Biology Commons^™

Effect Of Temperature And Genetic Structure On Adaptive Evolution At A Dynamic Range Edge In The North American Gypsy Moth (Lymantria Dispar L.), Trevor M. Faske

Theses and Dissertations

The study of biological invasions is not only essential to regulate their vast potential for ecological and economical harm, they offer a unique opportunity to study adaptive evolution in the context of recent range expansions into novel environments. The North American invasion of the gypsy moth, Lymantria dispar L., since its introduction in 1869 to Massachusetts, has expanded westward to Minnesota, northward to Canada, and southward to North Carolina. Fluctuating range dynamics at the southern invasive edge are heavily influenced by heat exposure over their optimal (supraoptimal) during the larval stage of development. We coupled genomic sequencing with reciprocal …

Characterizing The Role Of Key Planar Cell Polarity Pathway Components In Axon Guidance, Grayland W. Godfrey Ii

Theses and Dissertations

An essential process to the development of the neural network of the nervous system is axon guidance. The noncanonical Wnt/Planar Cell Polarity pathway has been identified as an integral component in controlling the projection of axons during axon guidance. Prickle, ROR1 and ROR2 are PCP related proteins that do not have clearly defined roles in the process. This study aims to use zebrafish CoPA neurons as a model to study the roles of Prickle, ROR1, and ROR2 in axon guidance. Using in situ hybridization, morpholino knockdown, and CRISPR/Cas9 loss of function experiments were able to identify ror1, ror2 and …

Zebrafish (Danio Rerio) As A Model For Orofacial Research, Kevin A. Ghaffari

Theses and Dissertations

Across species, the face and more specifically the mouth, serves as an essential facet of everyday life. Amongst humans the mouth serves as a tool for the ingestion of food, a marker for facial recognition and a medium for communication. In order for the mouth to properly form, a series of precise growth and fusion events are needed. In order to insure that these events are orchestrated properly is a wide array of signals, transcription factors and epigenetic regulators. Due to the needed precision of these events, congenital birth defects of the face such as cleft lip and cleft palate …

Effects Of Hydraulic Dredging And Vessel Operation On Atlantic Sturgeon Behavior In A Large Coastal River, Michael R. Barber

Theses and Dissertations

The tidal James River, a focus of VCU's Atlantic Sturgeon program, supports both commercial shipping and hydraulic dredging. These anthropogenic threats present documented but preventable sources of mortality to the endangered species. Using three separate VEMCO Positioning System (VPS) receiver arrays, spatial data of previously-tagged fish were collected. ArcGIS and Programita software were used to analyze fish spatial distributions in the presence and absence of potential threats, using additional data including automatic identification system (AIS) vessel locations, vessel passages compiled using camera footage, and dredge records provided by the US Army Corps of Engineers. The data showed a change in …

Carbon And Nitrogen Dynamics Of Anthropogenically Disturbed Seagrass Ecosystems, Alison Shepherd

Theses and Dissertations

As atmospheric CO2 concentrations continue to rise, understanding factors that influence size and longevity of carbon (C) pools within coastal and marine ecosystems (i.e., “blue carbon”) is critical. In 2013, the global average atmospheric CO2 concentration reached 396 ppm, which was the highest recorded level in the last 800,000 years. Recent research acknowledges the importance of “blue carbon” in the global C cycle, finding that these ecosystems capture up to 70% of organic C in the marine realm, rendering them one of the most efficient C sinks on the planet. Specifically, seagrass ecosystems are critically important to the global C …

Avian Communities In An Urbanizing Region: Abundance Patterns And Effects Of Local Habitat Features, John S. Brush

Theses and Dissertations

The Lower Rio Grande Valley of Texas has experience rapid population growth and increase of urban area since the mid-20th century. The goal of this thesis were to: 1) explore patterns of avian communities in suburban and remnant urban woodlands, with particular interest in native forest species, and 2) to assess how local habitat variables, such as number of native trees, affect avian communities in suburban habitats, and 3) provide recommendations to municipalities and homeowners to enhance urban habitats for birds. Results indicated that remnant urban woodlands provided habitat for common native forest bird species that otherwise avoided suburban habitats, …

Developing A Multimetric Index To Assess Resaca Ecosystem Health, Buford J. Lessley

