Biology Commons^™

A Comprehensive Analysis Of Different Types Of Databases Reveals That Cdh1 Mrna And E-Cadherin Protein Are Not Downregulated In Most Carcinoma Tissues And Carcinoma Cell Lines, Brihget Sicairos, Shorna Alam, Yuchun Du

Biological Sciences Faculty Publications and Presentations

Background

The CDH1 gene codes for the epithelial-cadherin (E-cad) protein, which is embedded in the plasma membrane of epithelial cells to form adherens junctions. E-cad is known to be essential for maintaining the integrity of epithelial tissues, and the loss of E-cad has been widely considered a hallmark of metastatic cancers enabling carcinoma cells to acquire the ability to migrate and invade nearby tissues. However, this conclusion has come under scrutiny.

Methods

To assess how CDH1 and E-cad expression changes during cancer progression, we analyzed multiple large transcriptomics, proteomics, and immunohistochemistry datasets on clinical cancer samples and cancer cell lines …

Assessing Stream Ecosystem Structure And Function In An Urban Canal And Logan River In Logan, Utah, Ellie Smith-Eskridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans have constructed canals to support agriculture, to mitigate flooding, and to discharge stormwater, especially in the Intermountain West. These canals are common in Cache Valley, where they receive flows from the Logan River during summer months. However, the ecological structure (e.g., water quality, freshwater invertebrates) and function (e.g., leaf decomposition) of these canals remains largely unknown. Studying ecosystem structure and function of these urban waterways is important because it can inform us of the health of these waterways.

My research had three objectives. First, I compared water chemistry, invertebrate assemblages, and leaf decomposition in an urban canal and the …

Fractally Sampling Diversity-Environment Relationships To Understand Plant Assemblage Health Across Spatial Scales, Elizabeth G. Simpson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans influence the health of ecosystems and rely on healthy ecosystems to support their livelihoods and well-being. By looking at how the parts of ecosystems interact we can understand and improve ecosystem health. Ecosystem interactions change across spatial scales or different size patches of area. For example, individual organisms interact with each other at small spatial scales, while at large spatial scales, communities of organisms interact with weather conditions. However, many research studies do not look at how ecosystem interactions change across spatial scales. To address this gap in ecological research, I use a fractal sampling design which samples at …

We Travel Together: Examining The Drivers And Functions Of Animal Movement In Biotic Seed Dispersal, Binod Borah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants and frugivorous animals exist in mutually beneficial relations, as these animals feed on fruits, ingest the seeds, and carry them away from the parent trees. Such dispersion of seeds over space helps them colonize new habitats, escape high mortality rates near their parent trees, and avoid competition with conspecifics. Therefore, seed dispersing animal movement can be critical for the persistence of plant populations. Yet what drives such seed disperser movement is often less understood and how it affects seed dispersal is little explored. In my dissertation, I investigate multiple drivers of seed disperser movement, link movement to potential seed …

Status And Enhancement Of Trissolcus Japonicus (Ashmead) (Hymenoptera: Scelionidae) For Biological Control Of Halyomorpha Halys (Stål) (Hemiptera: Pentatomidae) In Northern Utah, Kate V. Richardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The invasive brown marmorated stink bug (BMSB) is a major insect pest that invades human structures causing nuisance issues and attacks numerous fruit and vegetable crops in Northern America. As this pest threatens $23 billion worth of specialty and agricultural crops in the U.S. and is difficult to manage due to insecticide resistance, control practices such as the use of biological control through egg parasitoid wasps are critical. In its native range of Asia, BMSB populations are controlled primarily by members of the Trissolcus genus such as the samurai wasp, but U.S. native wasps have demonstrated low success of BMSB …

Consequences Of Host Life Cycles For Symbiont Genome Evolution, Ashley Elizabeth Dederich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aphids are small insects that feed exclusively on plant sap, a notoriously low source of nutrients due to the high sugar content and low amino acid content. To make up for these deficiencies in nutrition, aphids harbor Buchnera aphidicola, a bacterial endosymbiont that resides in a specialized organ called the bacteriome. B. aphidicola provides essential amino acids and vitamins for the aphid in exchange for a safe place to live. Over the course of the symbiosis (established 160 million years ago), B. aphidicola has lost much of its genome, including essential genes for cell envelope synthesis, DNA replication and …

