Integrative Biology Commons^™

Morphological Variation Of Lingual Glands In Wild American Alligator (Alligator Mississippiensis) Populations, Benjamin Angalet

Master's Theses

American alligators (Alligator mississippiensis) inhabit diverse aquatic ecosystems including freshwater wetlands, swamps, and estuarine rivers. As apex predators, their physiological resilience has implications for ecosystem stability and long-term conservation. With projected sea-level rise and increasing saltwater intrusion into coastal freshwater habitats, understanding the osmoregulatory capacity of alligators is increasingly important. Unlike marine-tolerant crocodilians such as the saltwater crocodile (Crocodylus porosus), which possess specialized salt-secreting lingual glands in addition to renal and cloacal mechanisms, the morphology and physiological significance of lingual glands in wild American alligators remain poorly understood. This study examined lingual gland morphology and plasma …

Impacts Of Halophila Stipulacea Invasion On Organic Matter Dynamics In Thalassia Testudinum Dominated Seagrass Meadows, Puerto Rico, Jonathan D. Herald

Master's Theses

Halophila stipulacea (Forsskål & Niebuhr) is a tropical seagrass native to the Red Sea, Persian Gulf, and Indian Ocean. In 2002, invasive populations of H. stipulacea were identified in the Caribbean Sea where it now forms large meadows, displaces native seagrasses, alters invertebrate and fish communities, and potentially affects organic matter dynamics in invaded meadows. This study investigated differences in organic matter dynamics between meadows of H. stipulacea and native Thalassia testudinum within the Jobos Bay National Estuarine Research Reserve (JBNERR) on the southern coast of Puerto Rico. From March 2023-March 2024, sampling was conducted across four sites to investigate …

Pollinator Plant Communities Within Restored Montane Longleaf Pine Ecosystems, Hanen Van Rossem

Master's Theses

Historically the fire-dependent and biodiverse longleaf pine (Pinus palustris) ecosystem was the dominant ecosystem of the Southeastern US. This ecosystem’s range was massively reduced due to land conversion and fire exclusion, causing the decline of many native species. Efforts to restore and protect longleaf pine stands are now ongoing with the goal of expanding habitat and refuge for threatened species. Differences in restoration practices and prior land use may influence the extent to which restored habitat patches can support pollinators and their plants. This study compared pollinator plant biodiversity between restored neighboring montane longleaf pine stands that differed in …

Assessing The Osmoregulatory Capabilities Of American Alligator Lingual Glands, Benjamin Angalet, Nicholas S. Green

Symposium of Student Scholars

Crocodilians inhabit a wide variety of aquatic, marine, and estuarine habitats on 4 continents. Saltwater-adapted species and populations face considerable osmoregulatory challenges in maintaining homeostasis with respect to plasma salt [NaCl] concentration. In addition to the kidneys and cloaca found in all crocodilians, crocodiles possess a salt-secreting lingual gland whose presence and function is less understood in other crocodilians. This study investigates the lingual gland anatomy, physiology, and potential function of American alligator (Alligator mississippiensis) populations exposed to varying salinity levels. At each of four sites (Jekyll Island, Sapelo Island, Okefenokee NWR, and Banks Lake NWR), we will capture 12 …

Tricolored Bat (Perimyotis Subflavus) Population Genetic Structure In The Southeastern United States, Laura Henderson

Master's Theses

Tricolored bats (Perimyotis subflavus) have experienced substantial population losses from white-nose syndrome (WNS), a disease caused by the pathogenic fungus Pseudogymnoascus destructans (Pd) which infects hibernating bats. Determining population genetic structure helps assess genetic diversity and the impacts of wildlife threats to populations. Pre-WNS data shows weak-to-negligible structure and panmictic P. subflavus populations at core portions of their range. However, current genetic data from their southeastern U.S. range is lacking. I sought to determine whether recent genetic data help resolve genetic structure among southeastern populations and assess genetic differences at two stages of impact: post-WNS and …

Genetic Influences On Individual Variability In Western Lowland Gorilla (Gorilla Gorilla Gorilla) Social Behavior, Hadley Mueller-Hill

Master's Theses

While primates are considered highly social animals, the evolutionary origins and mechanisms underlying their social behaviors remain unclear. Not only do they exhibit an extensive range of behaviors, but individuals within the same species can also vary widely in their social interactions. Genetics play a significant role in shaping these individual variations in behavior; multiple genetic variants have been associated with differences in social behavior in mammals. Examples of these include MAOA and OXTR genes, which influence the expression of behaviors associated with antisocial and prosocial temperaments. Genetic polymorphisms affect primate interactions, impacting an individual’s ability to maintain its status …

