Molecular Biology Commons^™

Molecular Mechanisms And Metabolic Consequences Of Glucocorticoid Resistance, Genesee J. Martinez

Theses and Dissertations--Pharmacology and Nutritional Sciences

Glucocorticoids are vital steroid hormones that govern metabolism, stress responses, and immune functions through intricate, tissue-specific mechanisms, both genomic and non-genomic. These hormones bind to the glucocorticoid receptor (GR), which then acts as a transcription factor to modulate gene expression. Chronic elevation of glucocorticoid levels may lead to glucocorticoid resistance, resulting in adiposity, inflammation, and insulin resistance, thereby adversely affecting multiple metabolic tissues. Whether produced endogenously or administered exogenously, excessive, chronic glucocorticoid concentrations impair glucocorticoid signaling. Although there are two primary isoforms of the receptor, GR⍺ and GRβ, only GR⍺ interacts with glucocorticoids.Through the research conducted in this dissertation, we …

Investigating The Effects Of Nucleopore Defects On The Cellular Response To Stress In Als/Ftd Ipsc-Derived Neurons, Alicia Christine Collins

Open Access Dissertations

Amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) is a progressive neurodegenerative disease spectrum characterized by motor dysfunction, cognitive decline, and death within a few years of clinical onset. Hallmark features of ALS/FTD include defects in nucleocytoplasmic transport (NCT) and abnormal cytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43, both of which have been shown to be exasperated by oxidative stress (OS). It remains unclear how these processes are connected and how they collectively contribute to neurodegeneration. To fill this gap of knowledge, we used human embryonic kidney cells, neuroblastoma cells, and induced pluripotent stem cell-derived cortical neurons harboring the ALS/FTD C9ORF72 …

From Theory To Ecosystems: Exploring Biodiversity And Ecosystem-Function In Pitcher Plant (Darlingtonia Californica) Microbial Communities, Gavin Sutter

Cal Poly Humboldt theses and projects

The relationship between biodiversity and ecosystem-function (BEF) has been a central focus of ecological research for the last three decades, yet the role of space in shaping BEF relationships remains relatively unknown. Research has shown that community diversity and composition can strongly influence productivity, nutrient cycling, and decomposition, but much of this work treats communities as spatially isolated, leaving open how dispersal and other spatial processes shape BEF at broader scales. To begin addressing this gap, I used microbial communities inhabiting Darlingtonia californica pitcher plant leaves to evaluate how spatial organization and successional change shape biodiversity and ecosystem-functioning. I quantified …

Perfluorooctane Sulfonate (Pfos)-Induced Disruption Of Mitochondrial Activity And Cell Adhesion In Liver Cells, Phuong Dam Nam Tran

Graduate Theses/Dissertations

Perfluorooctane sulfonate (PFOS) is a persistent environmental pollutant associated with potential hepatoxic effects and other health risks. Despite its widespread distribution, the mechanisms underlying its toxicities remain to be fully understood. To investigate PFOS toxicology, my study utilized HepG2 and THLE-2 human hepatic cell models to replicate conditions reflecting PFOS accumulation in the liver. Cell viability, cell stress, and cell death assays were conducted to assess the toxicological influence of the chemical on both cell lines. Total RNA extraction was performed, followed by cDNA sequencing, and RT-qPCR. The XTT viability assay revealed a dose-dependent decrease in number of viable cells …

N-Allylation Of Secondary Amides With Unsymmetrical Propionates, Remi Graff

Honors Theses

The combination of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and Et3N promotes the N-allylation of 4-methoxyacetanilide 2 with unsymmetrical propionates 1 (eq 1). The amide substrate is believed to undergo conversion to a nucleophilic silyl imidate in the presence of TMSOTf and the amine base, which concurrently promotes carbocation formation in the same flask through the loss of trimethylsilyl propionate, leading to N-allylation of the amide. A range of unsymmetrical propionates, accessed by varying the R and R’ substituents, react efficiently in this one-pot process with yields ranging from 44% to 99%, affording regioselective ratios of up to >20:1 through formation of regioisomers …

Development Of A Python Pipeline For The Inference Of Selection In Human Genomes And Applications To Adh1b*2, Aine Macdermott

Honors Theses

Human evolutionary genomics provides an avenue to understand how genetic variation has been impacted by the environmental pressures of the past, revealing how selective pressures impacted past populations and contributed to present-day biological diversity. In this thesis, I describe the construction of a Python-based computational pipeline designed to automate and integrate multiple analyses of positive selection across worldwide population datasets, including derived allele frequency calculation, haplotype-based tests of selection, RELATE-based genealogical inference, and CLUES2-based temporal modeling. By automating file preparation, format conversion, job submission, result aggregation, model comparison, and visualization, this pipeline streamlines the data interpretation process, and shifts focus …

