Genetics and Genomics Commons^™

The Diversity And Evolution Of Phenazine Biosynthesis Pathways In Enterobacterales, Christian Leise

Honors Theses

Enterobacterales is an order of Gram-negative bacteria that encompasses plant and animal pathogens and organisms of industrial importance. Some of these bacteria produce secondary metabolites classified as phenazines (Phz). Studies in other groups of microorganisms revealed that phenazines are redox-active and exhibit broad antibacterial, antifungal, and antiparasitic activity. Enterobacterales are known to produce phenazines, but details about the diversity, biochemistry, and function of phenazine metabolites in these organisms are missing. In this work, we screened the National Center for Biotechnology Information (NCBI) GenBank for genome sequences of phenazine-producing (Phz+) Enterobacterales. Additionally, genomes of Phz+ strains Pectobacterium carotovorum cc303 and …

Examining The Role Of The Drosophila Melanogaster Unc13 Protein In Open Field Activity Using Rnai, Islam Orabi

Honors Theses

Unc13 are proteins in the presynaptic neurons essential in controlling synaptic vesicle fusion and synaptic transmission. Recently, the reduction of Drosophila melanogaster Unc13 proteins (Dunc13), were found to result in a resistance to alcohol, highly reminiscent of tolerance formation. I investigated whether genetically reducing Dunc13 activity in Drosophila brain regions leads to different forms of behavioral plasticity using an open field activity paradigm. In my approach, a Dunc13 RNAi transgene was expressed in the Drosophila brain within the mushroom body, the ellipsoid body, and in all neurons. The activities of the flies were examined in the open field paradigm to …

The Biodiversity Of Deadwood-Associated Arthropods In The Southern Appalachian Mountains, Isabelle Ong

Honors Theses

A biodiversity hotspot is a location that has significantly elevated levels of biodiversity including many species found nowhere else, and which is also in danger of losing much of this diversity. By identifying biodiverse regions, conservation efforts can be targeted to those locations where they are likely to have the most beneficial impacts. We looked at deadwood associated arthropods within the Southern Appalachian Mountains to examine centers of biodiversity. Nine logs were sampled, three of which were located in Bankhead National Forest and six were located in the Great Smoky Mountains. Polymerase chain reaction was used to amplify the mitochondrial …

Association Of Trim Gene Variation And Lpdv Infection Patterns In Wild Turkeys, Bennett Fry

Honors Theses

Emerging infectious diseases pose a serious threat to various species throughout the globe, including humans. The lymphoproliferative disease virus (LPDV) in wild turkeys is an example of disease virus whose impact on its host requires additional study. Although the first description of lymphoproliferative disease came from outbreaks in domestic turkey flocks in Europe, it is now known that LPDV is widespread in wild turkey populations in North America. In an effort to understand what may affect an individual turkey’s susceptibility to this virus, variation in part of the anti-viral TRIM62 gene was investigated. DNA was extracted from hunter-collected, turkey blood …

Genetic Diversity & Connectivity Of Chasmanthium Latifolium (Poaceae) In Pennsylvania & The Effect On Conservation Status Of A Rare Species, Jonathan D. Hayes

Honors Theses

Chasmanthium latifolium (Michx.) Yates (Poaceae) is a loosely colonial, rhizomatous, perennial grass species that lives in riparian habitats, making it fittingly referred to as river oats. Native to the southern Midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Within Pennsylvania, eleven extant C. latifolium populations are found along four waterways: the Monongahela River, the Susquehanna River, and two tributaries to the Susquehanna River. This limited state distribution exhibits an east-west disjunct distribution, where western populations are largely separated from eastern populations with one centrally located population. Between the …

