Cell and Developmental Biology Commons^™

The Role Of Calcium In Regulation Of Glial Cell Line Derived Neurotrophic Factor By Skeletal Muscle Cells, Alicia M. Boynton

Masters Theses

Glial cell line-derived neurotrophic factor (GDNF) is an important signaling molecule for the somatic motor nervous system. GDNF protein is produced and secreted by skeletal muscle cells and helps maintain motor neuron innervation at the neuromuscular junction. Treatment with exogenous GDNF prevents denervation which is characteristic of aging and neurodegenerative disease. The therapeutic potential of GDNF cannot be fully explored without understanding the mechanisms by which GDNF protein production is regulated. The primary objective of this study was to determine the role of calcium in regulating GDNF protein expression by skeletal muscle cells. Skeletal muscle cells (C2C12) were grown in …

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 …

One Fish, Two Fish, Red Fish, Blue Fish: The Analysis Of The Specter Cell Cycle Mutant In Zebrafish, Tetiana Petrachkova

Masters Theses

Cell division is controlled by genes that regulate the cell cycle. Here we show that the zebrafish specter (spr) mutant is mutation in the cyclin B1 gene, a gene necessary for the G2 to M transition of the cell cycle.

The spr mutation mapped to the cyclin B1 gene. Sequencing showed a transition (C139→T) that caused a nonsense mutation in exon 2 of the cyclin B1 gene. In situ hybridization of cyclin B1 revealed that the mRNA is absent in the mutant embryo by gastrulation. We found that the earliest visible mutant phenotype was a darkening of the head caused …

Vaccinia Virus Flll Mediated Expedition Of Tanapoxvirus Replication In Cell Culture, Yih Wen Goh

Masters Theses

Tanapoxvirus (TPV) produces large but slow-forming plaques as opposed to vaccinia virus (VACV) that forms similar large plaques but more rapidly. A number of genes were identified in VACV, inclucding FllL, A33R, A34R and A36R that contribute to the regulation of virus release and dissemination, and are particularly responsible for the induction of actin tails. Among them, TPV lacks homologs of the FllL and A36R genes. F11Lmediated inhibition of RhoA-mDia signaling was shown to enhance the microtubules dynamics and modulates the cortical actin that assisted in the release of progeny virus from infected cells. To understand the possible effects of …

Characterization Of The Ap-1 And Nf-Kappa B Transcription Factors In The U-87 Mg Astrocytoma Cell Line, Denise L. Smith

Dissertations

Growth factors, signaling molecules and transcription factors are frequently mutated in cancer and platelet-derived growth factor (PDGF) has been shown to be over-expressed in most gliomas. In the astrocytoma cell line U-87 MG, the over-expression of PDGF has been shown to lead to over-expression of transcription factors activator-protein-1 (AP-1) and nuclear factor-kappa B (NF-κB), and it is believed that the individual subunits of AP-1 (c-Jun, JunB, JunD, c-Fos, FosB, Fra-1, and Fra-2) and NF-κB (c-Rel, p50, p52, p65, and RelB) play different roles in proliferation, survival and differentiation in the U-87 MG cell line.

To assess these different roles, transient …

Mapk Survival Signaling In Melanoma, Matthew W. Vanbrocklin

Dissertations

Extracellular signals activate mitogen-activated protein kinase (MAPK) cascades potentiating biological activities such as cell proliferation, differentiation, and survival. Constitutive activation of MAPK signaling pathways is implicated in the development and progression of many human cancers, including melanoma. Mutually exclusive activating mutations in NRAS or BRAF are found in ∼85% of all melanomas resulting in constitutive activation of the MAPK pathway (RAS-BRAF-MEK-ERK-RSK). We have previously demonstrated that inhibition of this pathway with small molecule MEK inhibitors selectively induces apoptosis in human melanoma cells both in vitro and in vivo, but not in normal melanocytes. These results support the notion that the …

The Effects Of Aging And Activity On Glial Cell Line-Derived Neurotrophic Factor Expression In Skeletal Muscle, Nathan Peplinski