Assessment Of Georgia’S Royal Catchfly (Silene Regia) Along A Forest-Edge Gradient In A Remnant Prairie Community, Megan Brooks

Master's Theses

Royal catchfly (Silene regia) is a perennial prairie forb known to grow in rocky, alkaline soils within tallgrass prairies of the eastern United States. S. regia is recorded from twelve states, including Georgia, and is now confined to fragmented habitats due to the loss of 95% of its natural environment. The species is now listed as critically imperiled in the state of Georgia. Attempts at reintroduction via outplanting have only shown limited success, necessitating more research on the environmental conditions in which this plant survives in its southern-most distribution. This study investigated the local ecological factors influencing the …

Patterns And Potential Mechanisms Of Phenotypic Changes In Urban Small Mammals, Leslie Lopez

Master's Theses

Urbanization is an example of human induced rapid environmental change that can have wide-reaching ecological effects, including habitat destruction, fragmentation, and alteration of local climates. Effects of urbanization have been shown to impact wildlife, as disturbances resulting from urbanization can create novel environments and selective pressures that could lead to changes in morphology, physiology, or both. Small mammals such as rodents are an ecologically important set of wildlife species because they are a key prey item for several predators, hold strong influence over plants as a primary consumer, and some species carry and transmit major human and animal diseases. Previous …

Regulation Of Intracellular Sorting Of The Bruno Protein In Drosophila Flight Muscles, Travis Main

Master's Theses

Understanding mechanisms of intracellular sorting is a fundamental inquiry of cell biology. We used the B-body and protein Bruno (Bru) as a model to study the formation of nuclear domains that are membraneless organelles inside the cell nucleus. Specifically, we sought to identify protein sequences that regulate Bru's affinity to B-bodies and protein aggregation. We generated various Bru mutants and subsequently tested them in vivo using fluorescence microscopy. We found that the protein solubility of Bru is determined through an interplay of RNA recognition motifs (RRMs) and intrinsically disordered regions (IDRs). Using truncation analysis, we identified a 31-amino acid region …

Controlled Radiation Capsule For Precision And Rapid Cancer Treatment, Hoseon Lee, Zsolt Kollar, Bailey R. White, Junia Nguyen, David Roque, Sowjanya Palagani

Symposium of Student Scholars

This research aims to transform cancer treatment through the optimization of brachytherapy, with a focus on reducing treatment duration, setup complexities, and financial burdens, all while emphasizing patient safety. Patients living at a distance from radiation clinics, particularly those undergoing extended Low Dose Radiation brachytherapy, often struggle with the formidable financial challenges associated with securing nearby accommodations. In response to these issues, the research introduces a radiation capsule designed to condense the conventional six-month treatment period to approximately just one week, thereby significantly reducing the duration of required accommodations. This capsule is especially relevant considering the construction cost of $40 …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Novel Collective Prey Evasion Response Of Pseudomonas Aeruginosa Pao1 To Soil Micropredator Myxococcus Xanthus Dk1622, Joshua Lummus

Master of Science in Integrative Biology Theses

The search for alternative therapeutics is on the rise because of the threat of multi-drug resistant bacteria. Looking at the hunting strategy of soil-based bacterial micropredators is one avenue of exploration. Myxobacteria are soil predators with a wide prey range including Gram-negative and Gram-positive bacteria, fungi, and archaea. In our lab we discovered a distinct and novel anti-predation behavior in Pseudomonas aeruginosa strain 01. P. aeruginosa is an opportunistic and nosocomial pathogen responsible for 10% of all hospital acquired infections. P. aeruginosa is also an ESKAPE pathogen, which are leading causes of nosocomial infections throughout the world, and they are …

Microbial Commensals Of Tricolored Bats In Georgia And Their Probiotic Potential, Jordyn Upton

Master of Science in Integrative Biology Theses

Pseudogymnoascus destructans (Pd) is a fungal pathogen that has been spreading in North American bats since its initial discovery in 2006. P. destructans is the causative agent of white-nose syndrome (WNS), a disease leading to as much as a 90% decrease in some eastern United States bat populations, with select hibernacula experiencing complete extirpation of the hibernating population. To date, there is no effective scaled probiotic for WNS, but probiotics inoculums have shown success in the management of other recently emerged fungal pathogens of wildlife, such as chytridiomycosis in amphibians. Host microbiomes have come under investigation in other disease systems …

