Biology Commons^™

Leucine Catabolism Is Associated With Longevity In Female Eastern Lubber Grasshoppers, Kerri R. Conklin

UNF Graduate Theses and Dissertations

Background & Aims: Dietary isoleucine restriction can improve metabolic health and increase lifespan. It has been hypothesized that shifts in branched-chain amino acid catabolism drives this longevity effect. Impaired branched-chain amino acid catabolism is linked to several age-related diseases. We investigated whether dietary isoleucine restriction increases leucine catabolism and associates with longevity and full reproduction.

Methods: In two experiments, adult female Eastern Lubber grasshoppers (Romalea microptera) were assigned to either a high-quality diet (Balanced ile), or diets with varying isoleucine content (Moderate ile-R and Severe ile-R). In Experiment 1, we used a low-energy (Low Lettuce) group as a positive …

The Presence Of Mercury (Hg) And Perfluoroalkyl Substances (Pfas) In The Guana And Tolomato Rivers, Morgan E. Lattomus

UNF Graduate Theses and Dissertations

The Guana and Tolomato Rivers provide essential habitat for several ecologically and economically important species and is a well-loved and recreated area. Spanning the northeastern Florida coast, the rivers are home to over 50 endangered or threatened species and host several habitat restoration projects due to their ecological significance and proximity to development along the coast. The effects of human influence and pollution, and specifically toxic metal mercury (Hg) and perfluoroalkyl substances (PFAS), are not well known within the system. Hg is known to biomagnify within food webs, and there is a considerable lack of literature concerning PFAS behavior within …

Environmental Pollutants: A Risk For Premature Aging And Transgenerational Toxicity, Alex Kathleen Daniels

Masters Theses

"This thesis aims to identify interactions between C. elegans’ reproductive system and global pollutants such as microplastics, HgCl₂, nicotine, and pesticides. Human exposure to these pollutants and their effect on reproduction can be analyzed using the C. elegans as a model organism. Systematic analysis of matricidal hatching, progeny production, germline apoptosis, and lifespan assays determined effects on reproduction and reproductive aging. Through my experiments, it was determined that no significant effects were produced from the selected polystyrene, polyethylene, vape juice, nicotine hemi sulfate salt, imidacloprid, or glyphosate regarding matricidal hatching or progeny production. I confirmed that HgCl₂ induced significant effects …

Evaluation Of The Impact Of Secondhand E-Cigarette Aerosols On Ros-Mediated Alterations Of Epigenetic Events: Implications For Copd Pathogenesis And Assessment Of The Efficacy Of Cold Atmospheric Plasma In Degrading Organophosphate Pesticides On Kevlar Materials, Ta-Chun Lin

Masters Theses

"We explored 1) the toxicological impacts of e-cigarette aerosols and 2) the decontamination efficacy of Cold Atmospheric Plasma (CAP) technology over organophosphates. In examining the effects of firsthand and secondhand e-cigarette aerosol exposure on A549 and BEAS-2B lung cells, we observed significant cytotoxicity, increased ROS levels, and epigenetic modifications, including heightened DNA methylation and downregulation of histone deacetylases (HDACs). These molecular alterations may contribute to chronic respiratory conditions, such as COPD, underscoring the health risks of e-cigarette exposure.

We investigated CAP’s effectiveness in degrading organophosphate pesticide (OP) residues on fabric surfaces, revealing that CAP treatment effectively decomposes OPs such as …

Disposal Of Nanoplastics By The Brain: Plastic Persistence And Upregulation Of A Putative Plastic-Degrading Enzyme After Exposure To Polystyrene-Infused Food, Callie C. Mauersberg

College of Graduate Studies: Theses & Dissertations

Plastic is a ubiquitous material used in many domestic and commercial applications. Widespread use of plastic has led to environmental accumulation of plastic waste, and microplastics have inundated human food and water sources. Once consumed, it is well established that microplastics translocate from the gut to other tissues, including the brain, via the circulatory system. However, it is unknown if nanoplastics persist permanently in the brain. Additionally, it is not known if microplastics can be enzymatically degraded by phagocytic cells in the CNS, such as microglia and astrocytes. Alkane monooxygenase-homolog 7 (Alkbh7) is a mitochondrial enzyme that may …

