Biology Commons^™

A Study Assessing Stress Induction Methods And Regulation Genes, As Well As Cellular Ultrastructure And Automated Image Analysis In Synechocystis Sp. Pcc 6803, Rebekah White

Theses and Dissertations

In the world of microorganisms, cyanobacteria are a uniquely skilled powerhouse. They participate in global nutrient and carbon cycling. They can photosynthesize, which allows them to use sunlight and carbon dioxide to produce cellular energy. However, photosynthesis involves a lot of molecular interactions where environmental stresses can interfere, increasing the chances of oxidative stress and nutrient imbalances that can amplify deleterious effects. One such stress, iron limitation, is well-studied and its responses in the cell are known. This study assesses the differences between responses when induced by two different iron limitation methods. Then, a specific stress response regulator DspA, also …

Using Rapid Protein Degradation To Determine The Effect Of Runx1 Loss-Of- Function On Dna Damage Accumulation And Repair., Jackriel Pina Morales

Theses and Dissertations

Germline mutations in RUNX1 are associated with familial platelet disorder with a predisposition to myeloid malignancy (RUNX1-FPDMM), in which patients present with low platelet counts,excessive bleeding and bruising, and an increased risk of Acute Myeloid Leukemia (AML)/Myelodysplastic Syndrome (MDS) development throughout their lifetime. To understand how these loss-of-function mutations in RUNX1 drive predispose to malignancy, it is important to develop a detailed understanding of the molecular basis of RUNX1 function. While RUNX1 is a transcription factor, preliminary data from our group and work from others suggests that RUNX1 also interacts with proteins that are critical for DNA damage …

Pipecolic Acid And Novel Insights Into Cerebral Malaria, Akua E. Mensah

Theses and Dissertations

Cerebral malaria (CM), a severe manifestation of Plasmodium infection, prompts our investigation into the nuanced role of pipecolic acid in its pathophysiology. To unravel the molecular intricacies, we conducted in vitro lysine labeling techniques of mice infected with P. berghei ANKA parasites, and human P. falciparum grown in vitro, aiming to discern the impact of Plasmodium on pipecolic acid production. Previous observations indicated an elevation in pipecolic acid levels correlating with neurological decline in children with CM. In our study, confirming elevated pipecolic acid presence in the plasma and brain tissues of CM patients and the animal model of CM, …

Foxo4 Impacts Akt In Glioblastoma Multiforme, David Uribe

Theses and Dissertations

Glioblastoma Multiforme (GBM) is an aggressive cancer with patients surviving 13 months on average after diagnosis. The PI3K-PKB/AKT pathway is conserved from flies to mammals. The PI3K signaling pathway aids in the growth and survival of tumor cells. Forkhead box transcription factors subclass O (FOXO1, FOXO3, and FOXO4) act as tumor suppressors in some contexts. In GBM, our group and others showed that FOXO transcription factors drive stem gene expression to promote growth and survival. We disrupted the FOXO4 gene in U87MG cells using CRISPR Cas9 genome editing and performed RNA-seq to identify targets of this …

Optimization Of Coral Restoration Along The Florida Reef Tract, Raymond Barry Banister

Theses and Dissertations

Historically, the reefs of Florida were dominated by two framework-building corals, Acropora cervicornis and A. palmata. However, these two populations have declined by 95% since the 1970s. The predominant contributors to the coral decline have been ocean warming and disease. In response to the decline, restoration organizations were established to improve survival, growth, and reproduction. Yet, there are gaps in current restoration practices and our knowledge of effective restoration techniques. This study uses large datasets to develop models that predict the most optimal locations for coral restoration in Florida and examines the relationships between the occurrence of wild acroporids …

Investigating The Antibacterial Properties Of Nanostructured Aluminum Surface, Quinshell Smith

Theses and Dissertations

Bacterial infections are a major public health concern. Bacterial infection can occur in any part of the body and can also cause the body to respond to its presence. Bacteria can be transferred to humans through water, food, air, and living vectors. The modes of transmission for bacterial infections are vectors, airborne, physical contact, and droplets. Current preventative measures have been put in place to combat this issue. These preventative measures include immunization of both animals and humans, personal hygiene measures, biocidal agents, and essential oils. Bacterial resistance has occurred due to these preventative measures being misused and overused. Bacteria …

Hormetic Modulation Of On Mtor Mitochondria Cross Talk For Mitigation Of Cellular Aging, Mahalakshmi R

