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Characterizing Gut Microbial Communities And Symbiont-Mediated Detoxification In Herbivorous Insects, Rachel C. Vargas

Biology Dissertations

Insect gut bacteria are vital contributors to host physiology, yet the broader prevalence and fitness implications of symbiont-mediated detoxification remain poorly understood. This thesis investigates these dynamics across three research chapters. Chapter 1 uses 16S rRNA sequencing to characterize how grasshopper gut microbial communities vary across species, dietary breadths, and gastrointestinal segments. Chapter 2 evaluates the detoxification capacity of over 150 bacterial isolates from diverse herbivores against the plant allelochemicals phenethyl isothiocyanate, rutin, and chlorogenic acid to determine if host dietary specialization predicts microbial metabolic ability. Finally, Chapter 3 employs fitness bioassays to test whether inoculating generalist herbivores with detoxifying …

Factors Affecting Detection Of A Cryptic Ambush Predator Using Camera Traps, With Implications For Snake Monitoring, Sarah Elizabeth Ebert

Theses, Dissertations and Capstones

Camera traps are becoming increasingly popular in wildlife research because they can be deployed for long time periods with little maintenance and are much less invasive than traditional trapping methods. However, they are primarily used to study large mammals and have not been extensively tested for snake species, many of which are cryptic and understudied. The Adapted-Hunt Drift Fence Technique (AHDriFT) arrays were designed to improve detection of herpetofauna by attaching camera traps to drift fences. In the summer of 2022, we installed 20 AHDriFT arrays at the Marine Corps Recruit Depot Parris Island in coastal South Carolina where we …

Effectiveness Of Walleye Stocking In Winter Kill Lakes, Tyler Haus

Journal of Earth and Life Science

Winter kill events, marked by extensive fish mortality due to hypoxic conditions under the ice, are a common phenomenon in shallow eutrophic lakes, especially in the northern lakes in the northern United States. These events can drastically alter fish communities and often result in the elimination of top predators. Though these lakes will typically slowly bounce back to what they were in a couple of years. This study evaluates the effectiveness of walleye, Sander vitreus, stocking in lakes after a winter kill. For this study, four known winter kill lakes that are consistently stocked with walleye were studied. Pre- …

Assessing Urban–Rural Differences In Largemouth Bass Abundance In Minnesota, Jonathan Gates

Journal of Earth and Life Science

Urbanization can significantly alter freshwater ecosystems and influence sport fish populations. This study examined differences in largemouth bass Micropterus nigricans catch-per-unit-effort (CPUE) between urban and rural lakes in Minnesota and evaluated temporal changes between 2000–2010 and 2011–2021. Forty lakes (20 urban, 20 rural) were selected using Minnesota Department of Natural Resources fisheries survey data. Lakes were classified using NLCD 2019 land cover data, with ≥10% developed land designated as urban. Nonparametric analyses (Wilcoxon rank-sum and signed-rank tests) were used to assess spatial and temporal differences in CPUE. Results showed that rural lakes had consistently higher median CPUE than urban lakes …

Statewide Northern Pike Response To Minnesota’S 2018 Regulation Change, Elijah Wozniak

Journal of Earth and Life Science

Management of northern pike (Esox lucius) is challenging because it attempts to balance ecological sustainability with angler interests. Northern pike often stunt their own growth by diminishing the size and abundance of prey fish, their food source. Anglers are often displeased when small pike occur in high population densities. In response to populations of small northern pike, the DNR implemented a new, statewide northern pike regulation in 2018. The objective of this study was to determine whether the regulation successfully changed the mean weight, length, and CPUE of northern pike in Minnesota. The secondary objective was to test …

Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber

Journal of Earth and Life Science

Brown Bullhead Ameiurus nebulosus, Yellow Bullhead Ameiurus natalis, and Bluegill Lepomis macrochirus are unique in their stark differences. Bullhead are scaleless bottom feeders that can tolerate high pollution and low O₂ conditions. In contrast, Bluegill are scaled, aggressive nesters and are less tolerant of high pollutants or low-oxygen conditions. Among these pollutants include a class of chemicals called neonicotinoids (hereafter referred to as neonics). Neonics are a class of insecticides primarily used within agriculture and pest management. Due to the effectiveness, application has escalated on a global scale. They have been well documented by many toxicology assessments. …

Comparison Of Calcified Structures To Estimate Ages Of Northern Pike Esox Lucius In Various Lakes, Kaed Rauk

