Cell and Developmental Biology Commons^™

Uncovering Novel Small Regulatory Rna In Protostome, Sweta Khanal

Dissertations

Small RNAs play pivotal roles in post-transcriptional gene regulation across diverse phylum of protostomes. In this study, we investigate the functional significance of atypical miRNAs, mirtron miR-1017 in Drosophila. Through ectopic expression in neuronal cells, we demonstrate that miR-1017 extends lifespan by targeting its host transcript, acetylcholine receptor Dα2, and influencing its splicing. This novel trans-regulatory function suggests a mechanism for mirtron evolution, highlighting the interplay between splicing and post-transcriptional regulation. Additionally, we profile small RNA populations in the polychaete developmental model Capitella teleta, shedding light on the small RNA landscape in annelid worms. Our analysis reveals a rich …

Towards Understanding The Function Of An Ets-Like Gene In Nematostella Vectensis: Generation Of A Knockout Mutant Line And A Transgenic Reporter Line, Emily Bullock

Biological Sciences Undergraduate Honors Theses

Due to their unique phylogenic position as sister to Bilateria, Cnidaria are often credited with the utility of allowing for reconstruction of ancestral biology based on characteristics shared with bilaterians and other animals. This factor makes investigation into the nervous systems of cnidarians critical in understanding early neural evolution. Wamides, a class of neuropeptides, have been shown to play a regulatory role in life cycle transitions across many different species. The cnidarian specific Wamide neuropeptide, GLWamide, has previously been identified to play an accelerator role in the metamorphic timing of a specific species of sea anemone, Nematostella vectensis. However, …

Characterization Of Mitochondrial Morphology In Drosophila: Early Embryogenesis Description Via Confocal Microscopy, Kendall Miller

Biological Sciences Undergraduate Honors Theses

Mitochondria are not static organelles, but instead are dynamic networks that undergo rapid changes in subcellular distribution, organization, and activity in response to external stimuli. Notably, mitochondria can undergo fission and fusion, collectively known as mitochondrial dynamics. Mitochondrial fusion creates assembled networks of mitochondria that are maximally efficient at generating ATP through oxidative phosphorylation. Conversely, mitochondrial fission leads to network fragmentation and a shift towards glycolysis, which is the dominant mode of ATP generation in oxygen-limiting and stressed conditions. While mitochondrial dynamics have been intensively studied in isolated cells under stressful conditions, much less is known about how mitochondria behave …

Investigating The Modulation Of Metastasis By Dax-1 In Adrenal Carcinoma Cells, Aarya Mishra

Undergraduate Honors Theses

The nuclear hormone receptor (NHR), DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1), is important in adrenal and gonadal development as well as steroidogenesis. It is encoded by the NR0B1 gene and functions mainly as a transcriptional repressor. Classified as an orphan receptor within the NHR superfamily, DAX-1 has been shown to inhibit other NHRs including estrogen receptor, androgen receptor and steroidogenic factor 1. DAX-1 is found to be underexpressed in breast and prostate cancers and, specifically in prostate cancer, is believed to be a transcriptional repressor of genes that are involved in epithelial-mesenchymal transition …

Role Of M6a Rna Methylation In Skeletal Muscle Regeneration, Isreal Ayobami Onifade

Legacy Theses & Dissertations (2009 - 2024)

Skeletal muscle is essential in orchestrating voluntary movement and contributes to approximately half of the body's overall mass. Dysregulation in proper skeletal muscle development can lead to muscle degenerative disorders, such as severe Duchenne Muscular Dystrophy (DMD). Understanding the process of muscle development has been the central focus of numerous biological studies, focusing on myogenic transcription factors and signaling molecules like Pax3, Pax7, Myf5, MyoD, WNT, TGF-β, and BMP, IGF1, AKT/mTOR pathway. Also, studies have suggested that m6A (N6-methyladenosine) plays a crucial role in various biological processes, including skeletal muscle regeneration and development. m6A modification is the prevalent form of …

The Role Of B Cell Activation State And Sex In Aryl Hydrocarbon Receptor Mediated Induction Of Chemokine Receptor 9 And Alpha4beta7 Expression In Vitro, Logan Bauerle

Master's Theses

Defense of mucosal tissues from microbial infection and allergy is reliant on continual production of antibodies. The aryl hydrocarbon receptor (AhR) is known to regulate B cell development and is associated with suppression of systemic humoral immunity. Recent attention has been paid to the role of the AhR in altering expression of cell adhesion molecules (CAMs). B cells express CAMs and chemokine receptors to migrate around the body for localized secretion of antibodies. AhR agonists promote B cell migration to the small intestine through upregulation of chemokine receptor 9 (CCR9) and integrin α₄β₇. Both the AhR …

Role Of Atp-Binding Cassette (Abc) Transporters As A Protector Of Testis Stem Cell Niche From Chemotherapy Drugs In Drosophila Melanogaster, Swagata Maity