Theses and Dissertations

As the only freshwater ecosystem in the lower Rio Grande Valley aside from the Rio itself, resacas are critical habitat for many species of flora and fauna. Old distributaries of the Rio Grande, resacas provided conveyance routes moving floodwater to the Laguna Madre. Today these wetlands are novel ecosystems and are artificially maintained. Urbanization and agriculture have lead to sedimentation, habitat loss, contaminants, poor water quality, and invasive species. The objective of this study was to assess and monitor resaca pools and to compose the Resaca Health Index (RHI) from selected indicators of ecosystem structure and function including leaf litter …

Sequencing Of The Complete Mitochondrial Genome Of Anastrepha Species, Francisco C. Rugama Ii

Theses and Dissertations

Several members of fruit flies in the vastly diverse Anastrepha (Schinner) genus (family Tephritidae), considered to be among the most important and devastating pests of vegetable and fruit crops, are distributed widely throughout the Americas. They attack several different kinds of fruit including citrus, which is of great economical importance in South Texas. The identification of these flies is based primarily on wing pattern and characteristics of the female genitalia, contrary to males, which cannot be distinguished at all. Misidentification of adults is a widespread problem, while identification at the larval stage is practically impossible. Currently, there are no published …

Calculating Evapotranspiration Of Arundo Donax Along The Rio Grande, Jose R. Escamilla Jr.

Theses and Dissertations

Invasive species have been recorded to cause large economic and ecological impacts on various ecosystems and their services. Locally, giant reed (Arundo donax L.), a woody grass native to the Mediterranean, adversely impacts riparian ecosystems in southwestern United States by aggressively displacing their native flora and fauna. Giant reed also has become a cause of concern for national water security, especially in water-limited areas of the arid southwestern United States. The main objective of this study is to provide the first, landscape-level estimates of water use by giant reed in the United States. Evapotranspiration was monitored using the eddy …

Modeling Reef-Coral Response To Climate Change, Christopher William Cacciapaglia

Theses and Dissertations

Coral reefs are one of the most diverse ecosystems on the planet. They provide goods and services to millions of people living in the coastal tropics. Recently, however, rising sea-surface temperatures have been threatening reef corals, causing episodes of thermal stress that lead to coral bleaching, mortality, and changes in reef composition. This increase in ocean temperature, along with the melting of glaciers and polar ice caps, is also causing an increase in sea level, which is threatening to ‘drown’ reefs that cannot keep up with sea-level rise. Some early models predicted that nearly all coral species would be unable …

Linking Transcriptional And Physiological Responses To High Light Stress In A Wild-Type And A Photomorphogenic Tomato Mutant, Jordyn Radke

Theses and Dissertations

Tomato (Solanum lycopersicon) is the leading vegetable crop worldwide and an important part of a healthy human diet. In this study we used Next-Generation Sequencing, metabolomics and gene ontologies to study the effects of high light stress on the photomorphogenic hp-2dg tomato mutant. Wild-type (cv. ‘Manapal’) and mutant plants were grown for six weeks under low light and transferred to high light for one week. Illumina-based RNA Sequencing was performed and analysis of differential gene expression identified over 650 transcripts that were strongly regulated by light intensity (FC>4, p2,p<0,01). HPLC analysis of tomato leaves showed differential accumulation of phenylpropanoid metabolites such as chlorogenic acid, rutin, and caffeoylglucaric acid which was strongly dependent on genotype and light condition. Our findings show insightful differences between the wildtype and the photomorphogenic mutant as well as novel genes involved in high light adaptation in plants.

The Effects Of Elevated Pco₂ And Temperature On The Embryonic Development, Larval Survivorship, Condition, Calcification, Morphology, And Behavior Of The Florida Stone Crab, Menippe Mercenaria, Philip Michael Gravinese

Theses and Dissertations

The emission of greenhouse gases into the atmosphere over the last century has increased atmospheric and oceanic temperatures, and has led to a decrease in oceanic pH. The increased ocean temperatures and reduced pH have been detrimental to marine life. In addition, Florida’s watersheds have suffered from decades of disrupted hydrology and diverted runoff, which has increased nutrients and changed coastal carbonate chemistry. Although the adult stages of many marine species are capable of tolerating fluctuations in environmental conditions (i.e., elevated pCO₂ tolerances to such conditions improve. and temperature), marine larvae that hatch in coastal habitats may not have the …

Effects Of Parasitism And Mite Control Methods On European Starling Development, Aderinsola Oluwasikemi Odetunde

