Biology Commons^™

Effects Of Arbuscular Mycorrhizal Fungi (Amf) On Growth And Herbivore Defenses In Sorghum Sudangrass (Sorghum X Drummondii), Jasleen Kaur

Theses and Dissertations

Chapter 2: In this chapter we have examined the role of trichomes in plant stress biology, reviewed the studies on herbivore X trichome interactions, and their role in plant defences. Ultimately, we have proposed new areas of research for future work.

Chapter 3: In this chapter, we examined whether AMF has cascading effects on insect community dynamics through attraction/repulsion of beneficial and damaging insects using Sorghum-sudangrass (Sorghum x drummondii), either inoculated with commercial AMF mix or left as control in lab and field experiments. Our results suggest positive effects of AMF on plant growth, and a lower initial incidence of …

Tobacco Enhances Bacterial-Induced Periodontal Bone Loss In Mice., Mina Iskander

Electronic Theses and Dissertations

Background: Tobacco smoking is the leading environmental risk factor for periodontal diseases. Delineation of the mechanisms underlying tobacco-induced or exacerbated periodontitis is hampered by the lack of an appropriate and reliable animal model. Hypothesis: We hypothesized that Porphyromonas-gingivalis-infected, cigarette smoke-exposed mice would represent reproducible models of acute (ligature model) and chronic (oral gavage model) tobacco-enhanced periodontitis that reflect multiple aspects of the disease noted in human smokers. Methods: In a chronic oral gavage disease model, Balb/c mice (6-8 weeks, 4 groups of n = 6 per group) were exposed to smoke produced by a Teague-10 smoking machine from 1R6F research …

Characteristics And Spatial Heterogeneity Of Prescribed Fire Behavior In North Dakota Grasslands, Megan Elizabeth Zopfi

Theses and Dissertations

Fire is a critical physical and chemical process required to sustain many grassland ecosystems. In North America, observations of grassland fire behavior in warm-season, southern grasslands are commonly used in fire behavior modeling efforts across the Great Plains. However, grasslands of the northern Great Plains contain a greater component of cool-season vegetation that may generate different fire behavior. To further our understanding of prescribed fire behavior in North Dakota grasslands, we quantified fuel, weather, and fire behavior characteristics associated with 27 prescribed fires conducted across three sites in North Dakota. We sampled 27 points on each fire arranged into a …

Toxoplasma Gondii Requires Its Plant-Like Heme Biosynthesis Pathway For Infection, Amy Bergmann, Kathleen Floyd, Melanie Key, Carly Dameron, Kerrick C. Rees, L. Brock Thornton, Daniel C. Whitehead, Iqbal Hamza, Zhicheng Dou

Publications

Heme, an iron-containing organic ring, is essential for virtually all living organisms by serving as a prosthetic group in proteins that function in diverse cellular activities ranging from diatomic gas transport and sensing, to mitochondrial respiration, to detoxification. Cellular heme levels in microbial pathogens can be a composite of endogenous de novo synthesis or exogenous uptake of heme or heme synthesis intermediates. Intracellular pathogenic microbes switch routes for heme supply when heme availability fluctuates in their replicative environment throughout infection. Here, we show that Toxoplasma gondii, an obligate intracellular human pathogen, encodes a functional heme biosynthesis pathway. A chloroplast-derived …

Chronoecology Of A Cave-Dwelling Orb-Weaver Spider, Meta Ovalis (Araneae: Tetragnathidae), Rebecca Steele

Electronic Theses and Dissertations

Circadian clocks enable coordination of essential biological and metabolic processes in relation to the 24-hour light cycle. However, there are many habitats that are not subject to this light cycle, such as the deep sea, arctic regions, and cave systems. This study analyzes the circadian pattern of isolated populations of a subterranean spider, Meta ovalis from two Tennessee caves and five Indiana caves. Locomotor activity was recorded with TriKinetics LAM50 Locomotor Activity Monitor under a 12-hour light (L), 12-hour dark (D) (LD 12:12) cycle preceding total darkness (DD). Significant differences were found within and among populations found in Tennessee cave …

