Life Sciences Commons^™

Evaluating Biogenesis Of 5’-Tailed Mirtrons, Jonathan D. Hoover

Honors Theses

MicroRNAs are 22 nucleotide, non-coding RNAs that serve as substrates for Argonaute proteins to induce RNA interference pathways. Intron-derived miRNA precursors called “mirtrons” have been identified and classified primarily through deep sequencing methods. Unlike most miRNAs, mirtrons are derived from splicing events and also exhibit high levels of post-transcriptional nucleotide addition to hairpin precursors. Most relevant among these modifications is 3’ uridylation as it inhibits mirtron biogenesis in multiple model systems. Mirtrons may also possess additional nucleotides adjacent to the pre-miRNA hairpin at the 3’ and/or 5’ ends. These nucleotide “tails” are removed prior to Dicer cleaving the hairpin. In …

Investigating Roles For Rna Turnover Processes In Cell Signaling Through Drosophila Melanogaster Genetic Mosaics, Sudiksha Rathan Kumar

Honors Theses

The process of cell signaling is vital in organisms for proper development as it determines the fate and function of cells. This process is highly regulated by myriad interactions between signaling pathway components and gene expression mechanisms. RNA turnover is a type of RNA processing that degrades RNA. It plays an essential role in homeostasis and environmental changes; however, its influence on signaling pathways is currently unknown. In the present study, the effect of RNA turnover processes on cell signaling was analyzed using the genetic mosaics in Drosophila melanogaster. Fly mosaics were created by breeding RNAi lines targeting cellular …

Mouse Embryonic Stem Cells Are Sensitive To The Cytotoxicity Of Nitric Oxide: Biological Implications For Early Embryogenesis, Mckenzie C. Hargis

Honors Theses

The early embryo, before implantation, is at a very vulnerable stage in development where it faces various inflammatory cytokines throughout the implantation process. In this stage, the cells in the blastocyst, the preimplantation stage embryo, must proliferate rapidly for tissue formation. However, it is known that inflammatory cytokines can inhibit cell proliferation. Previous studies have shown that embryonic stem cells (mESCs), the major cell component in the blastocyst, are unresponsive to treatments of tumor necrosis factor ⍺ (TNF⍺) and interferon 𝛾 (IFN𝛾), two inflammatory cytokines involved in the implantation process. Treatment of mESC-differentiated fibroblasts (mESC-FBs) with TNF⍺ and IFN𝛾 in …

Developing A New Water-Soluble Porphyrin As A Potential Photodynamic Cancer Therapy Agent, Catherine Shirley

Honors Theses

Photodynamic cancer therapy (PDT) is a type of treatment involving the use of light in conjunction with a photosensitive agent- a chemical or series of chemicals designed for activation when exposed to light. This research project investigated the synthesis and identification of the novel photosensitive agent, H2TPP-Pro-OH. To create the water-soluble porphyrin, (S)-(+)-prolinol was reacted with the tetra-carboxyl porphyrin, H2TPPC, to form the final H2TPP-Pro-OH product. This compound was then purified using syringe filtration and column chromatography, and subsequently characterized using infrared (IR), nuclear magnetic resonance (NMR), and Ultraviolet-visible (UV-vis) spectroscopies, as well as High Performance Liquid Chromatography (HPLC). Finally, …

Preparation And Cytotoxicity Of Novel Carbon Nano-Onion Materials, Cammie York

Honors Theses

The applications of carbon nanomaterials (CNM), including graphene and its derivatives such as carbon nanotubes (CNTs) in nanomedicine is well established. These nanomaterials have been widely used as theranostic delivery systems with the potential to deliver bioactive agents and simultaneously detect selectively diseased tissues. A rather underexplored CNM for biomedical imaging and theranostics delivery are carbon nano-onions (CNOs). CNOs are carbon-based nanomaterials that can potentially be used in cancer therapy when they are functionalized. Recent studies on cellular fate of different CNMs, including CNOs, have demonstrated that the surface composition is critical for the in vivo application of these CNM. …

Development And Validation Of Gene Delivery Methods For ​Crassostrea Virginica, Adrienne N. Tracy

Honors Theses

The Eastern oyster (Crassostrea virginica) is an important part of the East Coastal USA economy because aquaculture creates jobs. Sadly, the oysters are under constant threat due to increasing pollution, red tides, and diseases. Bivalves, and oysters in particular, are also becoming potential model organisms in medical research. With the sequencing of the oyster genome, scientists are focusing on deciphering the function of the predicted genes. However, the limited number of molecular and cellular tools available makes functional annotation of the genome challenging. A consistent, replicable gene delivery system needs to be developed to assess gene function and understand the …

