Theses and Dissertations

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Browsing Theses and Dissertations by Department "Biology"
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    A comparative study of stress physiology in the common watersnake (Nerodia sipedon), the diamondback watersnake (Nerodia rhombifer), and the queen snake (Regina septemvittata).
    (Middle Tennessee State University, 2018-04-13) McCallie, Katharine Louise ; Klukowski, Matthew ; Cobb, Vincent ; Otter, Ryan ; Biology
    Vertebrates respond to stressors in part by increasing the secretion of glucocorticoids from the adrenal gland. Both intrinsic and extrinsic factors (e.g., age, sex, season) have been shown to influence glucocorticoid secretion within a species, but understanding of species differences in glucocorticoid secretory patterns is limited. In this study, I examined corticosterone, progesterone, and testosterone levels in the common watersnake (Nerodia sipedon), the diamondback watersnake (Nerodia rhombifer), and the queen snake (Regina septemvittata) at a capture baseline and in response to an acute 30 minute confinement stress. I also examined the same steroids in Nerodia sipedon subjected to three weeks of laboratory housing, a known chronic stressor. All three species exhibited elevated corticosterone in response to acute stress but baseline and post- stress levels varied among species. Overall, Nerodia sipedon and Nerodia rhombifer exhibited similar corticosterone and testosterone levels both at capture baseline and after 30 minutes of confinement stress. Regina septemvittata had substantially higher corticosterone levels than the two Nerodia species. Nerodia sipedon subjected to chronic stress showed no significant changes in corticosterone levels from the baseline to post-lab housing, suggesting downregulation of the hypothalamo-pituitary-adrenocortical axis and glucocorticoid production.
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    A Metagenomic Analysis of the Honey Bee Gut Microbiome Following Oral Imidacloprid Exposure
    (Middle Tennessee State University, 2018) Gain, Emily ; Biology
    Thought to play a significant role in their health, the intestinal microbiota of honey bees is a growing subject of interest. Imidacloprid, one of the highest selling insecticides worldwide, is transferred to the nectar and pollen of treated plants and therefore is likely to be ingested by foraging workers. Little is known about the effects of imidacloprid (and pesticides in general) on bee microbiota. The purpose of this study was to test the hypothesis that exposure to the pesticide imidacloprid alters the community structure of commensal bacteria in the honey bee (Apis mellifera) gut. Workers were kept in captivity and fed a sucrose solution containing imidacloprid at 5 μg/L, a field realistic dose. The relative abundance of bacterial taxa in the gut was determined using MiSeq. Oral imidacloprid exposure did not appear to impact the community structure of the honey bee gut microbiome.
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    A NEW QUORUM SENSING MOLECULE IN C. NEOFORMANS, GIBBERELLIC ACID, INCREASES MELANIZATION IN THE PRESENCE OF TESTOSTERONE
    (Middle Tennessee State University, 2019) Tucker, Jamila ; Biology
    C. neoformans, a spore-producing pathogenic yeast, affects immunocompromised individuals causing meningoencephalitis. Once C. neoformans is introduced via the respiratory tract, it is engulfed by macrophages and other phagocytes. One of C. neoformans’s primary virulence factors is the pigment, melanin, which is produced in the cell wall and protects the yeast against UV radiation and oxidizing agents produced by macrophages during phagocytosis. To better understand the observed sex bias (3:1; male: female) in cryptococcosis infections, we determined the phenotype of various virulence factors in the presence of exogenous sex hormones. The data show a difference in melanization of C. neoformans cells in the presence of exogenous testosterone and estrogen, where C. neoformans melanizes faster in testosterone. Using a combination of RNA sequencing analysis and ELISA results, we have identified a new quorum sensing molecule, gibberellic acid (GA) in C. neoformans. These data suggest that this melanization difference in testosterone is due to increased production of GA, as GA is highly upregulated in the presence of testosterone. Thus, this may help explain the sex bias observed in C. neoformans infections.
