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Undergraduate Honors Theses

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Articles 1 - 30 of 34

Full-Text Articles in Cell Biology

Principles And Properties Of Rna Self-Assembly, Gabriel Tauber Jan 2019

Principles And Properties Of Rna Self-Assembly, Gabriel Tauber

Undergraduate Honors Theses

Ribonucleoprotein (RNP) granules are membraneless assemblies of condensed RNA and protein that form through multivalent interactions between the constituent components. Recently, RNA self-assembly has been shown to contribute to the formation of stress granules, which are RNP granules associated with the stress response and neurodegeneration. However, little is understood about the properties of self-assembled RNA. Here, I show that different RNA sequences can self- assemble into condensates with distinct material properties and partitioning preferences in vitro. Due to interactions that minimize surface free energy, RNA self-assembly can generate the spontaneous self-patterning of RNA assemblies. By reducing surface free energy, thereby ...


Predicting Persisters: Investigating Gene Regulation In Persister Cells, Sowmya Dhanwada Jan 2019

Predicting Persisters: Investigating Gene Regulation In Persister Cells, Sowmya Dhanwada

Undergraduate Honors Theses

Bacterial populations produce a small number of persister cells that remain tolerant to multidrug exposure by becoming metabolically dormant. This inquiry focuses on investigating metabolic gene expression levels in persisters to determine potential predictors of bacterial persistence. Strains from the E. Coli Promoter library were imaged using single cell microscopy, and gene expression levels were measured with the integrated reporter GFP. Persister cells were isolated using ofloxacin. Results indicate that bacterial cells that survive antibiotic exposure exhibit filamentous growth before dividing. Resumption of normal growth morphology is accompanied by increased proteolytic activity in daughter cells, however more investigation is required ...


Developing Novel Methods To Investigate Real-Time In Vivo Dopamine Dynamics In The Monogamous Prairie Vole, Emma Burt Jan 2019

Developing Novel Methods To Investigate Real-Time In Vivo Dopamine Dynamics In The Monogamous Prairie Vole, Emma Burt

Undergraduate Honors Theses

Humans are among a small percentage of mammals that form monogamous relationships. These relationships, along with other strong social bonds, are essential to human well-being. In the absence of strong social relationships, humans experience a variety of detrimental conditions such as depression, anxiety, and cardiovascular disease. Traditional barriers to studying social bonds stem from the use of lab rodents such as mice and rats which do not form selective social attachments. However, the prairie vole (Microtus ochrogaster) does form these selective social attachments. The robust social bonds – pair bonds – formed between adult prairie voles may be observed and therefore studied ...


Modeling Hypertrophic Cardiomyopathy In Neonatal Cardiomyocytes In Cultured In 3d, Esther Choi Jan 2018

Modeling Hypertrophic Cardiomyopathy In Neonatal Cardiomyocytes In Cultured In 3d, Esther Choi

Undergraduate Honors Theses

Heart disease continues to be the leading cause of death in both men and women. It is accompanied with cellular- and organ- level remodeling that cannot be mimicked or recaptured by cells on standard culture platforms. Polyethylene glycol hydrogels bridge this gap by providing user-defined tunability for cell culture. A novel 3D cell culture system was developed to encapsulate neonatal rat ventricular cardiomyocytes (NRVMs) in a single plane, and cell health was assessed. In parallel, recombinant adenoviruses containing the mutations responsible for human hypertrophic cardiomyopathy (HCM) in the beta myosin gene (R403Q and R453C) were generated and used as a ...


Investigations Of Interactions Between The Microtubule Binding Domain Of Centrosomal P4.1 Associated Protein And Polyglutamylated Microtubules, Caroline Rhoads Jan 2018

Investigations Of Interactions Between The Microtubule Binding Domain Of Centrosomal P4.1 Associated Protein And Polyglutamylated Microtubules, Caroline Rhoads

Undergraduate Honors Theses

Microtubules maintain particularly diverse and important functions within the cell despite being polymers made up of two highly conserved proteins: a- and b-tubulin. Some of these diverse roles are explained by the presence of post-translational modifications occurring on the C-terminal tail of tubulin proteins, primarily detyrosination, polyglutamylation and polyglycylation. Misregulation of C-terminal tail post-translational modifications are observed in disease phenotypes and may increase the risk of some forms of cancers; however, the role of these post-translational modifications is not well understood. Working towards a goal of designing in vivo methods to study specific post-translational modifications, this paper examines the specificity ...


