Integrative Biology Commons^™

Evaluating In Situ Grazing Patterns Of Lytechinus Variegatus And Their Effects On Seagrass Beds Of Thalassia Testudinum, Adrianna Parson

Master of Science in Integrative Biology Theses

The sea urchin Lytechinus variegatus is a known grazer of the seagrass Thalassia testudinum, and has been known to denude vast stands of seagrass beds at high densities. Outside of these denudation events, the effects of sea urchins on seagrass are poorly understood. This study examines the effects of L. variegatus on T. testudinum in situ, to understand how sea urchins are affecting seagrasses in situ. Results indicate that urchins were found in the offshore portion of the seagrass bed at densities up to 4 urchins/m². Changes in temperature and sediment size in the bay indicate …

Novel Use Of A Cell-Penetrating Peptide-Adaptor System To Characterize Akirin Constructs And Investigate Activity Of Bacterial Effector Proteins, Shaquanna Young

Master of Science in Integrative Biology Theses

In the late 1980s, HIV protein TAT was found to confer the passage of HIV through the plasma membrane of mammalian cells. The McMurry lab developed a CPP-adaptor system which consists of the fusion of TAT to calmodulin to which mediates the delivery of exogenous proteins into cells and prevents endosomal entrapment. Calmodulin (CaM) is capable of binding to the calmodulin binding site (CBS) of cargo only in the presence of calcium. TAT-CaM can be used to characterize Akirin constructs and investigate the activity of bacterial effectors, AopP and AvrA, in the NF-kB pathway. Akirin is a small nuclear protein …

Investigating The Molecular Function Of Akirin During Skeletal Myogenesis In Drosophila Melanogaster, Kristina Rowland

Master of Science in Integrative Biology Theses

The specification and differentiation of muscle precursor cells, or myoblasts, by the action of the mesodermal and muscle transcription regulator Twist is a key event in the formation of the Drosophila larval musculature. Akirin, a highly conserved nuclear protein, appears to play a critical role in the regulation of Twist-dependent gene expression during mesodermal specification and muscle development. Specifically, Akirin serves as a cofactor to promote interactions between regulatory transcription factors and multisubunit Brahma SWI/SNF-class chromatin remodeling complex to impact gene expression across varying targets. Using a genetic interaction screen in Drosophila, we have begun to identify other Akirin …

Ephrin Receptors, Aiy Interneuron Physiology, And Behavior, Tyler Hill

Master of Science in Integrative Biology Theses

In order to survive, an organism must be able to receive, integrate, and respond to sensory stimuli. However, the cellular basis of sensory perception and response is difficult to study in complex animals such as humans, and is therefore poorly understood. The nematode Caenorhabditis elegans is a relatively simple organism yet displays many distinct behaviors, making it an ideal system to understand the relationship between gene function, cell shape, cell physiology, and behavioral output. Much of the thermosensory and chemosensory information that the nematode receives from its sensory neurons is processed via a pair of interneurons called AIYL and AIYR. …

Transcriptional Regulation Of Kal-1 In The Nematode Caenorhabditis Elegans, Zachery E. Mielko

Master of Science in Integrative Biology Theses

X-linked Kallmann syndrome (KS) is a genetic disease that is caused by loss-of-function mutations in the human kal-1 gene. The disorder consists of a loss of sense-of-smell coupled with failure to undergo spontaneous puberty. At the cellular level, KS phenotypes are caused by olfactory neurons’ failure to properly migrate to the olfactory bulb. This also prevents gonadotropin-releasing hormone neuroendocrine cells from migrating to the pituitary, preventing the pulsatile release of sex hormones at puberty. While many kal-1 interacting proteins have been studied in model organisms, little is known about the regulatory mechanisms that control kal-1’s expression. Since a 5.27kb …

Evidence Of Language Prerequisites In Pan: Orofacial-Motor And Breath Control In Chimpanzees And Bonobos, Natalie Schwob

Master of Science in Integrative Biology Theses

Human spoken language requires the concomitant utilization of numerous cognitive and motor skills. Two particularly relevant skills are orofacial-motor control (OFM), the ability to purposefully move one’s facial muscles, and breath control (BC), subglottal air pressure that fuels sound production, as both are necessary in the voluntary production of speech. Many have claimed these competencies are uniquely human qualities without great ape antecedents. However, here we describe both skills in genus Pan, which contains our closest extant relatives: chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). We hypothesized that OFM and BC would be present in both species of Pan and …