Exploring Phosphoregulation Of Myo3a Using Quantitative Fluorescence Image Analysis In Cos7 Cells, Vu Hao Minh Nguyen Phan

Honors Theses

Myosin 3A (MYO3A) is an unconventional myosin involved in the formation and maintenance of hair-cell stereocilia of the sensory epithelia in the inner ear. The kinase domain has been implicated in phosphoregulation of MYO3A activity through intermolecular autophosphorylation. Previous studies using mass spectrometry identified two potential phosphorylation sites in the motor domain. To investigate the regulatory roles of these sites, we generated glutamic acid point mutations in our mchr-MYO3AΔK construct to mimic phosphorylation and assayed the constructs for their ability to tip-localize and influence filopodial density via transfection into COS7 cells. The phosphomimic constructs were less able to generate filopodia …

Effects Of Rnai Of Ribophorin 1, Eukaryotic Translation Initiation Factor 2 Beta, And Peptidylprolyl Isomerase A In Acyrthosiphon Pisum, Brandon L. Kennemer

Master's Theses or Doctor of Nursing Practice

Three genes found in the Unfolded protein response, Ribophorin 1, Eukaryotic translation initiation factor 2 beta, and Peptidylprolyl isomerase A are thought to be potential targets for RNA Interference (RNAi) in Acyrthosiphon pisum.  Ribophorin 1 (RPN1) is a transmembrane glycoprotein that assists in anchoring ribosomes to the rough endoplasmic reticulum membrane.  It acts as a substrate-specific chaperone.  It facilitates N-glycosylation by delivering newly synthesized proteins to the oligosaccharyltransferase (OST) complex.  Eukaryotic translation initiation factor 2 beta (eIF2B) is a key component of the eIF2 heterotrimer that facilitates protein synthesis initiation by binding GTP and recruiting a specific transfer RNA to …

Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp

Capstone Showcase

This thesis investigates the evolutionary relationships among disk-winged bats in the genus Thyroptera, a small group of Neotropical bats known for the adhesive suction disks on their wings and feet that allow them to roost inside tightly rolled leaves. The distinctive morphology and behavior of these bats have not been extensively documented, and their phylogenetic relationships remain only partially resolved. The goal of this research is to better understand how these species are related to one another and to determine whether the five recognized species of Thyroptera form a single monophyletic group. To address this question, morphological and genetic …

Overview And Methods Of Molecular Paleontology: A Review, Shelby Touchstone

Williams Honors College, Honors Research Projects

Molecular paleontology—the study of ancient biomolecules preserved in fossils and sediments, including ancient DNA, lipids, and proteins—has motivated researchers since the 1950s, inspiring both scientific inquiry and broader cultural imagination. Think Jurassic Park. This honors thesis presents a comprehensive review of the history, current state, and methods of the field of molecular paleontology. Drawing on peer-reviewed literature and scholarly resources accessed through databases such as EBSCO and Bierce library, this review examines key techniques such as Next Generation Sequencing and amino acid racemization and will go over limitations and controversies in the field. It will also explore potential new …

Disrupted Circadian Rhythms Affect Hallmark Pathologies In Alzheimer’S Disease-Related Mouse Models, Valeria Buzinova

Theses and Dissertations--Molecular and Cellular Biochemistry

Alzheimer’s Disease (AD) is a complex neurodegenerative disease with two hallmark pathologies: extracellular amyloid-b (Ab) and intracellular neurofibrillary tangles (NFTs). Ab is proteolytically processed from amyloid precursor protein (APP) by b-secretase and g-secretase as a monomeric peptide prone to aggregation. Eventually, the aggregate-prone monomers will form dense plaques that are difficult to break down and remove. These plaques begin to deposit into the cortex decades prior to the formation of NFTs and the onset of cognitive decline. NFTs are comprised of hyper-phosphorylated tau. Tau is a protein that serves to promote and stabilize the formation of microtubules. The formation of …

Characterizing The Human Metapneumovirus Matrix Protein And Its Role In Infection, Chase J. Heim

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) causes severe respiratory tract infections in all cohorts, but especially in vulnerable groups such as children, older adults, and the immunocompromised. The matrix (M) protein of HMPV, like the M proteins of other members of the Mononegavirales order, is involved in virus assembly and budding. However, other functions of the HMPV M protein have yet to be elucidated. To investigate these various functions of the M protein, we used a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO) antisense agent designed to block translation of the M gene to reduce M expression during infection. Treatment with varying concentrations of an …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

Development Of A Split Deoxyribozyme-Based Assay For Detecting Hepatitis B Virus, Dalila Zovko