Microbiome Community And Parasitic Infections In Wild Bees, Mark G. Young

Honors Theses

The microbiome is increasingly recognized for its complex relationship with host fitness. Akin to primates and other social animals, bumblebees harbor a specific microbiome derived from social contact. The bumblebee microbiome is characteristically species poor, with just a few “core” phylotypes accounting for the majority of total abundance. Genomic analyses reveal phylogenetic congruence and adaptation of the core endosymbionts to the bumblebee gut, indicating a shared evolutionary history. Prior investigations reveal that the relative abundance of core microbes is negatively associated with infection by a trypanosome, Crithidia bombi, and that the microbiome has a mechanistic role in immunity. As …

The Design And Validation Of A Qpcr-Based Approach To Cell Quantification Of Fungal-Algal Symbioses, Isabelle Katherine Garlotte

Honors Theses

Symbiotic relationships are extremely common in virtually all species. These relationships between organisms, particularly mutualistic symbioses, can have an incredibly large impact and can greatly affect the evolution of the species involved. Of particular interest is the suspected mutualistic relationship between green algae and fungi that may hold key evidence of how terrestrial plants evolved. In this experiment we established a method of quantifying the cells of each species involved in these symbioses through qPCR analysis to determine if the relationships are truly mutualistic. We developed a system for using DNA copies as a proxy for cell count in co-cultures …

A Summary Of Current Research Into Neurodegenerative Disorders Using Drosophila Melanogaster, Chase Cortese

Honors Theses

Neurodegenerative disorders such as Alzheimer’s disease are characterized by damage to neural cells causing widespread neurological deficits. Historically, these diseases were deemed as inevitable declines in cognitive and neurological function that occurred with aging. Recent research has revealed, however, that these diseases have molecular bases allowing potential clinical intervention. The groundbreaking discoveries have been made using differing model organisms, which can replicate the phenotype and physiological cause of these disorders. One major model organism that has been used is the fruit fly, Drosophila melanogaster. They have served various roles in elucidating gene pathways and neurophysiological bases seen in these diseases. …

The Embark® Protocol: Dog Genomics In Genetics Laboratories, Alexandra Kissel

Honors Theses

In a world of ever-advancing technology, it is imperative that young pre-health professionals are educated according to the most relevant research. One of the most fundamental, foundational concepts of health is genetics. This field is rapidly expanding, and quickly engraining itself into the realm of healthcare. Genetic testing and gene therapies, once subjects of science fiction, have become commonplace. It is more important than ever that health professionals have a concrete knowledge of genetics, and this begins with the proper education of pre-health students.

With this idea in mind, a laboratory protocol was designed for students of the Bisc 336 …

Population Genetics Of A Recent Range Expansion By The Southern Pine Beetle, Dendroctonus Frontalis, Into The Northeastern United States, Megan Stubbs

Honors Theses

Population genetics as a field of study aims to determine the genetic variation among individuals in a population, and differences among populations. Certain population genetic analyses can provide such information and be used to better understand the biological aspects to a species’ expansion beyond its native range. The southern pine beetle (SPB), Dendroctonus frontalis, has become an invasive pest to pine forests in northeastern United States with its recent range expansion. Nine microsatellite loci were first developed and then used in analyses. To determine what the genetic variation is among individuals in SPB populations across its entire range, including …

Use Of Embark Database And An Active Learning Protocol In A High School Classroom, Landon Goodreau

Honors Theses

With advances in technology, personal genome sequencing has become more affordable than ever before. With this wealth of genetic information come new individualized approaches to medicine and pharmacology, along with moral, legal, and ethical issues to carefully consider. Yet studies suggest that most members of the general public do not have the genetic literacy required to understand the implications of genomic data. It is important that today’s students are able to grasp concepts relating to their own genome to make informed medical decisions in the future. Here I describe an active learning-based activity designed to enhance high school students’ understanding …

Multi-Generational Effects Of ∆9-Tetrahydrocannabinol Exposure On Gene Expression In Liver Tissue, Kayla Lovitt