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    A STUDY OF ANTICANCER AGENTS DERIVED FROM PLANTS UTILIZED IN TRADITIONAL CHINESE MEDICINE (TCM)
    (Middle Tennessee State University, 2018-03-27) Almosnid, Nadin ; Altman, Elliot ; Gao, Ying ; Altman, Elliot ; Gao, Ying ; Farone, Anthony ; Farone, Mary ; Wang, Chengshan ; Biology
    ABSTRACT
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    Age Study of Red Efts (Notophthalmus viridescens viridescens) from a Cannon County, Tennessee Metapopulation
    (Middle Tennessee State University, 2015-06-22) Parker, Herschell ; Miller, Brian ; Klukowski, Matt ; Mullen, Dennis ; Biology
    ABSTRACT
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    Analysis of Sex Bias in Cryptococcus neoformans Infections
    (Middle Tennessee State University, 2018) Guess, Tiffany ; Biology
    Cryptococcus neoformans, a pathogenic yeast and the causative agent of cryptococcosis, is responsible for an estimated quarter million new cases of the disease resulting in more than 180,000 deaths each year worldwide. For decades, researchers have noticed that the prevalence of cryptococcosis is skewed between males and females. Numerous studies show sex-specific differences in C. neoformans infection rates, with males having a higher incidence of disease and death (~7M:3F). Sexual dimorphism in infection is not uncommon. However, the cause of these differences, in C. neoformans, has not been well elucidated. The aim of this project was to gain a deeper understanding of the causes underlying the sex bias observed in cryptococcosis. To accomplish this, a comprehensive approach was designed to examine the effect of sex-defining hormones on the pathogen itself as well as experiments to detect differences in the host-pathogen interface of males and females. There were three major components to this study. First, to establish whether sex hormones were taken up by C. neoformans, fluorescently tagged 17β-estradiol was incubated with wild type and mutant strains, and the results imaged on a confocal microscope. Second, to assess any changes in virulence factors in the presence of sex hormones, C. neoformans clinical isolates were grown in an environment designed to mimic the central nervous system (CNS) and a series of in vitro biochemical experiments were conducted to examine each of the virulence factors individually in the presence of sex hormones. Third, the response of healthy human male and female immune cells were evaluated during infection with C. neoformans. The results show that estrogen is, in fact, capable of entering C. neoformans at normal iv physiological levels seen in females. Additionally, a number of virulence factors are changed in the presence of estrogen and testosterone at normal physiological levels. Finally, the percentages of T cells differ between males and females during a C. neoformans infection, which may suggest differences in the adaptive immune response to this pathogen. Taken together, these results indicate that the sex bias observed for many years has a biologic basis and cannot simply be explained by environmental factors. Further, the sexual dimorphism stems from both differences in the pathogen and host-pathogen interface in the presence of a male and female environment.
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    Another layer: The Karenia brevis plastid transcriptome expands the complex story of dinoflagellate RNA processing and tertiary endosymbiosis.