Biochemical Characterization Of Fsa1572 From Fervidibacter Sacchari, The First Hyperthermophilic Gh50 With Β-1, 4-Glucanase Activity, Jonathan Covington

UNLV Theses, Dissertations, Professional Papers, and Capstones

The bacterium Fervidibacter sacchari is an aerobic hyperthermophile that catabolizes various polysaccharides and is the only cultivated member of the class Fervidibacteria within the phylum Armatimonadota. Among its glycoside hydrolase (GH) cache is an enzyme from GH family 50 (GH50), an understudied family with only 25 characterized representatives and two known activities from 1,518 predicted members in the Carbohydrate-Active EnZyme (CAZy) Database. Here, we expressed, purified, and functionally characterized an extracellular GH50 from F. sacchari called Fsa1572. Using colorimetric assays, we show it has novel β-1,4-glucanase activity and only weak agarose activity that is typical for GH50 enzymes. The purified …

Long-Range Regulation By The Shigella Virulence Gene Regulator, Virb, Cody Cris

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nucleoid-structuring proteins (NSPs) in bacterial cells can exert gene regulatory effects over great distances on DNA. This contrasts with the traditional view of bacterial transcriptional regulation, where transcription factors bind cis-acting regulatory sites proximal (<250 bp) to promoters to influence gene expression. In Shigella species, the histone-like nucleoid-structuring protein (H-NS) transcriptionally silences many genes on the large (~220 kb) virulence plasmid. During host colonization, however, silencing by H-NS is alleviated by the anti-silencer protein, VirB, which remodels the H-NS:DNA complex. This transcriptional anti-silencing is mediated by VirB:DNA interactions and the modulation of DNA supercoiling, which lead to the up-regulation of virulence genes. VirB is a central regulator of Shigella virulence, but the mechanistic basis for transcriptional regulation is incompletely characterized. Here, I focus on the potential for VirB to regulate transcription from remotely located DNA binding sites. Employing complementary in vivo approaches, I assessed the spatial stringency of the VirB binding site and elucidated how varying cellular VirB levels impacts regulation over different distances. I also evaluated how a molecular roadblock on DNA influences remote regulation by VirB. Additionally, I developed control tools to validate the ability of VirB to spread along DNA, an activity of VirB that putatively drives transcriptional regulation. These data are consistent with transcriptional anti-silencing being driven by VirB spreading along DNA. Overall, these findings highlight how VirB is not a conventional transcriptional regulator and broaden our perspective on transcriptional control in bacteria. Furthermore, this work contributes to our understanding of long-range gene regulatory effects, which are frequently overlooked and poorly characterized in bacteria.

Desert Spring Prokaryotes And Benthic Macroinvertebrates: Geological And Ecological Controls, Ariel D. Friel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Desert springs are aquatic oases, being considered among the most diverse and imperiled ecosystems on Earth. Despite the ecological significance and threatened status of desert springs, few studies have surveyed the microorganisms in these systems or their interactions with other community members. The primary goal of this dissertation was to describe the major controls influencing the community ecology of prokaryotic and BMI communities in cold- and moderate-temperature desert springs of the southern hydrographic Great Basin. Chapter 1 provides a broad overview of spring ecosystems and of each chapter included in this dissertation. Chapter 2 documents the first-ever, regional-scale survey of …

Poop! There It Is! Anti-Germinants And Biological Variables As Modulators Of Clostridioides Difficile Infection (Cdi), Jacqueline Renee Phan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridioides difficile infection (CDI) is a major cause of antibiotic-associated diarrhea. Due to its insidious nature, the Centers for Disease Control and Prevention (CDC) has declared CDI an urgent threat. A key characteristic of C. difficile is its ability to form dormant spores that act as the infectious vehicles for disease. In the gut, spores recognize bile salts to germinate into toxin-producing cells.Dysbiosis of the gut microbiome is a key factor in allowing the C. difficile spores to germinate. Normal gut microbiota naturally protects from CDI. However, biological variables such as diet and sex have been found to modulate to …