Effectiveness And Mechanism Of Action Of Modified Porphyrins For Photodynamic Therapy Of Triple Negative Breast Cancer Cells, Hannah Brandon

Honors Theses

Triple negative breast cancer (TNBC) is a particularly aggressive form of breast cancer that lacks the three molecules typically targeted for treatment. Standard treatment methods leave much to be desired--the rates of metastasis and recurrence are high and the prognosis for most patients with TNBC is poor. One potential treatment for TNBC is photodynamic therapy (PDT), which uses compounds called photosensitizers that are taken up by all tissues in the body. The tumor is exposed to light, activating the photosensitizer and creating reactive oxygen species that cause cell death. This method is relatively pain-free, effective, and does not harm cells …

Insects And The Evolution Of Developmental Pathways: Functional Analysis Of Genetic Sex Determination Mechanisms In Oncopeltus Fasciatus, Josefine Just

Honors Theses

Natural selection alters genetic pathways over evolutionary time. However, different pathways have been shown to maintain mutations at varying rates, leading to different levels of conservation across developmental pathways. Sex determination pathways, in particular, show vast diversity across animals despite the fundamental conservation of biological sex itself. Here, I investigated the sex determination pathway of the hemimetabolous insect, Oncopeltus fasciatus. The large milkweed bug, O. fasciatus, is part of the order Hemiptera, which provides a relevant outgroup study to other insects in which sex determination has been studied to date. I studied three sex determination genes, intersex, fruitless …

Killing Breast Cancer One Porphyrin At A Time, Taylor C. Lymburner

Honors Theses

New treatments for cancer are continuously being developed and improved. One such treatment is Photodynamic Therapy, more commonly referred to as PDT. PDT is quickly becoming more popular due to its relative lack of side effects that are present in other treatments. In PDT, light-sensitive agents are required and are activated by light in the targeted cells. There are many types of PDT agents but the one focused on in this research is a four-pyrrole ring structure known as a porphyrin. The combination of H2 TPPC with 3- amino-oxetane-3-yl-methanol created the final product ofH2TPP-Oxo-MeOH. Once the porphyrin was formed, it …

Examining The Effects Of Fadrozole, An Aromatase Inhibitor, On Testosterone And Estrogen Production Of Domestic Chicken Embryos (Gallus Gallus), Abby E. Joseph

Honors Theses

The hypothalamic-pituitary-gonadal (HPG) axis is responsible for the production of the hormones testosterone and estradiol, and testosterone is thought to contribute to regulation of the axis through a negative feedback mechanism. Regulation by negative feedback involves the product of a pathway turning off that pathway when enough product is made. However, because the enzyme P450 aromatase converts testosterone to estradiol, estradiol may also contribute to regulation of the HPG axis and other phenomena that have been attributed to testosterone, like the inhibition of immune function. Previous studies have injected birds with an aromatase inhibitor (presumably reducing estradiol production) and shown …

The Subcloning And Expression Of Munc18a In Escherichia Coli For Antibody Production And Analysis In Mast Cell Degranulation Reactions, Brandi Goble

Honors Theses

Mast cells are secretory cells responsible for fighting off infection through the early recognition of pathogens. This process is completed through the secretion of proinflammatory mediators that are stored in secretory granules within the cytoplasm of the cell. The degranulation secretion process relies on regulated fusion of secretory granules to the cell membrane via membrane-bound SNARE proteins that bridges the two opposed membranes. The intricate regulation of SNARE-mediated mast cell degranulation is not well understood. However, Sec1/Munc18 (SM) proteins, specifically the Munc18 isoforms, are known to play a critical role in the process (Brochetta, et. al., 2014). The Xu lab …

Effectiveness And Mechanism Of Action Of Modified Porphyrins For Photodynamic Therapy Of Triple Negative Breast Cancer Cells, Alex Abbott

Honors Theses

Triple negative breast cancer is an aggressive family of cancers that are extremely difficult to treat. Therefore, the prognosis for most patients with TNBC is poor. The goal of this research is to determine if photodynamic therapy could be a possible option for TNBC in the future using MDA-MB231 cells. MDA-MB231 cells were originally isolated from a patient with triple negative breast cancer and have been used for many studies, so they would work well for this study. Photodynamic therapy uses compounds called photosensitizing agents which are taken up by all tissues in the body and then activated by light. …

Killing Cancer With Light, Kaitlyn Thomas

Honors Theses

Photodynamic therapy (PDT) is a relatively new treatment option in medicine including treating some types of cancers. PDT utilizes light to activate small molecules for treatment. Some of these molecules used as PDT agents are porphyrin derivatives. While PDT is currently being used in the fight against cancer, it has several limitations and is currently being used in conjunction with chemotherapy and/or radiation in order to be effective. This research focused on synthesizing a new zinc (II) porphyrin and incorporating a fluorescent sulfocycline and testing the compound on the MB 231 breast cancer cell line.