    (Middle Tennessee State University, 2015-03-27) Newby, Robert ; Leblond, Jeffrey ; Salem, Mohomed ; Cahoon, Aubrey ; Biology
    Dinoflagellates are a diverse group of protists, which possess the ability to modify their genomic information at a rapid rate compared to other eukaryotes. When adding plastid organelles via endosymbiosis, the genome of the endosymbiont can also be modified by means such as fragmentation into circular chromosomes (minicircles), reorganization of protein structure, and transference of more of their photosynthesis genes to the nucleus than any other eukaryote. Due to being "suited" for endosymbiotic acquisition of organelles, the dinoflagellate family exhibits three distinct plastid types, two of which use chlorophyll a along with peridinin and fucoxanthin, respectively. The third plastid type is found in Lepidodinium, and appears to be derived from a chlorophyte inclusion, as it uses chlorophylls a and b. At this time, the peridinin dinoflagellates have been better studied than the fucoxanthin lineages such as Karenia brevis and Karlodinium veneficum. Although comparative studies have found phylogenetic evidence of similarities between the peridinin and fucoxanthin dinoflagellates, conflicting results and a significant body of empirical evidence suggests substantial differences between them in the areas of genome and membrane structure. In this study, we have used Illumina RNA sequencing to produce the most complete plastid transcriptome of Karenia brevis to date. We have analyzed the transcript structure and noted a number of dinoflagellate hallmarks, such as polyuridylation of the 3' end of mRNAs, and loss of consensus start codons. We have also identified evidence of polyadenylation of the 5' end of protein coding transcripts, which has not been reported so far. Six of the protein sequences produced were used to conduct a comparative phylogenetic analysis, which has identified both previously known, and unreported similarities, between the peridinin and fucoxanthin dinoflagellates, including shared instances of consensus loss when compared to broad group of reference taxa. We have also found discrete instances of invariant site substitution preferences, which are shared between these groups. These findings do not support previous studies that have suggested a common lineage for these groups, but further elucidate a complex pattern of endosymbiont genome modifications associated with the dinoflagellate host cell.
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    Assessing Passage of Lake Sturgeon (Acipenser fulvescens) through Cheatham and Old Hickory Dams, Cumberland River, Tennessee
    (Middle Tennessee State University, 2016-06-24) Ganus, John Eric ; Mullen, Dennis ; Miller, Brain ; Cobb, Vincent ; Biology
    While lake sturgeon stocking began in 2006 in the Cumberland River system, reservoir specific data is needed to assess restoration efforts as well as provide information to support sturgeon management decisions. The purpose of this study was to (1) assess dam passage and emigration rates of tagged hatchery-reared juvenile lake sturgeon through Cheatham and Old Hickory locks and dams, (2) estimate reservoir section use and movement by tagged hatchery-reared juvenile lake sturgeon within Cheatham Lake, and (3) estimate the minimum annual stocking rate for Cheatham Reservoir. Percent downstream passage of tagged lake sturgeon through Cheatham Lock and Dam (CLD) was 32% (n=11) in 2011 and 9% (n=3) in 2012. Percent upstream passage of tagged lake sturgeon through Old Hickory Lock and Dam (OHLD) was 32% (n=11) in 2011 and 28% (n=9) in 2012. The total emigration rate for Cheatham Lake was 68% in 2011 and was 38% in 2012. Upstream movement was high for each cohort as 75% (n = 25) in 2011 and 81 % (n = 26) in 2012 of tagged lake sturgeon moved upstream to a position just below OHLD within 5 days post-stocking. Average upstream distance traveled post-stocking was 25.2 river km (rkm) and downstream was 3.6 rkm for 2011. Average upstream distance traveled post-stocking was 35.6 rkm and downstream was 16.1 rkm for 2012. The estimated minimum annual stocking rates would be 1,770, 2,456 and 48,778 at 0%, 1% and 10% emigration rates when applied equally over 40 years of stocking.
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    Assessing the relationship between flowering time and fitness in Leavenworthia stylosa
    (Middle Tennessee State University, 2018-02-16) Banaszak, Caitlin C ; Herlihy, Christopher ; Morris, Ashley ; Walck, Jeffrey ; Biology
    Recent research has shown a trend towards early flowering time in a variety of species around the world. Leavenworthia stylosa, a cedar glade species endemic to the Central Basin of Tennessee, appeared to also follow this pattern. Herbarium specimens showed a trend towards earlier flowering in L. stylosa over the last century. In two years of research, there was no overall fitness cost or benefit to flowering earlier than the population average within years, but there was a fitness cost for individuals that flowered later than average. Between years, higher fruit set was found during a year with unusually early flowering compared to a year with more typical flowering time. Based on analyses of historical climate data, earlier flowering did not appear to be due to warmer spring temperatures. Early flowering was also not the result of earlier fall germination time.
