Biology Commons^™

Fear And Loathing In The Super Organism: Foraging Strategy Doesn't Change Forager Response In A Landscape Of Fear., Philip Schadegg

Electronic Theses and Dissertations

Understanding how predators impact keystone species, like ants, is very important for our understanding of ecology because of ants' importance in shaping community dynamics and ecosystem functions. In this thesis I present research investigating the role of the ant-specialized spider Anasaitis canosa in influencing the foraging behavior of four ant species (Formica pallidefulva, Odontomachus ruginodis, Pheidole obscurithorax & Solenopsis invicta). Collectively, these four species use foraging strategies exhibited by most ants. I conducted two experiments to quantify the impacts of spider predation on ant prey. The first used forty colonies of four ant species to investigate how A. canosa changed …

Assessing The Effects Of Habitat And Manatee Exclusion Devices On Red Drum (Sciaenops Ocellatus) Movement Patterns In Estuarine Impoundments, Steven Baker

Electronic Theses and Dissertations

The Integrate-Transfer-Launch (ITL) complex impoundments located within the Kennedy Space Center security zone are known spawning sites for red drum (Sciaenops ocellatus). However, recent construction of manatee exclusion bollards around culverts leading into these impoundments may impede movement to and from this critical habitat. The goals of this study were to: 1) utilize passive acoustic telemetry to document patterns of red drum movement and habitat use within and around the ITL impoundments to assess how manatee exclusion bollards and environmental conditions may impact movement of red drum; and 2) explore red drum movement in response to environmental disturbance, specifically a …

Direct And Indirect Effects Of Invasive Cirsium Arvense On Pollination In Southern Appalachian Floral Communities, Jesse Daniels

Electronic Theses and Dissertations

Invasive plants can alter pollination dynamics in invaded communities by disrupting patterns of pollinator visitation, pollen transfer dynamics (conspecific [CP] and heterospecific [HP]), and reproductive success. The direction of invasive effects (competitive, neutral, and facilitative) may be partially determined by spatial scale and species’ floral traits. Here, we investigated pollinator visitation, CP and HP receipt, and pollen tube growth for species in a C. arvense present community and non-present community at two scales. At the community-level, the effect of C. arvense on pollinator visitation varied among species. Floral symmetry seemed to explain this variation. At the floral neighborhood-level, we found …

Localization Of Sip470, A Plant Lipid Transfer Protein In Nicotiana Tabacum, Shantaya Andrews

Electronic Theses and Dissertations

SABP2-interacting protein 470 (SIP470), a non-specific lipid transfer protein (nsLTP), was discovered in a yeast two-hybrid screening using SABP2 as bait and tobacco leaf proteins as prey. SABP2 is an important enzyme in systemic acquired resistance that converts salicylic acid to methyl salicylate. Localization studies are an important aspect to understanding the biological function of proteins. nsLTPs are generally considered apoplastic proteins and has been localized intracellularly and extracellularly. Transient expression shows highest expression of SIP470-eGFP at 2 days post infiltration into Nicotiana benthamiana. Confocal microscopy showed localization near the periphery of the cell. Subcellular localization using differential centrifugation showed …

Characterization Of Sip68 For Its Role In Plant Stress Signaling, Saroj Chandra Lohani

Electronic Theses and Dissertations

Glucosyltransferases catalyze the transfer of glucose molecules from an active donor to acceptor molecules and are involved in many plant processes. SIP68, a tobacco glucosyltransferase protein, is a SABP2-interacting protein. It was identified in a yeast two-hybrid screen using SABP2 as bait and tobacco proteins as prey. SABP2, converts methyl salicylate to salicylic acid (SA) as a part of the signal transduction pathways in SA-mediated defense signaling. Subcellular localization is a crucial aspect of protein functional analysis to assess its biological function. The recombinant SIP68 tagged with eGFP was expressed transiently in Nicotiana benthamiana and observed under confocal microscopy. Fluorescent …

