Integrative Biology Commons^™

Ant Cuticle Microsculpture: Diversity, Classification, Evolution, And Function, John Paul Hellenbrand

Master of Science in Integrative Biology Theses

My thesis covers the intricacies of ant microsculpture diversity, classification, evolution and function. To do this, the thesis is organized into two chapters. The first chapter is a review of ant cuticle and microsculpture diversity as well as including analyses examining the evolution and lability of microsculpture traits. I then review the literature for functional hypotheses related to ant microsculpture. The second chapter explores the relationship of microsculpture and important morphological, physiological, and ecological traits to evaluate support for functional hypotheses.

The Evolution Of Honeycomb, Grace Cope

Master of Science in Integrative Biology Theses

The regular cells of honeycomb nests have fascinated scholars and mathematicians for millennia. In 36BC, the Roman scholar Marcus Terentius Varro first proposed the “honeycomb conjecture,” in which he postulated that bees build their comb using hexagons because it is the shape that requires the least amount of material to divide space into equal portions. Since this time, honeycomb has been used by engineers in applications that range from skyscraper supports to impact absorbers inside the feet of the lunar lander during the first moon missions, but mysteries remain about the biological origins of honeycomb and the mechanical properties of …

Noxious Cellular Injury Triggers An Oxidative Stress Gene Response, Shawyun Khoshneviszadeh

Master of Science in Integrative Biology Theses

Wound and regeneration involves a series of complex processes that can induce oxidative stress by elevating intracellular reactive oxygen species (ROS) levels. In this study, we used RNA-seq and qPCR to examine the molecular signature of Human Embryonic Kidney cells (HEK-293T) stimulated with Crotalus atrox (CA) venom. NGS data was assembled and annotated utilizing the Illumina paired-end RNA-seq approach with software packages HISAT2 and StringTie. Results showed 243 genes were differentially expressed (106 upregulated, 137 downregulated) between CA venom stimulated and non-stimulated cells (p<0.05). HEK-293T stimulated with CA venom for 4 hours showed an increase in the expression of oxidative stress response genes (e.g., TOMM6, EGR (1,2,3), HSP70 (1A, 1B), SPRY4, ETV5, and EMP1) (Fold-Change (fc) >2.0). Significantly downregulated genes were associated with many novel transcripts/proteins such as AC117378, AD000671, and AC023509. …

Studying Tissue Specific Diversity Of Splicing Regulator Muscleblind, Davron Hanley

Master of Science in Integrative Biology Theses

The muscleblind (mbl) family of RNA-binding proteins regulates alternative splicing, determining mRNA transcript composition for various types of tissue, and has been implicated in myotonic dystrophy. The mbl gene is subject to alternative splicing in Drosophila, leading to multiple isoforms, and has several paralogs in humans. Mbl proteins vary significantly in length, although the significance of such diversity and the role of specific isoforms have not been fully explored. Using immunofluorescence microscopy and polyclonal serum, we analyzed Mbl protein expression across adult Drosophila tissues. Mbl was detected in various locations, including the brain, gonads, muscle, and gut epithelium. Skeletal muscles …

Cross-Modal Perception Of Identity By Sound And Taste In Bottlenose Dolphins, Jason N. Bruck, Sam F. Walmsley, Vincent M. Janik

Faculty Publications

While studies have demonstrated concept formation in animals, only humans are known to label concepts to use them in mental simulations or predictions. To investigate whether other animals use labels comparably, we studied cross-modal, individual recognition in bottlenose dolphins (Tursiops truncatus) that use signature whistles as labels for conspecifics in their own communication. First, we tested whether dolphins could use gustatory stimuli and found that they could distinguish between water and urine samples, as well as between urine from familiar and unfamiliar individuals. Then, we paired playbacks of signature whistles of known animals with urine samples from either the same …

Sodium Mediates Developmentally Plastic Responses In Plants And Herbivores, Luis Santiago-Rosario

