Life Sciences Commons^™

Impairment Of The Glial Phagolysosomal System Drives Prion-Like Propagation Of Huntington’S Disease, Graham Davis

Theses and Dissertations

The ability of glia to tightly regulate neuronal health and homeostasis in the CNS is conserved across species. Yet, despite the ability to degrade protein aggregates, glia are vulnerable to the accumulation of neurotoxic amyloid aggregates during neurodegenerative disease progress, and even exacerbate their spread. A developing narrative highlights glia as a double-edged sword in neurodegenerative diseases: initially capable of dynamically responding to amyloid aggregate-ladened dying neurons but also capable of inducing chronic inflammation and creating seeding-competent amyloid oligomers. Thus, uncovering the mechanisms that allow glia to control aggregate deposition while preventing the neurotoxic effects and seed generation is vital …

Elucidating Aposematic Patterns In North American Hylids, Joseph S. Cannizzaro Iv

Theses and Dissertations

Recognizing form and function of animal defenses is paramount to understanding the ecological and evolutionary forces behind predator and prey dynamics. Color patterns are strongly related to defensive strategies in animals. Some rely on camouflage to avoid detection, while others are brightly colored and conspicuously signal their noxiousness to potential predators. Still others combine cryptic dorsal coloration with colorful patches that are concealed in resting position but are facultatively unveiled by special behavior or simply during activity. Such hidden conspicuous color patches may be an intermediate stage in the evolution from camouflage to aposematism. We investigated whether conspicuously colored thighs …

The Interaction Between Predation And Sound Pollution On The Internal And External Microbiome Of The Grasshoppers Melanopus Sanguinipes, Alanna Bond

Theses and Dissertations

Anthropogenic activities such as construction and agriculture directly affect its surrounding environments. Many studies have focused on how megafauna and flora are impacted by human activities, however, relatively little is known how new occupation of land affects smaller organisms such as insects and microbes. Additionally, other stressors such as predation can impact host physiology. The grasshopper species Melanopussanguinipes was chosen to be used in a study to measure how stress caused by artificial sound and predation can alter exoskeleton and gut microbiomes once exposed to these stressors.

Investigating The Role Of Plant Traits And Interactions In Emergent Wetland Nutrient Removal, Andrew Ryan Sample

Theses and Dissertations

Increasing wetland restoration in the Lower Mississippi Alluvial Valley has been identified as a method to reduce nutrient loading in the Gulf of Mexico. Wetlands have historically been used to treat water through processes facilitated by wetland plants, and relatively few species and plant traits have been identified as important in carrying out these processes. This study focuses on some of those species and traits and aims to identify species differences and plant traits that may be important for wetland nutrient mitigation. Chapter I provides background information on nutrient pollution, wetland biogeochemical mechanisms for nutrient sequestration, and the focal species …

Investigating The Localization Of Foxo4 Transcription Factor In U87mg Glioblastoma Cell Line, Millat Jahan

Theses and Dissertations

FOXO transcription factors perform diverse functions that have effects on significant biological processes like stem cell homeostasis, cell cycle, apoptosis, and cell fate determination. This research focuses on FOXO4 that is differentially localized in U87MG glioblastoma cells where FOXO4 is targeted to the nucleus. This research is aimed at investigating the mechanism and localization of FOXO4 in U87MG cell lines. Using chimeric fusion construct, we have mapped regions within FOXO factors that can determine specific cellular localization patterns. Finding the mechanism behind specific nuclear localization of FOXO4 can produce innovative data to better understand the distinctive subcellular localization patterns in …

The Effects Of Caffeine On Activity Levels And Motor Behaviors In The Honeybee, Apis Mellifera, Johana Castro