The Effects Of Habitat Isolation On Fine-Scale Genetic And Geographic Structure Of Populations Of Two Threatened Endemic Insects In Southern Nevada, Pseudocotalpa Giulianii And Icaricia Shasta Charlestonensis, Kristen Tovar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Assessing the role geographic isolation and ecological specialization have on phylogeographic patterns contributes to our understanding of the evolutionary history of a species and the processes that erode genetic diversity. I used mitochondrial and nuclear genomic sequences to assess whether habitat isolation has shaped the fine-scale patterns of present-day genetic structure and diversity in two threatened insect species endemic to southern Nevada. Pseudocotalpa giulianii (Coleoptera; Scarabaeidae) is a dune obligate scarab beetle endemic to only two small, isolated sand dunes in Nye County, Nevada, with a usable habitat of less than 4.2 km sq that is impacted by on-going degradation. …

Optimizing Resin Infiltration Treatment Of Post-Orthodontic White Spot Lesions By Increasing Infiltrant Penetration Duration — In Vitro Study, Hahnnah Park

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: This study focuses on evaluating the effect of increasing duration allowed for resin infiltrant penetration in improving the aesthetic outcome of resin infiltration treatment. Additional investigations into repeat treatment and long-term stability were also conducted. Artifically created white spot lesions were induced on one hundred extracted teeth made up of either incisors or canines. Teeth were divided into enamel and dentin groups depending on the extent of the lesion and then further subdivided into varying treatment protocol groups: 3-minute, 6-minute, and 9-minute penetration time. Teeth were thermocycled for one clinical year and then divided into a repeat treatment and …

Examining Transcriptional Regulators During Muscle Development In Drosophila Melanogaster, Chaamy Yapa

Student Theses and Dissertations

In Drosophila melanogaster embryos, a distinct approach to study the transcriptional regulation is to examine the larval somatic muscle development. Transcription factors are essential regulatory proteins that help to control gene expression and respond to signaling pathways and various cues. Today, there are at least twenty transcription factors that have been discovered to contribute to the development of the 30 distinct larval somatic muscles in each abdominal hemisegment of Drosophila melanogaster. Several studies have already been conducted on muscle regulatory transcription factors including midline and apterous. These transcription factors were shown to control the development of muscles through mutant …

The Effects Of Glycolytic Mutations In Drosophila Melanogaster Muscle Development, Coco Lim

Student Theses and Dissertations

Muscle atrophy, or muscle wasting, is caused due to lack of physical activity for an extended period of time, due to muscle diseases (such as muscle dystrophies), cancer chemotherapies, and aging. It is also extensively found on astronauts after spaceflight, particularly missions of long durations. Muscle cells are dependent on different metabolic pathways to optimize Adenosine triphosphate (ATP) production to compensate for muscle exertion. Glycolysis converts glucose into ATP producing pyruvate, which can be sent into the citric acid cycle or converted to lactate (lactic acid). Muscles preferentially use lactate production, despite the fact that fewer molecules of ATP are …

Transmission And The Evolution Of Diseases Caused By Chlamydia Trachomatis, Sars-Cov-2, And Plasmodium Species., Nathan Steffens

Electronic Theses and Dissertations

Principles of natural selection have proven valuable for explaining why pathogens cause the diseases that they do. In theory, the evolved level of host exploitation should reflect how dependent a pathogen is on host health for transmission. This dependency is shaped by transmission mode and transmission opportunity, which should therefore be predictors of disease manifestations. In this dissertation, I apply these principles to investigations of depression in Chlamydia trachomatis and virulence of SARS-COV-2 and Plasmodium species. This dissertation has five chapters. In chapter I, I describe the theoretical foundation of my dissertation research. I also briefly introduce each study system. …