Journal of Earth and Life Science

Northern pike Esox lucius are a dominant predatory fish in many aquatic systems. They can have significant impacts on the ecosystems they inhabit and are also a popular game fish among anglers. However, northern pike are a difficult species to age accurately. This study aimed to compare calcified aging structures to identify trends and determine which structure provides the most accurate age estimates. A total of 119 northern pike were sampled, and multiple structures from each fish were independently aged by two readers. The coefficient of variation (CV) was calculated for each structure to assess precision. Sectioned sagittal otoliths exhibited …

Size Structure Comparison Of Bluegill In Lakes With And Without Special Regulations, Jenna Lawin

Journal of Earth and Life Science

Lots of individuals have mixed feelings about special regulations for all sorts of game fish species such as northern pike Esox lucius, crappie Pomoxis spp., sunfish Lepomis spp., and so on. One species commonly sought after by many is bluegill Lepomis macrochirus. Bluegill are often deemed easy to find, catch, and clean. This study looks at three different categories of lakes (all lakes contain bluegill populations). The three categories are lakes with a five sunfish limit, lakes with a ten sunfish limit, and lakes without any special regulations. This study provides valuable insight into the size …

Ovipositional Behavior Of The Twig Girdler (Cerambycidae: Oncideres Cingulata) On Stems Of Mockernut Hickory (Carya Tomentosa) In Arkansas, R. Tumlison, L. Serviss

Journal of the Arkansas Academy of Science

The Twig Girdler (Cerambycidae: Oncideres cingulata) is a long-horned beetle that girdles stems of certain species of trees to prepare a habitat for its offspring. The stems eventually die, break, and fall from the tree, but the beetle usually had already laid its eggs within the stems. Eggs are laid singly, almost always at growth rings or leaf bases. Because the space for the young to develop is finite, laying too many eggs could cause reproductive failure and too few eggs would be suboptimal. We hypothesized that the female laying eggs should be able to evaluate the stem and …

Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp

Capstone Showcase

This thesis investigates the evolutionary relationships among disk-winged bats in the genus Thyroptera, a small group of Neotropical bats known for the adhesive suction disks on their wings and feet that allow them to roost inside tightly rolled leaves. The distinctive morphology and behavior of these bats have not been extensively documented, and their phylogenetic relationships remain only partially resolved. The goal of this research is to better understand how these species are related to one another and to determine whether the five recognized species of Thyroptera form a single monophyletic group. To address this question, morphological and genetic …

Lead Biosorption By Oceanobacillus Profundus Kbz 3-2: Strategies For Bioremediation Systems In Kabwe, Danielle S. Desmarteau

Scripps Senior Theses

Lead contamination remains a significant global public health concern, particularly in Kabwe, Zambia, the site of a former lead mining operation. Bioremediation, which utilizes biological materials and processes to remove environmental contaminants, represents a promising approach for addressing lead pollution. However, the development of effective bioremediation systems requires a detailed understanding of the mechanisms underlying metal removal and the feasibility of implementation in low-resource settings. Oceanobacillus profundus KBZ 3-2, a bacterium isolated from Kabwe mine waste, has demonstrated the ability to remove lead from aqueous environments. This study proposes to investigate the mechanism of lead biosorption by this organism, …

Mitochondrial Efficiency: Bridging Early-Life Environment And Organismal Performance, Kayla E. Lichtner

Master’s Theses

Mitochondria operate at the forefront of organismal-environmental interactions. Despite remarkable diversity in mitochondrial function both within and among species, all mitochondria serve a universal role in facilitating the flow of energy between organisms and their environment. Energetic efficiency, the way in which organisms assimilate and transform environmental substrate into physiological currency, is a major determinant of organismal performance. Although previous studies have shown that early-life environment can have lasting effects on metabolism, the underlying mechanisms driving the emergence of mitochondrial phenotypic variation remain poorly understood. Leach’s storm-petrels (Hydrobates leucorhous) provide a valuable opportunity to investigate longitudinal hypotheses of …

Ethanol And Iron Absorption Interactions Within Crayfish Invertebrate Models, James Rollman, Andrew Wissmar

Williams Honors College, Honors Research Projects

Analysis of the effects of alcohol consumption (ethyl-alcohol) on iron absorption within crayfish model. The use of tube-feeding provides a novel, more precise output, and less invasive procedure compared to the traditional approach of dissolving the target substance in tank water and measuring hemolymph changes. The project aims to determine the extent to which alcohol influences iron absorption. Ultimately, the choice of iron reflect the future potential to aid in research with genetic hemochromatosis and or Iron overload.