Theses and Dissertations

Caffeine is produced by plants as a defense mechanism against herbivores and pathogens. However, caffeine was found in floral nectar, which contradicts nectar's role in attracting pollinators. Interestingly, low concentrations of caffeine were shown to increase alertness and locomotion in mammals and invertebrates, indicating it may enhance the productivity of pollinators. This investigation examined how caffeine affects activity levels and motor behaviors in the honey bee, Apis mellifera. To test overall activity, forager bees were collected and fed 1 M sucrose to satiation. The following day, bees received 10 µl of 1.0 M sucrose alone or with caffeine ranging from …

Understanding The Distribution And Abundance Of Asclepias Prostrata In South Texas, Elizabeth Ann Gonzalez

Theses and Dissertations

Asclepias prostrata, commonly referred to as prostrate milkweed, is a rare South Texas native plant species. In February of 2023, A. prostrata was listed as a federally endangered species by the U.S. Fish and Wildlife Service. Due to the limited available observations and literature for A. prostrata, this study was completed to bring new information that could be utilized for future restorative efforts. This study includes multiple field observations of the plant’s morphology, plant-insect interactions, extraction and transplanting of the species, and a seed viability study. Results indicate that although A. prostrata has many pressures that limit its …

Soil Moisture Dynamics In Cover Cropping Systems: From Local To Global Scales, Manish Gautam

Theses and Dissertations

Cover cropping systems, which have gained recognition for their ability to enhance soil health and promote sustainability are also associated with potential risks related with declining soil moisture and pose a dilemma for farmers considering the adoption of cover crops in water deficit semi-arid settings worldwide. To address this pressing issue, we conducted a participatory cover cropping trial in the Lower Rio Grande Valley (LRGV) region, encompassing four different farms and supplemented this experiment with a meta-analysis to answer our soil moisture and climate parameters and quantify the impact of cover crops on soil moisture levels. The findings revealed that …

Comparative Analysis Of Soil Properties, Microbial Community Composition, And Yield Responses To Cover Crops In Different Ecoregions Of South Texas, Daphne Zapsas

Theses and Dissertations

Comprehensive understanding of soil properties, their interdependencies, and the effects of management practices is crucial for designing sustainable agricultural strategies. By adopting site-specific and need-based practices that enhance soil health, farmers can optimize crop growth, increase yield, and contribute to long-term environmental sustainability. Cover crops have been recognized for enhancing soil fertility, promoting microbial activity, and increasing organic matter content. However, while their effectiveness is well documented in temperate regions with readily available water, their impact in water limited systems in subtropical regions remains mixed. The aim of this study is to assess soil conditions in four different farms across …

Modulation Of Eif2Α Signaling And The Integrated Stress Response By Targeted Therapeutic Attenuation Of Pkr Activity Contributes To Protection Of Dyt-Prkra Cells From Apoptosis, Kenneth L. Frederick

Theses and Dissertations

Luteolin is a natural flavonoid present in vegetables, fruits, and medicinal herbs that possesses anti-oxidative, anti-cancer, and anti-inflammatory properties. In this study, we investigated the effect of luteolin on the integrated stress response (ISR), which is an evolutionarily conserved intracellular signaling network essential for adapting to environmental stresses to maintain healthy cells. Dysregulated ISR is involved in the etiology of many human diseases including the movement disorder DYT-PRKRA which is caused by mutations in the PRKRA gene. PRKRA encodes for PACT, the protein activator of interferon-induced, double-stranded RNA (dsRNA)-activated protein kinase PKR.PACT-mediated PKR activation regulates the …

The Effects Of Variations In Light And Nutrient Availability On Phytoplankton And Zooplankton, Jake Anthony Swanson

Theses and Dissertations

Aquatic ecosystems experience a wide range of variation in resource availability; two of the resources that are most essential to phytoplankton and zooplankton are light and nutrients. Light can vary in both its color and intensity; these variations can directly impact phytoplankton by altering the amount and color of light available for photosynthesis. Nutrient variability, particularly increases in nutrient levels, also alter phytoplankton communities by favoring the growth of certain taxa such as cyanobacteria.