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    Biochemical and bioinformatics approach to the study of lipids and their biosynthetic pathways in Chromera velia and Vitrella brassicaformis
    (Middle Tennessee State University, 2014-07-11) Khadka, Manoj ; Leblond, Jeffrey ; Farone, Anthony ; Robertson, James ; Walck, Jeffrey ; Seipelt-Thiemann, Rebecca ; Biology
    Vitrella brassicaformis and Chromera velia are marine microalgae that photosynthetic plastids of red algal origin, are closely related to non-photosynthetic apicomplexan parasites and are classified as the phylum Chromerida and familes Vitrellaceae and Chromeraceae, respectively. To dates, only one study has been performed on the galactolipid of Chromera velia and few other studies have been based on the ultrastructural and phylogenetic studies in Chromerida. We used a combination of mass spectrometry techniques and RNA-seq data to elucidate the sterol and galactolipid composition of the Chromerida, and to identify their biosynthetic genes, respectively. The identified genes were further utilized to perform the gene phylogenies of the Chromerida with red algae, dinoflagellates and apicomplexans.
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    Characterization of a cortical defect of the Ulna found in the Fernvale archaeological population (40WM51) of the South Harpeth River Valley in Middle Tennessee
    (Middle Tennessee State University, 2015-06-26) Foster, Alison Elise ; Miller, Brian ; Hodge, Shannon ; Berryman, Hugh ; Jetton, Amy ; Biology
    Osteological analyses of human remains from Fernvale (40WM51), a multicomponent site with Late Archaic Period interments along the South Harpeth River in Middle Tennessee, were conducted as part of a re-analysis project implemented by the Tennessee Division of Archaeology (TDOA). The main goal of this research was to describe and characterize a cortical defect, observed in 14 of 16 individuals (23 of 26 ulnae) from the site, that had not been previously documented in the anthropological or clinical literature and offer explanations to the biomechanical origins of the defect. The cortical defect, located in the proximal radioulnar joint appeared to be the imprint of soft tissue damage in response to physical stressors. Activities biomechanically similar to climbing and canoeing or accidental falls caused by habitually traversing rugged terrain possibly caused the avulsion injury to the lateral ligament complex that resulted in the cortical defect at the posterior attachment site of the annular ligament.
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    Characterization of Open Reading Frames in the Tobacco Mitochondrial Transcriptome
    (Middle Tennessee State University, 2013-06-28) Grimes, Ben ; Cahoon, Aubrey ; Elrod-Erickson, Matthew ; Seipelt-Thiemann, Rebecca ; Biology
    Initial annotation of the tobacco mitochondrial genome in 2005 identified numerous identifiable protein coding, tRNA, and rRNA genes plus 119 open reading frames (ORFs) with no clearly stated function. The purpose of this study was to explore expression of putative open reading frames in the Nicotiana tabacum mitochondrial genome. I surmised that if these gene products are transcribed and translated they may have a functional role in the tobacco mitochondria. In this study, these ORFs were screened for expression using RNA deep sequencing, qRT-PCR, and polysome analysis. Twenty-five of the 119 were found to have steady-state RNA amounts above background and 15 of those were found to be polysome associated. These ORFs were also bioinformatically compared to other genes. Some of the transcribed ORFs were found to be fragments of mitochondrial proteins, some were not identifiable while some were homologous to plastid or nuclear coding genes. Five of the expressed ORFs have been linked to cytoplasmic male sterility in other plants. The 10 remaining ORFs found to be polysome-associated have the potential to be novel mitochondrial proteins.