Microbial Associations With Metcalf's Tryonia, Tryonia Metcalfi (Gastropoda: Cochliopidae), An Imperiled Ciénega Endemic, Russell L. Minton, Kathryn E. Perez

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The Chihuahuan Desert swamps are a hotspot for imperiled organisms including freshwater springsnails and bacteria. Many of these taxa are endemic to the desert and to the individual waterbodies where they occur. Efforts to conserve diversity in these threatened areas must account for the life history of the organisms, but also interactions between organisms including microbes. We documented the microbial assemblage associated with Tryonia metcalfi, a critically imperiled freshwater snail endemic to a ciénega system in western Texas. We identified 14 bacterial families in our snail samples and determined a core assemblage of 19 bacterial taxa (4 of which …

Investigating Stormwater Parameters From Runoff On East Tennessee State University Campus, Abby Mciver, Dr. Joseph R. Bidwell

Undergraduate Honors Theses

Climate change has caused an increase in extreme rain events and flooding in certain regions across the globe. During rain events, water flows over impervious surfaces structures such as roads and sidewalks, picking up contaminants such as metals, fertilizers and other nutrients, and various organics that which may impact organisms in such as streams, river, and lakes. Previous work has found significant differences in survival of organisms that were exposed to contaminated stormwater runoff. This study investigated stormwater chemistry parameters at collection sites on the East Tennessee State University campus. Sites were selected based on the extent of human interaction …

Multi-Factor Disturbance Regimes Drive Soil Fungal Community Composition Across A Southwestern Us Riparian Cottonwood Landscape, Rich Wagner

Biology ETDs

In southwestern US riparian cottonwood forests, anthropogenic changes have replaced the structuring force of seasonal flooding with novel multi-factor disturbance regimes, driving these ecosystems to new states. While the impetus for restoration is high, little attention has been paid to understanding belowground feedbacks from these new drivers. Using high-throughput sequencing of environmental DNA, we compared the impacts of fires, exotic plants, restoration practices and lower levels of disturbance on soil fungal community composition and diversity across a riparian cottonwood landscape in New Mexico. We focused on mycorrhizal fungi for the benefits they may confer upon cottonwoods. We found that along …

Transcriptional Regulation Of Stem Cell Function In The Drosophila Central Nervous System, Amalia S. Parra

Biology ETDs

Development of multicellular organisms depends on coordination of various molecular mechanisms to ensure proper tissue size and structure. This is accomplished through intrinsic and extrinsic cues that regulate cell growth and proliferation both spatially and temporally. These well-coordinated signals are present from early developmental stages and remain active throughout development to ensure tissue structure is appropriate for function. This is particularly important in early cell types that form specialized lineages such as stem cells or those found throughout the body such as epithelia. While much progress has been made in understanding growth regulatory mechanisms, several fundamental aspects remain unknown. This …

Investigation Into The Roles Of Esxa N-Α-Acetylation In Pathogenesis Of Mycobacterium Tuberculosis And Potential Host-Binding Proteins, Javier Aguilera

Open Access Theses & Dissertations

EsxA (6-kDa early secreted antigenic target, ESAT-6) is a critical virulence factor of Mycobacterium tuberculosis (Mtb). EsxA is secreted in a heterodimer with EsxB (10-kDa culture filtrate protein, CFP-10) through the Type VII secretion system of Mtb, called ESX-1. The dissociation of EsxA and EsxB heterodimer (EsxA:B), upon acidification, is required for EsxA to penetrate into the phagosomal membranes, which has been implicated in Mtb translocation from the phagosome to the cytosol. However, the mechanism of EsxA:B dissociation is not clear. In this study, we investigated the role of N-α-acetylation of EsxA in the heterodimer dissociation, mycobacterial cytosolic translocation, and …

Bone Metabolite Profile Differs Between Normal And Femur Head Necrosis (Fhn/Bco)-Affected Broilers: Implications For Dysregulated Metabolic Cascades In Fhn Pathophysiology, Alison Ramser, Rachel Hawken, Elizabeth Greene, Ron Okimoto, Brenda Flack, Courtney J. Christopher, Shawn R. Campagna, Sami Dridi