Nociception And The Experience Of Pain Signaling Due To Nerve Damage, Crystal J. Smith

Master of Science in Integrative Biology Theses

Hyperalgesia is the increased sensitivity to pain which can present itself to many people no matter age or ethnicity. Having the ability to alleviate pain whether it be acute or chronic pain without the use of addictive medication can have the potential to change the course or modern medicine known today. Through the use of zebrafish, this thesis provides a preliminary understanding in pain signal blocking. Three distinct genes have found to be associated with perceiving pain, which include Transient Receptor Potential Ankyrin 1 (TRPA1), Transient Receptor Potential Melestatin 8 (TRPM8), and Cannabinoid Receptor 1 (CNR1). We hypothesize through knockdown …

Investigating The Role Of Long Distance Dispersal In The Response Of Stream Fishes To Urbanization, Andrea Davis

Master of Science in Integrative Biology Theses

I conducted a 7-month mark-recapture study in two watersheds differing in urban impact in order to assess the role that long distance dispersal plays in the response of tolerant stream fishes to urbanization. Our two stream sites included a heavily impacted urban stream (watershed impervious surface cover ~30%) and a mildly impacted rural stream (watershed impervious surface cover ~6%). Species of interest were marked with 12mm HPT PIT tags and included a specialist, Campostoma oligolepis (n=189 urban site, 200 rural site) and a generalist, Lepomis auritus (n=136 urban site, 182 rural site). Three resampling instances for each site were conducted …

The Adaptive Value Of Complex Socio-Communicative Behavior, Sara A. Skiba

Master of Science in Integrative Biology Theses

Human spoken language represents the most elaborate communication system, however the selection pressures leading to its emergence are still uncertain. Unlike humans, bonobos and chimpanzees do not have language. However, bonobos may have been subjected to similar selection pressures as early hominins, subsequent to their phylogenetic split from chimpanzees roughly 1.5 million years ago. The current study investigated the similarities and differences in sociality and communicative production between bonobos and chimpanzees in captive settings, using 9, 10-minute focal follows for each individual. Analyses revealed a significant positive correlation between social proximity score and total communicative signals produced, as well as …

Population Genetics And Host Specificity Of A Rare Parasitic Plant, Cuscuta Harperi, Brandy N. Rogers

Master of Science in Integrative Biology Theses

Cuscuta harperi is a rare parasitic plant endemic to a small number of widely disjunct populations in Georgia and Alabama. It is a habitat-specialist, occurring on sandstone and granite outcrops within its limited range; it is also exhibits a high level of host specificity, parasitizing only a few select species. C. harperi is of conservation concern due to small population sizes and threats from habitat degradation.

Here we develop genetic markers to address questions regarding population genetics of the species. We discuss the utility of microsatellites and single nucleotide polymorphisms as molecular markers to evaluate genetic variability between individuals and …

Effects On Campostoma Oligolepis Digestive Morphology And Gut Microbiota Composition Across A Gradient Of Urbanization, Hannah Grice

Master of Science in Integrative Biology Theses

Campostoma oligolepis, the Largescale Stoneroller, is a species of minnow native to northwest Georgia. This study investigated the impacts of urbanization on gut length and gut microbiota community composition in C. oligolepis from four small watersheds within the Etowah River drainage basin with different levels of impervious surface coverage (ISC). Individuals were collected from each sample site in the summer of 2016 between late July and early September. A second round of sampling was conducted in the fall between mid-October and mid-November. The gut length to total length ratio was calculated for each individual to allow for an unbiased …

Profiling Bat Activity And Species Presence In Managed Longleaf Pine Landscapes, Margaret Hunt

Master of Science in Integrative Biology Theses

Restoration of native flora or reintroduction of at-risk fauna includes management practices that while encouraging presence and proliferation of target species, may adversely affect non-focal species. An endemic ecosystem undergoing restoration within the southeastern U.S. is that of the longleaf pine (Pinus palustris). Bats inhabit key ecological niches in forest ecosystems, including the longleaf pine ecosystem, and can be indicators of ecosystem condition. This study investigated the effects of current forest management practices and landscape management history on bat species presence and activity levels within habitat undergoing longleaf pine restoration. We deployed bat detectors in two wildlife management …

The Effects Of Δ9-Tetrahydrocannabinol (Thc) On Development And Hyperekplexia In Embryonic Zebrafish Model, Olivia Christine Mistretta