Early Stage Or Curable Cancer Diagnoses In Minorities: A Journey Of Survivors, Lora Asberry

Master of Science in Integrative Biology Theses

Patients diagnosed with early-staged or curable forms of cancer experience physical, as well as, mental challenges associated with disease progression and treatment. Previous studies have demonstrated that minorities and underrepresented communities did not receive the same level of care in comparison to their non-minority counterparts. Previous studies have also demonstrated that health disparities among minorities affected their cancer journey. This study addressed: how medical disparities varied between minorities and non-minorities, the overall effects of the cancer diagnoses in minorities compared to non-minorities, whether these perspectives differed in male vs. female participants, and whether there were any possible communication barriers between …

Testing The Urban Dulling Hypothesis In An Iridescent Passerine Bird, Joanna Gresham

Master of Science in Integrative Biology Theses

Urbanization has brought grave consequences that lead to declines in many species; however, some species thrive in urban ecosystems. This allows us the opportunity to study evolution in real time, as species adapt and change in a new setting. Novel urban ecosystems have led to phenotypic divergence between urban and rural populations. There is a rich body of literature on how songbirds are affected by urbanization, however divergent signaling behaviors are less well understood. Urban color homogenization is well-documented in carotenoid-colored species. However, iridescent plumage is understudied in general, and little is understood about how environmental changes shape iridescent plumage. …

Comparing Four Indices Of Physiological Stress In An Urban-Adapted Songbird Between Urban And Rural Habitats, Rachel Kaplan

Master of Science in Integrative Biology Theses

Birds show tremendous variation in the extent to which different species tolerate life in urban habitats, yet it remains unclear why some species thrive while others cannot. My work explores possible phenotypes that make an urban-adapted species, the European starling (Sturnus vulgaris), so successful in both rural and urban areas. Literature on stress-urbanization relationship remains highly equivocal partly due to an array of different study systems being compared as well as to key methodological differences. The present study quantified metrics of both acute stress (i.e., stress-induced corticosterone and breath rate) and chronic stress (i.e., baseline corticosterone and total …

Influence Of Woody Vegetation Composition And Structure On Fuels And Prescribed Fire In Mountain Longleaf Restoration, Collin J. Anderson

Master of Science in Integrative Biology Theses

Longleaf pine (LLP) ecosystems have experienced a widespread ecological state shift largely due to fire exclusion which has allowed mesophytes, i.e., shade-tolerant, often fire-sensitive species to encroach, reducing flammability and biodiversity through a process known as “mesophication.” Although prescribed fire is commonly used to reverse mesophication, fire behavior, and thus prescribed fire utility for this purpose, is poorly characterized in mixed pine-hardwood stands with mesophyte encroachment. This study aimed to identify mechanisms by which tree composition, structure, and fuels contribute to fire behavior, focusing on the understudied mountain longleaf pine (MLLP) ecoregion in northwest Georgia. I hypothesized that woody vegetation …

Variation In Salamander Life History And Community Composition Across An Urban Gradient In Atlanta, Georgia, Usa, Leah Rittenburg

Master of Science in Integrative Biology Theses

Urbanization threatens to alter stream systems in watersheds in the eastern United States. These highly disturbed systems may result in many local extirpations of sensitive salamander species. One group of organisms that often persists in urban streams is the Eurycea bislineata (Two-lined Salamander) species complex. Many aspects of Two-lined Salamander life history are linked to environmental factors, particularly stream temperature, prey abundance, and stream hydrology. Urbanization threatens to alter these environmental factors, potentially influencing Two-lined Salamander life history. At 14 sites spanning an urban gradient in Atlanta, GA, I investigated the variation in life history and phenology in the Southern …

The Manhattant: Identification, Natural History, And Nutritional Ecology Of A Recently Introduced Pest In New York City, Lasius Emarginatus (Hymenoptera: Formicidae), Samantha Kennett

Master of Science in Integrative Biology Theses

New York City is one of the oldest and largest cities in North America, and it is a center for global trade and shipping. As such, it has also been the site of introduction for some of North America’s most damaging invasive pests, from chestnut blight to the Asian long-horned beetle. Despite these cautionary examples, there has been no formal research on a newly introduced ant species that was tentatively identified as a European ant species, Lasius cf. emarginatus. Since its discovery in 2011, L. cf. emarginatus has become among the most common urban ant species in New York …

