Biology Commons^™

How Plant-Soil Feedbacks At Varying Levels Of Plant Species Diversity Influences The Reestablishment And Performance Of Native Sagebrush Steppe Species, Sierra Santosuosso

Boise State University Theses and Dissertations

Increased frequency of wildfire has become a significant problem in the sagebrush steppe, altering soil biogeochemical properties that promote the establishment of invasives at the expense of native species. To reduce annual grass invasion, restoration efforts often include seeding with non-native bunch grasses such as Agropyron cristatum (L.) Gaertn (crested wheatgrass [AGCR]) that outcompete cheatgrass; however, this strategy does not lead to the return of a native sagebrush steppe ecosystem. Restoring ecosystems to higher levels of native species diversity may reduce invasion and promote sustained success of restoration efforts since biodiversity can improve ecosystem functioning and promote resilience. In 2019 …

Assessment Of Floral Resources From Three Tamaulipan Thornscrub Communities Of The Lower Rio Grande Valley, Gracie Makenna Granados

Theses and Dissertations

The Tamaulipan thornscrub is a transition zone between the neotropics and the temperate regions, harboring high biodiversity. This habitat supports a diverse insect community, including many pollinators of native and cultivated plants in Texas and northeastern Mexico. This ecosystem has been extensively degraded and lost; only 5% of its original cover remains north of the Rio Grande. Restoration of the Tamaulipan thornscrub has been ongoing for over three decades, but the important roles of pollinators in the success of such efforts and the functioning of the restored ecosystem have rarely been considered in restoration efforts. The purpose of this study …

Opa1-Mediated Mitochondrial Dynamics In Myogenic Differentiation Of C2c12 Myoblasts, Daniel Eloy Bazan

Theses and Dissertations

Mitochondria play a pivotal role in metabolic energy production, cellular signaling, and apoptosis. To carry out these key cellular roles, mitochondria dynamically balance their organization through opposing including fusion and fission processes. The balance between mitochondrial fusion and fission is regulated by key proteins such as OPA1 (optic atrophy 1) and OMA1 (overlapping activity with metalloprotease). More recently, mitochondria have been increasingly revealed to play key roles in cellular differentiation, where metabolic demands are reprogrammed. This study aims to elucidate the specific roles of OPA1 and OMA1 in the differentiation of C2C12 myoblast cells into myotubes.

Our data demonstrates that …

Phenotypic Plasticity In Response To Abiotic Factors In Silverleaf Nightshade (Solanum Elaeagnifolium), And The Effectiveness Of North American Lacebug (Gargaphia Arizonica Drake And Calvo) As A Biocontrol, Marco Andre Silguero

Theses and Dissertations

Silverleaf nightshade (Solanum elaeagnifolium) is a widespread invasive weed in South Texas and other arid regions, where it reduces crop productivity, competes with native vegetation, and resists conventional control methods. Its ability to thrive across different environments is linked to phenotypic plasticity, allowing it to adjust growth and physiology in response to light and water availability. In this thesis, I examine the role of plasticity in S. elaeagnifolium under field conditions and evaluate the potential of the North American lacebug (Gargaphia arizonica) as a biological control agent. Field observations were used to measure plant traits such as height, stem thickness, …

Gut Passage Time In Small Mammals: Influences Of Small Mammal Traits, Digesta Phase, And Particle Morphology, Noah G. Hale

Electronic Theses and Dissertations

Dispersal is crucial in maintaining healthy ecosystems, but little is known about mechanisms influencing fungal spore dispersal by animals. We aimed to develop a more mechanistic understanding of the influence of fungal spore traits and small mammal traits on gut retention time. We fed three species of small mammals (shrew, mouse, vole), which differ in gut morphologies, digestive strategies, and activity a combination of markers including: liquid digesta phase (CrEDTA), small particle (fungal spores with diverse morphologies), and large particles (glitter and beads, representing plant cells and seeds, respectively). We found that hindgut fermenters selectively retained the liquid markers, spores …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Small Stream Restoration In The Piedmont Of South Carolina: Comparison Of Evaluation Tools And Water Quality’S Effects On Salamanders, Camryn Lachica

All Theses

For many years, the United States Army Corps of Engineers (USACE) used the Guidelines for Preparing a Compensatory Mitigation Plan worksheets to guide pre-restoration evaluation and determine post-restoration mitigation credits in South Carolina. Recently, the USACE in South Carolina transitioned to the Stream Quantification Tool (SQT), which provides a more comprehensive assessment framework. Our first objective was to compare these assessment methodologies across different landscape types to determine what the SQT adds to mitigation calculations that were not considered in prior worksheets. We evaluated 16 streams in the Piedmont of South Carolina, with four replicates each of forested, suburban, urban, …

