Cell and Developmental Biology Commons^™

Protocol For Vibratome Sectioning, Immunofluorescence, And S-Phase Labeling Of Inner Ear Organoids, Jiayi Wu, Stefan Heller, Maggie S. Matern

Biology Faculty Publications

Inner ear organoids represent a potentially inexhaustible source of otic tissues, including sensory hair cells and supporting cells, for in vitro manipulation. Here, we present a protocol for labeling S-phase entry of cells in inner ear organoids using 5-ethynyl-2′-deoxyuridine (EdU), followed by fixation and vibratome sectioning. Nuclear EdU is then detected alongside protein markers of interest via immunofluorescence. This workflow enables the visualization of cell and tissue morphologies within developing organoids and assessment of how different manipulations affect cell proliferation.

Applying Transcriptomics For Technology Development And Conservation In North American Marine Organisms, Cory Von Eiff

Dissertations

RNA biology is a rapidly expanding field, with many avenues of discovery among marine organisms. In this study, we analyze both mollusks and sawfish. First, we perform an evaluation of sRNA biogenesis pathways throughout Mollusca, with emphasis on the easter oyster, Crassostrea virginica. Understanding these molecules prescribes RNAi-based gene silencing approaches, benefiting genetic investigation and biotechnology. Similar to other animal groups, mollusks have conserved microRNAs (miRNAs), with some shared with ecdysozoans and deuterostomes; however, there is no evidence of an endogenous small interfering RNA (siRNA) pathway. These results suggest that long double-stranded RNA (dsRNA)-based RNAi is not appropriate for gene …

3,5-Dihydroxy-4-Isopropylstilbene (Tapinarof) Is A Partial Aryl Hydrocarbon Receptor Agonist In Fish, Conner A. Dicks

All Theses

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is essential in regulating development, immune homeostasis, and drug and xenobiotic metabolism. Activation of the AHR by specific ligands results in its translocation to the nucleus where it induces a myriad of gene products, including cytochrome P450 (CYP) drug metabolizing enzymes (e.g., CYP1A1) and other components of the chemical defensome, as well as inflammatory control. Interestingly, the AHR can bind a wide variety of endogenous and xenobiotic ligands which are able to induce unique downstream effects dependent on cell type, inflammatory context, and ligand stability. The AHR is …

Impact Of S-Phase Kinase Protien 2 Blockades On Hematopoetic Stem Cell Metabolism, Nicole Elmaraghy

Electronic Theses, Projects, and Dissertations

Hematopoietic stem and progenitor cells (HSPCs) quiescence is vital for the success of bone marrow transplantation, as it preserves long term self- renewal and prevents premature exhaustion (Takubo et al., 2013; Wilson et al., 2008). However, bone marrow transplant (BMT) failure remains a clinical challenge, often due to lack of long-term engraftment and insufficient stress reliance. Both of these characteristics are tightly linked to disrupted stem cell quiescence and metabolic imbalance (Anso et al., 2017; Vannini et al., 2016). One key player is S-phase kinase protein (SKP2), an E3 ubiquitin ligase that targets cell cycle inhibitors, like p27, for proteosome …

Utilizing The Combinatory Power Of Chemotherapeutic Compounds In Triple Negative Breast Cancer Cells, Matthew I. Hyder

Biology Summer Fellows

Breast cancer is the leading cause of cancer-related deaths among women worldwide and the second most common cause of cancer deaths in women in the United States. Genetic variants that increase the risk of breast cancer include mutations in the breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2). Apoptosis, or programmed cell death, is a natural process that helps the body remove aged cells. However, in cancer, deregulated apoptotic signaling—especially the activation of anti-apoptotic mechanisms—enables cancer cells to evade this process, leading to uncontrolled proliferation, tumor survival, therapeutic resistance, and cancer recurrence. Most anti-cancer drugs function as chemotherapeutic …

Investigating The Capacity Of Tdp-43 Low Complexity Domain To Target Protein Aggregates In Yeast, Nicholas J. Grahame

Biology Summer Fellows

Utilizing protein TDP-43 and fluorescent proteins to:

Investigate TDP-43’s LCD region in protein aggregates. Use fluorescent protein tagging to visualize co-localization and aggregation. Leverage yeast as a model system for studying LLPS and aggregation.