Master of Science in Integrative Biology Theses

Marijuana is one of the most commonly used illicit drugs around the world. It has gained attention as an alternative medicine to many different disorders. Though initially investigated in modern medicine for its analgesic and antiemetic properties, cannabis has been recently found to benefit numerous neurological disorders. Though there are over 100 different cannabinoids produced by the cannabis plant, Δ⁹ – tetrahydrocannabinol (THC) has been shown to the most efficacious phytocannabinoid in neurological disorders. THC has been shown in numerous previous studies to be effective at treating spasticity caused by multiple sclerosis and spinal cord injury, as well as …

Comparisons Of The Socio-Behavioral Differences Between Chimpanzees (Pan Troglodytes) And Bonobos (Pan Paniscus), Investigating The Impact Of A Naturally Occurring Polymorphic Microsatellite Deletion In The 5’ Flanking Region Of Arginine Vasopressin Receptor 1a (Avpr1a) On Gene Expression And Sociality Within The Pan Genus, Robert E. Evans

Master of Science in Integrative Biology Theses

Among the great apes, chimpanzees are unique in having a polymorphic deletion of a ~350bp microsatellite containing region (DupB) in the 5’ flanking region of the arginine vasopressin receptor 1a (AVPR1a) gene. This results in three genotypes (DupB+/+, DupB+/- and DupB-/-) of AVPR1a in chimpanzees. Variations in the length of microsatellites 5’ of AVPR1a have been associated with social behaviors (pair-bonding, paternal care, degree of social interest) and differential levels of expression of AVPR1a in the brains of voles. The polymorphic DupB microsatellite in chimpanzees allows the investigation of microsatellite variation 5’ of AVPR1a in higher order primates. We hypothesized …

Distances Between Species In Food Webs: Evaluating Alternative Metrics' Predictive Power, Molly C. Johnson

Master of Science in Integrative Biology Theses

The complexity of ecological systems makes it difficult to predict how one species will react to the disturbance of another. Complex systems of species’ interactions can be described as ecological networks. One way in which ecological networks can give information concerning one species’ response to the perturbation of another is through the quantification of species’ proximity to one another in the network. In this study, we evaluate communicability, a topological metric that accounts for all of the direct and indirect interactions between species in a food web without additional information concerning the strengths of species interactions. Communicability is then compared …

Induced Phytoextraction Of Lead From Contaminated Soils By Panicum Virgatum, Enhanced With Edta, Citric Acid, Benomyl, Propiconazole And Nitric Oxide, Adrianna E. Beavers

Master of Science in Integrative Biology Theses

Soil lead (Pb) contamination represents a major environmental and public health risk. Conventional Pb remediation methods are typically expensive and risk further environmental damage. Phytoextraction has emerged as an alternative heavy metal remediation method with the potential for reducing both economic cost and negative environmental effects. For this study, North American native switchgrass (Panicum virgatum) was chosen due to its ability to achieve high biomass yields across a variety of climates and environmental conditions. The switchgrass plants in this study were treated with chemical chelates, fungal suppressants, and nitric oxide (NO) donors with the intent of optimizing Pb …

The Effects Of Amphetamine Exposure On Neurodevelopment And Behavior In Early Life Stages Of Danio Rerio, Jennifer D. Bullard

Master of Science in Integrative Biology Theses

Amphetamines are frequently prescribed to young children for attention deficit hyperactivity disorder (ADHD). Due to the recent rise in ADHD diagnoses and the resulting increase in amphetamine intake in children, we investigated how amphetamine exposure impacts the development of stereotyped behaviors and the neural circuit that governs these behaviors. The zebrafish (Danio rerio) was used as our model organism because of the extensively studied developmental milestones these fish provide. Using escape responses as a behavior model, we exposed embryos to three doses of amphetamine (10 μg/ml, 20 μg/ml, and 30 μg/ml) environmentally during the first 48 hours of …

Conservation Genetics And Mark-Recapture Monitoring Of The Rare Pigeon Mountain Salamander (Plethodon Petraeus) Within A Highly Restricted Range, Kate Donlon

Master of Science in Integrative Biology Theses

Globally, amphibian species are experiencing declines at an alarming rate largely due to habitat loss, disease and climate change. Species with limited ranges are at an elevated risk of a significant decline in population numbers and extinction because of the inability to avoid and recover from these impacts. Long-term management plans are critical for conservation of species with small ranges; however, the knowledge required to develop effective plans is absent from the literature for many species. One such species is the Pigeon Mountain Salamander. The distribution of the Pigeon Mountain Salamander, Plethodon petraeus, is restricted to roughly 17 kilometers …