Bugs In The Flux: Links Between Arthropod Diversity And Spatial Variation Of Soil Respiration In A Temperate Forest, Erin-Darby H. Mcclain

Theses and Dissertations

Soil respiration (Rs) is the largest terrestrial flux of carbon (C) to the atmosphere, with heterotrophic contributions to Rs varying spatially and temporally. While microbes are the primary and most thoroughly studied source of soil heterotrophic respiration (Rh), contributions from higher trophic organisms, including arthropods, are rarely quantified and poorly understood. Arthropod abundance and diversity correspond with variation in soil microclimate, which is influenced by site factors including canopy structure, site productivity, and disturbance. However, the extent to which these site factors influence arthropod abundance and diversity, and consequently, spatial variation in Rs is not known. The objective of our …

Factors Influencing The Discovery And Use Of Carrion By Vertebrate Scavengers From Human-Induced Mass-Mortality Events, Samantha J. Leivers, Michael J. Bodenchuk, Tyler A. Campbell, John M. Tomeček

Human–Wildlife Interactions

Scavengers play critical roles in ecosystem health and stability, and both biotic and abiotic factors can influence scavenger guild dynamics. Carrion is often limited both temporally and spatially on the landscape, but mass mortality events (MMEs)—in which there is an influx of carrion biomass on the landscape—may result in different scavenger community dynamics compared to when carrion is scarcely distributed. In this study, we investigated factors affecting the discovery and use of carrion by a natural, unharrassed scavenger guild during wild pig (Sus scrofa) MMEs conducted at East Foundation’s San Antonio Viejo Ranch in South Texas, USA. We …

Bio-Inspired Airfoil Design Based On The Aerodynamic Analysis Of A Bird Feather Microstructure, Jack C. Ihm

College of Graduate Studies: Theses & Dissertations

This study investigates the aerodynamic effects of a bio-inspired airfoil design based on the microstructure of a secondary feather from a female wood duck. The research hypothesized that incorporating barbs and barbules into an airfoil design would modify boundary layer behavior by introducing localized flow disturbances. To test this, a bio-inspired airfoil was developed by integrating the microstructure into a NACA 0012 airfoil and analyzed using computational fluid dynamics (CFD) simulations at angles of attack of 0°, 5°, 10°, and 15°. The results showed that the bio-inspired airfoil influenced boundary layer behavior, producing localized flow disturbances near x/c = 0.7 …

Survey And Identification Of Entomopathogenic Fungi In Millipede Species In Coastal Georgia, Kristin L. Campbell Bailey

College of Graduate Studies: Theses & Dissertations

Entomopathogenic fungi are well-known, species-specific pathogens of a wide diversity of insects that infect, manipulate, and kill their insect hosts to complete their life cycle. Recently in Savannah, Georgia, millipedes belonging to the genus Eurymerodesmus were observed exhibiting pre-death climbing behaviors associated with pathogenic fungal infection. Dying millipedes summited vegetation and subsequently died in elevated positions along edge habitat transitioning a recreational field and forest. Upon inspection, fungal structures found emerging from dead millipedes anatomically resembled Arthrophaga myriapodina, which is the first documented entomophthoralean fungus to infect millipedes. The goal of this research was to obtain species-level identification of the …

Testing The Life-History Dependence Of Dietary Restriction Effects On Oxidative Molecular Damage In Hornworms, Fahime Taheri

Masters Theses

DR and ambient temperature are two environmental factors widely implicated in shaping organismal maintenance and longevity through effects on metabolic rate and oxidative damage. This study tests whether DR and reduced body temperature independently or interactively reduce oxidative protein damage in the gut of tobacco hornworm larvae, a short-lived ectotherm whose life history may constrain typical DR responses. Larvae hatched from eggs were allocated to two feeding regimes (AL and DR) and to 20 °C and 30 °C. At a defined endpoint, guts dissected and homogenized, and analyzed for protein carbonyl content and total protein. Protein damage was expressed as …

