Cell and Developmental Biology Commons^™

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, …

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 …

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 …

Single Cell Pharmacodynamic Modeling Of Cancer Cell Lines, Arnab Mutsuddy

All Dissertations

Cancer is one of the leading causes of disease related death worldwide. Since the discovery of the genomic origins of cancer, targeted therapy has been developed towards specific mutations implicated for oncogenic transformation. However, current standard-of-care for mapping cancer patients to efficacious drug combination is often inadequate. The pathophysiology of tumor progression relies on the dysregulation of biomolecular pathways of which the topology and the dynamics challenge prognosis. Moreover, the overall genomic instability involved in disease states and the resulting inter-patient as well as intra-tumoral heterogeneity challenge rationalization of therapy and clinical decision-making. It highlights the need for the use …

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

College of Arts & Sciences Senior Honors 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 …

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 …

Deciphering The Functional Connections Between The Nuclear Paraspeckle And Rad51 Homologous Recombination Proteins Using A Yeast Protein Interaction System, Eric J. Nutz

Senior Theses

Homologous recombination (HR) is a repair pathway for DNA double-stranded breaks. Mutations in HR genes contribute to genomic instability and increase the prevalence of cancer. Exploiting HR deficiency in tumor cells has led to improved synthetic lethality outcomes. RAD51 paralogue protein complexes are known to be involved with HR. Proteomic analysis of RAD51 paralogues reveals a connection to the nuclear paraspeckle. A paraspeckle is a little-known, specialized organelle found in the interchromatin space of the nucleus in mammalian cells. Its three central protein components include SFPQ, NONO, and PSPC1. RAD51D is an HR protein shown previously to interact with SFPQ …

Species Delimitation Of Slimy Salamanders, Plethodon Kisatchie And Plethodon Mississippi, Across The Lower Mississippi River, Brock Hunter Stevenson

Master's Theses

Species are fundamental units of biodiversity yet delimiting species can be challenging. Slimy Salamanders of the Plethodon glutinosus species complex are a classic example of cryptic species for which species boundaries and relationships have proved difficult to determine. Once thought to be a single species ranging across the eastern United States, protein analysis revealed high genetic divergences among geographically distinct groups of populations, leading to 16 species being recognized within the group. Two of these species, the Louisiana Slimy Salamander (Plethodon kisatchie) and the Mississippi Slimy Salamander (Plethodon mississippi), are closely related but occur on opposite sides of the Mississippi …

Methamphetamine-Induced Dna Double-Stranded Breaks: The Impact Of The Dopamine Transporter And Insights Into The Mechanisms Of Dna Damage In Mouse Neuro 2a Cells, Lizette Couto

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) abuse remains a global health concern, with emerging evidence highlighting its genotoxic potential. In the central nervous system METH enters dopaminergic cells primarily through the dopamine transporter (DAT), which controls the dynamics of dopamine (DA) neurotransmission by driving the reuptake of extracellular DA into the presynaptic neuronal cell. Additional effects of METH on the storage of DA in synaptic vesicles lead to the dysregulated cytosolic accumulation of DA. Previous studies have shown that after METH disrupts intracellular vesicular stores of DA, the excess DA in the cytosol is rapidly oxidized. This generates an abundance of reactive oxygen species …

Functional Analyses Of The Polycomb-Group Genes In Sea Lamprey Embryos Undergoing Programmed Dna Loss, Cody Saraceno

Theses and Dissertations--Biology

During early embryonic development, the sea lamprey (Petromyzon marinus) undergoes programmatic elimination of DNA from somatic progenitor cells in a process termed programmed genome rearrangement (PGR). Eliminated DNA eventually becomes condensed into micronuclei, which are then physically degraded and permanently lost from the cell. Previous studies indicated that many of the genes eliminated during PGR have mammalian homologs that are bound by polycomb repressive complex (PRC) in embryonic stem cells. To test whether PRC components play a role in the faithful elimination of germline-specific sequences, we used a combination of CRISPR/Cas9 and lightsheet microscopy to investigate the impact …

Genomic Characterization Of Adolescent And Young Adult Cancers: Investigation Of Ewing Sarcoma Susceptibility And Chornobyl Thyroid Tumors, Olivia Lee

Dissertations & Theses (Open Access)