First Report Of Sex Chromosomes In Night Lizards (Scincoidea: Xantusiidae), Stuart V. Nielsen, Brendan John Pinto, IráN Andira Guzmán-Méndez, Tony Gamble

Biological Sciences Faculty Research and Publications

Squamate reptiles (lizards, snakes, and amphibians) are an outstanding group for studying sex chromosome evolution—they are old, speciose, geographically widespread, and exhibit myriad sex-determining modes. Yet, the vast majority of squamate species lack heteromorphic sex chromosomes. Cataloging the sex chromosome systems of species lacking easily identifiable, heteromorphic sex chromosomes, therefore, is essential before we are to fully understand the evolution of vertebrate sex chromosomes. Here, we use restriction site-associated DNA sequencing (RADseq) to classify the sex chromosome system of the granite night lizard, Xantusia henshawi. RADseq is an effective alternative to traditional cytogenetic methods for determining a species’ sex …

Parallel Evolution Of Tobramycin Resistance Across Species And Environments, Michelle R. Scribner, Alfonso Santos-Lopez, Christopher Marshall, Christopher Deitrick, Vaughn S. Cooper

Biological Sciences Faculty Research and Publications

Different species exposed to a common stress may adapt by mutations in shared pathways or in unique systems, depending on how past environments have molded their genomes. Understanding how diverse bacterial pathogens evolve in response to an antimicrobial treatment is a pressing example of this problem, where discovery of molecular parallelism could lead to clinically useful predictions. Evolution experiments with pathogens in environments containing antibiotics, combined with periodic whole-population genome sequencing, can be used to identify many contending routes to antimicrobial resistance. We separately propagated two clinically relevant Gram-negative pathogens, Pseudomonas aeruginosa and Acinetobacter baumannii, in increasing concentrations of …

The Importance Of Ile716 Toward The Mutagenicity Of 8-Oxo-2’-Deoxyguanosine With Bacillus Fragment Dna Polymerase, Michelle L. Hamm, Anarosa A. Garcia, Rachel Gilbert, Manavi Johri, Miranda Ricart, Samantha L. Sholes, Laura A. Murray-Nerger, Eugene Y. Wu

Biology Faculty Publications

8-oxo-2’-deoxyguanosine (OdG) is a prominent DNA lesion that can direct the incorporation of dCTP or dATP during replication. As the latter reaction can lead to mutation, the ratio of dCTP/dATP incorporation can significantly affect the mutagenic potential of OdG. Previous work with the A-family polymerase BF and seven analogues of OdG identified a major groove amino acid, Ile716, which likely influences the dCTP/dATP incorporation ratio opposite OdG. To further probe the importance of this amino acid, dCTP and dATP incorporations opposite the same seven analogues were tested with two BF mutants, I716M and I716A. Results from these studies support the …

Impact Of Epa And Dha Supplementation And 15-Lox-1 Expression On Colitis And Colitis-Associated Colorectal Cancer, Jonathan Jaoude

Dissertations and Theses (Open Access)

Inflammatory bowel disease (IBD) patients not only suffer from colitis but also from increased morbidity and mortality of colitis-associated colorectal cancer (CAC). The enzyme 15-lipoxygenase-1 (15-LOX-1) is crucial to converting omega-3 fatty acid derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to resolvins, potent anti-inflammatory products. 15-LOX-1 effects on the conversion of EPA and DHA to resolvins that subsequently exert anti-inflammatory and anti-tumorigenic effects have received little attention. To address this knowledge gap, we hypothesize that 15-LOX-1 expression in colonic epithelial cells is essential for resolvin biosynthesis from EPA and DHA to modulate immunophenotype, limit inflammation, promote resolution, and help …

Understanding Intercellular Signaling During Lung Injury-Repair, Margo Patricia Cain

Dissertations and Theses (Open Access)