Theses and Dissertations

Certain developmental stressors can lead to developmental trade-offs in young organisms. Hematophagous ectoparasites are a common stressor experienced by European starlings, and we wished to explore what aspects of an ectoparasite infestation drove trade-offs. The first part of this study was to test the hypothesis that blood loss was the sole mediator of trade-offs due to hematophagous ectoparasite infestation. We used nestlings that were exposed to mites in the nests, nestlings in mite-reduced nests experiencing supplementary blood loss, and nestlings in mite reduced nests with no supplementary blood loss. We also used a new heat treatment to reduce mites in …

Takeover On The Tallgrass Prairie: How Lespedeza Cuneata Establishes Dominance, Morgan Rae Walder

Theses and Dissertations

Invasion ecology aims to study mechanisms by which invasive species are able to enter, establish, and spread within an ecosystem. This study analyzed Darwin’s naturalization and the biotic resistance hypotheses as the most likely explanations for invasion by an exotic legume, Lespedeza cuneata, into a tallgrass prairie. Darwin’s naturalization hypothesis posits that exotic species are less able to establish in communities that have related species, because similarity in morphology and function promotes intense competition for resources. The biotic resistance hypothesis states that competitors, herbivores, and pathogens already present in the community limit the colonization, naturalization, and persistence of invaders, therefore …

Membrane Biophysics Of Listeria Monocytogenes: Analysis Of An Alternate Pathway Of Branched-Chain Fatty Acid Biosynthesis And Elasticity Of Fatty Acid Utilization, Laura E. Kuczek

Theses and Dissertations

The membrane homeostasis of the psychrotolerant foodborne pathogen Listeria monocytogenes involves maintaining fluidity in a range of different conditions by incorporation of specific branched-chain fatty acids (BCFAs). BCFAs are synthesized through a well-characterized pathway from branched-chain amino acids into short branched-chain acyl-CoAs followed by elongation by the FAS II system. Branched-chain alpha-keto acid dehydrogenase (Bkd) is a major player in this pathway. MOR401 is a transposon insertion mutant deficient in Bkd and has decreased membrane BFCAs. Low levels of BCFAs in L. monocytogenes are linked to diminished growth, less resistance to antimicrobials, and a severe reduction in virulence. Rescued growth …

A Gis Analysis Of Land Cover Effects On Water Systems: Nutrients And Algae In Stormwater Ponds, Nicole Lee Kappel

Theses and Dissertations

Anthropogenic land conversion is occurring rapidly and has the potential to impact our water quality. This study aims to explore the effect of watershed land characteristics on water quality within stormwater ponds (SWPs). Rapid land conversion is known to affect water quality of receiving water bodies, however not much is known about the effect of urbanization on SWPs. Geographic informational systems (GIS) was used to determine areas of land that drain into ponds. Water samples were collected and analyzed for total phosphorous, dissolved reactive phosphorous, nitrate, and ammonia. Algal pigment and percent cover measurements were taken in the field and …

Characterizing Mesophotic Reef Fish Communities At Five South Texas Relic Coral-Algal Banks, Linda Marie Jordan

Theses and Dissertations

The South Texas Banks are a mesophotic coral ecosystem (30-150m deep). Understanding the community structure, biodiversity and, geographic connectivity of the South Texas Banks is essential with increasing threats from climate change, ocean acidification, invasive species, and pollution. In this study, a remotely operated vehicle (ROV) was used to examine the fish communities at five of the South Texas Banks: Big Adam, Hospital, Mysterious, North Hospital, and Southern. Reef fish were identified to the lowest possible taxon and enumerated from ROV transect video footage. A total of 3,838 demersal and pelagic fishes were recorded representing 61 species in 22 families …

South Padre Island Beach Management: Assessment Of Dune Restoration, Shelby Rose Bessette

Theses and Dissertations

Dune restoration is a common method of increasing coastal resilience. A dune restoration program was initiated by the City of South Padre Island, TX in 2010 consisting primarily of plantings of Sea Oats, Uniola paniculata, and Bitter Panicum, Panicum amarum and has continued approximately annually thereafter. These restoration efforts were evaluated in this study by comparing dune ecological structure and function among reference sites and restoration plots ranging in age from 2 to 5 years. Plant and animal communities were examined using a combination of quadrat sampling, funnel traps, pit-falls and sweep nets. Soil organic content and soil electric …

The Effect Of Manganese (Mn) On Cell Proliferation And Migration In The Michigan Cancer Foundation-7 (Mcf-7) Human Breast Cancer Cell Line In Vitro, Justin Lloyd Wendel