Helminth Parasites Of Galápagos Mammals: A New Cestode Of The Genus Raillietina From The Endemic Rice Rat Nesoryzomys Swarthi And A Summary Of Parasites From Both Endemic And Invasive Rodents, Scott Lyell Gardner, Emma K. Chesley, Michael C. Friedle, Altangerel Tsogtsaikhan Dursahinhan

Scott L. Gardner Publications

In this first report of endoparasites from endemic land-mammals of the Galápagos Islands, we describe a new species of cestode of the genus Raillietina (Cyclophyllidea: Davaineidae) from a species of Nesoryzomys and summarize the extent of helminth parasitism in both oryzomyine endemics and introduced species of Rattus. Up to the current time, no helminth parasites have been reported from rodents of the Galápagos, and little work has yet been done describing and synthesizing Galápagos parasite diversity. In historical times, several species of autochthonous rodents have occupied the islands including: Nesoryzomys narboroughi Heller 1904, N. fernandinae Hutterer and Hirsch …

Isolating Confounding Abiotic And Biotic Effects On The Phenotype On Physa Acuta Snails, Ashley M. Bauer

Theses and Dissertations

Organisms match their phenotypes to prevailing environmental conditions leading to habitat specific polymorphisms. Polymorphisms arise from genetic divergence, phenotypic plasticity, or a combination of both processes. I examined the presence of habitat-specific polymorphism in Physa acuta snails collected from three streams and their corresponding downstream reservoir. In lotic systems shells were rotund with larger apertures, while those from lentic systems were more elongate with smaller apertures. In a reciprocal transplant lab experiment that crossed flow regime and crayfish predator cues, I tested for the underlying mechanisms responsible for the observed phenotypic differences. I found no evidence for plasticity in relation …

Diabetes Potentiates The Emergence And Expansion Of Antibiotic Resistance, John C. Shook, Benjamin P. Darwitz, Kaleb J. Tyson, Amanda Z. Velez, Sophia K. Bridwell, Joshua B. Parsons, Sarah E. Rowe, Christopher Marshall, Brian P. Conlon, Lance R. Thurlow

Biological Sciences Faculty Research and Publications

Individuals with diabetes mellitus frequently develop severe skin and soft tissue infections (SSTIs) that are recalcitrant to antibiotic treatment. We examined how diabetes affects the emergence of antibiotic resistance in a Staphylococcus aureus SSTI. We determined that S. aureus evolves antibiotic resistance rapidly in diabetic mice, while resistance did not occur in nondiabetic mice over the course of infection. Diabetes-associated immune cell dysfunction plays a minor role in the emergence of resistance, while hyperglycemia plays a dominant role facilitating the expansion and takeover of resistant mutants in diabetic infections. Furthermore, vancomycin intermediate resistant isolates display a pronounced fitness defect in …

The Rad6-Like Ubiquitin Conjugase Gene Osubc7 Has A Positive Role In The Early Cold Stress Tolerance Response Of Rice, Huy Phan, Michael Schläppi

Biological Sciences Faculty Research and Publications

Background/Objectives: Cold stress poses a significant threat to Asian rice cultivation, disrupting important physiological processes crucial for seedling establishment and overall plant growth. It is, thus, crucial to elucidate genetic pathways involved in cold stress tolerance response mechanisms. Methods: We mapped OsUBC7, a Radiation-sensitive 6 (RAD6)-type homolog of rice, to a low-temperature seedling survivability (LTSS) QTL and used genomics, molecular genetics, and physiological assays to assess its role in plant resilience against low-temperature stress. Results: OsUBC7 is cold responsive and has higher expression levels in cold-tolerant japonica than cold-sensitive indica. Overexpression of OsUBC7 enhances LTSS of indica and freezing tolerance …

Editorial: Women In Antimicrobials, Resistance And Chemotherapy: 2023, Cindy Shuan Ju Teh, Krassimira R. Hristova, Ana R. Freitas

Biological Sciences Faculty Research and Publications

No abstract provided.