Can we target chaperone proteins to TDP-43 LCD region?

Metabolic And Physiological Regulation In C. Elegans: Insights Into Sperm Activation And Peroxisome-Mediated Longevity, Yash Flora

LSU Doctoral Dissertations

Organelle dynamics lie at the heart of cellular signaling and metabolic regulation, orchestrating physiological processes such as reproduction and aging across the lifespan. In this dissertation, I investigate how organelle-based signaling coordinates sperm activation and modulates organismal aging in the nematode Caenorhabditis elegans. I identify SPIN-4, a previously uncharacterized Spinster family transporter, as a key regulator of spermiogenesis. SPIN-4 is strongly expressed in developing sperm, localizes to the plasma membrane, and promotes sperm activation by facilitating the export of sphingosine-1-phosphate (S1P). Loss of spin-4 results in defective pseudopod formation, reduced motility, and compromised fertility, phenotypes that can be rescued …

Exploiting Genomics To Advance Genetic Gain For Reproductive Traits In Sheep, Mujibur Rahman

ORBioM (Open Research BioSciences Meeting)

Poor reproductive performance has a negative impact on the profitability of sheep production systems with the number of lambs reared highlighted as a key driver of farm profitability. Nevertheless, the genetic improvement of reproductive traits in sheep has been constrained by their low heritability and pleiotropic nature. Understanding the underlying genetic architecture can improve genomic prediction estimates and enhance genetic gain.

This study will utilize large-scale genomic and phenotypic datasets to enhance genetic gain in sheep reproductive traits through four approaches: 1) to determine the effect of inbreeding depression on reproduction, 2) to identify causal variants impacting reproductive performance through …

The Anticancer Activity Of Novel Chromene Derivatives Against Colorectal Cancer Cells, Rym Magramane

Thesis/ Dissertation Defenses

Colorectal cancer (CRC) stands as the third most common cancer globally, accounting for nearly 10% of all newly diagnosed cancer cases. In the UAE, CRC was ranked as the third most frequently diagnosed malignancy, and the leading cause of cancer-associated deaths in 2023. Standard CRC treatment strategies include surgical resection, chemotherapy, immunotherapy, targeted therapy, or a combination of all, depending on the cancer stage and molecular profile. Despite these interventions, disease recurrence is experienced by a considerable number of cancer patients. Hence, there is an urgent need to develop novel alternative treatments to overcome poor prognosis. Recently, cancer research has …

The Impact Of Growth Hormone-Releasing Hormone Antagonist On Human Adipose-Derived Stem Cells, Jeanne Michelle Dugas

Master's Theses

Obesity is a condition that affects over 40% of American adults and contributes to numerous preventable health issues. This condition is caused by increased adipose tissue, which forms when stem cells transform into adipocytes. Mesenchymal stem cells, including human adipose-derived stem cells (hASC), are multipotent with the ability to differentiate into adipocytes, osteocytes, or chondrocytes. Many factors affect this transformation, including the peptide growth hormone-releasing hormone (GHRH). The main role of GHRH is to trigger the release of growth hormone, but it has also been found to play an important role in adipocyte metabolism. We expect that if the differentiation …

Network Analysis Of Antimicrobial Resistance In Staphylococcus Aureus: Characterization Of Hub Genes And Their Functional Implications, Md Imran Hasan, Davida Smyth, Jeong Yang, Ashley Teufel

Masters Theses (Archived)