LSU Doctoral Dissertations

Sodium plays a crucial role in organismal performance, trophic-level interactions, and eco-evolutionary dynamics. For plants, sodium impacts osmoregulation, growth, and water uptake. For animals, sodium is essential influencing osmoregulatory processes, muscle and neural development, and blood regulation. My dissertation aims to disentangle why sodium mismatch affects resource-consumer interactions and its influence on morphological and behavioral plasticity. First, I identified how sodium impacts plant performance and sodium accumulation strategies. I initially focused my research on understanding how increasing substrate sodium affects plant growth and tissue sodium accumulation strategies in controlled settings using a systematic review approach. I found that saltier plants …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Physiological Costs Of Total Cholesterol In European Starlings Across An Urban To Rural Gradient, Courtney Linkous

Master of Science in Integrative Biology Theses

Urban areas—characterized by high human densities and associated buildings and impermeable surfaces—are increasing globally and represents a leading threat to wildlife that is drastically altering the natural resources they are accustomed to. Prior studies suggest that living in urban habitats can cause wildlife to show increased cholesterol levels; in biomedical research, elevated cholesterol is linked to disease, but the consequence of elevated cholesterol in wildlife remains unclear. We measured total cholesterol in European starlings (Sturnus vulgaris)—an urban adapted species—across an urban and a rural site. We ask: (1) do urban starlings have elevated cholesterol, (2) does elevated cholesterol …

Pilfering Passerines? Inter-Class Competition: A New Direction In Foraging Ecology, Shannon Gillen

Masters Theses, 2020-current

Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia, the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda), were the focus of this study. Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. …

A Neuromuscular Look Into Genetics Of Muscle Aging, Christina Talley

Master of Science in Integrative Biology Theses

As individuals age throughout their life, they experience muscle tissue loss that impacts their quality of life such as a decrease in their physical capabilities and sometimes even their mental capacity. The process of muscle aging is the key point of this study. This involves the individual’s muscles and the motor neurons that control them. Skeletal muscles are used daily to maintain posture, stand, walk, etc. Throughout a lifetime these muscles undergo damage and need to be repaired. When the muscles are repaired, they express physical changes. The tissue shrinks in size and eventually the composition of the tissue is …

Determining The Distribution Of Elemental Compounds And Oxidative Potential Across Fine Particulate Matter (Pm2.5) Filters, Allie Michelle Sidwell

Honors Theses

Fine particulate matter (PM_2.5) is a complex mixture of particles and sorbed chemicals that poses serious, adverse effects on human health such as increasing cardiovascular and respiratory morbidity and mortality. There is ongoing research into the impacts of PM_2.5 of differing chemical compositions, sampling location, and the mechanisms for the observed health effects. To conduct these analytical and toxicology studies of PM_2.5, researchers often split filters into sections. This process allows multiple, often destructive, assays to be performed. Our previous research showed chemical composition differences across PM_2.5 filters. The goal of our study was …

Isolation Of Arabidopsis Thaliana Plants Homozygous For An Insertional Inactivation Mutation Within Atprp4., Sydney Raitz, Timothy D. Trott

Faculty Works

The AtPRP4 gene in Arabidopsis thaliana has been shown to function in several specific parts of the plant’s cell wall. It is shown to be expressed in the seeds, radicles, roots, leaves, inflorescences, and embryos of Arabidopsis thaliana. These patterns have suggested unique functions for ATPRP4 in determining cell-type-specific wall structure during the development of a plant as well as contributing to defense reactions against physical damage to the plant and pathogen infection within the plant. In this study, a simple DNA prep was performed on the true leaves of Arabidopsis thaliana. Subsequent PCR reactions were performed using …

Fire And Periodical Cicadas: Impacts On Soil Nutrients And Understory Plant Germination, Andrea Gamache

Master of Science in Integrative Biology Theses

Purpose

A compound disturbance, composed of a prescribed fire and a periodical cicada emergence, occurred in northern Georgia in the summer of 2021. Independently these disturbances have substantial effects on the surrounding ecosystems. This study investigated the collective impact on soil composition and seed germination.