Methyl-Cpg-Binding Domain As A Protein Interaction Partner In Promoter Regulation And Neurodevelopment Through Evolutionary Expanded Entanglement, Stephanie M. Bilinovich, Surya B. Chhetri, Jackson T. Mitchell, Gage O. Leighton, Vladislav Jdanov, Jacob K. Zieba, Taylor W. Cook, Krysta L. Engel, Robert M. Vaughan, Humza Bhatti, Sadie L. Heeringa, Amy M. Wilstermann, Sophie Vanderweele, Akansha S. Das, Emily C. Sherry, Stephen A. Duncan, Katie L. Uhl, David C. Hinds, Mark Mackiewicz, Sarah K. Meadows, Kimberly M. Newberry, E. Christopher Partridge, Sara G. Cline, C. Joy Shepard, D. Casey Smith, Antonio Bradley, Daniel Vogt, Daniel B. Campbell, Lucas Pozzo-Miller, Caleb P. Bupp, Austin J. Goodyke, Surender Rajasekaran, Rebecca C. Knickmeyer, Benjie Blair

Research, Publications & Creative Work

There is increasing evidence that the methyl-binding domain (MBD) is a protein-protein interaction motif that can function independently of methylated DNA binding. The MBD proteins found throughout plants and invertebrates duplicated into multiple vertebrate DNA and non-DNA-binding members (MBD1, MBD2, MBD3, MBD4, MBD5, MBD6, MECP2, BAZ2A, BAZ2B, SETDB1, andSETDB2). Although many invertebrate species possess MBD proteins that can bind and recognize DNA methylation, the DNA-binding function has been independently lost multiple times, with only minor alterations to the protein interaction residues. The nucleosome remodeling and deacetylase (NuRD) complex, which interacts with MBD2/3 and is colocalized with MBD1/4 ChIP-Seq, is maintained …

Elucidating The Effects Of Environmental And Physiological Conditions On Stem Cell Regulation In Vivo, Nimmy John

Electronic Theses & Dissertations (2024 - present)

The Notch signaling pathway is a highly conserved intercellular signaling pathway that any dysregulation can lead to a variety of human diseases. These diseases are further exacerbated by various environmental, pathological and genetic conditions. Previous studies have shown that these conditions have been known to affect the Notch transcriptional response. However, the molecular mechanisms by which such conditions influence Notch signaling remained largely unknown. Moreover, most Notch studies have relied on in vitro systems and indirect reporters, which can miss the dynamic and contextual nature of Notch signaling. Here, we systematically analyzed the effects of these conditions with single molecule …

Phylogenetic Analysis Of Metabolic Enzymes In Hypoxic/Anoxic Conditions In Cetaceans And Cancer, Samerna A. Masih

Electronic Theses & Dissertations (2024 - present)

Cancer cells often exhibit a Warburg-like metabolism, which includes increased fatty acid synthesis and storage that help them survive in hypoxic conditions. This shift is marked by the heightened synthesis and accumulation of fatty acids, acting as a survival mechanism in low-oxygen environments (Baumann et al., 2016). Interestingly, deep-diving whales may utilize a similar metabolic pathway to produce wax esters during their prolonged dives.

Our study focused on exploring the genetic and metabolic similarities between breast cancer cells and deep-diving whales, using computational analyses to investigate lipid metabolism genes. We looked for evolutionarily conserved variations that might reveal adaptive mechanisms …

The Role Of The Nasal Migratory Mass In Olfactory Bulb Formation And Fertility, Charisse Martin

Electronic Theses & Dissertations (2024 - present)

The olfactory migratory mass plays an essential role in the development of the olfactory bulb by facilitating the migration of the gonadotropin-releasing hormone neurons from the olfactory placode to the pre-optic hypothalamic area in the brain. In mammals, the migration of GnRH neurons is critical for establishing the hypothalamic-pituitary-gonadal axis (HPG axis), which regulates reproductive function through the production and secretion of gonadotropins. Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) instruct the gonads to function appropriately, ensuring sexual maturation and fertility. Disruptions in this migratory pathway have been linked with Kallmann syndrome, a condition characterized by low levels of GnRH, …