The mammalian lung is a complex system of specialized cell types with precise spatial organization designed to cooperate to perform gas exchange. These cell types together coordinate organ development, homeostasis, and repair after injury through signals either presented or secreted, known as ligands, to be received by receptors on the surface of another, or in some cases, the same cell. The alveolar region of the lung, the primary region of gas exchange, responds to various types of injuries with different lung repair mechanisms. In order to explore how the various cell types in the lung communicate to drive tissue repair …

The Tropical Seagrass Halophila Stipulacea: Reviewing What We Know From Its Native And Invasive Habitats, Alongside Identifying Knowledge Gaps, Gidon Winters, Sven Beer, Demian A. Willette, Inés G. Viana, Kelcie L. Chiquillo, Pedro Beca-Carretero, Betty Villamayor, Tomás Azcárate-García, Rachamim Shem-Tov, Bridget Mwabvu, Luciana Migliore, Alice Rotini, Michelle A. Oscar, Jonathan Belmaker, Inbal Gamliel, Ana Alexandre, Aschwin H. Engelen, Gabriele Procaccini, Gil Rilov

Biology Faculty Works

Halophila stipulacea is a small tropical seagrass, native to the Red Sea, Persian Gulf, and the Indian Ocean. It invaded the Mediterranean Sea 150 years ago as a Lessepsian migrant, but so far has remained in insulated, small populations across this basin. Surprisingly, in 2002 it was reported in the Caribbean Sea, where within less than two decades it spread to most of the Caribbean Island nations and reaching the South American continent. Unlike its invasion of Mediterranean, in the Caribbean H. stipulacea creates large, continuous populations in many areas. Reports from the Caribbean demonstrated the invasiveness of H. stipulacea …

Effects Of Management For Productivity On Adult Survival Of Snowy Plovers, Eleanor P. Gaines, Stephen J. Dinsmore, Michael T. Murphy

Biology Faculty Publications and Presentations

Understanding the factors contributing to variation in demographic parameters and their influences on population growth is fundamental to effective conservation of small populations, but this information is often not available. Among shorebirds, population growth is generally most sensitive to changes in adult survival so understanding the factors affecting this vital rate is important. We used a long‐term mark–resight dataset and Program MARK to examine the effect of management actions, initiated to improve nesting productivity, on adult survival in a threatened population of Snowy Plovers (Charadrius nivosus ) in Oregon, USA. Apparent adult survival averaged 0.71 ± 0.01 (SE), but …

Exposure Of Phlebotomus Argentipes To Alpha-Cypermethrin, Permethrin, And Ddt Using Cdc Bottle Bioassays To Assess Insecticide Susceptibility, Jacob Rex Andersen

Undergraduate Honors Capstone Projects

Background: Insecticide resistance for sand flies is a concern since sand flies are vectors for Leishmania spp. parasites which cause leishmaniasis affecting millions of people each year. The CDC bottle bioassay is used to assess resistance by comparing known insecticide diagnostic doses and diagnostic times from an insecticide-susceptible population. The objective of this study was to determine diagnostic doses and diagnostic times for α-cypermethrin and the lethal dose for 50% and 90% mortality for α-cypermethrin, permethrin, and DDT for Phlebotomus argentipes.

Methods: The CDC bottle bioassays were performed in 1,000 mL glass bottles with 15-25 sand flies from a laboratory …

Investigating The Localization Of Foxo Transcription Factors In Glioblastoma, Leetoria Hinojosa

Theses and Dissertations

The Phosphatidylinositol 3 Kinase (PI3K) pathway is an essential intracellular signaling pathway that regulates cellular growth, survival, and fate. Canonically, the activation of this pathway removes forkhead box subfamily O transcription factors (FOXO -1, -3, and -4) from the nucleus. However, in cancer cells such as glioblastoma multiforme, FOXO factors are at least in part nuclear despite the activation of the PI3K pathway. Previous research indicated that FOXO3 localization was not affected when the pathway was inhibited in breast cancer cells, which challenged the conventional paradigms for FOXO factor regulation. Therefore, we were interested in investigating the nuclear localization of …

