Life Sciences Commons^™

Caulobacter Clpxp Adaptor Popa’S Domain Interactions In The Adaptor Hierarchy Of Ctra Degradation, Thomas P. Scudder

Masters Theses

The degradation and recycling of protein is a process essential for the maintenance and regulation of cellular function. More specifically, in Caulobacter crescentus, the ClpXP protease is responsible for driving progression through the cell cycle and protein quality control. This protease utilizes three known adaptors to selectively degrade proteins that initiate different stages of development. This thesis will elaborate on the specific binding interface on one of these adaptors, PopA, with another, RcdA, and focus in on specific residues on PopA and investigate their roles in adaptor binding and delivery of CtrA, the master regulator of Caulobacter. Finally, I …

A Comparison Of Pm-Nato3’S Influence On Neural Progenitors And Mature Dopamine Neurons, Mary E. West

Masters Theses

This thesis presents significant findings regarding the role of PM-Nato3 in its interaction with developing neurons in the context of Parkinson's disease (PD) and regenerative medicine. We investigated the effects of PM-Nato3 on dopamine (DA) neurogenesis under different culture conditions, both in vitro and in vivo. In the standard dopaminergic culture condition, PM-Nato3 potentially increased the speed of DA neuron production but did not significantly increase the yield of DA neurons. In a minimal culture condition, there was no notable difference between the control and PM-Nato3 conditions, suggesting minimal impact on DA neurogenesis. In vivo studies using a mouse model …

Migratory Material: Epigenetics & Weaving At The Us-Mexico Border, Valerie Navarrete

Masters Theses

Discourse often sutures the body shut, disallowing representations of identity to outgrow sociopolitical interests. This issue may originate from borders, but also from the unnamable pathology that generational colonial trauma transmits to the mind, body, and environment. Without a direct form of translatability, this thesis proposes a new materialism that deviates from any object-oriented ontology. Untethered and intra-active, epigenetics and weaving represent objects that transform typical ways of knowing and seeing. Their sensitivity to the environment, in addition to their mobility across generations of time, broaden the spatiotemporal loci of the body and its embodiment. Proposing new materials that expand …

The Effects Of Deleting Lrb E3 Ligase Region 2 On Red Light Responses In Arabidopsis Thaliana, Sabina Liskey

Masters Theses

The ability of plants to absorb light through photoreceptors is essential for successful plant development. Phytochromes are important plant photoreceptors that detect and absorb red and far-red light and must function properly for plant survival. The Light Response BTB proteins (LRB) play an important role in a plant’s response to red light by degrading phytochrome B (PhyB) via the ubiquitin proteasome system (UPS). Although there has been a successful investigation into understanding the function of the LRBs, the function of a few regions within LRB proteins remains unknown, including a portion located on the N-terminal end of the protein, termed …

Developmental Exposures To Pfas Mixtures Impair Elongation Of The Exocrine Pancreas In Zebrafish (Danio Rerio), Emily M. Formato

Masters Theses

Poly- and perfluoroalkyl substances (PFAS) are a class of bioaccumulative toxicants used in numerous industrial and commercial products. Perfluorooctanesulfonic acid (PFOS) alters pancreatic organogenesis during development, and perfluorohexanesulfonic acid (PFHxS) has been suggested as a replacement for PFOS due to its shorter carbon chain, but they are often found together in surfactants, such as legacy aqueous film-forming foam. This study investigates how developmental exposures to a PFAS mixture (PFHxS + PFOS) impact the developing exocrine pancreas. Zebrafish embryos (Tg(ptf1a:GFP)) were exposed to 0.01% DMSO, or 8, 16, 32 μM PFHxS alone, 16 μM PFOS alone, and 8, 16, and 32 …

Microbial Experience Increases Cytotoxicity Of Tumor-Infiltrating Cd8+ T Cells And Controls Tumor Growth, Nicholas Aaron Bunda

Masters Theses

Cancer immunotherapy research is traditionally conducted with specific pathogen-free (SPF) mice, which most accurately mimic the immune system of a human newborn. This makes translational research challenging, as this mouse model is not an accurate reflection of the adult patients who ultimately receive newly developed treatments. It is necessary to further develop a mouse model that bridges this gap and increases translatability of current cancer immunotherapy research.