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    Characterization of the Human Inflammatory Response to Gardnerella vaginalis
    (Middle Tennessee State University, 2014-11-12) Vick, Eric ; Farone, Anthony ; Farone, Mary ; Elrod-Erickson, Matthew ; Seipelt-Thiemann, Rebecca ; Kline, Paul ; Biology
    Gardnerella vaginalis is a Gram-positive bacterium associated with BV (BV), pelvic inflammatory disease, and preterm birth. BV is the most prevalent vaginal infection in women, characterized by the absence of normal Lactobacilli and overgrowth of G. vaginalis and other bacterial species. This study tested the hypothesis that G. vaginalis induces an inflammatory response in the human cell line, THP-1. The objectives of the study were to 1) determine whether different strains of G. vaginalis cause proinflammatory cytokinesproduction in THP-1 cells, 2) characterize intracellular pathways by which these cytokines are produced, and 3) determine molecular mechanisms involved in death of cells treated with strains of G. vaginalis.
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    Characterizing the proteasomal subunit RPN-6.2 in C. elegans
    (Middle Tennessee State University, 2019) Evers, Joshua Michael ; Biology
    Spermatogenesis is the process whereby sperm cells develop into specialized reproductive cells capable of fertilizing an oocyte. The proteins that tightly regulate sperm cell development are in turn regulated by the ubiquitin proteasome system (UPS). Due to the proteasomes role in regulating meiosis, disruption of the proteasome during spermatogenesis may result in decreased sperm counts and other fertilization defects. We have identified a proteasomal subunit, RPN-6.2, exclusively expressed in sperm. RPN-6.2 surrounds the DNA in spermatids and the motile spermatozoa, while also appearing as dense puncta scattered around the cytoplasm. RPN-6.2 does not localize to membranous organelles or the mitochondria in spermatids or spermatozoa. rpn-6.2 knock-down or RPN-6.2 mutant C. elegans produce less progeny during their reproductive period. rpn-6.2 mutant C. elegans produce fewer sperm suggesting the decrease in progeny may be directly linked to a defect in spermatogenesis caused by dysfunctional proteasome.
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    COMPARATIVE ANALYSIS OF LUMINESCENCE INTENSITY OF SINGLE SPORE ISOLATES FROM THE NATURALLY BIOLUMINESCENT FUNGUS ARMILLARIA MELLEA (AGARICALES, PHYSALACRIACEAE)
    (Middle Tennessee State University, 2018-03-19) Poole, Virginia ; Bergemann, Sarah ; Salem, Mohamed ; Robertson, J. Brian ; Biology
    Bioluminescence is the production and emission of light by a living organism which requires the oxidation of a luciferin substrate by a luciferase enzyme or photoprotein to produce light. Nearly all the described fungi that bioluminesce are mushroom-forming, saprotrophic species belonging to four, distantly related lineages in the Agaricales (Basidiomycota). Here, I conduct comparative studies to examine the variation in luminescence intensity of single spore isolates (SSIs) of the bioluminescent fungus, Armillaria mellea. A diploid isolate of A. mellea was inoculated on sawdust, rice and tomato media and incubated to induce formation of basidiomata in vitro. Luminescence intensity of single spore isolates (SSIs) from haploid basidiospores were obtained and classified as three phenotypes (bright, dim and intermediate) based on their luminescence intensity. Three bright (>1000 AUs), four intermediate (200-999 AUs) and three dim SSIs (<200 AUs) were selected for pairings in the following combinations: i) bright bright; ii) intermediate intermediate and; iii) dim dim luminescence intensity. In addition, dim and bright luminescent isolates were paired with a non-luminescent transformant obtained from the USDA-ARS. The frequency and luminescence intensity of haploid SSIs (n = 241) obtained from matings from five compatible mycelial pairings that produced basidiomata and matured to generate viable basidiospores [bright bright (n = 2), intermediate intermediate (n = 1), dim transformant (n = 2)] and differences in luminescence intensity were compared at 14, 23 and 32 days post inoculation (dpi). Mean luminescence intensity of SSIs obtained from bright bright matings were greater than SSIs obtained from intermediate intermediate and dim transformant matings. The differences in mean luminescence intensity suggests that the expression of bioluminescence is a heritable trait and exhibits a continuous distribution in luminescence intensity. In addition, matings of bright bright isolates produced a higher frequency of SSIs with bright luminescence intensity (92%); however, 50% of SSIs obtained from the intermediate intermediate cross and 21% of SSIs generated from the dim transformant crosses exhibited bright luminescence intensity. This suggests that bioluminescence is a complex trait involving the interactions of multiple genes.