Antimicrobial resistance is a major cause of morbidity and mortality in patients with S. aureus infections. In this study, we analyzed genes, molecular mechanisms, and pathways driving drug resistance in S. aureus using network analysis. Using whole-genome sequencing (WGS) data and systems biology approaches, we identified 229 AMR-associated genes and constructed a protein-protein interaction network among these genes. Through network topology and functional enrichment analyses, we not only confirmed their association with resistance, but also highlighted the central roles of these genes in resistance pathways, such as efflux, target replacement, and target protection, which are directly linked to multiple drug …

Mechanisms That Contribute To Age-Dependent Segregation Errors In Drosophila Oocytes, Zihan Meng

Dartmouth College Ph.D Dissertations

Meiotic chromosome segregation errors in human oocytes are the leading cause of miscarriages and aneuploid pregnancies, and these errors increase dramatically as women age. Using Drosophila oocytes as a model system, this dissertation identifies the NAD⁺-dependent deacetylase Sirt1 as a key regulator of chromosome segregation and meiotic arm cohesion. Loss of Sirt1 activity during meiotic prophase leads to premature loss of arm cohesion and increased segregation errors in Drosophila oocytes. In addition, elevated acetylation of its substrate, histone H4K16, indicates that Sirt1 activity declines in oocytes during aging. Strikingly, dietary administration of the Sirt1 activator SRT1720 preserves Sirt1 deacetylase activity …

A Bitter Brew For Cancer: Egcg’S Impact On Ewing Sarcoma Cells, Lizzeth Holguin, Mary-Esther Leblanc, Mariana Reyes, Terry Jo Shackleford

Cell and Molecular Methods

Epigallocatechin Gallate (EGCG), a powerful antioxidant found in green tea, is an abundant treatment to treat Ewing Sarcoma cells, a pediatric cancer affecting the skeletal system. Given EGCG’s known role in other cancer treatments, these tests aim to investigate its effects as a standalone natural compound on Ewing Sarcoma cells. Focusing on the PI3K/AKT pathway, if the PI3K/AKT pathway is inhibited by EGCG, then it will lead to reduced cell survival and proliferation of EW8 cells. Using cell culture techniques, IncuCyte-based IC50 analysis, caspase 3/7, RNA purification, cDNA synthesis, and qRT-PCR, EGCG’s impact was assessed on cell apoptosis and gene …

The Effect Of Epigallocatechin Gallate (Egcg) And Alpha L-Mangostin On Tp53, Bax, And Vim Gene Expression And Apoptosis In Ewing Sarcoma Cells, Victoria Valdez, Terry Jo Shackleford

Cell and Molecular Methods

Ewing Sarcoma (ES) is a malignant pediatric bone tumor driven by chromosomal translocations and fusion oncogenes with limited targeted treatment options. This study investigated the chemopreventive potential of two natural compounds, Epigallocatechin Gallate (EGCG) found in green tea, and Alpha L-Mangostin from mangosteen, on apoptosis and gene expression in ES cells. We hypothesized that EGCG and Alpha L-Mangostin treatment would induce apoptosis and downregulate cancer-promoting genes. To test this, we performed tissue culture, IC50 assays, caspase-based apoptosis detection, RNA purification, cDNA synthesis, and qRT-PCR on ES cell lines treated with a high and low concentration of the two compounds. Our …

Identification Of Methylation Patterns, Associated Dna Methylating Proteins, And Methyltransferase Inhibitors On The Promoter Regions Of Dax-1, Brandon Tyler Toy

Master's Theses

The DAX-1 gene (Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1) encodes for an orphan nuclear hormone receptor and its mutation is implicated in multiple diseases including congenital adrenal hypoplasia, adrenal cancer, and breast cancer. Previous research has linked DAX-1 downregulation to tumor initiation in breast tissue, suggesting the gene acts as a tumor suppressor with respect to breast cancer. Additional studies completed by the Tzagarakis-Foster laboratory have shown that methylation of the DAX-1 promoter region is heavily influential in breast cancer development, with release of epigenetic repression resulting in slowing of cellular proliferation …