The Hv1 Proton Channel Of Lingulodinium Polyedrum Localizes To The Bioluminescent Scintillon, Juan D. Rodriguez

Master of Science in Integrative Biology Theses

In 1972, J. Woodland Hastings and colleagues predicted the existence of a proton selective channel that opens in response to depolarizing voltage (H_V1) across the vacuole membrane of bioluminescent dinoflagellates and conducts protons into specialized luminescence compartments (scintillons), thus causing the pH drop that triggers the light flash. RNA-Seq data from several luminescent dinoflagellate species provided candidate H_V1 genes. When expressed in mammalian cells, the predicted H_V1 from Lingulodinium polyedrum displays the hallmark properties of bona fide proton channels, including time-dependent opening with depolarization, perfect proton selectivity, and characteristic pH dependent gating. RT-PCR and …

An Empirical And Theoretical Comparison Of The Socio-Ecological Behaviors Of Captive Chimpanzees (Pan Troglodytes), Bonobos (Pan Paniscus), And Western Lowland Gorillas (Gorilla Gorilla): Social Tolerance And Behavioral Responses To Changes In Food Quality And Distribution, Scott C. Milne

Master of Science in Integrative Biology Theses

Chimpanzees and gorillas are sympatric in most of their range in Central Africa, however, bonobos do not overlap with either of the other two species. This difference has been hypothesized to be the main factor leading to the socio-ecological traits of each species. Access to, and competition for, terrestrial herbaceous vegetation (THV) in each of the three species in thought to be linked to the social relationships and female-female bonds of each species. This study sought to provide a direct comparison of the social relationships of each of the three African Great Apes in captivity in order to elucidate similarities …

Assessing Feeding Preferences And Spatial Patterns Of Lagodon Rhomboides Linnaeus, Alexandria V. Lamle

Master of Science in Integrative Biology Theses

Mesograzers have the ability to greatly mitigate the effects of eutrophication in seagrass systems. In this study we look at pinfish (Lagodon rhomboides Linnaeus) as a potential epiphytic grazer and assess feeding preferences during a transitional stage in the ontogenetic diet shift exhibited by these fish. Since pinfish are abundant in seagrass meadows in the northern Gulf of Mexico, their dietary preferences have the potential to greatly impact seagrasses in this system. Twenty-four hour feeding trials were conducted to determine pinfish preference between seagrass (Thalassia testudinum) and algal epiphytes. St. Joseph Bay, FL was also surveyed to …

Akirin-Mediated Gene Regulation During Cardiac Development, Austin M. Howard

Master of Science in Integrative Biology Theses

The highly conserved nuclear protein Akirin was previously identified as a cofactor that modulates Twist transcription factor activity during muscle development in Drosophila melanogaster. Akirin mediates an interaction between the Twist transcription factor and the multisubunit Brahma SWI/SNF-class chromatin remodeling complex at control elements of the Dmef2 locus to maintain optimal myogenic gene expression levels. Therefore, Akirin represents a class of novel secondary cofactors that work with transcription machinery to link transcription factor output with chromatin remodeling machinery to facilitate gene expression. Previous work establishes that Twist and Akirin also interact at Twist-responsive control elements of the tinman gene, …

Delineation Of Aeromonas Hydrophila Pathotypes By Dectection Of Putative Virulence Factors Using Polymerase Chain Reaction And Nematode Challenge Assay, John Metz

Master of Science in Integrative Biology Theses

Aeromonas hydrophila is a Gram-negative, bacterial pathogen of humans and other vertebrates. To delineate pathotypes, the genomes of twenty-eight Aeromonas isolates were screened by PCR to determine the presence of virulence factors including: aerolysin (aerA), cytotoxic enterotoxin (act), hemolysin (ahh1), elastase (ahyB), enolase (eno), S-layer protein (ahsA), serine protease (ser), Type IV Aeromonas pilus (tapA), lipase (lip), and Type Three Secretion System (T3SS) components (aopB, ascV). Genes for ahh1, lip, ser, and ahyB …

Eph-Ephrin Signaling And The Role Of Efn-4 In Caenorhabditis Elegans Nervous Systems Development, Alicia Schwieterman