To understand whether phytoplankton respond differently to changes in light availability I investigated whether the diversification of cryptophytes, phytoplankton with diverse light-capturing pigments, showed evidence of …

Diversity, Function, And Phenotypic Plasticity Of Cryptophyte Phycobiliproteins, Kristiaän Merritt

Theses and Dissertations

Cryptophytes are a group of unicellular eukaryotic algae that can be found in a wide range of underwater habitats. Part of their ecological success can be attributed to their diverse array of cryptophyte phycobiliproteins (Cr-PBPs), a pigment class that captures wavelengths of light that are poorly absorbed by chlorophylls. Cryptophytes gained photosynthesis via secondary endosymbiosis in which their ancestor engulfed a red algal endosymbiont. Following endosymbiosis, they deconstructed the red algal photosynthetic machinery to form the Cr-PBP. Since then, the Cr-PBPs have diversified into at least 9 spectrally distinct forms. I investigated the diversity of Cr-PBP light absorption across 76 …

Cytotoxic Activity Of Salvia Officinalis Extract Mediated By The Inhibition Of Jak2 In Breast Cancer, Salma Alawadi Dawood

Theses and Dissertations

Background: Breast cancer is the most common type of invasive cancer in women in their forties and fifties. Recent evidence suggests that JAK2/STAT3 signaling is constitutively active in breast cancer. Previous studies suggest that plant extracts, including Salvia Officinalis, have strong cytotoxic effects on breast cancer cells. The differential expression of miRNAs is also strongly linked to cancer development.

Aim: In the current study, we hypothesize that S. Officinalis extract suppresses JAK2 expression and has strong anticancer potential in MCF7 breast cancer cell lines.

Methods: GC-MS analysis showed the presence of flavonoids in dried leaf of …

Host-Acquired Virus Genes Support An Ancient Antiviral Role Of The Pirna Pathway In Dipterans, Rebecca Christian

Theses and Dissertations

Endogenous viral elements (EVEs) have been recently investigated as a source of transgenerational immune memory. These “viral fossils” are abundant in Aedes mosquitoes and partner with the host’s primary antiviral defense system, the RNA interference (RNAi) pathways. This partnership appears unique to mosquitoes, which encode an expansion of the Piwi endoribonucleases. To interrogate EVE-Piwi partnerships and their role in antiviral defense, I performed a comparative small RNA analysis of two naturally occurring EVE-virus pairs – one in the mosquito Aedes albopictus, and one in the midge Chaoborus americanus. Both express an EVE related to the nucleoprotein of their …

An Investigation Into Transcription Fidelity And Its Effects On C. Elegans And S. Cerevisiae Health And Longevity, Olivia S. Dinep-Schneider

Theses and Dissertations

mRNA molecules form an intermediate in the transfer of sequences from DNA to ribosomes in order to guide protein production. Errors can be introduced into mRNA, producing aberrant proteins which place a strain on cellular regulatory machinery, causing increased risks of apoptosis, cancer, and decreased fitness. These errors may be introduced due to decreased transcriptional proofreading capabilities, exposure to chemicals, or mistakes in RNA editing machinery. It is important to investigate these causes of transcription errors to better understand the long-neglected area of mRNA fidelity which has such significant impacts on our cellular functions. In this paper, it was determined …

Role Of Fungal Arv-1 Protein In Sterol Metabolism And Pathogenicity Of The Chestnut Blight Fungus Cryphonectria Parasitica, Soumyadip Kundu

Theses and Dissertations

Intracellular sterol redistribution is an important step in the lipid homeostasis of organisms, a process directly linked to the organizational arrangement in the plasma membrane (PM) of cells. Previous studies in the budding yeast Saccharomyces cerevisiae have demonstrated that the ARV1 (ACAT-related enzyme-2 required for viability 1) protein is a major regulator of sterol transport from the endoplasmic reticulum to the plasma membrane, contributing to the structural organization of the PM, rendering it resistant to anti-fungal compounds as well as maintaining ER integrity. This study assessed the significance of ARV1 in the plant pathogenic fungus Cryphonectria parasitica (Cparv1) …

