Life Sciences Commons^™

Muscle Defects Lead To Skeletal Deformities In A Zebrafish Model Of Distal Arthrogryposis, Emily A. Tomak

Electronic Theses and Dissertations

Distal Arthrogryposis Type 1 (DA1) involves mild muscle weakness and limb skeletal abnormalities thought to be caused by paralysis in utero. Why the limbs are particularly affected in DA1 and the degree of paralysis that leads to these skeletal deformities in utero remains unclear. Several muscle genes are known to cause DA1, including MYLPF (myosin light chain phosphorylatable), which encodes a myosin light chain protein that binds close to the force-generating head of myosin heavy chains. The zebrafish mylpfa^-/- mutant displays a phenotype consistent with DA1, including impaired myosin activity, reduced muscle force overall, and complete fin paralysis. I …

Endothelial Interleukin-17 Receptor D (Il17rd) Promotes Western Diet-Induced Aortic Myeloid Cell Infiltration, Shivangi Pande

Electronic Theses and Dissertations

The Interleukin-17 (IL17) family is a group of cytokines implicated in the etiology of several inflammatory diseases. Interleukin-17 receptor D (IL17RD), also known as Sef (similar expression to fibroblast growth factor), belonging to the family of IL17 receptors, has been shown to modulate IL17A-associated inflammatory phenotypes. The objective of this study was to test the hypothesis that IL17RD promotes endothelial cell activation and consequent monocyte adhesion. We utilized primary human aortic endothelial cells and demonstrated that RNAi targeting of IL17RD suppressed transcript levels by 83% compared to non-targeted controls. Further, RNAi knockdown of IL17RD decreased the adhesion of THP-1 cells …

Exploring The Impact Of Pqn-75 And Glh-1/Vasa On Germline Development, Maintenance, And Gsc Reprogramming Using Caenorhabditis Elegans As A Model, Jesse D. Rochester

Electronic Theses and Dissertations

This thesis combines research on PQN-75 expression, functional motifs of GLH-1/Vasa, and germ granule components in Caenorhabditis elegans to provide a comprehensive understanding of germline development, maintenance, and reprogramming, while also examining the role of pharyngeal gland cells in stress resistance and thermotolerance. In C. elegans, pharyngeal gland cells secrete mucin-like proteins, such as PQN-75, with similarities to human PRB2. The expression of PQN-75 in gland cells confers stress resistance and thermotolerance but does not affect fertility, instead it plays a role in the organism's ability to adapt to varying environmental conditions. While, GLH-1/Vasa, an ATP-dependent DEAD-box helicase, plays …

A Quantitative Visualization Tool For The Assessment Of Mammographic Risky Dense Tissue Types, Margaret R. Mccarthy

Electronic Theses and Dissertations

Breast cancer is the second most occurring cancer type and is ranked fifth in terms of mortality. X-ray mammography is the most common methodology of breast imaging and can show radiographic signs of cancer, such as masses and calcifcations. From these mammograms, radiologists can also assess breast density, which is a known cancer risk factor. However, since not all dense tissue is cancer-prone, we hypothesize that dense tissue can be segregated into healthy vs. risky subtypes. We propose that risky dense tissue is associated with tissue microenvironment disorganization, which can be quantified via a computational characterization of the whole breast …

Telomerase Reverse Transcriptase Marks A Novel Population Of Adult Stem Cells In The Mouse Brain That Respond To Metabolic Interventions By Modulating Adult Brain Plasticity, Gabriel S. Jensen

Electronic Theses and Dissertations

Telomerase reverse transcriptase (TERT) is expressed by quiescent adult stem cells (qASC) in numerous adult murine and human tissues but has never been explored in the adult brain. Here, these data demonstrate that TERT+ cells in the adult mouse brain represent a novel population of multipotent qASCs. TERT+ cells were localized to numerous classical neuro/gliogenic niches including the ventricular-subventricular zone, hypothalamus and olfactory bulb, as well as newly discovered regions of adult tissue plasticity such as the meninges and choroid plexus. TERT+ cells expressed neural stem cell markers such as Nestin and Sox2, but not markers of activated stem/progenitor cells, …