Sip-428, A Sir2 Deacetylase Enzyme And Its Role In Biotic Stress Signaling Pathway, Bal Krishna Chand Thakuri

Electronic Theses and Dissertations

SABP2 (Salicylic Acid Binding Protein 2) plays a vital role in the salicylic acid signaling pathway of plants both regarding basal resistance and systemic acquired resistance against pathogen infection. SIP-428 (SABP2 Interacting Protein-428) is a Silent information regulator 2 (SIR2) like deacetylase enzyme that physically interacts with SABP2 in a yeast two-hybrid interaction and confirmed independently by a GST pull-down assay. We demonstrated that SIP- 428 is an NAD+ dependent SIR2 deacetylase enzyme. Transgenic tobacco plants silenced in SIP- 428 expression via RNAi showed enhanced basal resistance to microbial pathogens. Moreover, these SIP-428-silenced lines also exhibited a robust induction of …

Bryophyte Assemblages On American Hornbeam (Carpinus Caroliniana) And The Surrounding Arboreal Communities Within The Forest Of East Texas, Cassey Edwards

Electronic Theses and Dissertations

The bryophytes, the non-vascular plants, include the mosses (Bryophyta with approximately 13,000 species), the liverworts (Marchantiophyta with approximately 5,000 species), and the hornworts (Anthocerotophyta with approximately 150 species). Initial observations indicated that the midstory tree Carpinus caroliniana Walter (American hornbeam) has a bryophyte composition with an unusually high diversity of leafy liverworts. Voucher samples were taken from the four intercardinal directions (Northeast, Northwest, Southwest, and Southeast) from six Carpinus trees and their nearest neighbor that was neither Pinus nor another Carpinus at each of six sites across East Texas. Percent coverage, species richness, Shannon’s diversity and Pielou’s evenness were computed. …

The Study Of Alcoholic Liver Diseases, Seun Emmanuel Owoseni

Electronic Theses and Dissertations

Excessive alcohol consumption is the primary contributing factor in the development of alcoholic liver diseases (ALD). Nicotine contained in tobacco is a major addictive alkaloid, which enhances the effects of ALDs. The major enzyme involved in nicotine metabolism is cytochrome P450 2A5 (CYP2A5) which is produced in the liver. Alcohol can stimulate the CYP2A5 enzyme. We utilized cyp2a5-/- knockout mice in this research to examine the effects of CYP2A5.

The cyp2a5-/- mice and wild-type (WT) mice were fed liquid ethanol diet with or without nicotine to induce ALD. Nicotine enhancing effects on ALD were observed in WT mice but not …

Spg Directs Arp2/3 Mediated F-Actin Networks To Support Syncytial Furrow Ingression In Drosophila, Shannon M. Henry

Electronic Theses and Dissertations

In the Drosophila embryo, nuclear divisions 10-13 occur in a syncytium with transient membrane furrows separating neighboring nuclei before the occurrence of cellularization. This process is driven by cytoskeletal and membrane trafficking networks, and while RalA and Rab8 have been identified to drive membrane addition to furrows, less is known about the control of dynamic F-actin networks needed for furrow formation. Here, the role of the DOCK protein Sponge (Spg) in furrow formation is explored through shRNA knockdown and live-imaging of syncytial Drosophila embryos. I have found that Spg is required for furrow ingression and that without Spg, furrows can …

Impact Of Reproductive Mode On Skeletal Development In A Reproductively Bimodal Squamate Species, Amanda Tedder

Electronic Theses and Dissertations

Viviparity has evolved multiple times within squamates. Eggshells are reduced in viviparous forms, which reduces calcium available to embryos during development. This study tested the hypothesis that reduced calcium impacts neonates of viviparous forms. Developmental series from oviparous and viviparous populations of Zootoca vivipara (reproductively bimodal) were cleared & stained to reveal bone development. Photographs (high magnification, calibrated to size) were used to obtain measurements of lengths of the body, humerus, femur, skull and lower jaw, and of ossified portions of limb bones. Percent ossification was scored for targeted skull bones. Results were analyzed using general linear models and revealed …