Minimal Anti-Cancer Effects Of Mushroom-Derived Compounds Hispidin And Chaga Extract On Ewing Sarcoma Cells, Jordan Cosgrove, Fiona Coulbourne, Iris Reyna, Giselle Serna-Flores, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma is a rare and aggressive cancer of adolescents and young adults driven by the EWSR1–FLI1 gene fusion. Standard treatments include chemotherapy, surgery, and radiation, though survival rates remain low. Natural compounds such as hispidin, derived from fungi, and Chaga mushroom extract have shown potential anti-cancer effects by disrupting cell cycle progression and promoting apoptosis in other cancer models. In this study, we tested the effects of hispidin and Chaga extract on Ewing sarcoma cells to evaluate their ability to suppress cell growth and identify potential therapeutic benefits.

The Effects Of Hispidin And Eribulin Mesylate On Cell Proliferation Of Ewing Sarcoma Cell Lines, Elena Mares, Angelina Juarrita, Sierra Munoz, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma is a type of cancer that targets the cells within bones and soft tissue and is most prevalent in younger populations. It is important to look at this specific cancer because there is no cure yet, and the risks increase, even after a patient has completed their treatment. We hypothesize that if we treat Ewing sarcoma cell lines with natural compounds, specifically Hispidin and Eribulin Mesylate, then the cell lines will decrease in cell viability and there will be an increase in apoptosis of the cancerous cell lines. We performed a series of experiments, which included IC50 analysis, …

Regulation Of Ccr7 Signaling Events By G-Protein-Coupled Receptor Kinases 2 And 3, Anahi Sanchez

Open Access Theses & Dissertations

G protein-coupled receptors (GPCR) can bind multiple ligands, leading to differential signaling events termed biased signaling. C-C chemokine receptor 7 (CCR7) is a GPCR known to have biased signaling between the two ligands it binds to, CCL19 and CCL21. Binding of C-C Chemokine Ligand 19 (CCL19) promotes a high level of CCR7 phosphorylation, while CCL21 leads to a much lower level of CCR7 phosphorylation; findings observed in HEK and dendritic cells. GPCR kinases (GRKs), which can control the phosphorylation patterns of a GPCR, are hypothesized to regulate biased signaling of a receptor. GRK expression differs between cell lines and cell …

Differential Regulation Of The Prkacaa Promoter In Zebrafish Melanoma Cell Lines, Maria Fiuk

Theses, Dissertations and Culminating Projects

The Inducible cAMP Early Repressor (ICER) comprises a group of isoforms that function as transcription factors within the cyclic AMP (cAMP) signaling pathway. These isoforms are encoded by the cAMP Response Element Modulator (CREM) gene. The cAMP signaling pathway and its associated transcriptional regulators have been implicated in the development of resistance to BRAF/MEK-targeted therapies in melanoma. Recent findings from our laboratory demonstrated that transgenic ICER expression in a zebrafish melanoma model promotes the formation of aggressive melanomas. Cell lines were established from tumors expressing ICER, as well as from control tumors expressing Green Fluorescent Protein (GFP). To begin characterizing …

Understanding The Properties Of Repair Protein P26 For Dry-State Preservation Of Biological Materials., Hannah Skaggs

College of Arts & Sciences Senior Theses

The preservation of complex biological materials in the frozen state has been well established and plays a critical role in the advancement of clinical applications and the pharmaceutical industry. Cryopreservation of complex biological materials has several clinical applications, including vaccine preservation, bone marrow transplants, cell therapeutics, and increasing the shelf life of red blood cells (RBCs) for transfusion. However, many challenges are present, including the use of toxic protective agents and the financial burden of maintaining extremely low temperatures between 193.15 and – 77.6 K (Parihar, Kumar et al. 2023). Lyophilization, or freeze-drying, presents an opportunity to mitigate such challenges. …