Honors Undergraduate Theses

Rapid, accessible nucleic acid-based detection methods are needed for hepatitis B virus (HBV). A split deoxyribozyme assay was developed for sequence-specific fluorescence detection. The assay was evaluated using synthetic target and plasmid-derived material. The assay showed target-dependent fluorescence and low-concentration linear range with a LOD of 1.9 nM. The assay supports detection and semi-quantification of HBV genetic material as shown using plasmid-derived transcript samples from HBV genotypes B, C, and D. The selected target corresponded to nt 363–406 of the HBV genome and was chosen based on sequence alignment showing conservation across most genotypes. Genotype-specific detection remains a future application …

Dna Half-Adder Based Calculator Driven By 4j Molecular Switches, Andrea Gissele Canizalez Covaleda

Honors Undergraduate Theses

DNA nanostructures have computing functions due to the predictable base pairing of nucleic acids (Watson–Crick). This property allows the programming of DNA circuits that integrate DNA logic gates capable of recognizing oligonucleotides. This molecular device offers the advantages of biocompatibility and potential applications in personalized medicine for diagnosis and therapies.

Our lab has developed DNA logic gates formed by the connection of YES strands via DNA four-way junctions (4J), which can function as molecular switches to develop a DNA-based calculator. Our DNA half-adder calculator nanostructure is designed to recognize up to three combinations of DNA inputs using three DNA strands …

Antiestrogens As Bone Protective Therapeutics For Estrogen Receptor-Positive Breast Cancer In The Presence Of Osteoporosis, Faith E. Parker, Emily K. Zboril, David C. Boyd, Rachel Myrick, J. Chuck Harrell

Undergraduate Research Posters

Breast cancer (BC) is one of the most significant causes of mortality among women and the second leading cause of cancer death in women. The estrogen receptor (ER) is a key oncogenic driver in the majority of breast cancer. ER+ BC is the most common molecular subtype of BC. Management of ER+ breast cancer varies depending on menopausal status. For premenopausal women, the goal is to suppress estradiol production from the ovaries with surgical oophorectomy and/or aromatase inhibitors. In postmenopausal women, endocrine therapy (ET) serves to suppress estradiol production from sources other than the ovaries. During the menopausal transition, estradiol …

Patterns Of Ovarian And Gonadotropin Hormones In Emerging Adult Oral Contraceptive Users, Summer Mcormond

Undergraduate Research Posters

Oral contraceptives (OCs) are often initiated during adolescence and emerging adulthood, a period of continued maturation of the hypothalamic–pituitary–gonadal (HPG) axis. Because hormonal exposure during this window may shape emotional, biological, and reproductive outcomes, it is important to understand the specific formulations young women take and the hormonal profiles these formulations produce. This study characterizes OC formulation features and measured hormone levels in young adult OC users (n = 30).

Ethinyl estradiol (EE) doses ranged from 0.01–0.035 mg (mean = 0.022 mg), with 70% using ≤0.02 mg. Pill regimens included 21/7 packs (83%), 24/4 packs (10%), and 84/7 regimens (3%). …

Psr Impacts Chromatin Condensation During Spermatogenesis In Nasonia Vitripennis, Jacqueline R. Solomon

CMC Senior Theses

Paternal Sex Ratio (PSR) is a supernumerary, selfish B chromosome found in the jewel wasp (Nasonia vitripennis). PSR is transmitted strictly paternally to progeny, and when present, it causes paternal genome elimination (PGE) just after fertilization. Due to the haplo-diploid reproduction of N. vitripennis, this PGE event results in all-male broods of progeny, ~90% of which carry and transmit PSR. Thus, PGE is beneficial for PSR’s transmission.  A previous study showed that PSR induces PGE by expressing a gene called haploidizer during spermatogenesis. Although how haploidizer functions in PGE is unknown, this finding suggests two basic models: that (i) the …

The Geminivirus Al2 Protein Interacts With Host Proteins Involved In The Plant Antiviral Response, Pheobean Atieno Odongo

Graduate Research Theses & Dissertations

Geminiviruses are economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, resulting in up to 100% crop loss. As a result of these heavy losses on food and cash crops, these viruses represent a new threat to global food security and sustainability. In this research, I use Tomato golden mosaic virus (TGMV) to study host-virus relationships with an overall goal of developing sustainable and eco-friendly crop resistance. TGMV belongs to the Geminivirus subgroup, Begomovirus, that is characterized by a split genome consisting of two single-stranded circular DNAs. The TGMV genome encodes proteins …