Post-Transcriptional Regulation Of Rsma In Pseudomonas Aeruginosa, Ian Miller

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative bacillus found in numerous environments. Gene regulatory mechanisms such as; Two-Component Systems, transcriptional and post-transcriptional regulators, and small non-coding RNAs control the expression of virulence factors that allow P. aeruginosa to initiate acute infections and persist as a chronic infection. A significant post-transcriptional regulator involved in these regulatory networks is the Regulator of Secondary Metabolites (RsmA). In this study, we investigated the contribution of a putative stem-loop on expression of RsmA. We constructed rsmA leader fusions to measure translation with and without the stem-loop present. Secondly, we introduced point mutations to disrupt the formation …

Investigating The Interaction Of Monoamines And Diel Rhythmicity On Anti-Predator Behavior In An Orb-Weaving Spider, Larinioides Cornutus (Araneae: Araneae), Rebecca Wilson

Electronic Theses and Dissertations

Circadian rhythms are ubiquitous among organisms, influencing a wide array of physiological processes and behaviors including aggression. While many neurophysiological mechanisms are involved in the regulation of aggressive behaviors, relatively few studies have investigated the underlying components involved in the interplay between circadian rhythms and aggression. Spiders are an ideal model system for studying circadian regulation of aggression as they are ecologically both predators and prey. Recent studies have revealed a nocturnal orb- weaving spider Larinioides cornutus exhibits a diel and circadian rhythm in anti-predator behavior (i.e. boldness) that can be manipulated by administration of octopamine (OA) and serotonin (5- …

Role Of Ataxia-Telangiectasia Mutated Kinase In Cardiac Autophagy And Glucose Metabolism Under Ischemic Conditions, Patsy Thrasher

Electronic Theses and Dissertations

Ataxia-telangiectasia mutated kinase (ATM), a serine/threonine kinase primarily located in the nucleus, is typically activated in response to DNA damage. Individuals with mutations in ATM gene develop a disease called Ataxia telangiectasia (AT). These individuals are more susceptible to ischemic heart disease and metabolic disorder. Our lab has previously shown that ATM plays a critical role in β-adrenergic receptor (β-AR) - and myocardial infarction (MI)-stimulated myocyte apoptosis and cardiac remodeling. This study tested the hypothesis that ATM plays a critical role in cardiac autophagy and glucose metabolism following MI and ischemia, respectively. Early during MI (4 hours after its onset) …

Unfolded Protein Response Pathways In Skeletal Muscle Homeostasis., Kyle R. Bohnert

Electronic Theses and Dissertations

Skeletal muscle mass, contractile properties, and metabolic function are regulated through the coordinated activation of multiple intracellular signaling pathways and genetic reprogramming. The endoplasmic reticulum (ER) plays a pivotal role in protein folding and calcium homeostasis in many cell types, including skeletal muscle. Disruption of calcium levels or accumulation of misfolded proteins in the ER lumen leads to stress, which results in the activation of a signaling network called the unfolded protein response (UPR). Further, recent studies have suggested that in certain conditions, UPR pathways can be activated independent of ER stress. However, the role of ER stress and the …

Unique Osmoregulatory Morphology In Primitive Sharks: An Intermediate State Between Holocephalan And Derived Shark Secretory Morphology, Matthew Eric Larsen

Electronic Theses and Dissertations

Discovery of an unusual rectal gland in the Atlantic sixgill shark, Hexanchus vitulus, led to examination of rectal glands in 29 species of epipelagic and deep-sea sharks. Eight of 14 deep-sea species of sharks had digitiform glands that were previously assumed to be characteristic of elasmobranchs (N=281; mean width-length ratio ± SD = 0.18 ± 0.07). Hematoxylin-and-eosin stained sections from deep-sea sharks were similar to those from shallow water sharks. Glands from the family Somniosidae were kidney bean-shaped (N = 3; mean width-length ratio ± SD = 0.46 ± 0.05); whereas those from the families Echinorhinidae and Hexanchidae appeared lobulate …

Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex

Electronic Theses and Dissertations

Lake Baikal is the oldest known lake and a unique ecosystem, home to several species of fresh water sponge. A disease outbreak affecting the dominant species, Lubormirskia baialensis, was recently reported. The cause of the disease has not been determined but one of the current hypothesis is that the increase in methane concentration is correlated to the disease outbreak. This pilot study characterized the microbiomes of sick and healthy sponges through the use of 16S rRNA sequencing. Sick sponge microbiomes shared a conserved group of taxa while the healthy sponge microbiomes had greater diversity. Indicator species analysis identified two significant …

A Role Of Vitamin B2 In Reducing Amyloid-Beta Toxicity In A Caenorhabditis Elegans Alzheimer’S Disease Model, Muhammad Tukur Ameen

Electronic Theses and Dissertations

Alzheimer’s disease (AD) is associated with amyloid-beta peptide deposition and loss of mitochondrial function. Using a transgenic C. elegans AD worm model expressing amyloid-beta in body wall muscle, we determined that supplementation with either of the forms of vitamin B₂, flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD) protected against amyloid-beta mediated paralysis. FMN and FAD were then assayed to determine effects on ATP, oxygen consumption, and reactive oxygen species (ROS) with these compounds not significantly improving any of these mitochondrial bioenergetic functions. Knockdown of the daf-16/FOXO transcriptional regulator or the FAD synthase enzyme completely abrogated the …

Identification Of “Fhua” Like Genes In Rhizobium Leguminosarum Atcc 14479 And Its Role In Vicibactin Transport And Investigation Of Heme Bound Iron Uptake System, Sushant Khanal

Electronic Theses and Dissertations

Siderophores are low molecular weight, iron chelating compounds produced by many bacteria for uptake of iron in case of iron scarcity. Vicibactin is a trihydroxamate type siderophore produced by Rhizobium leguminosarum bv. trifolii ATCC 14479. This work focuses on identifying an outer membrane receptor involved in the transport of vicibactin. We have confirmed the presence of the putative fhuA gene in R. leguminosarum bv. trifolii ATCC 14479. This bacteria shows mutualistic symbiosis with the red clover plant Trifoliium prantense. Leghemoglobin, with its cofactor heme is present in the plant root nodules that surrounds the infecting organism present in the nodules. …

Does Spaceflight Increase The Chance Of Female Astronauts Developing Uterine Cancer?, Areej Mosa

Electronic Theses and Dissertations

One of the main questions put forth by NASA and the European Space Agency (ESA) is whether or not an organism, especially mankind, can complete an entire life cycle in space. With this in mind, it is essential to study the effect of spaceflight on reproductive tissues. Using simulated microgravity techniques and whole-body radiation we sought to determine if females subjected to a simulated spaceflight environment have increased incidences of uterine cancer. Uterine tissue from mice subjected to simulated spaceflight was analyzed using immunohistochemical staining and western blot analysis. Two pathways commonly activated in cancer were investigated. Additionally, the uterine …

Tidal Creek And Substrate Effects On Oyster Reef Associated Fish And Decapod Condition And Density, Thomas S. Funk

Electronic Theses and Dissertations

Oyster reefs are essential fish habitat and a worldwide loss of reefs has the potential to negatively affect reef-associated nekton populations. Along the 100 km Myrtle Beach, SC shoreline, oyster reefs ostensibly have disappeared within swash tidal creeks, which are anthropogenically altered estuarine systems that drain into the coastal ocean directly over shoreline beaches. To address oyster reef losses, a series of shell bag reefs were constructed within multiple swash tidal creeks. Reefs also were constructed in tidal creeks associated with estuaries directly connected to the ocean by an inlet. The purpose of this study was to compare nekton usage …