Theses and Dissertations

Manganese (Mn) is a common environmental element necessary for mammalian physiological processes. However, dietary excess or deficiency can lead to detrimental health effects. Therefore, I investigated the effect Mn has on breast cancer progression in vitro. Utilizing MCF-7 breast cancer cells an MTT assay was performed to identify proliferative potential. After 5 days, results showed 100 nM manganese chloride (MnCl2) had a significant (p<0.01) increase in cell number over control. Using a scratch wound-healing assay, 100 nM MnCl2 was found to increase cellular motility as well as induce a possible change in morphology and cytoskeletal organization. Given Mn was shown to localize in the mitochondrial, we investigated Mn-induced ROS expression. 500 nM Mn significantly decreased (p<0.05) ROS levels. Collectively, I provide evidence that Mn may potentially drive less aggressive cancer cells towards a more invasive phenotype.

Geographic Range Limits In Salamanders: Interactions Between Physiological And Behavioral Systems, Timothy Allen Clay

Theses and Dissertations

Understanding the relationship between species distributions and their underlying mechanisms is a major question in ecology and evolutionary biology. The mechanisms involved and the degree to which they affect distributions vary among and within species. Examining the diversity of these mechanisms through behavioral, physiological, and integrative approaches can further our knowledge of the evolution of such traits and the maintenance of biodiversity and geographic distributions. Many of these traits may be conserved after speciation, therefore examination should be thorough, involve many species, and incorporate a phylogenetic approach. The salamanders in the genus Plethodon are an ideal system to test predictions …

P53 Alters The Cytotoxicity And Genotoxicity For Oxidized Graphene In Human B Lymphoblastoid Cells, Dayton Matthew Petibone

Theses and Dissertations

Widespread use of oxidized graphene nanomaterials in industry, medicine, and consumer products raises concern about potential adverse impacts on human health. The p53 tumor suppressor protein is crucial to maintaining cellular and genetic stability to prevent carcinogenesis. Here, we show that oxygen functionalized graphene (f-G) absorption and p53 functional status correlate with cytotoxicity and genotoxicity in human B-lymphoblastoid cells. Trends in f G absorption by were dose-dependent. Cells with functional p53 exposed to f-G arrested in G0/G1 phase of the cell cycle, suppressed f-G induced reactive oxygen species (ROS), and had elevated apoptosis. While compared to p53 competent cells, the …

Role Of Endoplasmic Reticulum Resident Proteins In Mediation Of Intrinsic Programmed Cell Death (Apoptosis), Surya Pramila Kilaparty

Theses and Dissertations

Inositol polyphosphates (InsPs) are signaling molecules that regulate various cellular processes including apoptosis. Among enzymes that metabolize InsPs, Multiple Inositol Polyphosphate Phosphatase1 (Minpp1) is the only enzyme located in the endoplasmic reticulum (ER). It dephosphorylates more phosphorylated InsPs to less phosphorylated InsPs in vitro. Changes in cellular InsPs are known to regulate apoptosis. Minpp1 is a member of the histidine acid phosphatase family of proteins with functional resemblance to phytases found in lower organisms. Its physiological function in higher animals is not clear. Besides its role in dephosphorylating InsPs, it has been shown to have mutase activity. This enzyme is …

Anal Fin Pigmentation In Brachyrhaphis Fishes Is Not Used For Sexual Mimicry, Kandace Mary Hugentobler

Theses and Dissertations

Pigmentation patterns can be used as a communication signal in a variety of taxa, and can convey information relative to sexual selection, dominance, and species identification. Pigmentation is also sometimes used in mimicry to deceive the signal receiver into thinking the signaler is something other than itself. Mimicry can occur in several contexts, including sexual interactions, where one sex mimics another. There are relatively few examples of species with females that mimic males. Proposed hypotheses to explain female mimicry of males are that mimicry is used to reduce male harassment or that mimicry is used to display dominance over other …

Phycotoxin Loads In Bottlenose Dolphins (Tursiops Truncatus) From The Indian River Lagoon Estuary System And Coastal Altlantic Waters, Florida: 2002-2011, Jeremy Alan Browning

Theses and Dissertations

Harmful algal blooms (HABs) are dramatic increases of algae that produce phycotoxins, and these toxins lead to subsequent neurological dysfunction with symptomatic illness leading, in extreme cases, to mass mortalities of marine mammals. This presents a conservation challenge since the frequency and severity of HABs are increasing on a global scale. Two HAB species that impact marine mammals residing in and utilizing an eastern Florida estuary and surrounding coastal Atlantic waters are Karenia brevis (K. brevis) and Pyrodinium bahamense (Pyrodinium); these HAB species produce the neurotoxins brevetoxin (PbTx) and saxitoxin (STX), respectively. These toxins are present at times in high …