3,5-Dihydroxy-4-Isopropylstilbene (Tapinarof) Is A Partial Aryl Hydrocarbon Receptor Agonist In Fish, Conner A. Dicks

All Theses

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is essential in regulating development, immune homeostasis, and drug and xenobiotic metabolism. Activation of the AHR by specific ligands results in its translocation to the nucleus where it induces a myriad of gene products, including cytochrome P450 (CYP) drug metabolizing enzymes (e.g., CYP1A1) and other components of the chemical defensome, as well as inflammatory control. Interestingly, the AHR can bind a wide variety of endogenous and xenobiotic ligands which are able to induce unique downstream effects dependent on cell type, inflammatory context, and ligand stability. The AHR is …

Using Livestreaming Technology To Answer Novel Questions About The Behavior And Physiological Ecology Of The Prairie Rattlesnake (Crotalus Viridis), Max C. Roberts

Master's Theses

Recent advances in remote monitoring technology are opening up new opportunities for developing innovative natural history and biological research methodologies. In particular, the emergence of livestreaming camera technology has made recording remote video of wild and secretive animals much easier and made it possible to collect data at extremely fine temporal resolutions. In 2024, Project RattleCam launched a livestreaming camera at a Prairie Rattlesnake (Crotalus viridis) den in Colorado. The goal of this work was to study Prairie Rattlesnake behavior 24-7 throughout the species’ active season with minimal human disturbance. Additionally, I used this system to study the …

Impact Of S-Phase Kinase Protien 2 Blockades On Hematopoetic Stem Cell Metabolism, Nicole Elmaraghy

Electronic Theses, Projects, and Dissertations

Hematopoietic stem and progenitor cells (HSPCs) quiescence is vital for the success of bone marrow transplantation, as it preserves long term self- renewal and prevents premature exhaustion (Takubo et al., 2013; Wilson et al., 2008). However, bone marrow transplant (BMT) failure remains a clinical challenge, often due to lack of long-term engraftment and insufficient stress reliance. Both of these characteristics are tightly linked to disrupted stem cell quiescence and metabolic imbalance (Anso et al., 2017; Vannini et al., 2016). One key player is S-phase kinase protein (SKP2), an E3 ubiquitin ligase that targets cell cycle inhibitors, like p27, for proteosome …

Activation And Suppression Mechanisms Of The Nrg1 Helper Nlrs, Yu-Ru Wang, Ruize Zhang, Daowen Wang, Yong Wang, Zheng Qing Fu

Faculty Publications

No abstract provided.

Resolving Intra-Tumoral Heterogeneity Of Breast Cancer Using Single-Cell Multi-Omics, Yun Yan

Dissertations and Theses (Open Access)

Breast cancer is a highly heterogeneous disease characterized by diverse genetic, transcriptional, and epigenetic landscapes. Understanding how intra-tumoral heterogeneity (ITH) influences therapeutic response and drives tumor evolution remains a central challenge in cancer biology. Here, we leverage single-cell multi-omics technologies to dissect the cell states and gene expression programs underlying breast cancer heterogeneity, with a focus on triple-negative breast cancer (TNBC) and estrogen receptor-positive (ER+) breast cancer.

In the first part, we applied single-cell RNA sequencing and spatial transcriptomics to profile over 400,000 cells from 101 treatment-naïve TNBC patients. We identified 4 archetypes at the patient level and 13 metaprograms …

Use Of The Protein Misfolding Cyclic Amplification For Food Safety And Drug Discovery, Maria R. Benavente Garcia-Huidobro

Dissertations and Theses (Open Access)

Prion diseases are fatal neurodegenerative disorders caused by the misfolding of the normal prion protein (PrP^C) into its infectious form (PrP^Sc). While the zoonotic potential of chronic wasting disease (CWD) remains uncertain, the presence of prions in food products raises public health concerns. Additionally, therapeutic strategies for prion diseases remain limited. This thesis presents a methodological exploration of the Protein Misfolding Cyclic Amplification (PMCA) technique to address these challenges in two key areas: (1) detecting CWD prions in processed meats subjected to common cooking procedures, and (2) identifying potential anti-prion compounds through a high-throughput PMCA adaptation. …

Evolutionary Biomechanics In Cetartiodactyla: Impacts Of Ecological Shifts On Bone Material Properties And Control Surface Morphology, Danielle S. Adams