Unearthing The Past And Present Of A Semi-Fossorial Lizard: Conservation Genetics, Phylogeography, And Taxonomy Of Plestiodon Egregius., Kathryn Mercier

Electronic Theses and Dissertations

Characterizing an organism's evolutionary history and population structure as well as understanding the forces shaping that divergence is crucial to conservation biology. A clear understanding of the patterns of diversity and divergence are imperative for the best management of the organism, while an awareness of what drives these patterns can lead to better predictions of how organisms will respond to future climate change. Historical climate changes and associated sea level change are among the main forces driving divergence in many species. To examine how effects of climate changes may have driven patterns of intraspecific divergence, I examined Mole Skinks, Plestiodon …

A Review Of The Serica (Coleoptera: Scarabaeidae: Melolonthinae) Of Mexico, Canada, And The Western United States, Reese John Worthington

Electronic Theses and Dissertations

Twenty-two species and subspecies of Serica occur in Mexico. Serica ensenada Saylor, 1948 is recognized as a junior synonym of Serica pilifera Horn, 1894. Two new species, Serica ascia Lago & Worthington and Serica fenestra Lago & Worthington are described from Mexico. Three genera of Sericini are recorded from Canada, Maladera castanea (Arrow), Nipponoserica peregrina (Chapin), and twelve species of Serica. Seventy-seven species and subspecies of Serica occur in the contiguous United States west of the 100th meridian. Eleven new species, Serica berriani Lago & Worthington, Serica cuneiverpa Lago & Worthington, Serica desolaterra Lago & Worthington, Serica katelinae Lago & …

Characterizing Biogeochemical Shifts In Two Salix Caroliniana Michx. Encroached Freshwater Subtropical Marshes, Janet Ho

Electronic Theses and Dissertations

Shrub encroachment is a common disturbance in wetlands, but little is known about how shrub encroachment impacts functions such as carbon (C) storage and nitrogen (N) cycling. The objective of this thesis was to identify differences in physiochemical properties (within soil, water and leaf tissue) and biogeochemical processes (soil respiration, enzyme activity, litter decomposition, and N cycling) in two subtropical freshwater marshes encroached by coastal plain willow (Salix caroliniana Michx.). Two study regions (Moccasin Island and Lake Apopka) were selected because of their location in the St. John's River watershed and their unique histories and hydroperiod, allowing for an investigation …

The Contributions Of Fc Gamma Receptors And Macropinocytosis To The Internalization, Sorting And Clearance Of Antibody Coated Nanovesicles In Macrophages, George Opoku-Kusi Jr.

Electronic Theses and Dissertations

Macrophages are tissue-resident phagocytes that play critical roles in immune response and tissue homeostasis. They have a tremendous capacity to internalize objects of various sizes ranging from nanoscale viral particles to micron sized bacteria and tumor cells. This phenomenon, termed phagocytosis for the uptake of large particles, or endocytosis for the uptake of small particles, is integral to the immune response in multicellular organisms. Macrophages express FcγRs, which are tyrosine kinase receptors that bind IgG on an opsonized target. Binding of IgG Fc domain to the extracellular domain of an FcγR triggers signaling cascades that coordinate internalization of the opsonized …

Evaluation Of Dietary Phytochemicals As Rumen Modifiers In Lactating Dairy Cows, Sonia Rodriguez Jimenez

Electronic Theses and Dissertations

Phytochemicals such as tannins included in dairy cow nutritional programs, as a natural feed additive, promise to improve rumen bypass protein and consequently reduce the feeding cost by decreasing the amount of CP needed in the ration. Additionally, if tannins are fed along with high quality protein sources, this could improve the AA profile reaching the small intestine and potentially improving health and performance of dairy cows. The black pepper, specifically its alkaloid piperine, is a nontoxic, natural dietary compound with a broad range of physiological activity. Lactating dairy cows ingesting these phytochemicals (tannin extracts and black pepper) will potentially …