Master's Theses

In chemotherapy treatments most tumor cells are destroyed by drugs, but some tumor cells are drug resistant, and these are known as cancer stem cells (CSCs). Normal adult stem cells are also chemo resistant. Therefore, investigation of normal stem cells can be useful to provide further knowledge of CSCs. One of the primary ways that CSCs achieve drug resistance is by drug efflux through transmembrane pumps called ATP-binding cassette (ABC) transporters. Many studies on ABC transporters have been performed in vitro using cultured cell lines, but very few studies have been performed on normal stem cell populations in vivo. Drosophila …

Sdf-1Α Mediates Primary Tumor Escape In Glioblastoma Through Activation Of Mesenchymal Transitions., Charles T. Froman-Glover

College of Arts & Sciences Senior Theses

Glioblastoma (GBM), a highly aggressive primary brain tumor originating in glial cells, poses a significant challenge due to its rapid growth and invasive nature within healthy brain tissue.

Current treatments involve surgical resection, chemotherapy, and radiation. These treatments alone are not enough to cure this disease, and a better understanding the mechanics of the tumor micro-environment is imperative to furthering the field of cancer research. This research focuses on understanding the tumor microenvironment's impact, specifically investigating the role of stromal cell-derived factor 1 (SDF-1) mechanics on GBM aggressiveness. SDF-1 is known to facilitate disease progression by facilitating chemotaxis toward the …

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald

College of Arts & Sciences Senior Theses

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in Western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …

Understanding The Role Of Minor Intron Splicing In Spermatogenesis, Jade Rosado, Kazumasa Takemoto, Rahul Kanadia

Honors Scholar Theses

The minor spliceosome is composed of the unique small nuclear RNAs (snRNA), U11, U12, U4atac, and U6atac, and is necessary for the splicing of less than 0.5% of introns, termed minor introns. Minor intron containing genes (MIGs) regulate diverse processes, one of which is spermatogenesis. Specifically, 111 testis-specific MIGs have been identified, suggesting that minor splicing is necessary for spermatogenesis. To interrogate the role of minor splicing in spermatogenesis, we conditionally ablated the Rnu11 gene, which encodes for the U11 snRNA, in the developing testes via Stra8-iCre, creating a Rnu11^Flx/Flx::Stra8-Cre⁺ mutant. We found, at postnatal …

The Study Of Dmrt1 In Zebrafish And How It Impacts Sex Determination, Raymond Michael Poirier

Graduate Masters Theses

The dmrt1 gene is common amongst most animals and functions to determine or maintain male sex during development. Similarly, in zebrafish dmrt1 is important for male sex determination and maintaining proper testis morphology. This gene is expressed in two different cell types of the testis in zebrafish, germ cells and Sertoli cells. While we know where this gene is expressed and what its role is, it is not known if it is sufficient to drive male fate. If so, then in which cells is it sufficient to drive male fate in the testis? I aimed to answer this question by …

Simvastatin Induces Autophaghy-Mediated Cell Death In Metastatic Breast Cancer Cells, Jessica Allagoa

Theses (2016-Present)

Breast cancer remains one of the leading causes of cancer deaths among women. Due to the limited effectiveness of current anticancer drugs, ongoing research has extended towards alternative drug categories for potential treatments. Recent findings indicate that statins possess the ability to suppress tumors across various cell types. Traditionally, statins are known as a class of cholesterol-lowering agents and function by inhibiting 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, a key enzyme in the mevalonate pathway. However, statins can also suppress cell proliferation and ultimately lead to cell death, which includes Type I apoptosis-induced cell death or Type II autophagy-induced cell death. Autophagy is …

Foxo1 Inhibitor, As1842856, Induces Cell Cycle Arrest And Reverses Anticancer Drug-Induced Cytotoxicity In Osteosarcoma Cells, Antanay Hall

Theses (2016-Present)

Forkhead box class O (FOXO)-1 transcription factor controls cell proliferation, apoptosis, oxidative stress, and other cellular activities; FOXO1 has also been implicated in cell cycle regulation. This research project aims to determine the contribution of FOXO1 to cell cycle regulation and response to anticancer drug treatment in osteosarcoma. Osteosarcoma is the most common bone cancer, with most cases occurring in people younger than 30 years old. The study explores the impact of FOXO1 inhibitor AS1842856 on the cytotoxic effects of anticancer drugs in CCHOSD, Hos, and LM7 osteosarcoma (OGS) cell lines. Following chemical inhibition of FOXO1 and anticancer drug treatment, …

College Of Natural Sciences Newsletter, Spring 2024, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message
Page 2 New Faculty and New Club on Campus
Page 3 2024 URSCAD Awards
Page 4 Day of Scholars 2024
Page 5 SDSU's First Representation at the Association for Anatomy's 2024
Annual Conference
Page 6-7 2024 Honor's College Convocation
Page 8 Other Student Activities
Page 9 Faculty Awards
Page 10-11 Other News
Page 12 2024 Drone Day and American Association of Geographers Convention - Hawaii
Page 13 55th Annual Geography Convention
Page 14 2024 Stethoscope Ceremony
Page 15 Open PRAIRIE Data