The Biosynthesis Of The Natural Product N-Nitroglycine, Gabriel Padilla

Graduate Studies Theses and Dissertations 2026

N-Nitroglycine (NNG) is a nitramine [R(R′)N–NO2; R′=H or alkyl] natural product (NP) produced by certain actinomycetes, such as Streptomyces noursei. At the beginning of this project, the biosynthesis of this NP was unknown. The goal was to determine how NNG and its nitramine moiety are enzymatically formed. This could lead to the discovery of novel nitramine NPs with diverse applications as well as alternative/green synthesis of nitramine explosives. This work begins by examining diverse biochemical N–N bond formation strategies. Nitrogen cycle enzymes, nitration of NPs, kutzneride biosynthesis, the aspartate/nitrosuccinate superfamily, hydrazinoacetic acid (HAA) biosynthesis, and streptozocin biosynthesis are among the …

Evaluating Novel Targeted Combination Therapies For Gastrointestinal Cancers, Joseph A. Goode

Graduate Studies Theses and Dissertations 2026

Gastrointestinal (GI) cancers remain among the leading causes of cancer-related mortality worldwide, with therapeutic resistance continuing to limit the effectiveness of current treatments. Three complementary studies were conducted to identify therapeutic vulnerabilities and evaluate novel combination strategies in pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC).  First, dual inhibition of fibroblast growth factor receptor 4 (FGFR4) and phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling was investigated in PDAC models. A combination of targeted drug treatments reduced viability, clonogenic survival, migration, and suppressed signaling pathways involved in translational control. This supported a functional interaction between FGFR4 and PI3K-mTOR co-activation in …

Role Of The Osaa Transcription Factor Gene In Development, Secondary Metabolism And Virulence In The Mycotoxigenic Fungus Aspergillus Flavus, Farzana Ehetasum Hossain

Graduate Research Theses & Dissertations

Aspergillus flavus colonizes oil-seed crops, contaminating them with aflatoxins; highly carcinogenic mycotoxins that cause severe health and economic losses. Genetic studies may reveal new targets for effective control strategies. Here, we characterized a putative WOPR transcription factor gene, osaA, in A. flavus. Our results revealed that osaA regulates conidiation and sclerotial formation. Importantly, deletion of osaA reduces aflatoxin B1 production, while, unexpectedly, transcriptome analysis indicated upregulation of aflatoxin biosynthetic genes, suggesting post-transcriptional or cofactor-mediated regulation. Cyclopiazonic acid production also decreased in the absence of osaA. In addition, the osaA mutant exhibited upregulation of genes in the imizoquin and aspirochlorine clusters. …

The Importance Of The Proline Residue In The Ldiapa Motif Of Cholera Toxin, Akash Bharathan

Honors Undergraduate Theses

Cholera is currently on its seventh global pandemic, disproportionately affecting developing countries. Vibrio cholerae, the bacterial etiologic agent, is able to cause infection by adhering to intestinal epithelial cells and secreting cholera toxin (CT), an AB-type exotoxin that dysregulates signaling pathways. Previous research by the Teter lab has shown that Hsp90, a host cytosolic chaperone, is required for CT to enter the cytosol where it produces toxic effects. Hsp90 binds to CT at two specific motifs, RPPDEI and LDIAPA. The prolines in the RPPDEI motif are essential for binding, but the proline in the LDIAPA has yet to be …

Fluorescent Protein Imaging Approaches Uncover Dynamic Subcellular Distribution Of Core Clock Proteins In Neurospora Crassa, Ziyan Wang

Dartmouth College Ph.D Dissertations

Circadian clocks are endogenous self-sustained timekeeping systems that allow organisms to anticipate and adapt to daily environmental cycles. Found in diverse forms of life, these molecular clocks regulate the expression of ~ 40% of the genome in animals, fungi, and plants. In animals and fungi, circadian oscillators are built on transcription-translation feedback loops (TTFLs), in which positive regulators drive the expression of negative regulators which, once synthesized and imported into the nucleus, inhibit their own activators. This precisely regulated negative feedback incorporates multiple steps of delays that are essential for generating ~24-hour rhythms. Through these mechanisms, circadian clocks temporally coordinate …

Analysis Of Alternative Oxidase In Non-Angiosperm Plants, Anissa M. Francis

Theses and Dissertations (Comprehensive)

Alternative oxidase (AOX) is a mitochondrial terminal oxidase that provides an alternative pathway for electron transport, allowing plants to maintain respiratory flexibility under environmental stress conditions. While AOX has been extensively studied in angiosperms (flowering plants), little is known about its distribution and conservation in non-angiosperms. Based on gaps identified in the literature, this thesis investigated the distribution of AOX across non-angiosperm plant lineages. Although AOX is present in many green algae and is therefore considered to be an ancient protein that originated before the existence of non-angiosperm plants, it remains unclear whether the protein is uniformly distributed across these …