Honors Theses

Cannabis is the most commonly used, cultivated, and trafficked illicit drug worldwide. Increased availability and acceptance of cannabis and cannabinoid-containing products provide the necessity for understanding how these substances influence aging. In this study, zebrafish (Danio rerio) were exposed to concentrations of Δ⁹-tetrahydrocannabinol (THC) (0.08, 0.4, 2 µM) during embryonic-larval development, the effects on aging were measured 30 months later and in the offspring of the exposed fish (F1 generation. We observed results indicating a biphasic and hormetic effect. Treatment with the lowest concentration of THC significantly increased egg production, while higher concentrations resulted in impaired …

Meta-Analysis Of Biological Research Literature, Evan Suggs

Honors Theses

Comparative studies have been powerful tools in generating a broad understanding about the evolution of animal social systems but they currently rely on the slow, manual process of reading thousands of abstracts and papers from research databases. A web application was created for researchers conducting a comparative survey, in order to speed up their research. This web application automates the retrieval of research papers and their selection process. Using previously obtained data sets on the orders Artiodacytla and Lagomorph, a machine learning application was created to classify the papers. These techniques and tools should greatly increase the speed at which …

Assay Development For Isolation And Characterization Of Anticancer Properties Of Marine Fungi, Kyra Ricci

Honors Theses

Metabolites from fungi have potential use in the drug discovery process and have been used in the past to develop therapeutic agents for human use. Initial characterization of potential therapeutic properties of fungi is thus an important first step in identifying novel therapeutic compounds. In the present study, marine fungi were isolated from Myrtle Beach and assayed for anticancer properties using the soft agar colony formation assay in a 3D in vitro cellular environment. Many species were isolated from environmental samples, displaying unique morphologies and growth patterns. To optimize the soft agar assay in a six-well cell culture plate for …

Development And Validation Of Gene Delivery Methods For ​Crassostrea Virginica, Adrienne N. Tracy

Honors Theses

The Eastern oyster (Crassostrea virginica) is an important part of the East Coastal USA economy because aquaculture creates jobs. Sadly, the oysters are under constant threat due to increasing pollution, red tides, and diseases. Bivalves, and oysters in particular, are also becoming potential model organisms in medical research. With the sequencing of the oyster genome, scientists are focusing on deciphering the function of the predicted genes. However, the limited number of molecular and cellular tools available makes functional annotation of the genome challenging. A consistent, replicable gene delivery system needs to be developed to assess gene function and understand the …

Fate Of Ingested Rna In The Two-Spotted Spider Mite, Obrie D. Scarbrough

Honors Theses

RNA interference, or RNAi, is a gene regulation mechanism that uses small noncoding RNAs (sRNAs) to silence the expression of certain genes. The application of RNAi has been extended to insect pest control. The two-spotted spider mite Tetranychus urticae is a persistent agricultural pest that tends to develop pesticide resistance at an alarming rate, making it a perfect candidate for RNAi technology development. It was hypothesized that unique sRNAs could be isolated from RNA soaked spider mites, and new synthetic RNAs could be synthesized to elicit greater knockdown than was achieved in previous studies. To perform this research, a small …

Insects And The Evolution Of Developmental Pathways: Functional Analysis Of Genetic Sex Determination Mechanisms In Oncopeltus Fasciatus, Josefine Just

Honors Theses

Natural selection alters genetic pathways over evolutionary time. However, different pathways have been shown to maintain mutations at varying rates, leading to different levels of conservation across developmental pathways. Sex determination pathways, in particular, show vast diversity across animals despite the fundamental conservation of biological sex itself. Here, I investigated the sex determination pathway of the hemimetabolous insect, Oncopeltus fasciatus. The large milkweed bug, O. fasciatus, is part of the order Hemiptera, which provides a relevant outgroup study to other insects in which sex determination has been studied to date. I studied three sex determination genes, intersex, fruitless …

Population Genetics Of The Eastern Subterranean Termite, Reticulitermes Flavipes, In The Southern Appalachian Mountains, Lee Ann Passarella