Theses and Dissertations

Cellular aging is a gradual process involving structural and functional deterioration of cells. Mitochondria, the biological clock in cells, are known to play a crucial role in the progression of cell aging. According to the mitochondrial free radical theory of aging, oxidative phosphorylation in the mitochondria produces free radicals, such as, reactive oxygen species (ROS), which lead to oxidative stress in cells. This, in turn, results in mitochondrial dysregulation, and eventually causes degeneration of cellular components, thereby propagating cell aging. However, it is to be underscored that aging, at its core, is a multifaceted phenomenon that involves a number of …

Identification Of A Novel Target For Declustering Supernumerary Centrosomes In Triple Negative Breast Cancer, Priyanga J

Theses and Dissertations

Triple-negative breast cancer (TNBC) confers considerable interventional challenge owing to its massive heterogeneity, aggression and metastatic prowess. These facets are attributed to chromosomal instability (CIN), a feature consequent to TNBC cell’s ability to harbor more than two centrosomes (supernumerary centrosomes; SNCs).

In principle, if a normal cell possesses SNCs, uneven pull forces are generated consequent to multipolar spindle, which activates cellular surveillance. This ensures error-free mitosis by either repairing the error or, in an irreparable condition, driving cells to death. This averts the possibility of aneuploidy (fundamental to tumorigenesis).

Unfortunately, TNBC cells, despite harboring SNCs, have devised a survival strategy …

Impairment Of The Glial Phagolysosomal System Drives Prion-Like Propagation Of Huntington’S Disease, Graham Davis

Theses and Dissertations

The ability of glia to tightly regulate neuronal health and homeostasis in the CNS is conserved across species. Yet, despite the ability to degrade protein aggregates, glia are vulnerable to the accumulation of neurotoxic amyloid aggregates during neurodegenerative disease progress, and even exacerbate their spread. A developing narrative highlights glia as a double-edged sword in neurodegenerative diseases: initially capable of dynamically responding to amyloid aggregate-ladened dying neurons but also capable of inducing chronic inflammation and creating seeding-competent amyloid oligomers. Thus, uncovering the mechanisms that allow glia to control aggregate deposition while preventing the neurotoxic effects and seed generation is vital …

Symbiosis Under Stress: Unraveling The Interplay Of Ocean Acidification And Rising Temperatures On Acropora Samoensis (Staghorn Coral), Jerald William Smolkin

Theses and Dissertations

This experiment explores the response of marine organisms to the combined challenges of ocean acidification and rising temperatures, with a focus on coral reef ecosystems. As global climate change threatens profound declines in coral reefs, understanding the multifaceted impacts of these stressors becomes crucial. The study observes cellular changes in A. samoensis tissues in four different groups, including control, Temp, pH, and Temp and pH. Results indicate significant breakdown of membrane compartmentalization and cell junctions, with notable degradation and calcium carbonate crystallization in pH-stressed samples. Additionally, chlorophyll extraction data support coral bleaching due to the expulsion of zooxanthellae. These findings …

Interplay Between Rna Editing And Alternative Splicing Modulates Biophysical And Pharmacological Properties Of The Ion Channel Cav1.3, Willy Munyao

Theses and Dissertations

Alternative splicing and adenosine-to-inosine (A-to-I) RNA editing are post-transcriptional mechanisms that promote proteomic diversity in the brain. The impact of RNA editing on brain physiology is underscored by its association with the etiology and pathogenesis of various neurological and neurodegenerative diseases. Alternative splicing of exon 43 within the CaV1.3 C-terminus produces long (CaV1.3L) and short (CaV1.343S) variants exhibiting distinct gating and pharmacological properties. While the physiological role of CaV1.3 A-to-I RNA editing in brain function is still unfolding, recent findings indicate that unedited CaV1.3 channels display larger calcium influx and enhanced neuronal excitability, suggesting that A-to-I RNA editing may act …

Persistence Of Wastewater-Associated Antibiotic Resistant Bacteria In River Microcosms, Aoife P. Mahaney

Theses and Dissertations

The spread of antibiotic-resistant bacteria (ARB) associated with wastewater is a significant environmental concern, but little is known about the persistence and proliferation of these organisms in receiving water bodies after discharge. To address this knowledge gap, we performed a series of microcosm experiments in which river water was amended with either untreated or treated wastewater, and the abundance of viable ciprofloxacin-, Bactrim-, and erythromycin-resistant bacteria was monitored for 72 hours.