By cohousing specific pathogen-free mice with regular pet store (PS) mice, we have generated a cohoused (CoH) mouse that reflects the microbial experience of an adult human immune system. We investigated antigen experience, …

The Effect Of Bovine Endometrial Cell Conditioned Media On In Vitro Produced Bovine Embryo Development And Gene Expression, Mary A. Oliver

Masters Theses

In vitro produced (IVP) bovine embryos provide enhanced genetic value and a means for studying early embryonic development. However, IVP embryos are developmentally compromised and are lower quality compared to in vivo derived (IVD) embryos. Consequently, after transfer pregnancy rates from IVP embryos are consistently lower, as they exhibit the highest amounts of pregnancy failure during the early embryonic phase (prior to day 28). Progesterone (P4) has been shown to influence bovine endometrial epithelial (EPI) and stromal fibroblast (SF) cells to secrete developmentally important molecules that promote early embryo development and conceptus elongation. However, IVP embryos are not exposed to …

Utilizing Fluorescence Microscopy To Characterize The Subcellular Distribution Of The Novel Protein Acheron, Varun Sheel

Masters Theses

All cells carry the genetic machinery required to commit cell suicide; a process known as programmed cell death (PCD). While the ability to initiate PCD serves a number of useful purposes during development and homeostasis, misregulation of PCD is the underlying basis of most human diseases, including cancer, autoimmunity disorders and neurodegeneration. Using the tobacco hawkmoth Manduca sexta as a model organism, the Schwartz lab at UMass has demonstrated that PCD requires de novo gene expression and has cloned many death-associated genes. One of these genes encodes a novel protein that was named Acheron after one of the rivers of …

Activation Of Nrf2 At Critical Windows Of Development Alters Protein S-Glutathionylation In The Zebrafish Embryo (Danio Rerio), Emily G. Severance

Masters Theses

Perturbation of cellular redox homeostasis to a more oxidized state has been linked to adverse human health effects such as diabetes and cancer. However, the impact of altering the regulation of redox homeostasis during development is not fully understood. Specifically, this project investigates the role of the Nrf2 antioxidant response pathway and its effect on glutathione (GSH; cellular redox buffer) at critical windows of development. To explore this, we used zebrafish embryos (Danio rerio) as a model due to the function of GSH and the Nrf2 being conserved among vertebrates. We exposed zebrafish embryos to three Nrf2 activators: two antioxidant …

Defining The Role Of Rbbp4 In Oocyte Maturation And Preimplantation Development Using Trim-Away, Holly L. Barletta

Masters Theses

Retinoblastoma-binding protein 4 (RBBP4) is a subunit of chromatin remodeling factor 1 (CAF-1) and is essential for mammalian oocyte maturation, embryo survival, and embryo implantation. RBBP4 also localizes to the chromatin and is a ubiquitously expressed nuclear protein. Previous methods used to study this protein include short interfacing RNAs (siRNAs) and CRISPR/Cas9. These techniques have limitations such as determining an indirect depletion of proteins, may trigger compensatory mechanisms, and may not be useful in non-dividing primary cells. A new, acute, and rapid endogenous protein depletion technique called Trim-Away, can overcome these limitations. Trim-Away is also widely applicable since it can …

Retinal Regeneration In A Genetic Mouse Model Of Glaucoma, Joshua Paris

Masters Theses

Glaucoma is a degenerative retinal disease characterized by progressive loss of retinal ganglion cells (RGCs). Previous studies have shown that application of a specific α7 nicotinic acetylcholine receptor agonist, PNU-282987 (PNU), onto the murine retina induces neurogenesis of numerous retinal cell types, including RGCs. The aim of this study is to characterize the short-term and long-term effects of PNU in a glaucoma model. The effects of PNU were analyzed in a DBA/2J mouse model that auto-induces a glaucoma-like condition in adulthood. These mice manifest an elevated intraocular pressure (IOP) starting at 6 months, followed by loss of RGCs. To assess …