Population Genetics Among Rhipicephalus Sanguineus Ticks In The Lower Rio Grande Valley, Bianca Liana Guerra

Theses and Dissertations

Rhipicephalus sanguineus is a common tick species in the lower Rio Grande Valley of both human and veterinary concern. Two lineages of R. sanguineus have been described across the United States known as the tropical and temperate lineage. Both lineages can be differentiated morphologically, genetically, biologically, and by vector competence. The species name for both lineages has not been well established therefore this thesis will utilize their widely used identification. Both lineages have been identified in Texas. While the distribution of these lineages has been well-defined in some regions across the world, recent studies have observed sympatric populations in certain …

Estimating The Functional Consequences Of Intra-Specific Trichome Variation Of Tomato, Solanum Lycopersicum On The Specialist Herbivore, Manduca Sexta, Satinderpal Kaur

Theses and Dissertations

Chapter 1: Plants have a wide array of defenses against herbivores and hence they must confer trade-offs between growth and defense related traits. By using Solanum as a model genus, the major plant defense fitness trade-off hypotheses are reviewed in this chapter along with their assumptions and examples.

Chapter 2: This chapter provides an overview of the enormous intra-specific diversity in trichome morphology in tomato, Solanum lycopersicum. Also, the trichome sub-types are analyzed for the variations in density and dimensions in 10 varieties of tomato by using desktop scanning electron microscope.

Chapter 3: This chapter examines the functional consequences …

Road Mitigation Structure And Road Effect Zone Impacts On Rodent Community Composition, Activity, And Predator-Prey Dynamics In South Texas, Adam F. Sanjar

Theses and Dissertations

The effects of road mortality mitigation structures on rodent activity and rodent community composition are not fully understood, both on the regional scale of south Texas and in the broader field of road ecology. This is primarily due to the low conservation priority of most rodent species and the difficulty of noninvasively surveying for rodents effectively. This thesis focused on characterizing how rodents were impacted by both roads and mitigation structures in south Texas, and if rodents are a significant factor to consider when studying the road ecology of rodent predators in south Texas, particularly ocelots, bobcats (Lynx rufus …

Body Bound, Rachel Allison

Theses and Dissertations

Body Bound is an exhibition catalog that corresponds to an exhibition of objects on display in the Emile Mathis Gallery that opened on February 23, 2023. The Exhibition traces the historically grounded and long-standing tradition of using bodily material as the basis for bookmaking. This practice has not subsided entirely in its traditional form but has also branched off and informed contemporary book-making practices. Contemporary books, specifically artist books, are a part of a longer history of using and presenting bodies with books. This exhibition includes historical books and contemporary artist books from the UWM special collections as well as …

Habitat Effects On Scorpion Densities And Microhabitat Use By Centruroides Vittatus And Vaejovis Waueri In South Texas, Jonathan Beltran