Both types of wastewater amendments increased the initial abundance of ARB compared to microcosms containing only river water. The increase was greatest with untreated wastewater, but that effect decreased …

An Investigation Into Splicing Variation And Expression Patterns Of Insulin-Like Peptide 4 (Ilp4) Within The Drosophila Genus, Zachary C. Griffith

Theses and Dissertations

The insulin-signaling pathway plays a crucial role in regulating metabolic homeostasis in both humans and insects. Dysregulation or mutation within this pathway can lead to various diseases, such as diabetes mellitus and insulin resistance. The insulin-like peptide 4 (ILP4) in Drosophila is an interesting subject for study due to its similarity to mammalian insulin and its role in regulating sugar metabolism. In this study, we investigate a novel splicing variation within the Drosophila takahashii Insulin-Like Peptide 4 (ILP4) gene. Our investigation identified a splicing variation found in four Drosophila species that introduces an additional codon in one isoform, resulting in …

Calcium Permeability Of Rat Trpv1 In A Close State When Expressed In Xenopus Laevis Oocytes, Zinnia Adhikary

Theses and Dissertations

Transient Receptor Potential V1 (TRPV1) is a nonselective cation channel, which is expressed in nociceptors/ pain detecting receptors. Activated by a wide variety of exogenous and endogenous physical and chemical stimuli such as heat, TRPV1 is involved in temperature detection, body temperature regulation, and pain perception. It is generally accepted that TRPV1's conductance to cations, including Ca2+, depends on its conformational change from a closed to an open state following gating. In the current study, I observed that the plasma membrane of Xenopus laevis oocytes, upon exogenous expression of rat TRPV1, exhibited weak permeability to Ca2+, as evidenced by the …

Searching For Novel Mutations That Regulates The Mouse Polycystin-2 (Trpp2) Ion Channel, Akhilraj Rajan Pillai

Theses and Dissertations

Polycystin-2 (PC2) is an ion channel belonging to the polycystin subfamily of the transient receptor potential (TRP) cation channel superfamily. Mutations in PC2 are associated with autosomal dominant polycystic kidney disease (ADPKD), one of the most common genetic diseases in humans. Despite extensive studies over the past decades, the role of PC2 in normal and ADPKD kidneys remains largely unknown, and the activation and regulation of this ion channel are elusive. To gain a better understanding of the structure and function of the mouse PC2 channel, this study focused on generating five pore mutations in a gain-of-function (GOF) mutant of …

An Exploratory Study Of The Effects Of Bis-Substituted Triazolium Bromide Salts On The Proliferation Of Wi-38 Lung Cells And H-1299 Lung Cancer Cells, Rakaiya Martin

Theses and Dissertations

Lung cancer is the leading cause of cancer deaths worldwide. The battle against this disease continues to challenge physicians and scientists daily, due to its various forms, treatments, and responses. Depending on the grade and stage of the disease, treatments can be extensive, encompassing surgery, chemotherapy, and radiation therapy. Though these therapeutics can prolong a patient’s life, they often have significant ramifications. For instance, radiation therapy has an extensive list of side effects, from organ damage to loss of fertility. These outcomes have driven scientists to explore the applicability of novel cancer treatments. Imidazolium and benzimidazolium salts have been shown …

Facilitative And Competitive Interactions Among Dune Grass Species In Monoculture And Polyculture Communities, Anne M. Sciolino

Theses and Dissertations

Coastal dunes are natural barriers between land and sea and are imperative to the protection and preservation of inland ecosystems and human infrastructure. However, due to global warming, seal level rise, and coastal development, coastal dunes are under constant threat of destruction. Restoration efforts have been implemented to rebuild the protective function of dunes through the planting of dune building grasses. Dune grasses build and maintain these vital sand dunes. However, little is known about facilitative and competitive relationships among the grasses. In order to maximize restoration efforts, research is needed to better understand the biotic interactions among restorative grass …

Evaluation Of Alternative Methods For Dna Recovery Of Compromised Skeletal Remains, Ciara N. Rhodes

Theses and Dissertations

Skeletal remains frequently serve as the sole source of genetic material available for developing a profile in cases concerning unidentified human remains or mass casualties. Nevertheless, as unidentified skeletal remains age and are exposed to uncontrolled environmental conditions, the success rates of conventional methods of bone analysis diminish significantly. The physical and mechanical processing of skeletal remains into fine powder for DNA isolation and downstream analysis can substantially impact the quality and quantity of recoverable genetic information. This concern may be exacerbated when dealing with degraded forensic skeletal remains. Few studies have explored whether pulverization of bone samples contributes to …