Adolescent and young adult (AYA) cancers, diagnosed between the ages of 15 and 39, can exhibit distinctive genetic and molecular characteristics. Reported epidemiologic findings and treatment outcomes based on pediatric and adult cancer studies are often not suitable for application to the AYA population, underscoring the need for more thorough genomic research. Advances in sequencing technologies have enabled comprehensive analyses of complex genomic characteristics of AYA cancers, crucial for understanding the underlying biology of these malignancies. Here, I have utilized advanced sequencing techniques and integrated analytic approaches to describe important genomic features in two different AYA cancer types: Ewing Sarcoma …

Characterization Of Developmental Phenotypes In Zebrafish With Mutations In Mmachc, Briana Elise Pinales

Open Access Theses & Dissertations

Methylmalonic aciduria and homocystinuria, CblC type (cblC) syndrome (MIM 277400) is a genetic disorder resulting from a mutation in the MMACHC gene. This gene plays a crucial role as a chaperone in the conversion of vitamin B12 into its active form, which is essential for proper cellular metabolism. cblC syndrome is heterogenous by nature, primarily attributed to the extensive damage it causes across multiple bodily systems. In cases of early onset of cblC syndrome, patients may exhibit a diverse range of clinical symptoms including difficulties with feeding, dysmorphic features, microcephaly, brain abnormalities, hypotonia, developmental delays, and seizures. The study of …

Dynamics Of Site Search Process And Formation Of Synaptosome Assembly Characterized By Single Molecule Approaches, Sridhar Vemulapalli

Theses & Dissertations

Genome dynamics and integrity are the two crucial features defining the successful functioning of cells and their maintenance and evolution. The genetic processes in the cell require distant communications between the regulatory regions controlled by specific proteins. Mistakes in this interaction process will lead to termination of the genetic process may lead to the cell damage, disease development or the cell death. Similar distant regulatory process is required for numerous genome integration systems such as Variable Diversity Joining (V(D)J) recombination system resulting in the specificity of the immunoresponse, a defining property of the adaptive immune system. A common feature of …

Recovery From Social Isolation In Drosophila: The Role Of Dopamine And The Autism-Related Gene Nlg3., Ryley T. Yost

Electronic Thesis and Dissertation Repository

Within a group, individuals establish their preferred distance from each other, or social space, a form of social behaviour. The resulting distance depends on the exchange of social cues from others that needs to be perceived and integrated within the organism’s neural circuitry. In humans, social spacing can be impaired in neuropsychiatric disorders such as autism and schizophrenia. When organisms are subject to social isolation, profound changes in social behaviour are observed in a variety of species from insects to mammals, including social space. However, the genetic and molecular mechanisms modulating a behavioural response to isolation and possible recovery remain …

Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer

Dartmouth College Ph.D Dissertations

The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …

Atomistic Assessment Of Drug-Phospholipid Interactions Consequent To Cancer Treatment: A Study Of Anthracycline Cardiotoxicity, Yara Elsayed Ahmed

Theses and Dissertations

Despite being one of the most effective chemotherapeutic agents developed to date, Anthracyclines are notorious for their cardiotoxicity. Their clinical use is frequently limited both in dosage and in prescription due to the severe cardiac damage they cause. The mechanism of anthracycline-induced cardiotoxicity is not yet fully understood. However, it is hypothesized that interactions with the myocardial membrane play an important role in imparting cardiotoxicity. In this study, we use molecular dynamics simulations and density functional theory calculations to study the anthracycline drug molecules and the interactions that they have with the myocardial membrane. We construct a myocardial membrane model …

Quantitative And Qualitative Analysis Of Mutation In Pam-1 Of Model Organism Caenorhabditis Elegans., Jessica Stein, Jessica Stein

Honors College Theses

The pam-1 gene in the model roundworm Caenorhabditis elegans governs meiotic exit and establishment of cellular polarity in the single-celled C. elegans embryo. Mutation of the pam-1 gene results in reduced fertility and fecundity in adult C. elegans and disrupts the anatomy of the germinal gonad. The aim of this study is to qualitatively and quantitatively define the changes in the germline cells associated with mutations to the pam-1 gene. Specifically, we examined the stages of germ cell development within the gonads of adult worms, both wild-type and pam-1 compromised, and identified the changes in the length of the mitotic, …

Investigating The Absence Of A Dietary Response At The Neuromuscular Junction In Larval Drosophila Melanogaster, Suzanna Marbach