The Polycomb Complex 2 Contributes To Developmental Delay When Histone Methylation Is Inappropriately Inherited, Sydney Morgan- Benitez

Master of Science in Integrative Biology Theses

Histone methylation is a post-transcriptional modification to the N-terminal tails of histone core proteins that regulates DNA accessibility, and consequently, gene expression. Like DNA, histone methylation can be inherited between generations, and is highly regulated during embryonic development. At fertilization, histone methylation must undergo maternal reprogramming to reset the epigenetic landscape in the new zygote. During maternal reprogramming of histone methylation in C. elegans, H3K4me is removed by the H3K4 demethylase, SPR-5, and H3K9me is subsequently added by the histone methyltransferase, MET-2. Recently, it was demonstrated that SPR- 5 and MET-2 maternal reprogramming antagonizes the H3K36 methyltransferase, MES-4, which …

Measuring The Physiological Effects Of Methylobacterium Oryzae Foliar Inoculation Onto Salt-Stressed Tomatoes Grown In A Greenhouse Semi-Hydroponic System, Collin Dice

Master of Science in Integrative Biology Theses

Salinity stress has been shown to improve hydroponic produce quality such as that of tomato but at the trade-off of produce yield. In order to improve demand for hydroponic produce, techniques that improve salinity tolerance could offset declines in yield without altering the improved quality of produce. In two separate trials, we tested whether foliar inoculation of the ACC deaminase-producing bacteria Methylobacterium oryzae CBMB20 improved salt tolerance in tomatoes grown in a semi-hydroponic system using an indeterminate variety exposed to 26mM NaCl (Trial 1) and a determinate variety exposed to 17mM NaCl (Trial 2). We also tested how salinity and …

The City Blues Of An Iridescent Canary: Physiological, Behavioral, And Developmental Impacts Of Lead (Pb) On Songbirds Along An Urban-To-Rural Gradient, Michelle Ross

Master of Science in Integrative Biology Theses

Urbanization is rapidly changing the environment and creating new challenges in the lives of animals across the globe. Anthropogenic contaminants found commonly in old construction materials—including heavy metals like lead— persist within the environment for prolonged periods of time and present a widespread problem for all who live near contaminated areas. Despite the phase-out of lead usage, it continues to threaten the health of all organisms but especially those from urban areas where historical lead use was more common. Currently, the sub-lethal effects of lead on wildlife are not well understood, though lead is known to affect physiology and behavior …

Proximate Causes Of Alternative Reproductive Tactics In Blue Ridge Two-Lined Salamanders (Eurycea Cf. Wilderae), Yatin Kalki

Master of Science in Integrative Biology Theses

Alternative reproductive tactics (ARTs) refer to discrete variation in reproductive behavior between members of a sex and within a species. ARTs are present in Blue Ridge two-lined salamanders (Eurcyea cf. wilderae) in the form of male polymorphism. Two male morphs exist: “searching” males and “guarding” males. Each phenotype has a unique reproductive ecology and associated discrete morphological differences. Another trait that shows discrete variation in E. cf. wilderae is the larval period, which may be one or two years in length. This thesis explores the proximate causes of ARTs in a population of E. cf. wilderae from the …

Investigating Biometrics Of Perimyotis Subflavus In Traditional And Nontraditional Hibernacula In The Southeastern United States As It Relates To Susceptibility To White-Nose Syndrome., Makayla Ferrari

Master of Science in Integrative Biology Theses

Perimyotis subflavus, or tricolored bat, populations have declined significantly since the emergence of white-nose syndrome (WNS) and has been proposed for listing as “endangered” under the United States Endangered Species Act. Traditionally, bats use caves as hibernacula, but as anthropogenic impacts have increased so has the use of manmade structures like culverts and bridges for roosting by several bat species. The internal environment of these anthropogenic structures is influenced by external temperature and humidity differently than caves and may influence P. subflavus winter activity, and thus susceptibility to WNS. One of the most significant differences in P. subflavus roosting behavior …