Theses and Dissertations

Co-existence between Centruroides vittatus and Vaejovis waueri is influenced by environmental factors that shape their habitats. Differences in surface activity frequency between the two species suggest differential microhabitat use. The observed frequency of scorpions using microhabitats in the Martinez Ranch and La Union Ranch were not significantly different from the expected frequencies. Frequency of scorpions observed using microhabitats in La Union South was significantly different from the expected frequency (P<0.001). Microhabitat use of catclaw was lower than expected and higher than expected for other vegetation. Conditional comparisons of microhabitats were significantly different among habitats (P<0.001), size classes were significantly different among microhabitats (P<0.001), and size classes were significantly different among habitats (P<0.01). Microhabitat use by scorpions on the ground was higher among all habitats. Scorpion use of ground and grass were different among size classes. Size class I-II scorpions had a higher frequency than size class III. Scorpion density for C. vittatus was significantly different among habitats (P<0.0001) and scorpion density for V. waueri was significantly different among habitats (P<0.0001). Centruroides vittatus was significantly higher in the Martinez Ranch and in La Union South. Vaejovis waueri was significantly higher in La iv Union South. Associations between plant densities and scorpion size classes were tested. Plant densities had a significant association with C. vittatus size classes I and II in the Martinez Ranch. Association between plants had a significant correlation with C. vittatus size classes I and IV in La Union Ranch. Association between plants had a significant correlation with V. waueri’s total density. These associations may suggest plant densities may have a synergistic effect on scorpion densities. Soil type composition for the different habitats was hypothesized to influence scorpion densities. Maps for each site were created to show soil type compositions. Soil type findings suggest that La Union South had the soil types with the lowest soil strength. Vaejovis waueri was shown to have a higher density in La Union South where soils are sandier. Results indicate that co-existence between C. vittatus and V. waueri is possible because competition is low through minimal overlap in microhabitat use and intraguild predation avoidance.

Genetic Mechanisms Underlying Maladaptation In Specialized Species Interactions, Nitin Ravikanthachari

Theses and Dissertations

Adaptation has been used as the framework to understand the power of natural selection in structuring biodiversity and driving biological interactions. However, recent examples have indicated that many organisms are maladapted to their local conditions. Maladaptation can result from various causes including rapid environmental change, novel environments, interplay of evolutionary forces (viz: gene flow-selection balance) and anthropogenic disturbance.

To dissect the genetic mechanisms underlying maladaptation, I used the interaction between Pieris macdunnoughii (Remington) (Lepidoptera: Pieridae) which lays eggs on an invasive mustard Thlaspi arvense (L.) (Brassicaceae), which is lethal to the larvae.

First, local adaptation to avoid laying eggs on …

Hydroxyurea Globally Inhibits Rna Synthesis, Destabilizes Mrnas, And Triggers Mec1-Opposed Rnapii Accumulation At 3’ Ends Of Genes, Pritpal Kaur

Theses and Dissertations

My dissertation includes two projects. The first project is focused on the regulation of glycolysis and oxidative metabolism by inducing heme synthesis in cancer cells. The second project deals with the effect of hydroxyurea on RNA synthesis. Heme is an essential cofactor for enzymes of the electron transport chain (ETC) and ATP synthesis in mitochondrial oxidative phosphorylation (OXPHOS). Heme also binds to and destabilizes Bach1, a transcription regulator that controls expression of several groups of genes important for glycolysis, ETC, and metastasis of cancer cells. Since many cancers are characterized by a high glycolytic rate regardless of oxygen availability, targeting …

Interferon Gamma Signaling In Ovarian Cancer Cells, Bijaya Gaire

Theses and Dissertations

Interferon gamma (IFNγ) is a pleiotropic cytokine that can have, depending on the cellular and molecular context, both anti-tumor and pro-tumorigenic functions. IFNγ expression can be induced in cancer cells in response to radiation therapy or immune checkpoint blockade used in cancer treatment. We have previously shown that IFNγ induces expression of the Bcl3 proto-oncogene in ovarian cancer (OC) cells, resulting in their increased proliferation and migration, but the mechanisms are unknown. Here, I demonstrate that the IFNγ-induced Bcl3 expression is dependent on JAK1 and STAT1 signaling, and on p65 NFkB. Furthermore, my data show that the IFNγ-induced Bcl3 expression …

Gating And Pathogenic Mechanism Of Polycystin Ion Channels, Yan Wang

Theses and Dissertations

Autosomal dominant polycystic kidney disease (ADPKD), one of the most common and life-threatening human genetic diseases, is caused by mutations in PKD1 or PKD2 genes. PKD1 gene encodes PKD1 (also known as polycystin-1 or PC1) protein, which are the founding members of the PKD1 proteins family; while PKD2 encodes TRPP2 (also known as polycystin-2 or PC2) protein, the founding member of the TRPP subfamily. PKD1 family consists of PKD1, PKD1L1, PKD1L2, PKD1L3, and PKDREJ. Whereas the TRPP subfamily includes: TRPP2, TRPP3, and TRPP5. Proteins in PKD1 and TRPP families are collectively called polycystins. TRPP proteins can either form homotetrameric ion …