Interactions Between Hiv-1 Tat And Tumor Suppressor P53, Kristen Lane Spotts

Theses and Dissertations

The most well studied cancer-related gene in history, p53, is responsible for protecting the integrity of the genome. A variety of different stresses are detected by p53 and its regulators, allowing for numerous post-translational modifications that activate p53. After activation p53 can then regulate transcription of a myriad downstream targets, resulting in either cell cycle arrest or apoptosis. One of the stress signals that activates p53 is viral infection in part through the induction of type-1 interferon. However some viruses, like the DNA tumor viruses have evolved factors capable of binding to p53 and inhibiting its ability to regulate its …

Individual Movement Rates Are Sufficient To Determine And Maintain Dynamic Spatial Positioning Within Uca Pugilator Herds, Eilea R. Knotts

Theses and Dissertations

Spatial location within aggregations (i.e. periphery, central) is of biological significance to gregarious animals. Because these positions are a potential consequence of consistent individual behavioral differences, or personality, a better understanding of potential mechanisms concerning personality is central to predicting an individuals’ location. To determine the effects of individual personality on the dynamic spatial positioning of Uca pugilator while herding, field data collection and agent-based modeling were employed. Individuals were assayed to establish their personalities and returned to the field for observation as a means of identifying location preference within selfish herds. There was a significant difference between the extreme …

Defensive Roles And Factors That Affect The Production Of Monoterpenes In Morella Cerifera, Florence C. Anoruo

Theses and Dissertations

Plants as sessile organisms encounter myriad biotic and abiotic challenges in their habitats. Pathogen and herbivore attack are among the prominent biotic challenges that plants face in their environment. Plants respond to these attacks by using chemical compounds including monoterpenes that are constitutively and inductively produced in some plants, and stored inside glands on their leaves. Among the abiotic factors that influence the production of defense compounds, especially monoterpenes are light intensity and nutrient availability.

The objectives of this dissertation are to 1) comprehend the defensive role of monoterpenes, specifically investigating the associational defense of a non-odorous species (Ilex vomitoria) …

Enhancing The Efficacy Of Thymidylate Synthase Inhibitors By Genetic Modulation Or Pharmacological Inhibition Of Bone Marrow Derived Cells In The Tumor Stroma, Nikeya Lashanna Tisdale

Theses and Dissertations

The impact of tumor associated stromal cells in tumor formation, progression, and response to therapy has led to a paradigm shift in cancer therapy. For many years, tumors were considered as a mass consisting only of actively proliferating cancer cells and therapies were design to target these cells. However, research in the last two decades has shown that tumors are not only comprised of a heterogeneous population of neoplastic cells, but they are also comprised of and infiltrated by a heterogeneous population of non-tumor cells that contribute to tumor progression and potentially affect the efficacy of tumor-directed chemotherapies. Tumors are …

The Cranial Morphology Of The Black-Footed Ferret: A Comparison Of Wild And Captive Specimens, Tyler Antonelli

Theses and Dissertations

The black-footed ferret (Mustela nigripes), a North American mustelid species, was once found abundantly throughout the Midwest until extreme decline in prairie dogs, the black-footed ferrets primary food source, brought the species to near-extinction. This resulted in the development of the Black-Footed Ferret Recovery Program which included bringing the entire species into captivity with the intention of breeding the species back to sufficient numbers to allow for successful reintroduction. While in captivity, many components of the ferrets’ health were accounted for, but the current study aims to address the effects that captivity may have had on the cranial morphology of …

Assessment Of The Probability Of Loggerhead Sea Turtle (Caretta Caretta) Recovery In The Northwest Atlantic Ocean Within 50 Years Of Federal And State Protection In The Us, Michael D. Arendt

Theses and Dissertations

Systematic implementation of sea turtle conservation measures have occurred in the U.S. since the 1970’s. As such, this dissertation assessed the probability that loggerhead sea turtles (Caretta caretta) in the NW Atlantic will meet or exceed recovery criteria in the minimum timeframe (i.e., 50 years) specified by the Recovery Plan. Mathematical modeling (Chapter 1) of a theoretical population resembling an important nesting assemblage in a stochastic environment for 200 years revealed broad (<20k to >106k) fluctuation in annual nest counts without extinction, as well as strong contemporary environmental influence on annual nest counts. Modeling also substantiated the importance of monitoring the …