Honors Program Theses and Research Projects

Research in Drosophila melanogaster (D. melanogaster) has been growing in order to identify the fundamental processes of human disorders of the central nervous system such as Alzheimer’s disease, diabetes, and other neurological disorders at a molecular level. Altered insulin signaling itself has been linked to widespread nervous system dysfunction including cognitive dysfunction, neuropathies, and susceptibility to neurodegenerative disease. However, knowledge of the cellular mechanisms underlying the effects of insulin on nervous system function is still incomplete. The focus behind investigating the insulin signaling pathway is derived from our observations in the adult D. melanogaster neuromuscular junction (NMJ) to changes in …

Review Of Biomedical Applications Of Cardiovascular Tissue Engineering, Natalie M. Howard

Honors College Theses

Tissue engineering can be defined as processes that aim to generate three-dimensional functional tissues in vitrothat have been favorably altered according to the structural, biochemical, electrophysiological, and biomechanical properties of the desired tissue before implantation into the human body. In relation to cardiac tissues, these properties would include the ability to conduct action potentials, withstand systolic pressure, permit sufficient O₂ and CO₂penetration, sufficient vascularization to supply nutrients for cellular activity, surface topology that enables cellular communication, and more. As heart diseases and instances of myocardial infarction continue to rise worldwide, there is an increasing need for …

Targeting Metabolic Alterations Associated With Smooth Muscle Α-Actin Pathogenic Variant Attenuates Moyamoya-Like Cerebrovascular Disease, Anita Kaw

Dissertations & Theses (Open Access)

Heterozygous pathogenic variants in ACTA2, encoding smooth muscle α-actin (α-SMA), predispose to thoracic aortic aneurysms and dissections. De novo missense variants disrupting ACTA2 arginine 179 (p.Arg179) cause a multisystemic disease termed smooth muscle dysfunction syndrome (SMDS), which is characterized by early onset thoracic aortic disease and moyamoya disease-like (MMD) cerebrovascular disease. The MMD-like cerebrovascular disease in SMDS patients is marked by bilateral steno-occlusive lesions in the distal internal carotid arteries (ICAs) and their branches. To study the molecular mechanisms that underlie the ACTA2 p.Arg179 variants, a smooth muscle-specific Cre-lox knock-in mouse model of the heterozygous Acta2 R179C variant, termed …

Methyltransferase, Glucose Adaptation, And Import Complex In Trypanosoma Brucei, Emily Knight

All Dissertations

Trypanosoma brucei is a kinetoplastid parasite responsible for human African trypanosomiasis (HAT) and nagana, a livestock wasting disease, which both endemic to sub-Saharan Africa. Unique to kinetoplastids are the specialized peroxisomes, named glycosomes, which compartmentalize the first several steps of glycolysis and gluconeogenesis, nucleotide sugar biosynthesis, and many other metabolic processes. Kinetoplastids are unique in that they have a single mitochondrion. In this work, I present the first study into SET domain proteins in any kinetoplastid parasites. We have characterized a predicted SET domain protein, TbSETD3, that localizes to the mitochondrion and a depletion of the protein results in growth …

Genetic Regulation Of Müllerian Duct Regression, Malcolm Moses

Dissertations & Theses (Open Access)

Mammals, including humans, develop progenitor tissues for both male and female reproductive tract organs before they fully differentiate into a male or female tract. The progenitor tissue for the male reproductive tract is known as the Wolffian duct (WD), and the progenitor tissue for the female reproductive tract is the Müllerian duct (MD). The WD further differentiates into the vas deferens, epididymis, and seminal vesicle, while the MD differentiates into the oviduct, uterus and upper vagina. An essential step in sex differentiation for males is the regression of the MD. This regression initiates with anti-Müllerian hormone (Amh) transcription …

Validating A New In Vivo Model To Study Als, Izabela J. Cimachowska

Student Theses and Dissertations

Buildup of oxidative stress and mitochondrial dysfunction are well known characteristics of both sporadic and hereditary amyotrophic lateral sclerosis (ALS). While both forms of the disease seem to arise from common cellular dysfunction, the genetic disease is studied to a much greater extent. Engineering novel animal models of the sporadic form of the disease is crucial for development of druggable targets to treat ALS and understand the underlying mechanisms. Interestingly, accumulation of oxidative stress by exacerbated emission of reactive oxygen species (ROS) from presynaptic mitochondria is a hallmark of both hereditary and sporadic ALS. Previous work by our laboratory showed …