Therapeutic Drug Monitoring Of Apixaban Using Chromogenic Kits, Brooke Vogel

Undergraduate Honors Theses

Apixaban is a novel oral anticoagulant that prevents clotting by directly inhibiting Factor Xa in the coagulation cascade. Due to its different pharmacokinetics, previous standards for testing anticoagulant concentrations are ineffective at measuring apixaban. In this study, Hyphen Biomed Biophen Direct Xa Inhibitor and Biophen Heparin chromogenic kits from Aniara Diagnostica were used along with a NanoDrop™ One/One^C Microvolume UV-Vis Spectrophotometer to see if either of these kits provide acceptable precision and accuracy for the quantification of apixaban in plasma samples, as well as if there is a significant difference in these two kits at varying concentrations of apixaban. …

Symbiosis And Immunity At The Tri-Kingdom Interface, Stephen Alexander Lazar

Theses and Dissertations

The rise in global sea-surface temperatures drastically and adversely impacts coral reefs worldwide through coral bleaching, diseases, and subsequent coral mortality. Corals become bleached by the expulsion of endo-symbiotic dinoflagellates, which reduces host pigmentation. Coral bleaching can also lead to enhanced disease prevalence immediately after thermal-stress and during the associated re-uptake of symbiotic dinoflagellates. This aspect has yet to be thoroughly investigated. A model system is necessary to study the relationships between symbiosis and disease that has sufficient flexibility to include a variety of host symbionts as well as pathogens. For this dissertation project, Exaiptasia pallida was investigated as a …

Glare Reduction By Dark Facial Markings And Bills In Birds, Clara Lebow

Electronic Theses and Dissertations

Avian facial plumage, bill coloration, and feather microstructure may serve one or more adaptive functions. Several researchers have proposed that dark eyestripes, bills, and facial masks aid in reducing glare, however, there have been relatively few tests of this hypothesis. Dark facial markings have been shown to have an adaptive glare-reduction function in recent field studies of a few species, but this hypothesis has never been tested in a broad multispecies analysis. It is likely that feather microstructure influences feather brightness and has an effect on the efficacy of glare reduction properties of feathers. I examined the link between dark …

Effects Of Nicotine On Contextual Fear Conditioning In Adult Zebrafish (Danio Rerio), Brianna Fann

Undergraduate Theses and Capstone Projects

The goal of this experiment was to investigate the effects of nicotine in fear-conditioned zebrafish. Fear was analyzed by the presence of freezing, which was defined as the absence of movement for at least two consecutive seconds, excepting gill-related or ocular motions. Zebrafish have been used as subjects in many experiments to understand the effects of drugs on behavioral mecahnisms, but their memory processes have not been extensively studied. The present experiment investigated whether or not nicotine, given immediately after contextual fear conditioning, enhanced memory consolidation. Zebrafish were randomly categorized into two groups: placebo and high-dose nicotine (100mg/L). Individual fish …

Rainbow Trout (Oncorhynchus Mykiss) Movement And Mortality In The Flat Brook-Roy Catch And Release Section Of New Jersey, Christopher J. Shea

Theses, Dissertations and Culminating Projects

Rainbow trout are a widely distributed species for recreational angling. The state of New Jersey has 14 streams in which the Bureau of Freshwater Fisheries stocks hatchery raised Rainbow Trout. This paper focuses on the Flatbrook-Roy catch and release section of the Big Flat Brook in northwest NJ. From 2012 to 2015, electrofishing surveys conducted by the NJDEP reported significantly less fish within the Flatbrook-Roy catch and release area, compared to the state’s other catch and release area in the South Branch of the Raritan River. This study was designed to investigate and understand the fate of the trout introduced …

Efficient Conditional Inactivation Of Rdh10 Reveals Important Role Of Retinoic Acid During Lung Branching Morphogenesis., Nhut Quang Huy Tran