All Dissertations

Extreme ecological transitions expose organisms to novel selective pressures that can reshape morphology and performance. This dissertation investigates how the transition from land to water has influenced form and material properties in cetaceans (whales, dolphins, and porpoises), a clade that has undergone dramatic morphological and physiological adaptations to a fully aquatic lifestyle. I integrate comparative morphology, material property testing, and phylogenetic analyses, to explore how ecological demands, particularly related to foraging mode and prey detection, have shaped multiple aspects of cetacean morphology and function. Using nanoindentation and microCT, I measured elastic modulus and bone density of the skull and mandible …

Applying Transcriptomics For Technology Development And Conservation In North American Marine Organisms, Cory Von Eiff

Dissertations

RNA biology is a rapidly expanding field, with many avenues of discovery among marine organisms. In this study, we analyze both mollusks and sawfish. First, we perform an evaluation of sRNA biogenesis pathways throughout Mollusca, with emphasis on the easter oyster, Crassostrea virginica. Understanding these molecules prescribes RNAi-based gene silencing approaches, benefiting genetic investigation and biotechnology. Similar to other animal groups, mollusks have conserved microRNAs (miRNAs), with some shared with ecdysozoans and deuterostomes; however, there is no evidence of an endogenous small interfering RNA (siRNA) pathway. These results suggest that long double-stranded RNA (dsRNA)-based RNAi is not appropriate for gene …

The Inside Scoop: Elucidating The Three-Way Relationship Between Schistosoma Mansoni, The Gut, And Vaccines, Mariam A. Mhanna

Biomedical Sciences Theses & Dissertations

Schistosomiasis is a neglected tropical disease that affects over 250 million people worldwide. This blood fluke infection burdens communities and areas with limited to no access to clean fresh water. When a host is exposed to cercariae, the infectious agent, in a body of water, it matures in the host’s circulation into adult female and male worms. Copulated adult worms migrate to the mesentery, in the case of Schistosoma mansoni, and produce eggs that can cross the intestinal barrier and get excreted in the feces to continue the lifecycle. The effects of S. mansoni infection on the host …

Investigating The Impact Of Psychoactive Plant Alkaloids On Bumblebee Behavior, Skylar Mathieson

Electronic Theses and Dissertations

The relationship between plants and their pollinators is often framed as a food-for-service exchange in which plants provide pollinators with nutrients in exchange for transport of their gametes. However, in addition to essential nutrients, many floral rewards (nectar, pollen) also contain defensive toxins such as alkaloids, with largely unexplored consequences for plant-pollinator interactions. I investigated how three psychoactive and addictive plant alkaloids — caffeine, nicotine, and morphine — affect foraging behavior in generalist bumblebees (Bombus impatiens) using robotic flowers. Each of these chemicals affected pollinator foraging behavior, influencing the number and duration of their visits to flowers in …

Investigating The Multiple Enzyme Complex In The Carotenoid Biosynthesis Pathway, Mercy Mormor

Electronic Theses and Dissertations

In nature, plant carotenoids are 40-carbon isoprenoids with polyene chains that may have double bonds. They are vital components of all photosynthetic organisms, playing several roles in the plant cell, including photosynthesis, pigmentation, phytohormone synthesis, signaling and photoprotection. In this study, we investigated protein-protein interactions among key enzymes involved in the carotenoid biosynthesis pathway using the Bimolecular Fluorescent Complementation (BiFC) assay. Our results revealed several interactions that suggest a coordinated regulation of enzymatic activity within this pathway, highlighting potential regulatory complexes that influence carotenoid production. The study also highlights the pivotal role of Zeta-Carotene Isomerase (Z-ISO) as a key regulatory …

Trophic Roles And Climate-Driven Vulnerability For Benthic Invertebrates At Artificial Reefs In The Northern Gulf Of Mexico, Amanda Kirkland

LSU New Orleans Theses and Dissertations

Artificial reefs are deployed to enhance marine habitats and fisheries, yet their role in supporting secondary production and their vulnerability to climate stressors remain understudied. This dissertation investigates the trophic ecology and climate sensitivity of benthic invertebrates at artificial reefs in the northern Gulf of Mexico. Chapter 1 assessed reef food webs using stable isotopes from fishes, invertebrates, and primary producers across six reefs and two seasons. Mixing models showed that most fishes rely on benthic reef carbon, while suspension feeders consume plankton and sediment microphytobenthos. Isotopic niche analysis revealed functional diversity and seasonal shifts in δ¹³C and δ³⁴S, though …