Honors Theses

As an area rich in biodiversity, the Appalachian Mountains are an ideal place for biological research. The pronounced impacts of Pleistocene climatic cycles on forest distributions over time have shaped the evolutionary history of animals that depend on these habitats, underpinning the research that is presented here. The present study on the eastern subterranean termite, Reticulitermes flavipes, was conducted to better understand the spatial distribution of genetic diversity within and among populations of this species in the context of the aforementioned historical climatic changes in the southern Appalachian Mountain region. I hypothesized that there would be geographically localized, distinct genetic …

Disruption Of Rna Metabolism By Zika Virus, Maggie Lea Dickerson

Honors Theses

Flaviviruses are positive, single-stranded, enveloped RNA viruses that are a part of the family, Flaviviridae. West Nile virus, Dengue, Zika virus and more are a part of this family. Mosquitoes are the vectors for these viruses. In order for the virus to infect mosquitoes, it must evade the RNA interference (RNAi), which is the major antiviral immune mechanism of insects. One study found the 3’ untranslated region (UTR) of the West Nile virus that inhibited the RNAi (GP et al. 2016). The goal of this study is to investigate if the 3’ and 5’ UTR region of the Zika virus …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Functional Significance Of Branch Points In Mirtrons, Britton A. Strickland

Honors Theses

MicroRNAs are a heterogeneous group of small regulatory RNAs generated by many pathways. Mirtrons (miR) are a class of microRNAs produced by splicing, and some mirtrons contain a 3’ tail located downstream from the self-complementary hairpin. During RNA splicing, a loop-like “lariat” intermediate structure is created when the 5’ end of the RNA is attached to an adenine called the branch point. The goal of this project is to uncover the contribution of branch point location to the processing of tailed mirtrons into functional gene regulators. This project approaches this issue from two directions. First, branch points were identified by …

The Uas-Gal4 System In D. Melanogaster: An Insight Into The Influence Of Micrornas On The Developmental Pathways Of The Wing, Emily R. Wilson

Honors Theses

By examining genetic pathways in D. melanogaster, a better understanding of the homologous regulatory mechanisms in humans can be utilized to further enhance knowledge of the roles of microRNA within development. This study utilizes the UAS-Gal4 system in order to produce a mutant phenotype capable of being visually studied and analyzed, focusing on the developmental pathway of the wing in D. melanogaster. Dissections of the wandering third instar larvae yielded wing disc tissue expressing the downregulation of loquacious and CG17386.

Tracking Plastid Gene Migration In Karenia Brevis, Kelly E. Scott

Honors Theses

Karenia brevis is a marine dinoflagellate responsible for the harmful algal blooms (also known as red tides) in the Gulf of Mexico. K. brevis expresses antisense (AS) RNAs, each of which has a complementary region to the messenger RNA (mRNA) of a variety of genes. In dinoflagellates, many plastid (and mitochondrial) genes have migrated to the nuclear genome. It is unknown whether chloroplast genes, such as photosystem – D2, have migrated in K. brevis. It is also unknown where the gene that expresses the AS RNA for photosystem D2 resides. The protein-coding gene and the AS RNA-expressing gene could …

The Differential Roles Of D-Pax2 Variants In Regulating Drosophila Eye And Bristle Development, Colin J. O’Shea

Honors Theses

The ability to appropriately interact with the environment is crucial to an organism’s survival. The establishment of functional sensory systems, such as the bristles and eyes in Drosophila, is a critical event during the development of the organism. The transcription factor D Pax2 is involved in the differentiation of the shaft and glial cells in the developing bristle (Kavaler et al., Dev, 126:2261-2272, 1999) and of the cone and primary pigment cells in the developing eye (Fu and Noll, Genes Dev, 11:389-405, 1997). How D-Pax2 contributes to distinct differentiative pathways in different cell types is not known. Recent work by …

Comparative Rates Of Ndna Degradation Using Rat Models In Southeastern Tennessee, Matthew F. Pullen