Electronic Theses and Dissertations

Birth defects are complicated pathological processes. Many birth defects can be traced back to disrupted regulation of molecular signaling pathways during embryogenesis. One of the most important gene regulatory factors during embryo development is retinoic acid (RA). However, studying the specific roles of RA in each organ during embryogenesis in vivo is challenging. The Sandell laboratory has a conditional mutant mouse model that can potentially be used for studying the role of RA during embryogenesis by inducing stage-specific RA deficiency. This model allows retinol dehydrogenase 10 (Rdh10), a gene required for RA production, to be inactivated at a …

Allometric Scaling Laws Linking Biomass And Rooting Depth Vary Across Ontogeny And Functional Groups In Tropical Dry Forest Lianas And Trees, Chris M. Smith-Martin, Xiangtao Xu, David Medvigy, Stefan A. Schnitzer, Jennifer S. Powers

Biological Sciences Faculty Research and Publications

• There are two theories about how allocation of metabolic products occurs. The allometric biomass partitioning theory (APT) suggests that all plants follow common allometric scaling rules. The optimal partitioning theory (OPT) predicts that plants allocate more biomass to the organ capturing the most limiting resource.
• Whole-plant harvests of mature and juvenile tropical deciduous trees, evergreen trees, and lianas and model simulations were used to address the following knowledge gaps: (1) Do mature lianas comply with the APT scaling laws or do they invest less biomass in stems compared to trees? (2) Do juveniles follow the same allocation patterns as mature …

Reversible Inhibition Of Mycobacterial Dnab Protein Splicing By Zinc, Gabrielle Hardison

Honors College Theses

Inteins are emerging as post-translational regulatory elements, undergoing conditional protein splicing in response to a variety of environmental cues. Inteins are seamlessly removed by self-splicing from exteins, or flanking portions of the host protein, which they interrupt. DnaB of Mycobacterium smegmatis, a helicase essential for replication, harbors two inteins known as DnaBi1 and DnaBi2, each with discrete structural characteristics and insertion positions. DnaBi1 was used here to design a reporter system which links splicing with resistance to the antibiotic kanamycin. We built a construct that strictly requires catalytically active DnaBi1 for survival in the presence of kanamycin and used …

An Investigation Of The Impacts Of Traditional, Virtual, And Hybrid Biological Laboratories On College Students’ Achievement And Motivation To Learn Biology, Shavonda Jackson

Dissertations

Virtual courses function in a different manner than traditional courses, therefore they require teaching methods and assessment techniques geared specifically to maximize this learning experience. Internet-based learning and distance-education are no longer new concepts in the science field. Because of this, many collegiate biology programs have created courses that can be taken virtual or hybrid. A number of experimental studies have had great influence in terms of the effects and impacts of educational technology in relation to virtual laboratories.

However, not many studies emphasize the impact of hybrid laboratories on student achievement or assess students’ motivation to learn in a …

Herbivory Changes Soil Microbial Communities And Greenhouse Gas Fluxes In High-Latitude Wetlands, Karen M. Foley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Herbivory by migratory animals in high-latitude ecosystems is known to impact greenhouse gas emissions from soils. However, few studies quantify the relationships between changes herbivores make to plant communities and soil conditions, and the biological interactions soil organisms have with their environment that result in changes to greenhouse gas emissions. These relationships are important to understand because they capture important carbon-climate feedbacks that may have implications for climate change policy and land management decisions, especially since high-latitude systems are experiencing unprecedented changes in climate.

In the Yukon-Kuskokwim (Y-K) Delta in western Alaska, herbivory by migratory geese affects the magnitude of …

Characterization Of The Is200/Is605 Insertion Sequence Family In Halanaerobium Hydrogeniformans, Michael Sadler, Melanie R. Mormile, Ronald L. Frank

Biological Sciences Faculty Research & Creative Works

Mobile DNA elements play a significant evolutionary role by promoting genome plasticity. Insertion sequences are the smallest prokaryotic transposable elements. They are highly diverse elements, and the ability to accurately identify, annotate, and infer the full genomic impact of insertion sequences is lacking. Halanaerobium hydrogeniformans is a haloalkaliphilic bacterium with an abnormally high number of insertion sequences. One family, IS200/IS605, showed several interesting features distinct from other elements in this genome. Twenty-three loci harbor elements of this family in varying stages of decay, from nearly intact to an ends-only sequence. The loci were characterized with respect to two divergent open …