A Review Of Rheb Activation Of Mtorc1 And The Great Mystery Of One Missing Gef, Jack Gregory

Senior Honors Theses

The mTORC1 pathway is involved in the regulation of cell growth and translation. The pathway has a complex web of activators and inhibitors to activate mTORC1. mTORC1 is regulated via a small GTPase called Rheb, which interacts directly with mTORC1. This GTPase and its GTPase activating protein (GAP), TSC1/2, have been widely studied to understand how the variety of regulators of mTORC1 interact with these proteins. Despite this, the guanine nucleotide exchange factor (GEF) of Rheb has yet to be identified. This review broadly analyzes Rheb and mTORC1, their structures, regulations, and interactions, and explores the mystery of the missing …

The Role Of The Transcription Factor Cebpa In Regulating Lung Alveolar Type 2 Cell Fate In Vivo, Dalia Hassan

Dissertations and Theses (Open Access)

Cell plasticity can extend across all possible cell types, yet it naturally diminishes as cells progress through differentiation. This plasticity can be reactivated during injury repair, engaging developmental flexibility. Our investigations reveal the critical role of the transcription factor (TF) CEBPA, specific to lung alveolar type 2 (AT2) cells, in modulating AT2 cell plasticity within the mouse lung. We demonstrate that CEBPA constrains AT2 cell plasticity by promoting the AT2 differentiation program and recruiting the lineage-specific TF NKX2-1. Without CEBPA, AT2 cells, in both neonatal and mature, show a diminished AT2 program; however, only neonatal cells re-activate the SOX9 progenitor …

Stability Of Dna In Saliva Evidence Collected With Two Different Swabbing Solutions, Kuanwei Lu

Student Theses

As the significance of trace DNA has increased over time, it has become more important to optimize each process to avoid any loss of genetic material. Factors that could negatively affect the quality and quantity of DNA during transport or storage include environmental temperature, the DNA collection devices, the packaging, and possible contamination. This study compared the DNA stability of saliva stain swabs collected by moistening the swab with deionized water or Sample Keeper and stored at room temperature. Sample Keeper (Microread Genetics, Beijing) is a proprietary buffer marketed as a DNA stabilizing agent. We swabbed 110 saliva stains from …

Advancements In Crispr-Cas9 Gene Editing: Applications And Future Implications For Sickle Cell Disease And Β-Thalassemia Treatment, Swetha Battini

Honors Scholar Theses

This literature review explores the utilization of CRISPR-Cas9 gene editing technology in addressing Sickle Cell Disease (SCD) and Beta-Thalassemia. CRISPR, leveraging the Cas-9 enzyme inspired by bacterial defense mechanisms, serves as a precise molecular tool for targeted genetic modifications. The process involves guide RNA directing Cas-9 to specific DNA sites, allowing for meticulous gene editing. Focusing on the specific applications of CRISPR in SCD and Beta-Thalassemia, the review critically analyzes recent methods, including CRISPR-Cas9 editing targeting the BCL11A enhancer for SCD and the HBG1/HBG2 promoters for both SCD and Beta-Thalassemia. The synthesis of findings highlights the potential and challenges of …

The Role Of Mettl21a In Kras-Driven Cancers, Xiaojie Yang

Dissertations and Theses (Open Access)

Abstract

More than 100 lysine methyltransferases (KMTs) were predicted to be present in the human proteome, and many were implicated in cancer etiology. However, the catalytic activity and substrate specificity for many of these enzymes remain unknown. Our work aimed to explore the role of Methyltransferase like 21A (METTL21A), amember of the little-studied seven β- strand family of candidate lysine methyltransferases (KMTs), and its role in regulating pancreatic ductal adenocarcinoma (PDAC) and lung adenocarcinoma (LUAC) tumorigenesis. Through the meta-analysis of publicly available gene expression datasets, I found that METTL21A is significantly downregulated in PDAC and LUAC versus normal tissue, and …

Oxidative Phosphorylation In Melanoma Brain Metastases: A Regulator Of The Tumor Immune Landscape, Renato A. Guerrieri

Dissertations and Theses (Open Access)

Previously, we demonstrated via RNA-sequencing analysis of murine intracranial melanoma tumors that pharmacologic inhibition of oxidative phosphorylation (OXPHOS) results in increased expression of genes consistent with activated anti-tumor immune responses. The central hypothesis of this dissertation is that OXPHOS plays a critical role in the pathogenesis and immune regulation of melanoma brain metastases (MBMs).

The functional significance of OXPHOS was assessed through genetic inhibition, involving knockout (KO) of key regulatory genes such as Ppargc1a (PGC1a) and Ndfus4 (NDUFS4), a component of mitochondrial complex I. PGC1a KO in an RCAS-TVA mouse model of autochthonous lung and brain tumors developing from primary …