Exploration Of The Association Between Muscle Volume And Bone Geometry Reveals Surprising Relationship At The Genetic Level, Prakrit Subba

Masters Theses

The evolution of jaws in cichlid fishes of the East African Great Lakes is a textbook example of adaptive radiation in vertebrates. Karl Liem postulated that this adaptive radiation has been possible due to the functional decoupling of two cichlid functional units – the pharyngeal jaw (PJ) and the oral jaw (OJ). This functional decoupling of the jaws has enabled the OJ to be relieved of its dual role of prey capturing and processing and has allowed the PJ to take on the role of prey processing. As a result, African cichlids have adapted the morphology of their functional units …

The Investigation Of Group 1 Late Embryogenesis Abundant Protein 6 And Its Role In Arabidopsis Thaliana Desiccation Tolerance, Joann Eise Thomson

Masters Theses

Like most seeds, Arabidopsis thaliana seed development is divided into three major phases: morphogenesis, storage deposition, and maturation drying. During maturation drying the seed becomes desiccation tolerant (DT) at some point and the seed rapidly loses water until its moisture level is approximately 10% on a fresh weight basis. The ability of the seeds to withstand this extreme water loss is hypothesized to be due, in part, to the accumulation of late embryogenesis abundant (LEA) proteins. In A. thaliana, there are 51 LEA proteins which are divided into seven groups based on amino acid sequence similarities. Group 1 LEA …

Putative Flagellar Channel-Lining Residues And Their Role In Filament Synthesis, Morphology And Stability, Troy Burtchett

Masters Theses

Bacterial flagella are comprised of ~20,000 repeating subunits called flagellin and are synthesized by transporting unfolded flagellin monomers through the central channel of the flagellar filament to the distal end where they are folded and incorporated into the growing structure. The transport mechanism is predicted to be facilitated by a hydrophilic coating of amino acid side chains on the inside wall of the central channel that repels the mostly hydrophobic surface of the unfolded flagellin monomer. The lack of interaction between the flagellin monomer and the central channel wall is thought to allow for the passive diffusion of protein monomers. …

Evaluation Of Autoreactivity In Vh4-34-Containing Antibodies From Human B-1 Vs B-2 Cells, Michelle E. Ray

Masters Theses

B-1 cells are a unique population of lymphocytes, with distinct phenotypic and functional characteristics in comparison to conventional B-2 cells. B-1 cells are thought to be more closely related to the innate immune system than the adaptive, and B-1 cells constitutively secrete antibody that is recognized as broadly reactive with low levels of autoreactivity. The antibody heavy chain segment, VH4-34, is overutilized by the human B-1 cell population. VH4-34 antibodies are associated with autoreactivity, although not all VH4-34 antibodies are autoreactive. The primary objective of this study was to determine whether autoreactive forms of VH4-34 antibodies are localized only to …

Therapeutic Dna: Delivery And As A Delivery Vehicle, Natalie J. Holl

Masters Theses

"A review of gene delivery methods and gene editing methods, as well as original research utilizing DNA as a delivery vehicle is presented in the following thesis. Thousands of diseases have been linked to genes. Gene therapy, either delivering therapeutic genes or editing DNA bases, has arisen as a treatment option with the potential to cure diseases, rather than just ease symptoms. Genes and editing tools need to be delivered to cells for these therapies to be effective and many techniques have been developed to address the issue of delivery. Nonviral and viral methods have been used to deliver nucleic …

Investigation Of Glutamate Carboxypeptidase Ii Roles In The Folate Cycle Dependent Reproduction And Development Of Caenorhabditis Elegans, Jessica M. Derham

Masters Theses

Glutamate Carboxypeptidase II (GCPII) is a transmembrane, zinc metallopeptidase that is expressed in a wide range of organisms, including roundworms, mice, and humans. In humans, GCPII is primarily expressed in the prostate, kidneys, small intestine, and central nervous system. Within the small intestine, the expected function of GCPII is to aid in the absorption of dietary folate from the intestinal lumen. GCPII cleaves excess glutamates from folate to yield monoglutamated folate which is then readily transported into the enterocyte. Folate can then be used through the one carbon metabolic cycle for the synthesis of nucleotides, conversion of homocysteine to methionine, …