Saliva & Circadian Rhythm In Medical Profiling For Early Disease Prevention, Joseph Lewis

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Circadian rhythms affect almost every biological process from hormone secretion, gene expression, immune regulation, and metabolism. Studies show that disruption to these internal rhythms through irregular sleep, artificial sleep, and irregular sleep can significantly increase risk for chronic disease such as diabetes, cardiovascular disorders, neurodegeneration, and cancer. Saliva presents a viable alternative for capturing biomarkers found through blood or cerebrospinal fluid, offering substantial utility for diagnostic and chronobiological profiling. Saliva contains hormones such as cortisol and melatonin while containing inflammatory markers that fluctuate rhythmically throughout the day. Due to its ease of collection, saliva is well suited for longitudinal monitoring, …

Fluoride Toxicity And Benefit: An Integrated Review Of Mechanisms, Risks, And Public Health Impact, Sophia Chavarria

Graduate Student Dissertations, Theses, Capstones, and Portfolios

Fluoride has long been praised for its role in preventing dental caries, primarily through its effects on enamel remineralization and antibacterial effects. However, growing evidence from molecular and cellular studies suggests that excessive fluoride exposure, especially during tooth development, can lead to dental fluorosis and systemic toxicity. This paper examines the biological mechanisms underlying fluoride-induced dental fluorosis, with a focus on stress responses in ameloblasts, oxidative damage, impaired autophagy, and disrupted protein processing. It integrates data from in vitro, in vivo, and human studies to evaluate the cellular thresholds at which fluoride shifts from therapeutic to toxic. Systemic risks, including …

Effects Of Sediment Composition On Spartina Alterniflora And Juncus Roemerianus Productivity In Coastal Virginia: A Thin-Layer Sediment Placement Experiment, Caitlin Hemphill

Biological Sciences Theses & Dissertations

Climate change poses a major threat to the health of estuaries and their coastal wetland systems. The Chesapeake Bay’s coastal salt marshes are at high risk of inundation due to sea-level rise and land subsidence. Restoration techniques for maintaining coastal marsh resistance to sea-level rise are being developed and refined, with thin layer placement (TLP) emerging as a feasible solution in many areas of the United States. Despite TLPs use across the country, additional research is needed on species-specific responses, sediment types, and geographically focused studies in the lower Chesapeake Bay. My research addresses these gaps by combining both greenhouse …

Cucurbit Plant Defenses Against Aboveground Or Belowground Insect Herbivores Are Distinct And Shaped By Eco-Evolutionary Factors, Morgan N. Thompson, Emily M. Russavage, Jeremy G. Garces, B. Jack Bradford, Danielle Merrell, Charles P.-C. Suh, Anjel M. Helms

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Plant defense strategies against insect herbivores are classified broadly as resistance or tolerance. Resistance deters insect growth or feeding, while tolerance mitigates negative effects of herbivory on plant fitness. Plant investment into resistance or tolerance strategies likely falls along a continuum that has been shaped by eco-evolutionary factors, such as plant domestication or coexistence histories with herbivores. Relatively little is known about how general defense strategies differ against aboveground foliar herbivores and belowground root herbivores. In the current study, we investigated defense strategies of plant species in the gourd family (Cucurbitaceae) against aboveground squash bug (Anasa tristis) or …

Isolation And Characterization Of Siderophore(S) From Pseudomonas Mosselii, Casey J. Stophel

Electronic Theses and Dissertations

Iron is essential for growth of most microorganisms. It functions as an important cofactor in many important biological processes. However, iron found in soil is rendered insoluble and unavailable to microorganisms for use. To overcome this, many bacterial species produce siderophores, a small organic molecule that has high affinity for iron. Siderophores allow for bacterial cells to obtain otherwise insoluble iron. Pseudomonas mosselii, a Gram negative bacterium, was isolated from a local soil sample. P. mosselii was found to produce siderophore(s) under iron restricted environment, however, they have not been characterized. Therefore, it was of interest to isolate, purify and …

Improved Autofluorescence Lifetime Decay Analysis For Identification Of Cellular Autofluorescence Biomarkers For Label-Free, Single-Cell Assessment Of Mitochondrial Membrane Potential, Olivia Isabel Kolenc