Genetically Encoded Iron Sensor Cell Line: A Model For Studying Ferroptosis And Cellular Iron Metabolism, Daoud F. Rahman

Theses and Dissertations

Cell death is a biological process that is essential in proper cellular homeostasis, development, and function. Malfunction of this system can lead to different diseases and cancers. Ferroptosis is a form of cell death that occurs as a result of the accumulation of lipid peroxides, that are dependent on intracellular levels of iron. Iron is essential to multiple metabolic processes in the cell, including the catalyzation of lipid peroxides. Thus, intracellular iron levels must be tightly regulated. Our goal is to create a cellular model to study and detect changes in intracellular iron levels. Through the use of a genetically …

Insight Into Eleutherodactylus Coqui Resilience And Anuran Hypoxia Tolerance Utilizing Pincho, Randy Ortiz

Theses and Dissertations

The onset of high-throughput RNA-sequencing (RNA-seq) technology allowed research into transcriptomics to accelerate exponentially aided by the rapid advancement of bioinformatic pipelines. The Pincho workflow, my first research endeavor, is a transcriptomic workflow developed to create an avenue of high-quality reconstructions from RNA-seq data. High-quality reconstruction standards entail longer transcripts, more complete transcripts, and more raw data utilization. We have discovered an ideal trio of assemblers between transABySS, rnaSPAdes and TransLiG that would best reconstruct next-generation sequencing data according to these standards. We utilized Pincho to drive two distinct experiments: (1) exploring the genetic basis for the successful invasion of …

Salinization Impacts On Heterotrophic Respiration, Ecosystem Respiration, And Plant Productivity In Tidal Freshwater Marshes, Kelsie J. Moses

Theses and Dissertations

Tidal freshwater marshes have preserved substantial stocks of soil carbon, which represents carbon dioxide that is no longer in the atmosphere. There is conflicting evidence in the literature about how disturbances such as sea level rise and associated wetland salinization impact the accumulation and long-term stability of this stored carbon. The goal of this experiment was to quantify how salinization impacts total ecosystem respiration and its component parts, autotrophic and heterotrophic respiration. This was a microcosm experiment using a C4 plant (Spartina cynosuroides) grown in soil derived from C3 plant matter and exposed to different salinities (0 to …

Dune Building Dynamics Impact Cross-Island Connectivity And Barrier Island Characteristics, Alexander Sabo

Theses and Dissertations

Located at the land-sea interface, barrier islands are important protective features that reduce wave energy and erosion from mainland areas. Further, barrier islands provide habitat for many different organisms and serve as popular areas for recreation and tourism. As sandy landforms, barrier islands are easily disturbed, but often recover after disturbance as a result of island plant communities, specifically dune building grasses. Disturbance on barrier islands is driven by storms, tides, and overwash events. After disturbance has occurred, dune grasses colonize the dunes allowing for dune building and habitat restoration. On the Virginia barrier islands, there are three dominant dune …

Plant Trait Effects On Tidal Wetland Methane Emission, Adam M. Dunn

Theses and Dissertations

High rates of carbon (C) sequestration exhibited by coastal wetlands is an important natural climate solution to global environmental change. At the same time, however, wetlands are the largest natural source of methane (CH₄) to Earth’s atmosphere, a potent greenhouse gas that influences the global climate. Wetland CH₄ emissions display high degrees of uncertainty in accounting for spatial and temporal variations in emissions due to the complex interactions between biotic and abiotic factors that influence methane production and transport, in addition to simultaneous influences from climate-driven effects on wetlands such as rapid sea level rise and increased …