Characterizing The Role Off The Sp1/Klf Transcription Factor Huckebein In The Drosophila Melanogaster Ventral Nerve Cord, Benjamin Almond

Distinguished Undergraduate Researcher Program

Over the course of embryonic development, the ectodermal cell layer gives rise to a vast array of neurons and glia patterned across the central nervous system (CNS). Neurulation and specification is achieved in the ectoderm through temporospatial patterns of transcription factor (TF) expression, many of which are conserved across evolutionary history. These conserved regulatory motifs allow the use of Drosophila melanogaster to study the mechanisms of neurodevelopment across the animal kingdom. The huckebein (hkb) gene encodes a conserved SP1/KLF TF known to play important roles in cell cycle regulation, tissue morphogenesis during tubular organ development, and gut specification in Drosophila. …

Analysis Of The Pervasiveness Of Per- And Polyfluoroalkyl Substances (Pfas) And Their Relationship With The Incidence Of Neurological Health Disorders, Emma Waters

2026 Research Poster Competition

Per- and polyfluoroalkyl substances (PFAS) are a contaminant of emerging concern due to their chemical structure that afford a plethora of issues with regards to degradation on environmental and metabolic fronts. PFAS are amphiphilic and contain a carbon-fluorine bond, which complicates their movement through the environment and ensures their longevity in biological systems. Their persistence in biological systems has led them to be marked as “forever chemicals” and have emphasized them as a priority area for research in recent years. Current work on PFAS relationships to human health have pointed to some causes for concern. Much of the research on …

Effects Of Warmer Springs And Urbanization On The Nest Choice Of Temnothorax Ants, Keana Royce

Williams Honors College, Honors Research Projects

Climate change is altering winter and spring conditions in northeast Ohio, with urbanization and the urban heat island effect likely intensifying these changes. This preliminary study examined how Temnothorax ants alter nest-site preference in response to climate change and urbanization. I hypothesized that colonies exposed to warmed treatments would select hickory nuts to buffer against thermal/urban stressors. Identical in situ experimental setups were deployed at a rural site and an urban site and data collection occurred from late winter to early spring. Control colonies experienced ambient temperatures while experimental colonies were warmed +4°C above ambient temperatures. Colonies had the choice …

Activity-Dependent Remodeling Of Muscle Architecture During Distinct Locomotor Behaviors In Caenorhabditis Elegans, Adina Fazyl, Akash Anbu, Sabrina Kollbaum, Andres G. Vidal-Gadea

Faculty Publications – Biological Sciences

Muscle structure is dynamically shaped by mechanical use, yet how distinct locomotor behaviors influence sarcomere organization remains poorly understood. In Caenorhabditis elegans, crawling and swimming constitute discrete gaits that differ in curvature, frequency, and mechanical load, providing a tractable model for studying activity-dependent remodeling. Using confocal imaging of phalloidin-stained body-wall myocytes, we quantified myocyte geometry, sarcomere length, and sarcomere number across anterior, mid-body, and posterior regions in animals reared exclusively under crawling or swimming conditions. Quantification and hypothesis testing used linear mixed models that accounted for repeated myocyte measurements within animals, with interaction terms testing region-specific effects of locomotor …

Parasite Party: Investigating Ecological Drivers Of Trematode Parasite Prevalence Across The Isles Of Shoals, Aimee D. Bousquet, April Blakeslee, Amy Fowler, David Buck

UNH URC Open (2026 and after)

Parasite Party: Investigating Ecological Drivers of Trematode Parasite Prevalence Across the Isles of Shoals

Dosage Sensitivity And The Evolution Of Dosage Compensation: Tests Of The Insensitive Sex Chromosome Hypothesis In Flour Beetles, Shana Pau

Biology Dissertations

Sex chromosome evolution generates imbalances in gene dosage that can disrupt gene expression and organismal function. These imbalances are often resolved through dosage compensation mechanisms, yet the factors that drive the emergence and diversity of these systems remain poorly understood. This dissertation addresses a central question in evolutionary genomics: what governs the evolution of dosage compensation?