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    Comparison of bias and precision of fin rays, otoliths, and scales for ageing Brook Trout (Salvelinus fontinalis), Brown Trout (Salmo trutta), and Rio Grande Cutthroat Trout (Oncorhynchus clarki virginalis)
    (Middle Tennessee State University, 2017-01-11) Parsley, Phillip Mark ; Bergemann, Sarah ; Stewart, David ; Mullen, Dennis ; Biology
    The precision, bias, and accuracy of age estimates from scales, pelvic fin rays, and otoliths were compared for Brook Trout (Salvelinus fontinalis), Brown Trout (Salmo trutta), and Rio Grande Cutthroat Trout (Oncorhynchus clarki virginalis). Calcified structures were collected for each fish and age estimates were obtained by counting the number of annuli by two independent readers. The precision of age estimates was estimated by coefficient of variation (CV), and percent agreement (PA) between readers. Bias and accuracy were investigated through analysis of age-bias plots and Wilcoxon matched pairs rank tests. In all analyses, age estimates of Brook Trout, Brown Trout and the Rio Grande Cutthroat Trout were most precise using otoliths and fin rays. Typically, age estimates of otoliths and fin rays were more accurate than scales particularly for age classes > 4. Age estimates with scales typically underestimated the age of older fish whereas age estimates of fin rays and otoliths were closer in agreement. The differences of age estimates from fin rays, otoliths, and scales found in this study emphasize the importance of validating calcified structures for these species. Additionally, the accuracy and precision of age estimates from fin rays demonstrate that this method is a viable nonlethal alternative to the lethal sampling required for obtaining otoliths.
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    A Comparison of Three Types of Compost Materials for the Reduction of Bacterial Pathogens
    (Middle Tennessee State University, 2013-06-23) Lee, Justin Wayne ; Farone, Mary ; Farone, Anthony ; Newsome, Anthony ; Biology
    This study compared three compost materials, sand, soil, and stall waste, for their ability to inactivate pathogenic bacteria. For this purpose, a series of mounds were constructed for large-scale testing during the first summer of the project. This was followed by small-scale testing for two winter trials and a second summer trial. In all trials Escherichia coli and Salmonella spp. were used as indicator organisms, either in unison or individually. Large-scale testing showed complete inhibition of indicator organisms in sand compost mounds. Soil and stall compost mounds showed little to no inhibition of coliforms over the course of both trials. In small-scale winter trials, ANOVA testing showed no significant difference between compost types using turbidity to measure bacterial growth. During the small-scale summer trial, stall compost completely inhibited the Salmonella population by day 9; however, by the end of the trial there was no statistically significant difference between compost types.