Once the metallated porphyrin was …

Using Light To Kill Cancer: Development Of A Novel Photodynamic Therapy, Alicia Hamilton Moore

Honors Theses

Photodynamic therapy (PDT) is a treatment that uses special drugs called photosensitizing agents along with light to kill cancer cells. The specialized drugs only work after they have been activated or "turned on" by light. Photodynamic therapy may also be called photoradiation therapy, phototherapy, or photochemotherapy. In this research, I focused on the addition of four separate hydroxyl-amines to the unsubstituted porphyrin core, H₂TPPC. The hydroxyl-amines attached to the porphyrin core were 5- amino-1-pentanol, 2-amino-2-ethyl-1, 3-propanediol, 3-amino-propanediol, and 5-aminovaleric acid. The novel water soluble PDT agents, H₂TPP-A50H, H₂TPP-2ET, H₂TPP-3NH, and H_{2 …}

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Is Stem Cell Transplantation A Practical Treatment For Macular Degeneration?, Zachary Slepchuk

Honors Theses

No abstract provided.

Vein Patterning During Juvenile Wing Development In Oncopeltus Fasciatus And Jadera Haematoloma, William R. Simmons

Honors Theses

Wings are a defining characteristic of all pterygote insects and are agreed to originate from a single common winged ancestor. However, essentially nothing is known about the molecular mechanisms that regulate wing development and patterning outside of Endopterygota, and the vast majority of this knowledge comes solely from Drosophila melanogaster. There is reason to suspect that the drastic developmental differences that exist between Endopterygota and Exopterygota have resulted in changes in the mechanisms, timings, or even genes that govern wing development. This study examined the roles of several genes known to be involved in D. melanogaster wing development and patterning …

The Uas-Gal4 System In D. Melanogaster: An Insight Into The Influence Of Micrornas On The Developmental Pathways Of The Wing, Emily R. Wilson

Honors Theses

By examining genetic pathways in D. melanogaster, a better understanding of the homologous regulatory mechanisms in humans can be utilized to further enhance knowledge of the roles of microRNA within development. This study utilizes the UAS-Gal4 system in order to produce a mutant phenotype capable of being visually studied and analyzed, focusing on the developmental pathway of the wing in D. melanogaster. Dissections of the wandering third instar larvae yielded wing disc tissue expressing the downregulation of loquacious and CG17386.

The Effect Of Degrading The Transcription Factor Nf-Kb Subunit Proteins On Nf-Kb' S Oncological Activity, Seongmin Lee

Honors Theses

Nuclear factor-kappa B (NF-κB) is a transcription factor that becomes functional when any two of its five component proteins (p50, p52, p65, c-Rel, and RelB) join together. NF-κB plays an important role in bringing out cell proliferation, or cell growth. When NF-κB malfunctions and becomes hyperactive, excessive NF-κB activity promotes abnormally high cell growth, which is a symptom of cancer. Because of its tie to cancer, NF-κB is commonly subjected to modification to curb cancer growth. In this project, each component protein of NF- κB was degraded via a method called RNAi to see if it would have any negative …

Is The Zebrafish Zombie Mutant Caused By A Mutation In Cdc20?, Peyton Johnston

Honors Theses

The zombie mutant was identified as an early arrest mutant, stopping in development around the 10-somite stage (14 hours of development). Further inspection revealed that this mutant was a cell cycle mutant and cells in the mutant arrest during metaphase as early as the 5-somite stage (11.6 hours of development). A similar phenotype is seen in the Drosophila melanogaster cell cycle gene fizzy, known to be to be a homolog of the Saccharomyces cerevisiae gene, cell division cycle 20 (cdc20). CDC20 is an activator protein of the anaphase promoting complex/cyclosome (APC/C), an ubiquitin E3 ligase that is …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

Activation Of Nf-Κb Transcription Factor During In Vitro Differentiation Of Mouse Embryonic Stem Cells, Natalya A. Ortolano

Honors Theses

Embryonic stem cells (ESCs) are a promising cell source for regenerative medicine. However, recent studies indicated that ESCs and ESC-derived cells (ESC-DCs) lack functional innate immunity against various pathogens and inflammatory cytokines. This presents a barrier to clinical application, as ESC-DCs would be placed in a wound site and exposed to pathogens and inflammatory cytokines. Using mouse ESCs (mESCs) as a model, we recently demonstrated that they are deficient in expressing type I interferons (IFN) and inflammatory cytokines. To determine the molecular basis for this finding, this study examined the activation state of nuclear factor-κB (NF-κB), a transcription factor that …

