang Huy Tran

Electronic Theses and Dissertations

Birth defects are complicated pathological processes. Many birth defects can be traced back to disrupted regulation of molecular signaling pathways during embryogenesis. One of the most important gene regulatory factors during embryo development is retinoic acid (RA). However, studying the specific roles of RA in each organ during embryogenesis in vivo is challenging. The Sandell laboratory has a conditional mutant mouse model that can potentially be used for studying the role of RA during embryogenesis by inducing stage-specific RA deficiency. This model allows retinol dehydrogenase 10 (Rdh10), a gene required for RA production, to be inactivated at a …

Tobacco Enhances Bacterial-Induced Periodontal Bone Loss In Mice., Mina Iskander

Electronic Theses and Dissertations

Background: Tobacco smoking is the leading environmental risk factor for periodontal diseases. Delineation of the mechanisms underlying tobacco-induced or exacerbated periodontitis is hampered by the lack of an appropriate and reliable animal model. Hypothesis: We hypothesized that Porphyromonas-gingivalis-infected, cigarette smoke-exposed mice would represent reproducible models of acute (ligature model) and chronic (oral gavage model) tobacco-enhanced periodontitis that reflect multiple aspects of the disease noted in human smokers. Methods: In a chronic oral gavage disease model, Balb/c mice (6-8 weeks, 4 groups of n = 6 per group) were exposed to smoke produced by a Teague-10 smoking machine from 1R6F research …

Understanding Object Motion Encoding In The Mammalian Retina., Victor Julian Depiero

Electronic Theses and Dissertations

Phototransduction, transmission of visual information down the optic nerve incurs delays on the order of 50 – 100ms. This implies that the neuronal representation of a moving object should lag behind the object’s actual position. However, studies have demonstrated that the visual system compensates for neuronal delays using a predictive mechanism called phase advancing, which shifts the population response toward the leading edge of a moving object’s retinal image. To understand how this compensation is achieved in the retina, I investigated cellular and synaptic mechanisms that drive phase advancing. I used three approaches, each testing phase advancing at a …

Transforming Moss P. Patens With Lignin Peroxidase Through Heterologous Protein Expression., Jesse Lee Rozsa

Electronic Theses and Dissertations

Lignin peroxidase is an enzyme secreted by white-rot fungi Phanerochaete chrysosporium. Our laboratory is attempting to produce several lignin degrading enzymes in our protein expression system that utilizes the moss, Physcomitrella patens. During our experiments we discovered that this particular species of fungus produces altered splicing variants that are not represented in the previously reported reference sequence. Despite several attempts to produce a positive transformant containing a desired transgene encoding; lignin peroxidase, production of the proper construct eluded our efforts, possibly due to toxic effects associated with lignin peroxidase expression. Our laboratory has created a stepping stone for other laboratories …

A Bug Eat Bug World : Does Urbanization Decrease Survivorship Of Pollinators., Amy L. Cherry

College of Arts & Sciences Senior Honors Theses

Human impact on the environment is responsible for the sixth mass extinction on Earth as well as rapid population declines in many taxa. Land use change, via increasing urbanization and intensity of agricultural practices, is the most important aspect of human impact on the environment, and it is associated with population decline and extinction in several taxa, but especially in pollinator species. Pollinators, which are essential for crop production, are experiencing declines as a result of the loss of habitat and host plants associated with urbanization. Urbanization negatively affects pollinators, but in the wake of lost naturalized habitat, some researchers …

Pparγ And High Molecular Weight Adiponectin In White Adipose Tissue In An Obesity Model., Katelyn M. Mcdowell

College of Arts & Sciences Senior Honors Theses

Adiponectin is a protein secreted from adipose (fat) tissue. It is secreted into the blood as either a trimer (low molecular weight), hexamer (middle molecular weight) or an 18-mer (high molecular weight). Adiponectin, particularly the high molecular weight (HMW) isoform, has been shown to increase insulin sensitivity, which is important for maintaining healthy blood glucose levels. Adiponectin levels have been shown to be decreased in individuals who are obese, and this may play a role in the diabetes which often accompanies obesity. PPARγ is a protein that is highly expressed in white adipose tissue and is responsible for regulating portions …