Graduate Theses and Dissertations

Optical imaging of metabolism using the autofluorescence of the metabolic cofactors NADH, NADPH, and FAD has a wide range of sensitivities and the capability to collect a great deal of metabolic information. Multiphoton microscopy (MPM) is a non-invasive, label-free optical imaging technique capable of performing fluorescence lifetime imaging (FLIM) using time correlated single photon counting (TCSPC). However, autofluorescence FLIM presents a challenge in collecting sufficient photons to provide adequate signal to noise ratios (SNR) for analysis. Additionally, the specificity of autofluorescence biomarkers of metabolism has not been well-defined. Contextualizing these autofluorescence measures using established functional biomarkers can improve interpretability of …

Host-Virus Interaction Dynamics Using Sulfolobus Spindle-Shaped Virus And Host Sulfolobales System, Yeasin Ahmed

Graduate Theses and Dissertations

The Sulfolobus Spindle-shaped virus (SSV) is among the most studied archaeal viruses, particularly in extreme environments. This virus predominantly infects multiple Crenarchaea from the Sulfolobaceae family. These hosts thrive in extreme environmental conditions, such as sulfuric hot springs, with a pH of 2 to 4 and a temperature of 76-80˚C. Sulfolobales exhibit a wide geographical distribution across volcanic hot springs. The Sulfolobus Spindle-shaped Virus (SSV), encompassing strains such as SSV1 and SSV8, employs a non-lytic replication strategy in hosts belonging to the order Sulfolobales. The SSV-Sulfolobales system can be cultured in liquid and gellan gum solid media. A comprehensive study …

Stress-Survival Pathway Genes In Colorectal Cancer: Crc Progression And Hispanic Disparities, Highlighting Mcm10 As A Potential Player, Urbashi Basnet

Open Access Theses & Dissertations

Despite advances in screening and treatment, colorectal cancer (CRC) remains a leading cause of cancer-related deaths in the U.S., with notable disparities across racial and ethnic groups. Hispanic populations face a disproportionate burden, underscoring significant differences in incidence and outcomes. This study examines the role of the Stress-Survival Pathway (SSP) in colorectal cancer (CRC), with a focus on addressing health disparities among Hispanic populations. Twenty-eight differentially expressed SSP genes identified from bioinformatic analysis were validated in CRC cell lines and cDNA arrays using qRT-PCR and tissue microarrays by immunohistochemistry. SSP genes were further analyzed in CRC tissues from Hispanic and …

Investigating The E74-Mediated Regulation Of A Gata Factor In Aedes Aegypti Mosquitoes, Jacklyn Marie Estrada

Open Access Theses & Dissertations

The mosquito species Aedes aegypti has a significant impact on public health as a vector for multiple pathogens. Its ability to transmit deadly diseases, including Yellow Fever, Dengue Fever, and Zika, emphasizes the urgency of understanding its reproductive biology. In female mosquitoes, reproductive success hinges on obtaining a vertebrate blood meal, which triggers vitellogenesis - the synthesis of yolk protein precursors (YPPs) necessary for egg development. Without a blood meal, female Ae. aegypti remain in a state of previtellogenic arrest, where the YPP gene vitellogenin (Vg) is repressed by a type of transcriptional factor, GATAr (AaGATAr) (Attardo et al., 2003). …

Spatial And Thermal Aspects Of The Ecology Of Three Sympatric Rattlesnakes In The Montane Northern Chihuahuan Desert, Joshua James Mead

Open Access Theses & Dissertations

To understand how animals coexist on the landscape, the individual aspects of a species life history must first be understood. Animals need to find locations that provide the resources they need to survive. Movement, microhabitats, and temperature can alter such areas where animals occur. Understanding animal movements provide important information on space use and microhabitats on the landscape. Ectothermic animals must acquiesce to ambient temperatures or use behavioral modifications to alter their body temperature. The ability to maintain suitable body temperature is essential for physiological function, reproduction, and ability to avoid predation. Research on the variation in a species ecology …

Mode Regulates Alternative Nitrogenase Expression In Themethanogen Methanosarcina Acetivorans, Melissa Chanderban, Daniel J. Lessner

Biological Sciences Faculty Publications and Presentations

All methanogens that can fix nitrogen use molybdenum (Mo) nitrogenase. Some methanogens, including Methanosarcina acetivorans, also contain alternative vanadium- and iron-nitrogenases, encoded by the vnf and anf operons, respectively. These nitrogenases are produced when there is insufficient Mo to support Mo-nitrogenase activity. The factors that control the expression of the alternative nitrogenases in response to Mo availability are unknown in methanogens. Here we show that ModE is the regulator that represses transcription of the vnf and anf operons in M. acetivorans when cells are grown with Mo. CRISPRi repression of modE results in a significant increase in the transcription of …