Master of Science in Integrative Biology Theses

Eph receptor tyrosine kinases and their ephrin ligands are required for multiple aspects of nervous system development including axon outgrowth, synaptic plasticity, and the formation of topographic maps in the visual system. The Caenorhabditis elegans ephrin-A, efn-4, has a defined role in hypodermal patterning but its role in nervous system development is not well understood. We find that loss-of-function mutations in efn-4 lead to suppression of axon branching in C. elegans model of X-linked Kallmann syndrome, a human genetic disorder that presents with loss of sense of smell and failure to undergo spontaneous puberty. In addition, efn-4 mutants have …

Phytoextraction Of Lead From Contaminated Urban Soils By Panicum Virgatum Enhanced With Phytohormone, Edta, Benomyl, And Citric Acid Application, Matthew Aderholt

Master of Science in Integrative Biology Theses

Lead (Pb) contamination in soil represents a threat to human health and cleanup efforts often requires expensive or environmentally disruptive techniques. Phytoextraction has gained attention as a possible alternative to traditional remediation methods because of lower cost and minimal soil disruption. Panicum virgatum L. (switchgrass) was chemically enhanced with applications of the soil-fungicide benomyl, chelates (EDTA and citric acid), and phytohormones for phytoextraction of Pb from contaminated urban soils in Atlanta, GA. EDTA is often regarded as the most effective chelate, but has potential problems associated with its use due to long persistence time in soil and possible Pb mobilization …

Induced Phytoextraction Of Lead From Contaminated Urban Soil Through Manipulation Of Rhizosphere And Plant Biogeochemical Functions In Switchgrass (Panicum Virgatum), Deayne M. Johnson

Master of Science in Integrative Biology Theses

Contamination of soils with lead (Pb) continues to pose a risk to the health of humans especially in residential urban areas. Remediation of these soils is necessary to reduce the amount of Pb and alleviate risk to human health. Phytoextraction of Pb through chemically induced accumulation of Pb in the harvestable foliage and removal of contaminated plant material has great potential in offering a solution to this environmental problem. The effects of the combined application of a soil fungicide (benomyl), synthetic chelates (ethylenediamineteteraacetic acid, EDTA), and foliar-Fe supplement on lead (Pb) phytoextraction from contaminated soil by switchgrass (Panicum virgatum) was …

Phenotypic Analysis Of The Regulatory Role Of The Leucine-Responsive Regulatory Protein (Lrppa) In Pseudomonas Aeruginosa, Stephanie D. Larson

Master of Science in Integrative Biology Theses

Nutrient acquisition is critical to survival and infection by the opportunistic bacterium Pseudomonas aeruginosa. This pathogen expresses a number of virulence factors that are a part of the starvation response and are important in host-pathogen interactions. Additionally, P. aeruginosa is resistant to a large number of antibiotics and has become difficult to treat once it has colonized a tissue. New pharmaceutical treatments are sought while the metabolism of this organism must be fully understood to select new targets for therapy. The leucine- responsive regulatory protein (Lrp) could be a promising target for treatment. The ortholog in Escherichia coli is …

Water Use And Water Tolerance In The Riparian Species American Sycamore (Plantanus Occidentalis L.) And How Its Physiology Compares To The Coexisting Black Willow (Salix Nigra Marshall), Eric Duncan

Dissertations, Theses and Capstone Projects (Full IR Collection)

This study set out to compare aspects of water use and tolerance to inundation and drought of two riparian tree species, Platanus occidentalis L. and Salix nigra Marshall. The main goal of the study was to better understand the two species and assess the suitability of P. occidentalis for use in riparian restoration. To accomplish this, potted individuals were subjected to treatments of drought, inundation, or control, under greenhouse conditions, and separately, in order to estimate water use in trees, season-long diurnal measurements of sap flux (using Granier type thermal dissipation probes) were determined in situ for trees growing in …

Differences In The Communicative Behavior And Neurobiology Of Chimpanzees (Pan Troglodytes) And Bonobos (Pan Paniscus), Brittany Moore

Master of Science in Integrative Biology Theses

Chimpanzees and bonobos have distinctly different vocalizations, but it is unclear why these differences have evolved. We hypothesized that differences in habitat and feeding ecology have selected for bonobos to have an increased reliance on vocal communication compared to chimpanzees. To evaluate this hypothesis 1571 chimpanzee vocal events and 612 bonobo vocal events were analyzed. After analyzing and coding video of communicative interactions it was determined that chimpanzees are more likely than bonobos to utilize multimodal communication and to direct vocalizations to an individual conspecific. Bonobos were more likely than chimpanzees to produce a vocalization that was not bound to …