Nat10 Stabilizes Immune Response Factors Aiding With Cellular Immune Response To Zika Virus Infection, Shawn Gianola

Electronic Theses & Dissertations (2024 - present)

Zika virus (ZIKV) remains a significant public health concern due to major gaps in our understanding of its infection mechanisms and immune evasion strategies. Despite its link to severe complications such as microcephaly and Guillain-Barré Syndrome (GBS), no vaccine or targeted antiviral therapies exist. Compounding this concern is the expanding habitat of ZIKV-carrying mosquito vectors, driven by climate change, which increases the risk of future outbreaks in previously unaffected regions.

One promising area of investigation involves post-transcriptional modifications (PTMs) chemical alterations to RNA that influence its stability, translation, and function. Although over 170 PTMs have been identified, their roles remain …

Transcriptome-Wide Gene Expression Analysis Of Skeletal Muscles Of Duchenne Muscular Dystrophy Mouse Models And Patients, Olivia N. Ransiear

Electronic Theses & Dissertations (2024 - present)

Duchenne Muscular Dystrophy (DMD) is an X-linked recessive muscle degenerative disease that frequently proves fatal by age 30. It primarily affects adolescent males with symptoms appearing as early as age 6. Patients quickly lose their ability to walk due to muscle weakness and are confined to wheelchairs for the remainder of their lives. DMD is caused by a mutation in the dystrophin gene. Without dystrophin, mechanical stress, injury, or shock takes a drastic toll on muscle tissue and muscle stem cells, rendering them unable to regenerate or be repaired. This results in a rapid loss of muscular strength and muscle …

Blattella Germanica As A Vector Of Salmonella Typhimurium, Matthew Turner

Dissertations and Theses

The following investigates the role of the German cockroach (Blattella germanica) as a vector of the bacterium Salmonella enterica subspecies enterica serovar Typhimurium (S. Typhimurium). As such, this work examines various host-pathogen-microbiome interactions that define the vectorial capacity of the German cockroach for Salmonella. To date, the majority of literature focuses on the general association of the German cockroach with various human pathogens, claiming any dissemination to be carried out via passive mechanical transmission. This project recognizes those claims, while expanding to include the possibility of biological transmission, involving active and complex host-pathogen interactions, including mechanisms like replication within the …

Understanding Trends In Zostera Research, Stressors, And Response Variables, Hannah R. Lyford, Emma Guerrini Romano, Shayna A. Sura, Sarah Joy Bittick

Biology Faculty Works

Background. Seagrass meadows are ecologically significant habitats that are globally threatened. Thus, there is increased interest in conservation of seagrasses as they face widespread decline. Biotic and abiotic factors that influence seagrass can be classified as stressors, such as rising temperature and eutrophication. Our study met an imminent need to consolidate data from previous studies to discern knowledge gaps and identify trends in studies, stressors, species, and geographic origination of research for the genus Zostera. For our systematic review, the objectives were to (A) qualitatively assess and summarize the current state of literature focused on seagrass species within the Zostera …

A Comprehensive Embryonic Staging Series Of The Turtle Trachemys Scripta, Christina M. Noravian, Perla G. Rand, Amira Mahomed, Maxellende Ezin, Annie Rickard, Oscar D. Juvera, Maria Elena De Bellard

Biology Faculty Works

Background: Turtles hold a unique place in vertebrate evolutionary history, making them critical assets in embryology research. Yet, they remain understudied as potential model organisms in the field. Here, to support experimental manipulations with turtle embryos, we have created a complete normal table of development for comprehensive embryonic staging of Trachemys scripta, one of the most common invasive turtle species worldwide.