Insect Availability And Parental Care Behavior In A Common Bird, Cole Bourque

Symposium of Student Scholars

Populations of aerially insectivorous birds are declining throughout North America. Urbanization may indirectly contribute to this decline through its negative effects on populations of insects, an important food source in insectivores' diets, where low insect availability may be especially challenging for birds during breeding. How fluctuations in insect populations impact various species at higher trophic levels is an important area of current study for future conservation biology. Here, we examine whether nestling provisioning, brooding and guarding behaviors in a breeding bird—the European starling (Sturnus vulgaris)—may be altered depending on the relative insect availability in the environment. We found …

Characterization Of Caenorhabditis Elegans F07a5.4, Human Ortholog Of Olfactomedin 1, Sade K. Thomas, Karunambigai Kalichamy, Martin Hudson

Symposium of Student Scholars

Accurate control of nervous system development is critical for normal brain patterning, and defects in this process can lead to neurological disorders such as schizophrenia and Autism Spectrum Disorder. The transcription factor neurogenin is necessary for the development of neural subtypes and is deeply conserved across species. However, the transcriptional targets of neurogenin are poorly understood, creating an imperative for further study. We have used the nematode Caenorhabditis elegans as a model to better understand ngn-1/neurogenin function. Previous work from our lab revealed that ngn-1 plays a role in nerve ring architecture, and neural cell fate specification. In addition, …

Chemically Induced Phytoextraction Of Lead (Pb) Contaminated Soil By Switchgrass (Panicum Virgatum L.), Assisted With Bap And Nta Applications, Genna Hart

Master of Science in Integrative Biology Theses

The accumulation of lead (Pb) deposits in soil is a growing global concern. Phytoextraction of Pb-contaminated soil can be enhanced by soil chelation to increase the bioavailability of Pb. In the initial study nitrilotriacetic acid (NTA) 5mM, the alkylpolyglucoside (APG) Triton X-100 (2%), and nano-silica were applied to switchgrass (Panicum virgatum L.) growing in 5L pots of Pb-contaminated soil. The second experiment used 10mM NTA, the alkylpolyglycoside Triton X-100 (2%), foliar application of the plant growth regulator 6-benzylaminopurine (BAP) twice per week, Triple-12® nutrients, and Infuse™ a soil fungicide which were applied to switchgrass Plants were grown in a controlled …

The Influence Of Land Coverage And Soil Chemical Factors On Soil Bacterial Community Diversity And Structure In Cedartown, Ga, Usa, Jake Smith

Master of Science in Integrative Biology Theses

Heavy metals pose serious threats to organisms due to their mobility and solubility in soil. Bacteria communities are vulnerable to heavy metal stress, but the response of different bacterial groups may vary depending on the level and type of heavy metal contamination. When subjected to heavy metal stress, many bacterial species or populations may become extirpated, while some may survive to form the foundations of a new microbial community. A study of the bacterial community at a lead (Pb) contaminated study site in Cedartown, GA, found that the microbiome in the Pb contaminated soil had significantly lower species richness. But …

Heavy Metal Distribution Across Three Georgia Estuaries Using Coastal Sharks As Sentinel Species, Allyson Stiles

Master of Science in Integrative Biology Theses

Estuaries are transitional environments that play key roles in coastal ecosystem functioning by providing essential habitats to ecologically important plant and animal species. Estuaries are exposed to a number of anthropogenic impacts, including heavy metal contamination from human activities. However, few studies have examined heavy metal distribution within Georgia’s estuaries and how intact salt marsh ecosystems could play a role in filtering and sequestering contaminants, such as Mercury (Hg). This thesis examined blood total mercury (THg) concentrations of four coastal shark species and concentrations of five heavy metals (Hg, As, Cr, Cu, and Pb) within the water and sediments of …

The Effects On Soil Fungal Community Of Excluding Select Above-Ground Herbaceous Species In A Montane Longleaf Pine Savanna Restoration Area, Sean Davis

Master of Science in Integrative Biology Theses

Due to anthropogenic pressures, by the 1990s longleaf pine forests were at 3% its peak area. Restoration is difficult as vegetation communities constitute a mosaic across the longleaf range. Hence, vegetation description is important wherever longleaf pine communities exist. Vegetation strongly associates with specific soil fungi operational taxonomic units (OTUs) and description of longleaf pine ecosystems are incomplete without description of microbial taxa.

My goals were to begin describing soil fungal communities of the longleaf pine at Sheffield Wildlife Management Area (SWMA) and describe changes to the fungal community after the removal of dominant plants in a longleaf savanna. I …