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    DEMOGRAPHIC CHARACTERISTICS, INCIDENCE OF RANAVIRUS INFECTION, AND SEASONAL CORTICOSTERONE LEVELS IN THE EASTERN BOX TURTLE, TERRAPENE CAROLINA CAROLINA, IN A SUBURBAN WETLANDS HABITAT OF MIDDLE TENNESSEE
    (Middle Tennessee State University, 2016-01-01) Vannatta, Jessica Marie ; Klukowski, Matthew ; Miller, Brian ; Bailey, Frank ; Biology
    The Eastern Box Turtle, Terrapene carolina carolina, is a species of concern in Tennessee because of population decline. Decline is due mainly to anthropogenic causes including, but not limited to, road mortality, disease, and habitat fragmentation. The purpose of this study was to assess the general health of the T. c. carolina population in a suburban wetlands habitat in Murfreesboro, TN, USA (Nickajack) by measuring demographic characteristics, infection status, and physiological characteristics. Demographic characteristics recorded include population density, age class, sex ratio, and several body size measurements (e.g., carapace length and carapace height). A small blood sample (≤0.2 ml) was drawn to measure corticosterone levels, triglycerides, uric acid, innate immunity, and to determine Ranavirus infection status. The population density was estimated to be approximately 14-15.5 turtles per hectare. The age class structure had a normal distribution with most turtles falling within the middle age class (10-14 years). The sex ratio was 1.26 male:1 female. For body size, the only variable with a significant difference between males and females was straight-line carapace length in which males were longer than females. A single turtle (LPW) was positive for Ranavirus infection out of the 102 turtles sampled and tested, accounting for 1% prevalence in the sampled population. Females had higher body condition indices than males. In 2013, corticosterone levels were significantly higher in summer than in spring. In 2014, corticosterone levels were significantly higher in fall than in both spring and summer. The difference in the seasonal timing of peak corticosterone levels between the years may be related to weather conditions or associated with opportunistic mating. Corticosterone levels were positively correlated with hemolysis titer, possibly because of an immunoenhancing effect of stress hormones. In both 2013 and 2014, triglyceride levels were significantly higher in females than in males. The higher triglyceride levels of females were most likely associated with the energetic demands of egg production, carrying eggs, and nesting. Triglycerides were positively correlated with body condition, indicating greater lipid reserves in individuals with a better body condition. All other physiological measures, including total leukocytes and heterophil counts, failed to exhibit significant seasonal or sex related differences. To my knowledge, this is the first report of baseline corticosterone values and innate immunity in free-ranging T. c. carolina. The results obtained will aid in the conservation and protection of this species of concern.
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    Demography, Topographic Orientation, and Migratory Patterns of Two Ambystomatid Communities on the Southern Cumberland Plateau in Franklin County, Tennessee.
    (Middle Tennessee State University, 2013-10-31) Campbell, Joshua Ray ; Miller, Brian ; Cobb, Vincent ; Mullen, Dennis ; Biology
    Habitat degradation and loss has been identified as one of the major causes of amphibian declines worldwide. Alterations to the terrestrial landscape can alter or eliminate migrations of amphibians and disrupt amphibian assemblages. Degradation of the upland habitat surrounding wetlands can have severe consequences for emigrating juvenile amphibians, decreasing gene flow within metapopulations. Analyses of topographic orientation of migratory amphibians can indicate habitat used and the occurrence migratory corridors on the landscape. This study occurred simultaneously at two wetlands located on the Southern Cumberland Plateau. The primary goals were to (1) determine the amphibian and reptile assemblages, (2) determine if migrations of ambystomatid salamanders were uniformly oriented, and (3) determine, through the use of telemetry, if current habitat management is impacting salamander migration patterns.
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    Demonstration of the utility of a dual-color luciferase reporter in S. cerevisiae
    (Middle Tennessee State University, 2015-06-01) Krishnamoorthy, Archana ; Robertson, James ; Erickson, Matthew ; Jessen, Jason ; Biology
    A reporter gene helps determine the regulation of a gene of interest by producing a protein product that can be easily detected when the gene of interest is active. The luciferase gene from click beetles can be used as a reporter because its protein product emits light that can be measured. Monitoring transcription by luciferase activity is hampered in fast growing organisms due to sudden changes in oxygen concentration and cell number as these variables also affect light emission. This study uses green luciferase to report transcription of a gene of interest and red luciferase to simultaneously report activity of a reference gene. The ratio of these colors can (i) mitigate sudden changes in rapid growth conditions, and (ii) be used to predict productivity of the cell population during processes such as the Yeast Respiratory Oscillation. We envision this tool to provide valuable insights into genetic control in S. cerevisiae.