Design, Synthesis, And Characterization Of Chemical Tools To Study Peroxisomal Import, Jhalak N. Timilsena

Masters Theses

Peroxisomes are dynamic and interconnected single lipid membrane bound organelles found in the eukaryotic cells which are involved in various biochemical processes including the b-oxidation of very long chain and branched chain fatty acids, metabolism of reactive oxygen and nitrogen species, and reduction of hydrogen peroxide among others. These organelles are known to host numerous proteins and enzymes depending on the cellular environment. All of the proteins needed in the peroxisomes are encoded in the nucleus and synthesized in the cytosol which are then transported to the peroxisomes with the help of a sophisticated protein-transport machinery. Pex5 is one of …

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

Reprograming Neuronal Cells By Overexpression Of Fibroblast-Specific Transcription Factors, Abdulmohsen Alanazi

Masters Theses

In mammals, a complex system of regulatory signals distinguishes tissues, structures and functions. Combinations of transcription factors and co-factors regulate activation and repression of genes that result in cellular differentiation. Whole genome arrays allow the monitoring of genomic expression in specific tissues. Fibroblast microarray studies have shown candidate genes that may be involved in fibroblast identification, including genes that express transcription factors Prrx1, Snai2 and Twist1. A previous study showed that the Prrx1 and Snai2 could reactivate a fibroblast phenotype in hybrid cells that had lost fibroblast identity. Furthermore, overexpression of these factors in liver-derived cells strongly repressed liver gene …

Investigating The Role Of Lbh During Early Embryonic Development In Xenopus Laevis, Emma Weir

Masters Theses

LBH is a highly conserved protein whose role during vertebrate development is relatively under-studied. In collaboration with the Albertson lab, our lab has previously shown that it is necessary for cranial neural crest cell migration in the zebrafish and in Xenopus laevis. The molecular mechanisms through which it acts are not well understood.

In Xenopus, LBH is a maternally deposited protein. As such, studying its role in early development has not been feasible through the morpholino-mediated knockdown techniques that prevent translation of target genes. Recently, a technique for degrading endogenous proteins was developed, called Trim-Away. This was developed in mammalian …

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior …

Xylan Metabolism By Caulobacter Crescentus, Viet Bui

Masters Theses

Bacteria present unique opportunities to explore the molecular mechanisms of nutrient acquisition processes at single cell level under various experimental conditions. Caulobacter crescentus is a gram-negative oligotrophic environmental bacterium with adaptive physiological responses, such as slow growth or complete arrest of cell cycle, presence of sessile and motile progenies with the sessile cells growing stalk to enhance nutrient uptake for growth in low-nutrient conditions. Details of plant polysaccharide-derived carbon compound, such as cellobiose, maltose, and xylose utilization by C. crescentus can be found but molecular details or mechanisms of polysaccharide utilization, such as xylan, has not been reported. Database analyses …

Reprogramming Of Rat Hepatoma Cells With Fibroblast-Specific Protein Twist1, Kezban Ucar Cifci

Masters Theses

In mammalian development, a complex system comprised of regulatory signals causes tissue distinction with unique structures as well as functions. Gene expression controls these functions through specific combinations of transcription factors and cofactors that influence cell differentiation by both activation and repression of genes.

Whole genome microarray studies of fibroblasts have identified candidate genes that can serve as master regulators of fibroblast identity. A previous study showed that Prrx1 and Snai2 play important roles in activating expression of fibroblast identity, and Snai2 overexpression in hepatoma cells (Fg14) activated expression of fibroblast specific genes. Moreover, Snai2 overexpression resulted in repression of …

Influences Of Antroquinonol And 4-Acetylantroquinonol B On Inflammatory Tumorigenesis In The Mcf-7 Breast Cancer Cell Line With Or Without Tnf-Α Stimulation, Ting-Chun Lin