Primary Cilia Of The Cardiac Neural Crest & Hedgehog-Mediated Mechanisms Of Congenital Heart Disease, Lindsey A. Fitzsimons

Electronic Theses and Dissertations

Elimination of primary cilia in cardiac neural crest cell (CNCC) progenitors is hypothesized to cause a variety of congenital heart defects (CHDs), including atrioventricular septal defects, and malformations of the developing cardiac outflow tract. We present an in vivo model of CHD resulting from the conditional elimination of primary cilia from CNCC using multiple, Wnt1:Cre-loxP, neural crest-specific systems, targeting two distinctive, but critical, primary cilia structural genes: Intraflagellar transport protein 88 (Ift88) or kinesin family member 3A (Kif3a). CNCC loss of primary cilia leads to widespread CHD, where homozygous mutant embryos (MUT) display a variety of outflow tract malformations, septation …

Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek

Electronic Theses and Dissertations

JC polyomavirus (JCPyV) is a human-specific pathogen that infects 50-80% of the population, and can cause a deadly, demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). In most of the population, JCPyV persistently infects the kidneys but during immunosuppression, it can reactivate and spread to the central nervous system (CNS), causing PML. In the CNS, JCPyV targets two cell types, astrocytes, and oligodendrocytes. Due to the hallmark pathology of oligodendrocyte lysis observed in disease, oligodendrocytes were thought to be the main cell type involved during JCPyV infection. However, recent evidence suggests that astrocytes are targeted by the virus and act …

The Impacts Of Embryonic Arsenic Exposure Of Fundulus Heteroclitus, Torey Bowser

Electronic Theses and Dissertations

Arsenic is a toxic metalloid that exceeds safe drinking water standards in groundwater in many locations worldwide. Arsenic exposure in fish has been linked to destruction of gill tissues, impairment of growth, decreased muscle mass, memory impairment, increased aggression, and avoidance behaviors. We examined the behavior of mummichogs (Fundulus heteroclitus) following arsenic exposure during development in two studies. Embryos were collected from fish from three reference sites: Scorton Creek (SC), Massachusetts, Wells Harbor (WE), Maine, and Block Island (BLOC), Rhode Island and two contaminated sites: Callahan Mine (CM), Brooksville, Maine, and New Bedford Harbor (NBH), Massachusetts. Embryos were …

Translational Fidelity And Its Role In Neuronal Homeostasis, Markus Terrey

Electronic Theses and Dissertations

The process of translation, which refers to decoding genetic information from mRNA to protein, is vital for all cellular function. Translational fidelity starts at the level of aminoacylation of transfer RNAs (tRNA). This reaction is catalyzed by aminoacyl tRNA synthetases where each amino acid is transferred to its corresponding cognate tRNA. Because tRNAs harbor the anticodon sequence to decodes a particular mRNA codon, the specific aminoacylation of the tRNA with a cognate amino acid establishes the rules of decoding genetic code into proteins. Aminoacylated tRNAs are then delivered to ribosomes, where ribosomes in a highly organized manner need to accurately …

Neuromuscular Development And Phenotypic Variation In Zebrafish Models Of Dystroglycanopathy, Erin Bailey

Electronic Theses and Dissertations

Skeletal muscle is highly conserved among vertebrates and is essential for strength and locomotion. This tissue becomes integrated with the skeletal system via tendons at the myotendinous junction and with the nervous system at the neuromuscular junction. Both of these specialized junctions are rich in extracellular matrix, a protein scaffold that occupies the extracellular space of cells. Skeletal muscle is also highly plastic and can grow in size (hypertrophy) or lose mass (atrophy) in response to genetic or environmental cues. Muscle atrophy is found in individuals battling a number of neuromuscular conditions, including muscular dystrophy. Muscular dystrophies are a suite …

Muscle Degeneration In A Zebrafish Model Of Lysosomal Related Myopathy, Elizabeth Coffey