Methods

Through the soil analysis of cicada turrets, burned soil, and unburned soil, we hope to understand the composition of each soil type. Additionally, a 2 x 2 factorial study was performed with those same samples, providing insight into the impact on seed germination these disturbances have. The two factors were between burned and unburned …

Fish Community Assembly At Multiple Spatial Scales In East Texas Streams, Jake R. Swanson

Electronic Theses and Dissertations

Stream communities are structured by environmental processes that vary in strength across different spatiotemporal scales. Therefore, revealing how stream fish communities are influenced by environmental gradients may clarify how communities respond to disturbance associated with anthropogenic change. I investigated the relative role environmental variables play in the processes that structure the taxonomic and functional diversity of stream fish communities, as well as historical trends in occurrence and local habitat associated with a species of greatest conservation need within east Texas. The results of this study indicate that stream sites with more habitat complexity and stability support a more taxonomically and …

Repeated Boat Noise Exposure Damages Inner Ear Sensory Hair Cells And Decreases Hearing Sensitivity In Atlantic Croaker (Micropogonias Undulatus), Gina A. Badlowski

LSU New Orleans Theses and Dissertations

No abstract provided.

Fluctuating Parasite Prevalence Is Not Linked To Patterns Of Mhc Class Ii-Ss Diversity In An Island Endemic Reptile, Gina Zwicky

LSU New Orleans Theses and Dissertations

Few studies have explored the evolutionary mechanisms that maintain adaptive immunogenetic diversity in nature. We took advantage of museum samples to test for evidence of parasite-mediated fluctuating selection at MHC Class II-ß loci in an endemic island reptile. The Saban anole Anolis sabanus is commonly infected with three species of malaria (Plasmodium). Proportions of each parasite species detected in anole blood samples fluctuated over space and time, suggesting competitive interactions between parasites or differences in vector ecology. Our analyses of parasite prevalence and MHC Class II-ß allelic variation found that malaria infection was not associated with patterns of …

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 …

Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair

Dissertations and Theses (Open Access)

KRAS, a 21 kDa small GTPase protein, functions as a molecular switch playing a key role in regulating cell proliferation. Dysregulation of KRAS signaling by oncogenic mutations leads to uncontrolled cell proliferation, a hallmark of cancer cells. Attempts to therapeutically target oncogenic KRAS have led to limited success resulting in a need to identify new mechanisms to targeting KRAS. The interaction of KRAS with its regulators, effectors, and the membrane present one such avenue. In this study, we investigated how post-translational covalent and environmental modifications could modulate these interactions of KRAS. Using computational molecular dynamics simulations, nuclear magnetic resonance spectroscopy …

Computational Approaches To Understand Chemoresistance & Tumor Evolution Using Longitudinal Clinical Data And Lineage Tracing, Sahil Seth

Dissertations and Theses (Open Access)

Tumors are highly heterogeneous and dynamic, continually adapting and evolving in response to their microenvironment as well as external perturbations. Multi-region (spatial) and single cell sequencing has enabled us to anatomize the heterogeneity further and provide evidence of its association with chemo and drug resistance. To investigate this further we took two different approaches to understand the chemo-resistance, and functional heterogeneity in Triple negative breast cancer (TNBC) and Pancreatic ductal carcinoma in situ (PDAC) from an evolutionary perspective.

The first approach was to leverage tumor profiling from an ongoing randomized clinical trial in triple-negative breast cancer (ARTEMIS) to assess mechanisms …

Supertertiary Structural Dynamics Modulate Function In Postsynaptic Density Protein 95, George L. Hamilton Iii

All Dissertations

Proteins, RNA, and DNA serve as the primary sub-cellular machinery that give rise to the necessary functions of life. The long-standing paradigm has been that the structures of biomolecules, or the arrangement of the subunits that make up a biomolecule, determine biological function. However, biomolecules are not static objects. Instead, they often undergo structural rearrangements that are crucial to enabling and regulating their functions. In my thesis I present several studies of the interplay between the structures, dynamics, and functions of biomolecules that combine experimental fluorescence spectroscopy and computational methods to probe these systems at the single-molecule level. In particular, …