A Comparison Of Coyote Diets In Urban And Rural Habitats In The Piedmont Of South Carolina, Bethany Krug

Graduate Theses

With increasing rates of urban expansion, interactions between humans and wildlife become inevitable. These urban environments present novel situations to native species, frequently resulting in their displacement or extirpation. However, some species, often referred to as “urban adapters”, have thrived in these landscapes. Coyotes (Canis latrans) are a prime example of a species that has adapted to exploit urban habitats. Coyotes are omnivores with food choices ranging from small/medium mammals to invertebrates depending on habitat. With their recent range expansion into the Southeast, little is known of their behavioral ecology in the region, especially details relating to their diet. Macroscopic …

Construction Of A Target-Specific Crispr-Cas9 Vector For The Purpose Of Introducing Mutations Into The Fum1 Gene Of Fusarium Verticillioides, Jennifer Petsche

Honors Program Theses

In molecular biology, CRISPR-Cas9 is a useful gene editing tool that takes advantage of a powerful cleaving enzyme and DNA sequences found in prokaryotes. In this study, a target-specific CRISPR-Cas9 vector containing an RNA-guided Cas9 nuclease specific for the FUM1 gene was constructed for the purpose of introducing mutations into the FUM1 gene of Fusarium verticillioides. Plasmids pFC332 and pFC334 were isolated. A guide RNA sequence was designed and amplified using Polymerase Chain Reaction (PCR) with pFC334 as the template. Sticky ends were created through restriction enzyme digestion of pFC332. These pieces were combined using Uracil-Specific Excision Reagent (USER) …

Rapid Evolution Of Starvation Resistance In Drosophila: Physiological And Molecular Mechanisms, Austin Joseph Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Gibbs lab has maintained starvation-selected Drosophila melanogaster for >130 generations. These starvation-selected flies evolved an obese phenotype with a suite of physiological differences compared to control-fed flies. Previous studies have shown that long-term starvation-selected Drosophila contain more lipids, have lower metabolic rates and develop more slowly than controls. This dissertation encompasses 1) Examining the molecular mechanisms contributing to starvation resistance, 2) Functional validation of the candidate plin1 allele, and 3) Rapid physiological and genomic evolution in starvation-selected Drosophila.

Starvation-selected Drosophila survive starvation conditions much longer than control-fed flies. This study took a simple approach to identify possible differences in …

Can Desert Mosses Hide From Climate Change? The Ecophysiological Importance Of Habitat Buffering & Water Relations To A Keystone Biocrust Moss In The Mojave Desert, Theresa Ann Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Empirical and observational studies suggest a keystone biocrust moss, Syntrichia caninervis, may be sensitive to future climate change in the American Southwest due to its uniquely sensitive water relations that appear particularly challenged during summer hydration-desiccation cycles. However, the potential mitigating roles of habitat buffering, acclimatization, and winter recovery on the vulnerability of this species remain largely unexplored. I investigated potential abiotic and biotic resiliency factors driving summer stress resistance and recovery in S. caninervis along present-day aridity gradients in the Mojave Desert to strengthen the climate change vulnerability assessment for this species common to biocrusts of North America, northern …

Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey

Master's Theses

Aedes aegypti, the primary mosquito vector of the yellow fever virus, threatens global health by passing on this virus, as well as chikungunya, dengue, and Zika viruses. Through its natural tendency to live in highly urban areas and bite human hosts; understanding the factors that affect the historical and current range of the pest is invaluable (Gubler, 1998). Although these viruses are not normally found in the United States, lack of vaccinations and wide-spread presence of the mosquito could lead to these diseases being reintroduced with potentially devastating effects (Monath, 2001). To determine a partial historical range of A. aegypti …