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Full-Text Articles in Cell Biology

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 ...


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 ...


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 ...


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 ...


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 ...


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 ...


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 ...


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 ...


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 ...


Modeling Drosophila Stem Cell Development Through Ex Vivo Live-Cell Imaging Studies, Mohima Sanyal Apr 2014

Modeling Drosophila Stem Cell Development Through Ex Vivo Live-Cell Imaging Studies, Mohima Sanyal

Undergraduate Honors Theses

Stem cell specification, maintenance, and differentiation are imperative to proper organogenesis and tissue maintenance. Understanding the mechanisms and steps of these developmental processes is invaluable to advancing tissue grafting, cancer treatment, and other organ therapies. The Drosophila melanogaster testis is one of the best-characterized systems for studying these processes. Currently, studies in the Drosophila testis have thoroughly characterized when stem cells develop and what the resulting adult testis morphology will be. A major question that remains to be answered is how stem cells develop – what controls what cells become functional stem cells and how stem cell fates are dictated. To ...


Investigation Of Complemented Transformants Of "Kluyveromyces Lactis" Temperature Sensitive Cell Division Cycle Mutants Rcy426 And Rcy435, Elysia Carnagey Jan 2009

Investigation Of Complemented Transformants Of "Kluyveromyces Lactis" Temperature Sensitive Cell Division Cycle Mutants Rcy426 And Rcy435, Elysia Carnagey

Undergraduate Honors Theses

This study involves the previously identified temperature sensitive (ts) cdc K. lactis mutants RCY246 and RCY435. In order to determine its defective gene, RCY246 was transformed with a K. lactis genomic DNA library and screened for transformants that grew at the restrictive temperature. A complementing transformant for RCY246 was found and designated RCY946. To amplify the complementing plasmid, the plasmid DNA from RCY946 was isolated and transformed into E. coli. Retransformation of RCY246 with the proposed complementary plasmid indicated partial complementation of RCY 246; however, the plasmid was unstable. In an attempt to amplify the insert region of the plasmid ...


Affecting Wnt3a In The Inner Ear Of Xenopus Laevis, Heather Elina Hodges Jan 2006

Affecting Wnt3a In The Inner Ear Of Xenopus Laevis, Heather Elina Hodges

Undergraduate Honors Theses

Problems associated with the development of the ear can result in vertigo and partial or complete hearing loss. Efforts to better understand the development of the inner ear have been made in mouse, frog, chick, and other species. However, there is still relatively little known about the mechanisms that control the processes during development. This research has used the African Clawed Frog, Xenopus laevis, to study embryonic and inner ear development. The gene Wnt3a was previously determined to be expressed in the dorsal half of the developing otocyst. This suggested a possible role for Wnt3a in inner ear development, but ...