Fibroblast Growth Factor Receptor Function In Muscle Stem Cells, Tashi Hackett Jan 2018

Fibroblast Growth Factor Receptor Function In Muscle Stem Cells, Tashi Hackett

Undergraduate Honors Theses

Skeletal muscle has a remarkable ability to regenerate itself following injury and this is reliant upon a group of stem cells known as muscle stem cells Muscle stem cell dysfunction contributes to variety of muscle wasting diseases and insights into mechanisms that regulate MuSC function could lead to new therapies and further our understanding of stem cell biology in general. Fibroblast Growth Factor 2 (FGF2) is a protein that regulates muscle stem cell behavior through stimulation of cell surface tyrosine receptor kinases known as Fibroblast Growth Factor Receptors (Jones, 2001). Activation of the receptors by FGF will induce intracellular signaling ...


The Role Of Rnf4 In Stripping Transcriptionally-Active Huntingtin, Jen Peek Dec 2017

The Role Of Rnf4 In Stripping Transcriptionally-Active Huntingtin, Jen Peek

Undergraduate Honors Theses

Altered gene expression is a hallmark of neurodegenerative disorders such as Huntington’s disease. The causative agent of Huntington’s is a mutant, aggregation-prone fragment of huntingtin (htt) that aggregates in the cytosol and nuclei of neuronal cells. The severity and onset of Huntington’s is correlated with the length of a polyglutamine (Q) tract encoded in the N-terminus of htt. Little is known about the nuclear accumulation of polyQ expanded htt, how it interacts with chromatin, and dysregulates transcriptional activity. In this thesis, we investigate the effect of nuclear localized htt on reporter gene activation and demonstrate that the ...


A Study Of A Novel Self-Fertility Mechanism In The Hermaphroditic Nematode Rhabditis Sp. Sb347, Xiaoxue Lin May 2017

A Study Of A Novel Self-Fertility Mechanism In The Hermaphroditic Nematode Rhabditis Sp. Sb347, Xiaoxue Lin

Undergraduate Honors Theses

Germ cell development and gametogenesis are essential for the continuity of future generations in most eukaryotic organisms, including humans. One well-established system for studying the complex mechanisms of gametogenesis is the nematode species, Caenorhabditis elegans. The fact that C. elegans hermaphrodite germlines undergo different cellular development at the same life stage in a linear progression makes C. elegans a model system for the study of the conversion of uncommitted germ cells into either oocytes or sperm. C. elegans hermaphrodite produces spermatocytes during the final larval stage and then makes a one-time switch over to oogenesis as the worm enters adulthood ...


Variations In Flanking Residues Of Thyroid Hormone Receptor Alpha1 Isoform, Christine W. Gao May 2017

Variations In Flanking Residues Of Thyroid Hormone Receptor Alpha1 Isoform, Christine W. Gao

Undergraduate Honors Theses

The thyroid hormone receptor (TR) is a transcription factor that represses or activates genes whose regulatory regions bear thyroid hormone (T3) response elements (TREs). Modulation of this function requires shuttling into and out of the nucleus. This is mediated by the binding of importins and exportins to amino acid sequences within TR, called nuclear localization signals (NLSs) and nuclear export signals (NESs), respectively. The fine balance between nuclear import, retention, and export of TR has emerged as a critical control point for modulating T3-responsive gene expression, including genes that control cell proliferation, differentiation, and apoptosis. NLS-2 is a specific NLS ...


Receptor Gone Rogue: Investigating Localization Of A Cancerous Thyroid Hormone Receptor, Michelle Barbeau May 2017

Receptor Gone Rogue: Investigating Localization Of A Cancerous Thyroid Hormone Receptor, Michelle Barbeau

Undergraduate Honors Theses

Thyroid hormone receptors play a crucial role in regulating differentiation, growth and development in response to thyroid hormone, and mutations in these receptors can have severe medical consequences ranging from endocrine dysfunction to cancer. Tumors of patients with hepatocellular carcinoma (HCC) display a high incidence of mutant thyroid hormone receptors (TRs), and one such mutant is TRα1 (K74E, A264V). The binding partners and gene targets of this mutant have been characterized, but the role of intracellular localization in the pathogenesis of TRα1 (K74E, A264V) has not yet been determined. Here, it was observed that the mutant receptor has a tendency ...