Focusing on dosage sensitivity as a potential driver, I evaluate the Insensitive Sex Chromosome Hypothesis (ISCH), which predicts that chromosome-wide compensation is more likely to evolve in genomic contexts that are not depleted of dosage-sensitive genes. Using flour beetles (Tribolium spp.) as a …

From Chaos To Clockwork: Investigating The Role Of Circadian Genes In Metabolic Development Of 2nd And 3rd Instar Drosophila Larvae, Elliott Ruegsegger

2026 Research Poster Competition

Connecting deficits in circadian rhythm machinery to the severity of other health conditions is a common task that chronobiology, the study of physiological rhythms, undertakes. Disruptions to circadian rhythms and sleep are linked to increased risk of developing multiple different diseases, including Alzheimer’s Disease and obesity. Circadian rhythms are expressed at the molecular level through rhythmic variations in the concentration of specific proteins. While the central clock genes that produce these proteins, such as period and timeless, are evolutionarily conserved across the animal kingdom, not much is known about the consequences of disruptions in circadian rhythm machinery during early development, …

Moving Towards Defining The Evolutionarily Ancient Role Of Notch Signaling In Animals., Paige Norris

2026 Research Poster Competition

The notch signaling pathway is deeply conserved across animals from humans to sponges. It functions through direct cell-to-cell communication, where ligand binding triggers the cleavage of the Notch receptor’s intracellular domain (NICD), which then translocates to the nucleus to regulate transcription. In bilaterian lineages—animals with bilateral symmetry— Notch signaling is known to regulate binary cell fate decisions in diverse contexts ranging from neurogenesis to cancer. However, the functions of Notch signaling in early-branching animals, including cnidarians (e.g. jellyfish, corals and sea anemones), are still not fully understood; consequently, evolutionarily ancient roles of Notch remain ill-defined. To address this fundamental knowledge …

Investigating Pituitary Specific Transcription Factor-1 (Pit-1) In Neuronal Development In The Sea Anemone Cnidarian Nematostella Vectensis, Emily Ye

2026 Research Poster Competition

In bilaterians — animals with bilateral symmetry, like vertebrates and insects — the pituitary specific transcription factor-1 (pit-1) is essential for regulating growth hormone and prolactin expression in the pituitary gland. However, in non-bilaterians, the ancestral function of pit-1 remains unknown. Cnidarians, such as the sea anemone Nematostella vectensis, form a sister group to bilaterians and lack a pituitary gland, making them a powerful model for investigating the early evolutionary role of conserved developmental genes, like pit-1.Using CRISPR-mediated gene editing, pit-1 knockout mutants — anemones without the pit-1 gene — were generated, and their transcriptomic, cellular, and behavioral phenotypes were …

A Chromosome-Level Assembly And Functional Genomic Resources For The Model Annelid Capitella Teleta, Billie E. Davies, Paul Gonzalez, Abhinav Sur, Jingcheng Wei, Tom Frankish, Jimena Montagne, Allan M. Carrillo-Baltodano, Kero Guynes, Yan Liang, Rory D. Donnellan, Travis Moreland R., Sumeeta Singh, Suiyuan Zhang, Reynold Yu, Tyra G. Wolfsberg, Néva Meyer, Elaine C. Seaver, Andreas D. Baxevanis, José M. Martín-Durán

Biology

The polychaete Capitella teleta is a primary model for evolutionary developmental biology, comparative genomics, conservation, and ecotoxicology. Although it was the first polychaete genome sequenced, the original assembly is outdated by modern standards. Here, we combine long-read and short-read sequencing with Hi-C chromatin conformation capture to assemble chromosome-level nuclear and mitochondrial genomes of the laboratory strain of C. teleta. This reference assembly accurately reflects the expected genome size (∼243.6 Mb) and contains a highly complete, evolutionarily conserved gene repertoire. Notably, the nuclear and mitochondrial genomes are heavily rearranged, indicating a decoupling between gene family repertoire and chromosomal evolution. The analyses …

Invasion Of Microplastics Into The Reproductive Tissues Of Feral And Domestic Felines, Emma K. Quade

Honors Undergraduate Theses

Although plastics have many useful properties in modern society, once these materials are introduced into the environment, they can cause extensive damage. Following degradation into microplastics (MP), plastic particles less than 5 mm in size, these contaminants can make their way into a variety of different environments and organisms. There are many studies that have investigated the prevalence of MP in marine environments, but fewer studies have looked into terrestrial systems, and even less that have focused on contamination in companion animals. This study sought to investigate the invasion of MP into the reproductive tissues of felines, Felis catus, …