Impact Of Temperature And Microbial Infection On The Honey Bee Hemocytes, Michael E. Oeth

Master's Theses

Introduction

Honey bees (Apis mellifera) rely on hemocytes for immunity, wound healing, and hemolymph homeostasis. While 32°C reflects optimal hive conditions, suboptimal temperatures (22°C) and stressors like pathogens (Varroa destructor, bacteria) or pesticides impair hemocyte function. Using clodronate liposomes (CLD) to deplete hemocytes, we assessed how immune suppression interacts with these stressors.

Methods

Newly emerged (5-day-old) and older (15-day-old) bees were assigned to: CLD, control liposomes (LP), PBS, injection wound, or no treatment. Cohorts were exposed to 32°C (optimal) or 22°C (stressful for non-immunosuppressed bees). Fifteen-day-old bees were challenged with Escherichia coli or Staphylococcus aureus. Survival, hemolymph volume, and hemocyte …

Development Of A Behavioral Paradigm To Monitor Seizure Susceptibility And Severity In A Zebrafish Model Of Cblx Syndrome, Claudia Berenice Gil

Open Access Theses & Dissertations

Methylmalonic acidemia and homocysteinemia cblX type (cblX) (MIM#309541) is a rare, X-linked recessive disorder caused by a mutation in the HCFC1 gene. This disorder is characterized by multiple congenital anomalies which include intellectual disability, brain malformations, intractable epilepsy, microcephaly, and facial dysmorphia. The most severe symptom of cblX is intractable epilepsy which is 100% penetrant. Our lab developed a zebrafish model with a mutation in the zebrafish hcfc1a ortholog to study the mechanisms underlying seizure phenotypes in cblX. Our laboratory previously showed that mutation of hcfc1a results in increased number and proliferation of neural precursor cells (NPCs) and an increase …

The Role Of Ucp2 In Pancreatic Cancer Metabolism And Its Potential As A Radiosensitizer, Emily Rieff

Dissertations and Theses (Open Access)

Uncoupling protein 2 (UCP2) is a mitochondrial protein that regulates the flow of protons down the gradient established by the electron transport chain (ETC) without generating ATP, thus uncoupling the proton gradient from ATP generation. In tumors, specifically pancreatic cancer (PDAC), the ETC is highly stimulated to generate the copious ATP needed by the tumor to grow. However, extended ETC use increases reactive oxygen species (ROS), and if left unchecked, results in cell death. To evade this, PDAC employs antioxidant strategies, including upregulating UCP2 in tumor cells. In addition to its uncoupling function, UCP2 indirectly controls ROS levels by maintaining …

Passive Electronic Cigarette Exposure Initiates Squamous Metaplasia In A Developing 3d Human Tracheobronchial Epithelial Tissue In-Vitro Model, Edgar Rolon

Electronic Theses, Projects, and Dissertations

The prevalence of vaping has rapidly increased. ECs are often perceived as less harmful than tobacco cigarettes. A recent meta-analysis showed electronic cigarette (EC) aerosols adversely affected the respiratory system, similar to cigarette smoke, with some effects specific to EC use. Failure to prevent these alterations could lead to life-long comorbidities, and predisposition to respiratory diseases, including COPD and squamous cell carcinoma. While these effects are the result of active vaping, EC aerosols can also settle on indoor surfaces, be absorbed passively through the skin or orally, enter the blood stream, and subsequently expose internal organs, including the airway basal …

Bibliometric Analysis Of Research Trends Related To Human Immunodeficiency Virus., Madyson E. Johnson, Kaitlyn R. Coffman, Valerie Rivas, Elizabeth Barrett