Beyond "Self-Eating": The Role Of The Pseudophosphatase Mk-Styx In Regulating Autophagy, Patrick Christian May 2017

Beyond "Self-Eating": The Role Of The Pseudophosphatase Mk-Styx In Regulating Autophagy, Patrick Christian

Undergraduate Honors Theses

Cells carry out their day to day functions through the cellular work horses, proteins. Proteins work together like bees in a hive, each having its own specific task to accomplish. This specificity creates a fine-tuned division of labor where different types of proteins work together, completing their own work for the overall functioning of the cell. This division of labor can be mapped out nicely with cellular pathways. One such pathway is the stress response pathway. One of the major “workers” in this pathway is MK-STYX [MAPK (mitogen-activated protein kinase) phosphoserine/threonine/tyrosine-binding protein]. MK-STYX is a pseudophosphatase, a member ...


Cytological And Bioinformatical Analysis Of Spe-26, A C. Elegans Kelch-Like Protein That Functions During The Karyosome Stage Of Spermatogenesis, Stephen A. Gurley Apr 2017

Cytological And Bioinformatical Analysis Of Spe-26, A C. Elegans Kelch-Like Protein That Functions During The Karyosome Stage Of Spermatogenesis, Stephen A. Gurley

Undergraduate Honors Theses

Prior to the meiotic divisions, spermatocytes undergo extended developmental processing termed meiotic prophase. As these spermatocytes transition out of meiotic prophase, they must cease transcription and prepare the chromosomes for the meiotic division. Our knowledge of the mechanisms that drive this transition remains incomplete.

In this study, we analyze through cytological and bioinformatics methods a poorly understood Kelch-like protein required for Caenorhabditis elegans spermatogenesis, SPE-26. Analysis of spe-26 mutants reveals precocious meiotic spindle maturation relative to chromatin morphology beginning during the poorly-understood spermatogenesis-specific karyosome stage of late meiotic prophase. spe-26 spermatocytes also display chromosome alignment and segregation defects during the ...


Correlative Light And Electron Microscopy On Mouse Polyomavirus-Infected Fibroblasts, Christina Henderson Jan 2017

Correlative Light And Electron Microscopy On Mouse Polyomavirus-Infected Fibroblasts, Christina Henderson

Undergraduate Honors Theses

Polyomaviruses are small, DNA tumor viruses that can infect multiple species, including humans. In recent years, the number of identified human polyomaviruses (huPyV) has grown. To identify possible therapeutic targets for huPyVs, a better understanding of virus infection at the structural level is needed. Confocal microscopy allows for the visualization of fluorescently-tagged proteins but without seeing the cell’s subcellular structures, functional information can be lost. Electron microscopy provides structural insight but does not always provide biological or biochemical details. Combining these two approaches can relate biological function to structural information about virus replication. Polyomaviruses (PyV) co-opt host proteins that ...


Homothorax Is A Modifier Of Radiation Sensitivity In Drosophila Melanogaster Bantam Mutants, Geoffrey Meyerhof Jan 2017

Homothorax Is A Modifier Of Radiation Sensitivity In Drosophila Melanogaster Bantam Mutants, Geoffrey Meyerhof

Undergraduate Honors Theses

Radiation resistance in human cancers represents a massive impediment for successful tumor treatment. The fruit fly Drosophila melanogaster is an excellent model for human radiation resistance because of its largely conserved apoptotic pathways and malleable genome. This thesis investigates the genetic regulatory mechanisms for bantam (ban), an anti-apoptotic microRNA. To first identify genes that interact with ban, a forward genetic screen was conducted. This screen looked for genes that yielded radiation dependent pupal lethality in a ban deficient background. From this screen the transcription factor, homothorax, was identified as displaying radiation dependent synthetic lethality with ban. To investigate the mechanism ...


Characterization Of Tumor Protein P63 Regulated 1-Like Function In Xenopus Laevis, Julia Mo Jan 2017

Characterization Of Tumor Protein P63 Regulated 1-Like Function In Xenopus Laevis, Julia Mo

Undergraduate Honors Theses

Of the approximately 20,000 genes in the human genome, about 6,000 have unknown or poorly characterized function. Tumor protein p63 regulated 1-like (TPRG1l) is one of those genes with no functional data. TPRG1L is expressed during embryonic development and adulthood with strongest expression in the brain. It is implicated in carcinogenesis because its gene expression is activated by tumor regulators p63/73. To elucidate TPRG1L function during embryogenesis, CRISPR-Cas9 genome editing system was utilized to induce Tprg1l mutations in Xenopus laevis. Embryos injected with Tprg1l sgRNA and Cas9 mRNA displayed axis formation and convergent extension defects suggesting that ...