Masters Theses

Breast cancer (BC) is one of the most common cancers among women worldwide that ~25% of new cancer cases diagnosed every year would be BC; moreover, ~15% of cancer deaths per year caused by BC makes it the leading cause of cancer death among women worldwide. To date, though the cause of a large proportion of BC are still unclear, recent studies have revealed that a supportive breast tissue microenvironment is critical for the development and progression of BC, especially the communication with immune cells within breast tissue. Therefore, breast inflammatory microenvironment is currently received a substantial attention in the …

14-3-3 Protein Rad24 And Its Effect On Mid1 Localization And Contractile Acto- Myosin Ring Assembly During Cytokinesis In S. Pombe, Anissa P. Grawe

Masters Theses

In animal and yeast cells, cell division (cytokinesis) is facilitated by the formation of a contractile acto-myosin ring (CAR). Proper CAR formation and constriction is heavily reliant on the temporal regulation, phosphorylation, and localization of key proteins. In the fission yeast S. pombe, Mid1 is an important dimeric CAR scaffolding protein that connects the contractile apparatus to the plasma membrane at the right place and time during cytokinesis. Mid1 is confined to both the nucleus and protein assemblies called nodes during interphase, and transitions to the cell cortex at mitotic entry as nodes mature and coalesce into the CAR. Rad24 …

Microenvironment Regulates Fusion Of Breast Cancer Cells, Peiran Zhu

Masters Theses

Fusion of cancer cells has been observed in tumors for more than a century and is thought to contribute to tumor development and drug resistance. The low frequency of cell fusion events and the instability of fused cells have hindered our ability to understand the molecular mechanisms that govern cell fusion. We have developed a patterned gel system that can isolate cell fusion events and we demonstrate that several breast cancer cell lines can fuse into multinucleated giant cells in vitro, and the initiation and longevity of fused cells can be regulated solely by biophysical factors. Dynamically tuning the adhesive …

Developmental Exposure To Xenoestrogens: Effects On The Mouse Mammary Gland Development And Response To Estrogen, Durga Kolla

Masters Theses

Humans experience ubiquitous exposures to estrogenic environmental chemicals from food, personal care products, and other industrial and consumer goods. Bisphenol A (BPA), a well-studied xenoestrogen, is known to alter development of estrogen-sensitive organs including the brain, reproductive tract, and mammary gland. Bisphenol S (BPS), which has a similar chemical structure to BPA, is also used in many consumer products, but its effects on estrogen-sensitive organs in mammals has not been thoroughly examined. In our study, pregnant CD-1 mice were orally exposed to BPS or ethinyl estradiol (EE2, a positive control for estrogenicity) from gestational day 9 through postnatal day (PND) …

Evaluation Of The Phylogenetic Relationships Of The Marine Rivulariaceae., Jose Alberto Martinez Yerena

Masters Theses

Historically, the Rivulariaceae family has grouped all heteropolar, tapered and heterocitous Cyanobacteria, however recent description of multiple cyanobacterial populations with this morphotype using 16S rRNA phylogenies have reported that the populations with this morphotype are polyphyletic, and many new and old tapered and heteropolar genera (Cyanomargarita, Gloeothrichia, Rohoaltiella, etc.) have been classified and reclassified to different families than the Rivulariaceae. This is also the case of the main genera of the family (Rivularia and Calothrix), which have been repeatedly reported as polyphyletic, and whose separation to different families has been called for. In this project I carried out the evaluation …

The Role Of Prrx1 And Snai2 As Master Regulators Of Fibroblast Identity, Huda A. Alzahrani

Masters Theses

Mammalian development involves a complex system of regulatory signals and reactions, leading to the creation of distinct tissues with specific structures and functions controlled by various gene expression profiles. Tissue-specific gene expression is by controlled specific combinations of transcription factors and cofactors that dictate cell differentiation via activation and repression of genes in mammalian cells.

Whole genome microarray analyses of fibroblasts have revealed candidate genes that may serve as master regulators of fibroblast identity, such as Prrx1 and Snai2, that activate downstream genes such as Bmp3, Twist, Shox2, Cfos, Slug, Sema3A, Spp1, and Col1a1. A previous study showed that Prrx1 …