Unique Transcriptional Profiles Underlie Osteosarcomagenesis Driven By Different P53 Mutants, Dhruv Chachad

Dissertations & Theses (Open Access)

Missense mutations in the DNA binding domain of the Trp53 gene are characterized as structural (p53R172H) or contact (p53R245W) mutations based on their effect on the conformation of the protein. These mutations show gain-of-function activities such as increased metastatic incidence as compared to p53 loss, often mediated by their interaction with a repertoire of transcription factors. These interactions are largely context specific. In order to understand the mechanisms by which these mutations drive osteosarcoma progression, we created a mouse model, wherein either the p53 structural mutant p53R172H, or the contact mutant, p53R245W, are expressed specifically in …

Investigating The Role Of Spatial Compartmentalization And Genomic Translocations In Metastatic Cancer: A Multi-Omic Analysis, Joshua Harris Garretson

Chancellor’s Honors Program Projects

No abstract provided.

P53 Dimers Elicit Unique Tumor Suppressive Activities Through An Altered Metabolic Program, Jovanka Gencel-Augusto

Dissertations & Theses (Open Access)

p53 is the most frequently mutated tumor suppressor in human cancer. As a tetrameric transcription factor, mutation of the p53 Tetramerization Domain (TD) is a mechanism by which cancers abrogate wild-type (WT) p53 function. p53 TD mutations result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. Although it is accepted that tetrameric p53 is required for full tumor suppressive activities, the physiological relevance of monomeric and dimeric states of p53 is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome …

Regulation Of De Novo And Maintenance Dna Methylation By Dnmt3a And Dnmt3b, Yang Zeng

Dissertations & Theses (Open Access)

DNA methylation (5-methylcytosine, 5mC) is essential for the regulation of gene expression and integrity of the mammalian genome. It occurs predominantly in the context of CpG dinucleotides to form a symmetrical pattern on both DNA strands, which allows DNA methylation patterns to be semi-conservatively maintained during DNA replication. There are two classes of DNA methyltransferases (DNMTs): DNMT3A and DNMT3B function primarily as de novo methyltransferases that establish DNA methylation patterns, whereas DNMT1 is the major enzyme responsible for maintaining DNA methylation patterns by converting hemi-methylated CpGs to fully methylated CpGs during DNA replication. Two accessory factors also play critical regulatory …

Gonads Without Glp-1: Silencing Glp-1 In The Male Somatic Gonad In Caenorhabditis Elegans, Matthew Titus

Undergraduate Theses

In C. elegans, the gene glp-1 encodes for a Notch receptor called GLP-1, one of two found in C. elegans’ genome. The gene has been previously implicated in the development of the hermaphroditic germline as well as playing a role in the mitosis/meiosis decision. Genetic screening has further identified it as potentially playing a role in the development of the male somatic gonad, making it an ideal candidate for a reverse genetic. We did this by silencing glp-1 and observing if any alterations to the gonad’s phenotype occur.

Normally this could be done by performing a gene knockout. …

Understanding The Expression And Role Of Pros-1 In The Male Gonad Of C. Elegans, Jack Bozik

Undergraduate Theses

The gene pros-1 is a transcription factor that is highly expressed within neuronal sheath cells, glial cells, and excretory canal cells. pros-1 plays a role in cell determination of those cell types in the nematode C. elegans, which promotes organismal development. But the degree to which pros-1 presence is important is still not fully understood, because there are many genes involved in development that when mutated or damaged can result in unexpected phenotypes or even total loss of function to a certain developmental mechanism. What makes pros-1 valuable to research is that it is a functional homologue to a …

Role Of Cdx4 And Sp5l In Zebrafish Development, Wesley Tsai

Honors Theses

The Caudal Type Homeobox transcription factors cdx are a family of genes found in vertebrates that regulates body regionalization and anterior-posterior patterning. They are also responsible for regulating axial elongation, but the mechanisms behind this behavior are not known. Previous studies in mouse embryonic stem cells have shown that the cdx genes are necessary for upregulating the gene sp5 which may be linked to axial elongation. Sp5 is a zinc-finger transcription factor belonging to the specificity protein (sp) family. Our group has used in-situ hybridization experiments on zebrafish embryos to show that sp5-like (sp5l) is transcribed within tailbud tissues that …