In Vitro Investigation Of The Effect Of Exogenous Ubiquitin On Processes Associated With Atherosclerosis, Chase W. Mussard May 2016

In Vitro Investigation Of The Effect Of Exogenous Ubiquitin On Processes Associated With Atherosclerosis, Chase W. Mussard

Undergraduate Honors Theses

Atherosclerosis, characterized by the build-up of cholesterol, immune cells and cellular debris within arterial walls, is accelerated following myocardial infarction by poorly understood mechanisms. Ubiquitin, a small, well-studied intracellular protein involved in protein turnover via the proteasome pathway, has recently been shown to exert extracellular effects on cardiac myocytes, in vitro, and in mice undergoing myocardial remodeling. This study investigates the potential role of extracellular ubiquitin in atherosclerosis by determining its effects on two critical atherosclerotic processes: the migration of vascular smooth muscles cells and the uptake of modified LDL by monocyte/macrophages in foam cell formation. In the presence ...


Characterizing Importin Binding To Thyroid Hormone Receptor Α1, Emma Lynn Mcgregor Apr 2016

Characterizing Importin Binding To Thyroid Hormone Receptor Α1, Emma Lynn Mcgregor

Undergraduate Honors Theses

Thyroid hormone, or T3, is essential in many bodily functions, from early development to the maintenance of health in adults. It is crucial for growth and skeletal development, development of the nervous system, cell differentiation, and maintenance of metabolic balance. The thyroid hormone receptor, TR, is a major mediator of thyroid hormone action. TR is a transcription factor and able to activate or repress transcription depending on the binding of its ligand, T3. There are two isoforms of TR, encoded by different genes: TRα and TRβ. Each of these isoforms have multiple alternative splicing products.

While TR’s ...


Double Knockout Of Munc18b And Munc18c Reduces Translocation Of Glut4 In Response To Insulin, Zoe A. Praggastis Jan 2016

Double Knockout Of Munc18b And Munc18c Reduces Translocation Of Glut4 In Response To Insulin, Zoe A. Praggastis

Undergraduate Honors Theses

Insulin resistance has become a prominent issue in the United States, causing serious comorbid conditions. One crucial step in insulin response in adipose and muscle tissue is the movement of glucose transporter GLUT4 to the cell surface from storage vesicles. This process requires the SNARE complex to drive membrane fusion. Munc18b and Munc18c are syntaxin binding proteins associated with the SNARE complex during fusion. While protein binding assays have revealed interactions of these proteins, their function in GLUT4 translocation has not been well understood. In an effort to establish the role of these proteins in GLUT4 translocation and insulin response ...


With Or Without You: Studying The Requirement Of P53 For Anti-Cancer Responses To Nuclear Export Inhibitors, Andrea E. Doak Jan 2016

With Or Without You: Studying The Requirement Of P53 For Anti-Cancer Responses To Nuclear Export Inhibitors, Andrea E. Doak

Undergraduate Honors Theses

Exportin-1 (XPO-1) is responsible for the movement of cargo proteins out of the nucleus and into the cytoplasm. Selective inhibitors of nuclear export (SINE) bind XPO-1 at cysteine-528, which results in the sequestration of cargo proteins in the nucleus. SINE drugs are currently being developed and tested in the treatment of many types of cancers. One of the cargos, p53 may play an important role in the efficacy of SINE. To test the necessity of p53 in the action of SINE drugs, matched pairs of cell lines with wildtype or functionally disrupted p53 were analyzed for differences in their cell ...


Endoplasmic Reticulum Area Expands Upon Onset Of The Unfolded Protein Response, Katelyn Camille Cook Jan 2016

Endoplasmic Reticulum Area Expands Upon Onset Of The Unfolded Protein Response, Katelyn Camille Cook

Undergraduate Honors Theses

The endoplasmic reticulum (ER) is a dynamic organelle responsible for essential cell functions such as protein folding, calcium storage, and lipid synthesis. It also directly interacts with and regulates other organelles in the cell, such as endosomes or mitochondria, and is the site of bulk protein synthesis for both secretion and the cellular endomembrane system. However, cellular stressors such as heat shock, chemical imbalance, or calcium depletion can disrupt the protein-folding capacity of the ER, causing activation of the ER-mediated unfolded protein response (UPR) in order to either restore homeostasis or initiate apoptosis. Chronic ER stress is a hallmark of ...