Honors Theses

The advent of DNA identification methods has revolutionized forensic science. It is now possible to identify criminals from trace evidence, eliminate false leads, and discover the identity of a deceased individual long after their death. As DNA plays such important roles in criminal investigatious, determining the quality of DNA due to its exposure time enviroment is imperative. This experiment seeks to help narrow down the time frame that useful nuclear DNA (nDNA) can be extracted from a decaying body. The rate of DNA degradation was measured in Sprague-Dawlwy rat models placed in varied environmnts of Southeastern Tennessee. The environments included …

Examination Of The Ace And Actn3 Genes In Utc Varsity Athletes And Sedentary Students, Ian Mayne

Honors Theses

Growing evidence suggests that genetic variants of certain genes are linked to athletic performance. This study presents a comparative analysis of genetic variation of the ACE and ACTN3 genes in varsity athletes (n=90) and sedentary students (n=48) at the University of Tennessee at Chattanooga. The ACE gene codes for the Angiotensin Converting Enzyme (ACE), which is an integral part of the Renin-Angiotensin system. It is responsible for regulating blood volume,arterial pressure, electrolyte balance, and cardiac and vascular function.Polymorphisms of the ACE gene effect serum and tissue levels of the enzyme, and are genetically distinguished by either an insertion (I-allele) or …

A Broad-Spectrum Mer Operon In A Multi-Drug Resistant Strain Of The Fish Pathogen, Aeromonas Salmonicida, Erin Parry

Honors Theses

Aeromonas salmonicida AS03, a potential fish pathogen, was isolated from Atlantic salmon, Salmo salar, in 2003. This strain was found to be resistant to ≥1000 mM HgCl2 and ≥32 mM phenylmercuric acetate as well as multiple antimicrobials. Mercury (Hg) and antibiotic resistance genes are often located on the same mobile genetic elements, so the genetic determinants of both resistances and the possibility of horizontal gene transfer were examined. Specific PCR primers were used to amplify and sequence distinctive regions of the mer operon. A. salmonicida AS03 was found to have a pDU1358-like broad-spectrum mer operon, containing merB as well as …

Molecular Evolution Of Insecticidal Spore-Forming Bacteria, John Pool

Honors Theses

Molecular methods are increasingly being used to determine the phylogeny of microorganisms. This research was intended to determine phylogenetic relationships for bacteria of the species Bacillus thuringiensis and other members of the Bacillus cereus group. Each strain was analyzed by its sasp-B gene sequence to determine its species classification and relation to other strains studied. Results of this study indicated that according to the sasp-B gene tree, the species Bacillus thuringiensis is a paraphyletic with respect to both Bacillus cereus and Bacillus anthracis. Some unexpected results and implications for species designations are also discussed.

Scientific Investigation Of The Plant Pathogen Agrobacterium Tumefaciens, Casey M. Flanagan, Christopher B. Crowell Ii, Bryan P. Markelz

Honors Theses

A. tumefaciensis a plant pathogen and causative agent of Crown Gall Disease, an ailment that results in the development of tumors in plants. It is a unique organism in that it is the only known non-viral pathogen that transfers its DNA into the host cell. Consequently, the majority of the research conducted on A. tumefaciensinvestigates its mechanism of infection. However, A. tumefaciensis also rare to the bacterial world in that its genome is comprised of two chromosomes: one circular and one linear. Most other bacteria only have one circular chromosome. This area of research has been grossly overlooked and therefore …

Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson

Honors Theses

One side effect of today's industrialized world is increased levels of heavy metals in the environment. Many of these metals are necessary for biological function as trace elements, but at higher concentrations are toxic. Other metals, such as cadmium, are not beneficial at any level, and have only deleterious effects on living organisms. Cadmium is primarily thought to interfere with normal biological function of proteins. Human exposure to cadmium appears to primarily damage the kidneys, but may also affect the liver, lungs, immune system, and central nervous system. Bacteria, however, have developed several methods for handling toxic heavy metals: cation …