Electronic Theses and Dissertations

Muscle development and homeostasis are critical for normal muscle function. A key aspect of muscle physiology during development, growth and homeostasis is modulation of protein turnover. Protein turnover is the balance between synthesis and degradation of muscle proteins. The rate of protein degradation is the major factor underlying overall muscle growth during development. Protein degradation mainly takes place in the lysosome. The efficiency of lysosomal protein degradation depends upon lysosomal pH, which is generated and maintained by proton pumps. Despite the importance of protein degradation in muscle growth during development, the impact of dysregulated lysosomal pH on muscle development, growth, …

Providing Experimental Evidence For Mouse Telomerase Reverse Transcriptase As A Novel And Unique Adult Neural Stem Cell Marker, Caroline Dean Curtis

Electronic Theses and Dissertations

With the prevalence of neurodegenerative pathologies in our society today it is imperative that we begin to look at novel approaches to the underlying problem of dying neurons that are not replaced. Adult neural stem cells exist naturally and could potentially be manipulated into targeted repair of damaged brains, given substantial research. The first step in this process is to find a way to specifically mark the earliest subset of these cells, the quiescent adult neural stem cells. Here we provide evidence for the existence of a novel and unique qANSC marker in mouse telomerase reverse transcriptase (mTERT). mTERT has …

The Effect Of Wild Blueberry Bioactives On Endothelial Cell Migration And Angiogenesis: An In Vitro Mechanistic, Genomic And Proteomic Approach, Panagiotis Tsakiroglou

Electronic Theses and Dissertations

The goal of this study is to investigate the effects of wild blueberry fractions (Anthocyanins and Phenolic acids) on vascular function and physiology. More specifically the potential effects of the above fractions and their combination in physiological concentrations on endothelial cell migration, angiogenesis, gene expression and proteins synthesis of markers related to the above processes. The objectives are to study whether anthocyanins, phenolic acids and their combinations (ACNs:PAs) affect: a) cell proliferation, b) speed of endothelial cell migration, c) angiogenesis, d) gene expression of genes critical for cell migration and angiogenesis such as RAC1, RHOA, AKT1, eNOS and VEGF and …

Characterization Of Phosphorylated G Protein Function And Membrane Culstering By Super Resolution Imaging, Sarah A. Alamer

Electronic Theses and Dissertations

Heterotrimeric G proteins play crucial roles in various signal transduction pathways, where they act as molecular switches in transducing a signal from G protein coupled receptors (GPCRs) at the plasma membrane to downstream effectors. Although their mechanism of action is mostly concentrated at the plasma membrane, their dynamic membrane organization and how it is regulated are not understood. Due to the diffraction limited resolution of fluorescence microscopy, studying the precise organization of membrane proteins can be challenging. In this study, we took advantage of super-resolution fluorescence photoactivation localization microscopy (FPALM) to overcome this challenge. Dictyostelium discoideum was used as a …

Effect Of Arsenic Exposure On Early Eye Development In Zebrafish (Danio Rerio), Remy S. Babich

Electronic Theses and Dissertations

Arsenic is a metalloid that contaminates drinking water supplies worldwide. Due to concerns for human health, the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA) have established a safe level in drinking water of ≤ 10 ppb. Arsenic has been shown to have carcinogenic effects in humans at high and low doses. Chronic exposure may result in dermal conditions such as hyperkeratosis and hyperpigmentation. Recently, arsenic exposure has also been linked to lower IQ values in children. The effect of arsenic on neurogenesis, specifically eye development, has not been widely explored. This study aimed to examine the …

Pi3k/Akt Signaling Activates Hsf1 To Preserve Proteostasis And Sustain Growth, Zijian Tang

Electronic Theses and Dissertations

Signaling through oncogenic PI3K/AKT kinase pathway is crucial to cell and organ growth. Phosphorylation by AKT has long been perceived as a key factor to enhance protein biosynthesis that enables cell growth and survival. Here, we report that HSF1, the master regulator of the proteotoxic stress response (PSR), is a new AKT substrate. Beyond mobilizing the PSR under heat shock, the AKT-mediated HSF1 activation supports robust growth. In a mouse model of human megalencephaly, expression of a constitutively active PI3KCAsuffices to drive brain overgrowth, and strikingly, it also provokes proteomic chaos including protein aggregation and amyloidogenesis. Deletion of Hsf1 …