ATU Scholars Symposium

Human immunodeficiency virus poses major health burden across the globe including the United States of America and has its zoonotic origin from the Simian Immunodeficiency viruses of sooty mangabey monkey and chimpanzee in Africa. Epidemiological trends indicate that even though the mortality rates for HIV are falling globally, the rates of new cases have been rising since 2010 in several countries including the USA. An estimated 0.5% of the human population is currently infected with the virus with countries like USA, India, Nigeria and South Africa carrying the highest burden of the disease. Host receptors such as CD4 and coreceptors …

A Natural Short Sleep Mutation Promotes Longevity Through Mitochondrial Respiration In Drosophila, Pritika Pandey

LSU Doctoral Dissertations

Aging is an irreversible process characterized by progressive physiological decline and an increased risk of metabolic disorders, cognitive impairment, cardiovascular diseases, and neurodegeneration. Disruptions to the circadian clock—whether due to genetic mutations or behavioral factors—accelerate aging and age-related pathologies, highlighting a strong link between circadian regulation and longevity. However, certain individuals harbor a dec2^P384R mutation, which enables natural short sleep without the detrimental effects of chronic sleep deprivation. This suggests that these individuals have evolved adaptations that activate pro-health pathways, allowing them to function optimally with reduced sleep. To investigate the genetic mechanisms underlying these changes, we developed a …

Biology Department Publications: 2024, Sam Lindgren

Biology Department Bibliographies

This document is a non-comprehensive list of publications made by graduate students, post-doctoral researchers, and faculty members in the Biology Department in 2024. It indexes those publications available through PubMed, and serves as an archival record of the Department's robust scholarly contributions.

The Impact Of Paternal Obesity On Placental Development And Function During Pregnancy, Delaney G. Wolfe, Delaney G. Wiolfe

Department of Nutrition Student Projects

Paternal obesity is a rising concern in conception and reproductive health, with increasing evidence suggesting its impact on pregnancy outcomes. While maternal obesity's effects on fetal development and placental function are well-documented, the role of paternal obesity remains less understood. The placenta, crucial for nutrient exchange and fetal development, can be disrupted by inflammation, oxidative stress, and epigenetic modifications, potentially leading to long-term health implications for both maternal and fetal health. Understanding the paternal influence on placental development is essential for improving pregnancy outcomes and offspring
health. This study aims to investigate the relationship between paternal obesity on placental function …

Solving The Structure Of An Ancestral Protein Tyrosine Phosphatase, Natalie Turcsanski, Edna Armah

Student Research Symposium

Protein tyrosine phosphatases (PTPs) regulate cell signaling by removing phosphate groups from tyrosine residues. Malfunction of these enzymes can lead to diseases such as diabetes and cancer. A conserved feature among PTPs is the catalytic acid loop, essential for phosphate removal. Computational analysis of PTP structures revealed that ancestral PTPs have considerable variation in conformations of this loop, sparking interest in their further study. The Asgard group, identified as ancestral to eukaryotic PTPs, was successfully expressed and purified under optimized conditions. Current efforts focus on optimizing crystallization to obtain larger crystals for structural analysis. This project will investigate the allosteric …

Metabolic Transitions In Embryos Of Artemia Franciscana: Regulation And Consequences For Oxidative Stress, Daniel Anthony Arabie

LSU Doctoral Dissertations

Embryos of Artemia franciscana survive harsh conditions in diapause and anoxia-induced quiescence for years by undergoing deep metabolic transitions. I investigated the relationship between phosphorylation of pyruvate dehydrogenase (PDH) and carbon flux to the tricarboxylic acid (TCA) cycle during metabolic depression. The difference in catalytic activity of the PDH complex (PDC) in maximally phosphorylated and dephosphorylated samples was 16.5-fold. Western blot analysis confirmed the changes in phosphorylation of PDH. Analysis of PDH expression in diapause and post-diapause embryos via phospho-PDH showed no significant differences. Investigation of post-diapause embryos under anoxia showed that phosphorylation of PDH decreased and activated the enzyme. …