Poultry Science Faculty Publications and Presentations

Femur head necrosis (FHN), also known as bacterial chondronecrosis with osteomyelitis (BCO), has remained an animal welfare and production concern for modern broilers regardless of efforts to select against it in primary breeder flocks. Characterized by the bacterial infection of weak bone, FHN has been found in birds without clinical lameness and remains only detectable via necropsy. This presents an opportunity to utilize untargeted metabolomics to elucidate potential non-invasive biomarkers and key causative pathways involved in FHN pathology. The current study used ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC–HRMS) and identified a total of 152 metabolites. Mean intensity …

Investigating The Nectar Preferences Of Bumblebees While Foraging: Are Total Responses A Good Metric?, Alexander Entwistle, Becky Hansis-O'Neill, Aimee Dunlap Dr

Undergraduate Research Symposium

The declining population of bumblebees worldwide poses an unmistakable threat to ecological systems and biodiversity. Therefore, a deep understanding of the factors at play when bees are foraging is crucial to conservation efforts. This research aims to explore the energy that foraging bumblebees are willing to expend at a known food source after the food has stopped, and if these responses reveal sugar concentration preferences. In this experiment a novel approach was used, adapted from psychology research on addiction, to measure bee’s preferences for different concentration of sugar-water (nectar). First, how many rewards the bees earned if they were given …

Does A Bumblebee’S Size Influence Foraging Behavior?, Alametta Thompson-Hinton, Becky Hansis-O'Neill, Aimee Dunlap Dr

Undergraduate Research Symposium

Current studies of Bumblebees (Bombus impatiens) have shown that they prefer plants that have a higher concentration of sugar over those that are of a lower concentration. However, there is little research analyzing the impact of the size difference amongst bumblebee foragers. During our experiment, we tested if larger bumblebees demonstrate a propensity to pursue nectar rewards more frequently compared to smaller bees. We hypothesized that the smaller bumblebees would forage less than the larger ones under a fixed ratio and three different sugar concentrations. We found that our hypothesis was partly correct: smaller bees initially earned fewer rewards, …

Amongst The Trails: Analysis Of A Small Predator Location Survey, Jesse Laseter

Undergraduate Research Symposium

Small predators, despite their size, play pivotal roles in ecosystem balance. Primarily, through their predation of herbivores, they indirectly benefit native plant communities. By reducing the damage from herbivory, herbaceous plants have a higher likelihood to thrive and proliferate. This is crucial in the restoration of Missouri glades. However, for small predators to achieve this, they rely heavily on their ability to navigate through their environment. One factor that may influence their ability to traverse their environment is recreational trails. Trails can cause habitat fragmentation by disconnecting one larger area into two. Trails also have significantly different microclimate than the …

Extracting And Analyzing Body Pitch Frequency To Test For Mimetic Convergence In Ithomiine Butterflies, Lauren Kim, Angela Robles, Victoria Valenzuela

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Speyeria Beyond The Bay Area: Utility Of Dna Barcode In A Region Known For Mixed Phenotypes, Lorraine S. Lee, Alan H. Lin, Karine T. Nguyen, Jiwon Woo

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Oak Apple Gall Natural History And Elementary Citizen Science, Christina Flores

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Exploration Of Spider Silk Assembly, Natalie Naseib, Joshua Navarro, Nadia Duong, Seohyun Lee, Daniel Kim, Danbir Somal, Sevak Manucharyan, Josephine Kim, Seha Park, Alice Lan, Karen Kwong, Mason Tri

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Study Of The Assembly Trigger For Spider Silk Proteins, Katina Zhu, Amanda Lee, Megan Lau, Sungkyung Lee, Kaden Chen, Katherine Yoo, David Eum, Daniel Eum, Austin Cho, Jiho Choi

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Eardrum Tuning Of The Túngara Frog, Robert A. Wong, Mary Paduano, Justine Tang, Betty Lee, Trisha Vo, Mark Morozumi, Marcos Gridi-Papp

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.