Stability Of Escrt Iii Snf7 Polymer Influenced By: Bro1 And Vps2/Vps24, Troy K. Coody Iii Jan 2016

Stability Of Escrt Iii Snf7 Polymer Influenced By: Bro1 And Vps2/Vps24, Troy K. Coody Iii

Undergraduate Honors Theses

The endosomal sorting complexes required for transport (ESCRT) are protein complexes that remodel cellular membranes. The ESCRT III membrane machinery has been implicated in regulating membrane bound receptor proteins through the multi-vesicular body (MVB) pathway, during the end of cytokinesis, and being manipulated by the HIV virus during infection. My thesis project focuses on the in vivo regulation of ESCRT III. Bro1 binding to the Snf7 protein polymer helped stabilize ESCRT III. With this understanding that Bro 1 stabilizes the Snf7 polymer, two questions can be posed: Does it block Vps4 mediated Snf7 disassembly? Or does it block Vps2 and ...


Synaptogyrin 3 Binds Amyloid Beta And May Alter Dopamine Transport In Alzheimer’S Disease, William Gierach Jan 2016

Synaptogyrin 3 Binds Amyloid Beta And May Alter Dopamine Transport In Alzheimer’S Disease, William Gierach

Undergraduate Honors Theses

Alzheimer’s Disease effects 35 million elderly individuals globally by causing dementia, memory loss and eventually death. Amyloid Beta (Aß), a neurotropic peptide and a hallmark of AD pathogenesis, disrupts cellular organization and impairs neuronal systems. The dopaminergic system regulates learning, motor function and behavior and malfunctions in early AD. Aß causes dopaminergic transmission to dysfunction by unknown mechanisms. To elucidate these mechanisms, we screened solubilized mouse synaptosomes for proteins that specifically bind Aß 1-42. 107 proteins that bound Aß were identified by mass spectrometry. Human orthologs were further screened in HEK293 cells for Aß binding. Of the thirteen proteins ...


The Effects Of Sustained, High-Velocity Exercise On Gene Expression In California Yellowtail (Seriola Lalandi), Kelli Hatter May 2015

The Effects Of Sustained, High-Velocity Exercise On Gene Expression In California Yellowtail (Seriola Lalandi), Kelli Hatter

Undergraduate Honors Theses

California Yellowtail muscle fibers have been observed to exhibit two drastically different development patterns resulting from the speeds at which they are exercised. When fish are exercised at a moderate rate their epaxial fast-twitch muscle fibers grow in diameter—hypertrophy; when they are exercised at a fast speed, more new epaxial fast-twitch muscle fibers are produced—hyperplasia. To determine the underlying reason for this difference in muscle development, my summer research project and honors thesis exercised fish at: fast, moderate, and control speeds for a sustained amount of time to determine what is happening on a cellular level to cause ...


Genetic And Cytological Analysis Of Spe-6, A C. Elegans Tau Tubulin Kinase, Jackson J. Peterson May 2015

Genetic And Cytological Analysis Of Spe-6, A C. Elegans Tau Tubulin Kinase, Jackson J. Peterson

Undergraduate Honors Theses

To acquire motility, Caenorhabditis elegans sperm must undergo the

regulated cellular remodeling process of sperm activation, but in the complete

absence of new protein synthesis. Nematode sperm utilize two general

mechanisms to overcome this obstacle: 1) They pre-package many proteins

involved in this remodeling and subsequent sperm motility within the unique

Fibrous Body-Membranous Organelle (FB-MOs) complexes; 2) They employ

large numbers of protein kinases and phosphatases, including SPE-6, in the

acquisition and regulation of motility. Genetically, spe-6 is represented by two

classes of alleles. In null alleles, spermatocytes fail to assemble FB-MOs or

complete their meiotic divisions. In a second ...


Development Of Photodegradable Hydrogel Platforms For Cardiomyocyte Culture, Amanda Panepento Jan 2015

Development Of Photodegradable Hydrogel Platforms For Cardiomyocyte Culture, Amanda Panepento

Undergraduate Honors Theses

It’s been shown that the microenvironments to which cells are exposed influence their shape and gene expression. Traditionally, because of the difficulty of studying cells in the body, cells are removed from the organism and are cultured on glass or plastic surfaces such as tissue culture polystyrene (TCPS). One limitation of studying cells on TCPS is its non-physiologic stiffness. In fact, TCPS is 106-fold stiffer than a healthy heart. In the interest of studying cardiac disease in a more physiologic context, we used a photodegradable hydrogel cell culture platform that can be manipulated with light to more ...