Indole Sensitivity In Various Insect Herbivores., Rakhi Patel

College of Arts & Sciences Senior Honors Theses

When plants in nature are attacked by herbivores, they frequently release airborne volatiles. These herbivore-induced plant volatiles (HIPVs) help plants defend themselves against herbivore attack by calling in natural enemies, but HIPVs may also be directly toxic to herbivores. Indole (C₈H₇N) is a common HIPV that is toxic to caterpillars, but its relative toxicity to different caterpillars has not been explored. I tested the toxicity of indole on six caterpillar species (Spodoptera frugiperda, Trichoplusia ni, Spodoptera exigua, Anticarsia gemmatalis, Heliothis virescens, and Helicoverpa zea). Results show that indole is …

Relationships Of Protein Biomarkers Of The Urokinase Plasminogen Activator System With Expression Of Their Cognate Genes In Primary Breast Carcinomas., Seth B. Sereff

College of Arts & Sciences Senior Honors Theses

Background: Urokinase plasminogen activator (uPA), its receptor uPAR and serine protease inhibitors PAI-1 or PAI-2 play key roles in tissue membrane remodeling and invasion of basement membranes by induction of a fibrinolytic pathway. Earlier studies reported that uPA and PAI-1 protein levels in breast carcinomas assist in prediction of response to chemotherapy. Our goal is to develop molecular signatures of candidate genes and identify novel relationships with these four protein biomarkers that demonstrate clinical utility for assessment of breast carcinoma outcomes.

Methods: This retrospective study used de-identified biomarker results and clinical outcomes from primary breast cancers that were stored in …

Defects In Fetal Mouth Movement And Pharyngeal Patterning Underlie Cleft Palate Caused By Retinoid Deficiency., Regina Friedl

Electronic Theses and Dissertations

Cleft palate is a common birth defect. Etiologic mechanisms of palate cleft include defects in palate morphogenesis, mandibular growth, or spontaneous fetal mouth movement. Cleft palate linked to deficient fetal mouth movement has been demonstrated directly only in a single experimental model of loss of neurotransmission. Here, using retinoid deficient mouse embryos, we demonstrate directly for the first time that deficient fetal mouth movement and cleft palate occurs as a result of mis-patterned development of pharyngeal peripheral nerves and cartilages. Retinoid deficient embryos were generated by inactivation of retinol dehydrogenase 10 (Rdh10), which is critical for production of …

Unfolded Protein Response Pathways In Skeletal Muscle Homeostasis., Kyle R. Bohnert

Electronic Theses and Dissertations

Skeletal muscle mass, contractile properties, and metabolic function are regulated through the coordinated activation of multiple intracellular signaling pathways and genetic reprogramming. The endoplasmic reticulum (ER) plays a pivotal role in protein folding and calcium homeostasis in many cell types, including skeletal muscle. Disruption of calcium levels or accumulation of misfolded proteins in the ER lumen leads to stress, which results in the activation of a signaling network called the unfolded protein response (UPR). Further, recent studies have suggested that in certain conditions, UPR pathways can be activated independent of ER stress. However, the role of ER stress and the …

Dsba-L Protein Levels In White Adipose Tissue In An Obesity Model., Madison E. Kerley

College of Arts & Sciences Senior Honors Theses

Adiponectin is an adipose tissue-secreted protein found in three isoforms. Disulfide bond A oxidoreductase-like protein (DsbA-L) is thought to assist with protomeric disulfide bonding to generate the HMW (high molecular weight) isoform, which regulates insulin sensitivity. Both adiponectin and DsbA-L were previously found to negatively correlate with obesity.

Immunoblots were conducted on adipose tissue samples from male mice fed a high or low-fat diet for 6, 10, or 16 weeks. Immunoblots from high-fat diet-fed mice revealed double bands for DsbA-L. High and low molecular weight bands were analyzed together, revealing significantly higher relative band densities with 10 and 16-week high-fat …

Regulation Of Haplid Phenotypes In Ustilago Maydis By Ammonium Transporters And Components Of The B Mating Locus., Rena Margaret Wallen

Electronic Theses and Dissertations

Fungi that can switch from budding to a filamentous infectious state have evolved mating type loci. Ustilago maydis, the maize pathogen, must mate with compatible partners possessing different alleles at two mating type loci for successful host infection. The a locus encodes pheromones and receptors, while the b locus encodes subunits of a heterodimeric transcription factor that regulates expression of virulence genes. Mating is triggered by environmental signals, including nutrient deprivation. My goal was to determine the fate of nitrogen starved haploid cells without a compatible mating partner. On solid low ammonium media, wild-type U. maydis filaments. I examined …