Subcloning And Expression Of Complexin Isoforms Involved In Mast Cell Degranulation, Cameron Blake King

Honors Theses

Mast cells play an important role in the immune system by releasing chemicals such as chemokines and cytokines once they are stimulated. These products are released after stimulation by a process called mast cell degranulation. Mast cell degranulation is accomplished when vesicles containing the chemicals inside the mast cell fuse with the mast cell membrane via SNARE-mediated (Soluble NSF Attachment Protein Receptors) membrane fusion. This family of proteins consists of syntaxin, SNAP 25-like protein, and synaptobrevin/VAMP (Vesicle Associated Membrane Protein)(2). Comlexin isoforms (complexin 1,2,3,and 4) have been known to regulate this system in a fashion that is still unclear. In …

Investigating The Co-Regulatory Role Of Midline And Extramacrochaetae In Regulating Eye Development And Vision In Drosophila Melanogaster, Lillian M. Forstall

Honors Theses

The Honors thesis research focused on the roles of extramacrochaetae and midline in regulating eye development and the vision of Drosophila melanogaster. It is known from previous studies that extramacrochaetae (emc) and midline (mid) independently regulate the formation of ommatidial units in the Drosophila compound eye. However, the thesis focuses on the interaction of these two genes and their co-dependent roles in regulating eye development. This study also attempts to explain the recovered formation of ommatidial units and interommatidial bristles when the expression of both of these genes is reduced and whether flies doubly mutant …

Caring For Cancer, Jason Monroe Stevenson

Honors Theses

"Your child has cancer" are words that no parent wants to hear, and no physician wants to speak. However, approximately 1 in 10,000 children each year will receive this unfortunate news (Society). Another unsettling statistic is that a number of families will be hearing these unsettling words in a less than appropriate fashion, such as brief phone calls, voicemails, and unsympathetic consultations....

Investigating The Mechanism Behind The Cytotoxic Effects Of Ajulemic Acid (Aja) On Ewing's Sarcoma By Employing Smap And Sybyl-X1.3 Surflex Dock Software Programs To Find Receptors For Aja, Rebekah Ward

Honors Theses

Ewing's Sarcoma (ES) is a malignant cancer characterized by the formation of tumors in bones or soft tissues of primarily children and young adults. With the tendency for local recurrence and metastasis, ES is an aggressive cancer. The treatment is intensive and often yields poor long-term results. A cannabinoid derived compound, ajulemic acid (AJA), has shown strong cytotoxic effects on ES cell lines. The synthetic compound is unlike its cannabinoid counterpart tetrahydrocannabinol by lacking psychotropic effects. To investigate the possibility of utilizing AJA as a chemotherapeutic drug, the biochemical mechanism behind the cytotoxic effects of AJA needs further research. A …

Developmental Expression Profile Of Bric Á Brac 2, Midline And H15 In The Developing Eye And Central Nervous System Of Drosophila Melanogaster, Petra Visic

Honors Theses

Aberrant activity of a single gene can lead towards development of cancerous cells. Drosophila melanogaster is a useful model system to study cancer because there is high degree of evolutionary conservation in signaling pathways between humans and flies that play major roles in regulating cell proliferation and growth (Miles et al., 2011). At The University of Southern Mississippi (USM), Dr. Leal’s lab has gathered evidence suggesting that bab1 and bab2 interact with the T-box gene midline (mid) and its paralog H15, while the early developmental function of bab1 and bab2 remains unknown. That is why elucidating the early …

Elucidating The Role Of Apoptosis During Cyclical Body Regeneration In Botryllus Schlosseri, Meredith Adamo

Honors Theses

Apoptosis is the principal form of programmed cell death by which multicellular animals rid themselves of old cells in order to allow new cells to grow. The colonial ascidian Botryllus schlosseri is a model system for homeostatic cell death and regeneration. During its unique, weekly budding cycle known as blastogenesis, new buds are produced asexually and eventually replace the old adult zooid generation through resorption via circulating phagocytes. Using polyester wax-embedded tissue sections, we have shown that TUNEL-positive (terminal deoxynucleotidyl transferase nick end-labeling), apoptotic cells are observed within circulating phagocytes in all stages of the colony’s death phase (takeover), including …

Characterization Of Aebp2 Mutant Mice, Arundhati Bakshi

Honors Theses

No abstract provided.

Effects Of Synthetic Histone Deacetylase Inhibitors On 3t3l1 Preadipocyte Adipogenic Differentiation Potential, Vikramjeet Singh

Honors Theses

No abstract provided.