Tarbp2 -Mediated Post-Transcriptional Regulation Of Gene Expression During Murine Embryonic Development And Spermatogenesis, Sri Ramulu N. Pullagura

Electronic Theses and Dissertations

Micro RNAs (miRNAs), which are ~22 nucleotide (nt) long RNA molecules and several RNA binding proteins (RBPs) engage in an RNA dependent post-transcriptional gene silencing process known as RNA interference (RNAi). In the canonical miRNA biogenesis pathway, an enzyme known as DICER cleaves the ~70nt pre-miRNA to a ~22nt long miRNA that is loaded into the RNAi effector mechanism, the RNA induced silencing complex (RISC).

Several in vitro studies provide suggestive evidence that mammalian double stranded RNA binding proteins (dsRBPs), such as TARBP2, act as DICER cofactors in miRNA processing and RISC loading to promote RNAi activity. A screen attempting …

Thinking Beyond The Fried Egg Model: How Accurately Do Students Perceive Cells In A Living Context?, Milissa Knox

Electronic Theses and Dissertations

This exploratory study investigated three aspects of introductory undergraduate biology students’ understanding about cells. The study, which took place at the University of Maine with voluntary students in Basic Biology (“BIO100”) in the summer and fall of 2009, examined (1) students’ pre-course perceptions of cells as they exist in a living context and (2) gains in students’ perception and knowledge about cells after completing the one-semester course (BIO100). Results are based on lecture exam scores, pre-post surveys developed as a part of this thesis, and interviews with two groups of biology students. A total of 498 students participated in the …

Microengineering The Neural Tube, Christopher Demers

Electronic Theses and Dissertations

Early embryonic development is a complex and highly regulated orchestra of instructive cues that collectively guide naïve stem cells towards progressively more specialized fates. In the neural tube, the precursor structure to the brain and spinal cord, these signals emanate from ‘organizing centers’ surrounding the neural tube. These organizing centers send out soluble cues or morphogens that diffuse tens to hundreds of microns to recipient cells residing in the neural tube. Re-creating this dynamic landscape of cues in vitro is impossible using standard cell culture tools and techniques. However, microfluidics is perfectly suited to fill this gap, allowing precise control …

Developmental Cis-Regulatory Analysis Of The Cyclin D Gene In The Sea Urchin Strongylocentrotus Purpuratus, Christopher Michael Mccarty

Electronic Theses and Dissertations

Proper execution of animal development requires that it be integrated with cell division. In part, this is made possible due to cell cycle regulatory genes becoming dependent upon developmental signaling pathways that regulate their transcription. Cyclin D genes are important bridges linking the regulation of the cell cycle to development because these genes regulate the cell cycle, growth and differentiation in response to intercellular signaling. In this dissertation, a cis-regulatory analysis of a cyclin D gene, Sp-CycD, in the sea urchin, Strongylocentrotus purpuratus, is presented. While the promoters of vertebrate cyclin D genes have been analyzed, the cis-regulatory sequences across …

Transcriptional Alterations During Mammary Tumor Progression In Mice And Humans, Karen Fancher

Electronic Theses and Dissertations

Family history, reproductive factors, hormonal exposures, and subjective immunihistochemical evaluations of in situ lesions, and to a lesser extent age, remain the best clinical predictors of an individual's risk of developing breast cancer. Identification of early markers predictive of impending invasive breast cancer from in situ carcinoma is a long-term goal. The latent mammary cancer transgenic mouse model of human breast cancer, C57BL/6JTg(WapTag)1Knw (Waptag1), develops characteristic stages of tumorigenesis in a highly predictable manner: atypical hyperplasia advances to ductal carcinoma in situ (DCIS), which progresses to papillary adenocarcinomas and/or solid, invasive tumors. Microarray analyses of whole mammary glands and tumors …