Redesign, Evaluation, And Validation Of A Commercially Viable High-Resolution Melt Based Mixture Screening Tool, Chastyn Smith

Theses and Dissertations

Analysis of evidentiary samples containing DNA from multiple contributors (“mixtures”) is a time intensive process for a forensic analyst and one where the contributor nature of a sample is not revealed until the end of the traditional forensic workflow. Often, at this stage, retesting or additional testing of mixture samples may not be possible, particularly if the DNA collection device did not preserve the DNA well enough; consequently leaving only trace amounts of a contributor’s DNA present. Thus, a new collection device that would allow for the increased preservation/integrity of evidentiary samples as well as a method that would allow …

Characterization Of Tonneau1 Recruiting Motif Proteins And Ton2 Signaling Functions, Tyler Falk

Theses and Dissertations

Plants cells are fixed in place. As a result they have to carefully divide in order to function properly. Plants use a number of complex microtubule arrays to ensure proper division and orientation including the preprophase band (PPB) and the phragmoplast. The PPB orients the cell prior to division and marks the cortical division site, which is where the phragmoplast is guided to. The phragmoplast is a dynamic microtubule array that builds the cell plate which later becomes the cell wall that divides daughter cells. Proteins involved with PPB formation include Tonneau1 (TON1) and Tonneau2 (TON2) which localize to and …

Climate Change And The Shifting Geography Of Coral-Reef Development, Victor Rodriguez-Ruano

Theses and Dissertations

Coral-reef development is modulated by growth processes that deposit calcium carbonate onto the reef, such as calcification, and destructive processes that remove calcium carbonate from the reef, such as bioerosion. Wherever calcification rates exceed bioerosion rates, there is a net accretion of the reef through time, but where bioerosion rates exceed calcification rates, there is a net destruction of the reef through time. A reef’s framework is the legacy of the interaction of these processes throughout a reef’s history. Studying the fossil frameworks of reefs can shed light on the environmental factors that have controlled reef development in the past, …

Age-Related Oligodendrocyte Lineage And Learning Abnormalities Driven By Nf1 Mutation In Mice, Saul Lopez

Theses and Dissertations

Neurofibromatosis Type 1 (NF1) is an autosomal dominant disease caused by mutations in the NF1 gene, on chromosome 17. NF1 patients suffer from a number of neurological issues including learning deficits and increased risk of age-related dementia. Additionally, NF1 patients present with multiple white matter and myelin abnormalities. Whether and how myelin abnormalities impact learning in NF1 is not known; therefore, we aimed to gain insights on potential links between Nf1 mutation and learning issues Unpublished data indicate that NF1 female-but not male- mice with Nf1+/- germline mutation show defects in a myelin-regulated learning/memory test (the complex wheel; CW) at …

The Role Of Insulin Signaling In Controlling Oogenesis In Drosophila Melanogaster, Tancia W. Bradshaw

Theses and Dissertations

Adult stem cell activity responds to organismal nutrient status to maintain and support tissue homeostasis. Despite the intricate relationship between dietary input, adipose tissue and peripheral organ function, we are at the tip of the iceberg regarding our understanding of the cellular and molecular mechanisms underlying adipose communication to other tissues. The Drosophila ovary receives nutritional signals from the fat body with multiple nutrient-sensing pathways functioning in adipocytes to control distinct stages of oogenesis. Insulin/insulin-like growth factor signaling (IIS) within adult adipocytes remotely controls oocyte production at distinct stages of oogenesis. The PI3K/Akt1 axis in adipocytes promotes germline stem cell …

The Effect Of Antibiotics On Immune Cell Infiltration Of Colon In A Mouse Model Of Early Onset Colorectal Cancer, Valerie Hinsch

Theses and Dissertations

Early onset colorectal cancer (EOCRC) is an aggressive form of colorectal cancer diagnosed before the age of 50. While colorectal cancer cases in patients 50 years and older have been declining, EOCRC cases have been steadily increasing globally in the last few decades, and the cause is unknown. Many agents, called exposomes, have been associated with EOCRC based on their emergence and prevalence prior to and in parallel with the rise in EOCRC cases. Among these are antibiotics (Abx). Abx are indispensable in our fight against infectious diseases, however their overuse is becoming a global epidemic. They are prescribed globally, …