The Bbc3 Antisense Intragenic Transcript, Bait, Contributes To Puma Expression By A P53-Autonomous Mechanism, Nicole C. Michael Jan 2015

The Bbc3 Antisense Intragenic Transcript, Bait, Contributes To Puma Expression By A P53-Autonomous Mechanism, Nicole C. Michael

Undergraduate Honors Theses

p53 is a tumor suppressor protein which orchestrates cell cycle arrest or apoptosis to prevent the hyperproliferation of cells which could lead to cancer. However, when p53 is inactivated, which happens in over 50% of cancers, it fails to induce PUMA, a potent apoptotic protein. Loss of PUMA makes cancer cells less likely to undergo apoptosis upon stress stimuli. Recent GRO-seq data revealed unique antisense transcription initiated 6kb into the PUMA locus, creating a small noncoding RNA transcript dubbed BAIT (BBC3 antisense intragenic transcript). This project focused on understanding the expression and function of BAIT, which we hypothesized could modulate ...


The Interactions Of Vigilin And The Mirisc Within Caenorhabditis Elegans, Brett Weum Jan 2015

The Interactions Of Vigilin And The Mirisc Within Caenorhabditis Elegans, Brett Weum

Undergraduate Honors Theses

Developmental robustness and redundancy are properties of biological systems that facilitate adaptation and survival in stressful environments. Through use of novel screens for synthetic phenotypes, we have elucidated a fascinating interaction between miRNAs and Vigilin, an RNA binding protein predicted to have a variety of different cellular functions within development. Synthetic screening indicates that mir-52, mir-59, mir-83, mir-254, and mir-265 all interact redundantly with Vigilin to modulate larval progression. Computational analysis and further RNAi testing yielded a list of potential downstream targets that these miRNAs might regulate to control development in a complex and robust manner. RT-qPCR and genetics will ...


Isolation Of Myogenic Nuclei From Whole Muscle Tissue, Owen Brewer Jan 2015

Isolation Of Myogenic Nuclei From Whole Muscle Tissue, Owen Brewer

Undergraduate Honors Theses

Isolation of myogenic cell populations from whole skeletal muscle is necessary to elucidate the molecular repair mechanisms involved in skeletal muscle maintenance and regeneration that can be damaged when affected by diseases or aging, often severely impacting quality of life and lifespan. Skeletal muscle tissue is composed of hundreds of myofibers that are syncytia comprised of hundreds of nuclei named myonuclei. External to the sarcolemma(plasma membrane) of each myofiber is the basal lamina. Satellite cells, which reside between the basal lamina and the sarcolemma, are self-renewing muscle stem cells that maintain and repair muscle tissue. I have developed a ...


Mouse Polyomavirus T Antigens: Directors Of Cell Cycle Signaling, Catherine Nicholas Jan 2015

Mouse Polyomavirus T Antigens: Directors Of Cell Cycle Signaling, Catherine Nicholas

Undergraduate Honors Theses

Polyomaviruses (PyV) efficiently replicate by disrupting host cell signaling pathways. Disruption of the cell cycle is implicated in nearly all tumor formation. Studies of cellular transformation by primate PyV, SV40, and mouse polyomavirus (MPyV) have led to numerous findings concerning tumor suppressor proteins and cell cycle regulation pathways (Das D. and Imperiale 2009, Dahl et. al. 2005). Expression of PyV T Antigens (TAg) modifies signaling pathways and cell cycle checkpoints to the virus’ advantage. Expected modifications include inhibiting checkpoint proteins between G1 and S phases as well as promoting kinases with downstream signaling effects that result in progression to S ...


Evolutionary Conservation Of A Modified Spermatogenesis Program In Rhabditis Nematodes With Skewed Sex Ratios, Ethan S. Winter May 2014

Evolutionary Conservation Of A Modified Spermatogenesis Program In Rhabditis Nematodes With Skewed Sex Ratios, Ethan S. Winter

Undergraduate Honors Theses

The cellular divisions in Rhabditis sp. SB347 male spermatogenesis have been modified to re-purpose an asymmetric division. This results in the dramatically skewed sex ratios observed in the progeny of males of this species. Here we confirm this asymmetry in the division of tubulin and major sperm protein (MSP). MSP, a necessary sperm component, is segregated exclusively into spermatids bearing the X chromosome while tubulin is segregated into the nullo-X sperm. Timing of the partitioning events reveals that MSP migration is not directly dependent on tubulin spindle asymmetry. Additionally, the endoplasmic reticulum is also segregated asymmetrically to the nullo-X spermatid ...