Mechanisms By Which Mechanotransduction Promotes Proliferation In Keratinocytes, Chhavi Chaudhary

Electronic Theses and Dissertations

Chronic wounds are wounds that do not heal within 30 days and often they can last over a year. Interference in any of the wound healing stages may hinder the process. Some of the local and systemic factors such as infection, old age, diabetes, AIDS, and the regular application of corticoids may also have negative effects on the healing process. Cell proliferation is an important phase in epidermal wound healing in which surviving epithelial cells replicate independently into daughter cells through mitosis and maintain a balance between cell growth and cell loss during the cell cycle. Physical and chemical stimuli …

Identification Of Macropinocytosis Regulating Proteins And Signaling From Macropinosomes, Louise Monga

Electronic Theses and Dissertations

Understanding macrophage cell biology is important due to macrophages key roles in human health and diseases including proper immune function, wound healing, atherosclerosis, and cancer. Despite their importance, relatively little is understood about macrophage activation, growth factor signaling, and cytoskeletal regulation. This thesis presents data from investigations into mechanisms of macrophage growth factor signaling and actin polymerization for ruffling and macropinocytosis. Alt-R CRISPR-Cas9 method and dextran uptake assay were used to knock out individual genes (SHP-1, Lyn, Syk, BTK, Vav1) and determine their role in macropinocytosis and CSF-1R signaling. Dextran uptake was disrupted in SHP-1 and Lyn targeted knockout cells, …

Impact Of Human Disturbance On The Behavior And Physiology Of The Endangered Ringed Sawback Turtle (Graptemys Oculifera), Jessica Mary Heppard

Electronic Theses and Dissertations

Turtles are one of the most threatened taxa worldwide. In addition to direct anthropogenic impacts such as hunting and pollution, unintentional indirect human disturbance affects poikilothermic turtles by disrupting thermoregulatory basking behavior. In this thesis I assess the behavioral and physiologic impacts of high boat traffic, reductions of basking structures, and environmental factors on basking behavior, rates of disturbance, thermoregulation, parasite load, shell condition, and population recruitment in two populations of the endangered ringed sawback (Graptemys oculifera), also known at the ringed map turtle, on the Pearl River outside Jackson, MS. Basking behavior was influenced by availability of basking structures, …

Transcriptome Analysis Of Root Development In Wheat Triticum Aestivum Using High Throughtput Sequencing Technologies, Ghana Challa

Electronic Theses and Dissertations

Root provides plant water, nutrients and anchorage from soil. Most our knowledge of molecular mechanisms of root development is from the dicot model plant Arabidopsis, but very few studies have done in monocot crop systems like rice, maize, and wheat. We are studying very short root (VSR) phenotype in wheat, and lack of a sequenced reference genome in wheat prompted us to sequence and assemble the root transcriptome of the reference cultivar Chinese Spring (CS). A root transcriptome was assembled from the sequenced reads generated from root tip and the mature root tissues of CS. Approximately 169 million reads were …

Black-Tailed Prairie Dog (Cynomys Ludovicianus) State-And-Transition Model For Loamy Ecological Sites In Mlra 62 In Custer State Park, South Dakota, Mark R. Hendrix

Electronic Theses and Dissertations

Black-tailed prairie dogs (Cynomys ludovicianus) are native burrowing rodents that occupy large areas in the shortgrass and mixed-grass prairies of the Northern Great Plains. They are an important component of these prairie systems due to their impacts on plant communities. Currently State-and-Transition models (STMs) for grassland Ecological Site Descriptions (ESDs) address grazing by livestock as a major factor affecting states and phases within states. Impacts from other grazers, such as prairie dogs, are either not addressed directly, or are included only in a transition to a generalized early seral state. There are, however, dramatic differences in plant communities …