Results: The development of T. scripta embryos from 0 days post-oviposition (DPO) to hatching (~60 DPO) was described from approximately 300 viable eggs collected at California State University, Northridge during the 2021–2024 nesting seasons. Thirty-one stages between oviposition and …

Investigating Mitochondrial Stress Response Mechanisms In Aging, Aileigh E. Daniel

Theses and Dissertations

Mitochondrial dysfunction is widely recognized as a key contributor to aging and age-related diseases. The concept of mitohormesis suggests that low levels of ROS can activate stress-responsive transcription factors, promoting adaptive mechanisms that enhance longevity. We hypothesized that changes in protein abundance under conditions of mild mitochondrial stress reflect an adaptive response, and that commonly altered proteins across diverse genetic backgrounds of mitochondrial stress can help identify key regulators of stress resilience and aging. Our study identified conserved mitochondrial stress response pathways and highlighted candidate regulators for further investigation. These regulators appear to impair mitochondrial energy production by downregulating ATP …

Climate Change-Induced Shifts In Mediterranean Fungal Fruiting Phenology And Productivity, Rachel Demay

Theses and Dissertations

We used a 29-year dataset of mushroom fruiting from the Pinar Grande forest in northern Spain to investigate the effects of climate change on the phenology, productivity, and diversity of mycorrhizal and saprotrophic mushrooms. We investigated the long-term trends in fruiting season length, yield (by count, total weight, and average weight), and genus richness. Additionally, we identified associations between monthly temperature and monthly precipitation with these fungal responses across functional groups: mycorrhizal, saprotrophic, litter-decaying saprotrophic, and wood-decaying saprotrophic mushrooms, and the economically-important edible genera Boletus and Lactarius. We found that autumnal season length in the Pinar Grande has shortened over …

Molecular Mechanisms Of Kynurenine-Mediated Lifespan Regulation In Yeast, Ryan E. Counterman Jobb

Theses and Dissertations

The kynurenine pathway is a highly conserved pathway that acts as the primary pathway for tryptophan catabolism and has been found to be involved in lifespan regulation across many diverse organisms. Caloric restriction (CR) is the only known dietary intervention to date that both increases the mean lifespan and the health span of multiple organisms, although the molecular mechanisms of these effects are not fully understood. There are known and sometimes contradictory relationships between the kynurenine pathway activity and the life- extending effect of CR but the crosstalk between the two is not well characterized. Understanding these relationships could lead …

Soils From Different Solidago Altissima Clones Mediate Intraspecific Interactions In Schizachyrium Scoparium, Sarah Alharbi

Masters Theses

While previous studies have examined plant intraspecific competition and soil microbial effects separately, fewer studies have investigated how these factors interact, particularly in the context of genotype-specific soil conditioning effects. Plant-soil feedbacks can significantly alter interspecific competitive outcomes, yet few studies have examined how local variation in soil conditioning influences plant responses to density-dependent competition. I investigated how soil inocula derived from four Solidago altissima clones that were previously shown to differ in their soil conditioning effects (Foster et al., 2022) affected the growth and root traits of Schizachyrium scoparium across a gradient of intraspecific competition (1, 2, or 4 …

Gustatory Behaviors Of House Flies: Body Parts Used And Response To Bitter, R M Panchalie Bhagya Gunathunga

Graduate Research Theses & Dissertations

Insects use multiple body parts, not just their mouth, to taste. Whether a particular body part has a taste function can be determined indirectly by examining the morphology or electrophysiological response of its sensilla (sense organs) or directly by the insects’ behavioral response. Understanding the taste system of insects allows development of better management strategies against pest insects and strategies to protect beneficial insects.House flies, Musca domestica L., are pests at livestock facilities. House fly numbers are controlled mainly by manure management and chemical controls. Toxic granular fly baits remain one of the most popular and effective forms of chemical …

Geology, Paleoecology And Vertebrate Biostratigraphy Of The Hell Creek Formation, Carter County, Montana, Usa, Joshua Collin Mathews

Graduate Research Theses & Dissertations

The Hell Creek Formation of the Northern Great Plains records one of the greatest mass extinction events in Earth’s history, bringing to a close the reign of the dinosaurs at the end of the Cretaceous period. This rock unit comprises one of the most studied geological formations in the world and is one of the few locations on the planet that preserve terrestrial deposits containing ejecta from the bolide impact that slammed into the Yucatan Peninsula 66 million years ago. This profound event in the geologic record has led to numerous studies of paleobiotas, climate change, ecosystem recovery dynamics, and …