Friends In Niche Places: An Examination Of Anole Abundance And Habitat Use In An Urban Environment Using Point Transect Distance Sampling, Ethan Gau

Honors Undergraduate Theses

Lizards in the genus anolis occupy a wide range of ecological niches, often sharing the same environment due to niche partitioning. In central Florida, the main species of anoles found are the native A. carolinensis and the invasive A. sagrei, two generalist anole species that partition into trunk-crown and trunk-ground niches in each other’s presences respectively. I surveyed the UCF main campus using Apollo Circle as the border for my study area, and I used point sampling to estimate the population abundance and density, while also collecting data on perch substrate, height, and canopy coverage. Population estimates for A. …

Modeling Inherited Retinal Disease In Zebrafish, Meet Patel

Theses and Dissertations--Biology

Inherited retinal diseases (IRDs) affect millions of people worldwide. Majority of IRDs are caused by degeneration of rod and cone photoreceptor cells (PRCs) due to gene mutations. The overarching goal of my dissertation is to model and evaluate the molecular role of various gene candidates involved in IRDs such as cone rod dystrophy (CRD) and retinitis pigmentosa (RP).

Mutations in CDHR1, a photoreceptor specific cadherin have been associated with CRD and recapitulated in mouse CDHR1 knockouts. However, the molecular function of CDHR1 remains unknown. CDHR1 has been shown to localize at the leading edge of murine rod nascent outer segment …

Assessment Of The Antimicrobial Properties And Skin Microbiota Of Unisexual (Ambystoma) Salamanders Within Defensive Toxins, Sydney Stanton

Senior Honors Theses and Projects

As antibiotic resistance continues to pose a significant threat to public health, discovery of novel antibiotics could provide tools to combat this threat. Amphibian skin exhibits complex pathogen defense physiology and diverse skin microbiota, which suggests that it could be a potential source of novel antibiotics. A critical feature of amphibian skin is mucus, which is secreted as a defense mechanism and contains many immune system components such as symbiotic microbiota and antimicrobial peptides. To test the antibacterial properties of amphibian mucus, this study assesses whether mucus secretions from unisexual Ambystoma salamanders are effective at inhibiting the growth of safe …

Data And Code From: Migration Speed, Timing, And Long-Term Shifts In Age Structure In North American Passerines During Fall Migration, Dylan M. Osterhaus, Martha J. Desmond, Timothy F. Wright

Biology: Datasets

No abstract provided.

Population Genomics And Evolution Of Pseudomonas Aeruginosa, Samara T. Choudhury

Electronic Theses & Dissertations (2024 - present)

Pseudomonas aeruginosa is a Gram-negative bacterium ubiquitous in diverse environments and an opportunistic pathogen in humans. It is a leading cause of chronic lung infections in cystic fibrosis patients and of hospital-acquired pneumonia and sepsis. With a large flexible genome and abundant mobile genetic elements, P. aeruginosa exhibits high levels of antimicrobial resistance (AMR), making it a significant public health threat. Evolutionary processes such as homologous recombination, and horizontal gene transfer generate extensive genomic diversity in this species and facilitate the spread of resistance genes. In this dissertation, I investigate the genetic and evolutionary factors shaping P. aeruginosa population structure …

A Metabolite-Dependent Mechanism By Which Bifidobacterium Animalis Subsp. Lactis Promotes Bacteroides Colonization, Khashayar Shahin, Liang Wang, Zihan He, Bomin Lv, Arya Van Alin, Richard Lo-Man, Hao Wu, Philippe Sansonetti, Jean Marc Collard

Research outputs 2022 to 2026

Prokaryote-prokaryote symbiotic relationships influence interactions within microbial communities, affecting colonization, survival, and organization. Unlike competition, consortium species facilitate growth via metabolite cross-feeding. This study explored interactions between two early human gut colonizers: partially aerotolerant Bifidobacterium spp. and strict anaerobic Bacteroides spp., using omics techniques. Promotion of Bacteroides spp. growth by Bifidobacterium animalis subsp. lactis was demonstrated through co-culture experiments in anaerobic conditions. Metabolomic analysis revealed over 150 unique metabolites present in B. animalis subsp. lactis supernatants are absent in other Bifidobacterium species, including 3-hydroxycapric acid, D-alanyl-D-alanine, 2-isopropylmalic acid, and D-glucose 2-phosphate. These compounds served as nutritional substrates, including carbon and …