Application Of Computational Tools To Identify Variations Associated With Peromyscus Dominant Spot, Zhenhua Shang

Theses and Dissertations

Peromyscus are the most prevalent mammalian species in North America, and they're employed extensively in both laboratory and field studies. P. maniculatus and P. polionotus, the deer mouse and the old-field mouse, are closely related and can produce viable and fertile hybrid offspring. However, a comprehensive database of polymorphisms, particularly in those kept as living stocks and supplied to university researchers, is lacking. In chapter 2, we performed comparative genomic study on P. maniculatus and P. polionotus and used the polymorphic data to identify the range of genetic complexity that underlies physiological and behavioral differences between two species. We also …

Dephosphorylation Of Mpk6 And Mpk3 By Phosphatases Modulates Responses To Herbivory In Arabidopsis, Claire Teresa Hann

Theses and Dissertations

As sessile organisms, plants rely on extracellular signals and chemical responses to defend against stressors. Extracellular stress signals inducing defense responses originate both from biotic or abiotic threats, and from products of tissue damage or hormones. In defense against herbivores, essential responses include rapid generation of jasmonic acid (JA) at the wound site, followed by the global expression of genes that impede digestion and growth. Early defense gene expression amplifies JA production, while later JA-responsive gene expression causes the accumulation of defense products. MAP kinase (MAPK) pathways play a central role in mediating the perception of self, non-self, and hormonal …

Regulation Of Stress Responses And Membrane Morphology By Dspa In Synechocystis Sp. Pcc 6803, Rebekah Kathryn White

Theses and Dissertations

In the world of microorganisms, cyanobacteria are a uniquely skilled powerhouse. They participate in global nutrient and carbon cycling. They have the ability to photosynthesize, which allows them to use sunlight and carbon dioxide to produce cellular energy. However, photosynthesis has a lot of points were environmental stresses can interfere, increasing the chances of oxidative stress and nutrient imbalances that can amplify deleterious effects. One regulator in particular will be the target of this study. DspA, also known as Hik33, is a histidine kinase that perceives and regulates multiple overlapping stress responses. In this project, abiotic stress effects will be …

The Interaction Between Predation And Sound Pollution On The Internal And External Microbiome Of The Grasshoppers Melanopus Sanguinipes, Alanna Bond

Theses and Dissertations

Anthropogenic activities such as construction and agriculture directly affect its surrounding environments. Many studies have focused on how megafauna and flora are impacted by human activities, however, relatively little is known how new occupation of land affects smaller organisms such as insects and microbes. Additionally, other stressors such as predation can impact host physiology. The grasshopper species Melanopussanguinipes was chosen to be used in a study to measure how stress caused by artificial sound and predation can alter exoskeleton and gut microbiomes once exposed to these stressors.

Nanoscale Modeling Of Membrane Systems Under Mechanical Deformation In Traumatic Brain Injury Using Molecular Dynamics, Anh Thi Ngoc Vo

Theses and Dissertations

Neuronal membrane disruption and mechanoporation are nanoscale damage mechanisms that critically affect brain cell viability during traumatic brain injury (TBI). These nanoscale cellular impairments are elusive in experiments and necessitate in silico approaches such as molecular dynamics (MD) simulations. Implementing MD, this research aims to investigate the effects of different key factors related to membrane deformation and damage, including force field resolutions, lipid compositions, and loading conditions.

To examine the impact of force field resolution, MD deformation simulations were conducted on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayer membranes, using all-atom (AA), united-atom (UA), and coarse-grained Martini (CG-M) force fields. The mechanical responses …

Evaluation Of Occidiofungin Activity On Yeast-Hyphae Morphogenesis And Biofilm Formation By Candida Species, Rabina Kumpakha

Theses and Dissertations

Invasive fungal infections are a significant clinical challenge especially for hospitalized patients as traditional antifungal therapy often fails to resolve these infections. The ability of Candida to undergo yeast-to-hyphae morphological transition is central to this invasive behavior. Morphogenesis is also important for the formation of biofilms which are highly structured communities of microorganisms attached to one another or substratum and embedded within a protective extracellular matrix material. The refractory nature of cells within a biofilm to current antifungal therapies has created a need for alternative antifungal agents for the management of Candida biofilm-related infections. The novel antifungal occidiofungin is a …