Dissertations

Glial cell line-derived neurotrophic factor (GDNF) is an extracellular signaling protein that is produced by skeletal muscle and is important for the motor neurons that control muscle movement. GDNF has been shown to keep neurons alive under conditions that they would otherwise not persist. In skeletal muscle, GDNF has been shown to be one of the most potent neurotrophic factors that influence motor neuron survival. While the role of GDNF has been well studied during early development, not much is known about what happens to GDNF expression in the adult and with advanced aging. Previous results from our lab have …

Characterization Of Membrane Potentials In Vascular Smooth Muscle Of Hagfish, Lamprey And Trout, Prentiss Jones Jr.

Dissertations

The objective of this study was to characterize membrane potentials in systemic arteries of Pacific hagfish, Eptatretus stouti, Rainbow trout, Onchorhyncus mykiss, and Sea lamprey Petromyzon marinus. Previous studies have characterized membrane potentials in piscine tissue. However, these studies utilized non-vascular tissues such as cardiac muscle and skeletal muscle (69, 161). Characterization of membrane potentials in fish vasculature is without precedent in the literature. The hypothesis of this study was that membrane potentials in fish vascular smooth muscle differ little between species when comparable vasculature is evaluated.

Exposure Of Nervous System Cells To Polychlorinated Biphenyls (Pcbs), Results In Alterations Of Neurotrophic Factor Expression, Gordon H. Gurley

Dissertations

Toxic insult by PCBs results in learning and memory deficits in humans. Alterations in expression of neurotrophic factors (NF) and/or their receptors have been linked to changes in learning and memory. How PCBs affect cognition is not known. We suggest that PCBs affect cognition by altering NF expression.

We exposed cultured C6 rat glioblastoma cells (an astrocyte cell-line) to medium containing PCB (Aroclor 1254 (10ppm)). Control cells were treated with dimethyl sulfoxide (DMSO) or regular medium. Enzyme-linked immunosorbent assays (ELISA) were used to determine glial cell-line derived neurotrophic factor(GDNF) and nerve growth factor (NGF) concentrations in all samples. We also …

Molecular Analysis Of The Effects Of Atrazine On Xenopus Laevis Frogs, Ronald Edward Celestine

Dissertations

Atrazine, the most commonly used herbicide in the U.S., has been implicated as one of the factors that may be causing the worldwide decline of amphibians. First, I examined effects of atrazine on laboratory raised Xenopus laevis tadpoles, treated from 5 days post fertilization to NF stage 65/66 with a concentrationof 25 ppb of atrazine. This study showed no significant difference in body weight, length and metamorphic rate.

Second, I used DNA microarrays to examine mRNA expression levels of genes in atrazine treated and control Xenopus laevis tadpoles. I found significant changes in gene expression levels of 18 genes. These …

Olfactory Bulb Neurons Of Adult Zebrafish Morphology, Distribution, Cellular Interactions And Structural Stability Following Deafferentation, Cynthia L. Fuller

Dissertations

The zebrafish is becoming an increasingly popular model for studies involving olfactory function, yet there is still much to be learned about the anatomy and circuitry of different cell types in the olfactory bulb. This study focuses on identifying the morphology and distribution of output neurons and interneurons in the olfactory bulb of adult zebrafish, Danio rerio . Furthermore, this investigation examines the cellular interactions of the primary output neuron, the mitral cell, and addresses the issue of neuronal plasticity by considering the structural stability of this cell type following loss of afferent innervation.

Using retrograde tract tracing with various …

Comparative Genomic Analyses And Expression Of A Set Of Overlapping Open Reading Frames Of Frog Virus 3, Type Species Of Ranavirus (Family Iridoviridae), Wendy Guat Hoon Tan

Dissertations

Frog virus 3 (FV3) is the type species member of the genus Ranavirus (family Iridoviridae ). To better understand the molecular mechanisms involved in the replication of FV3, including transcription of its highly methylated DNA genome, the complete nucleotide sequence of the FV3 genome has been determined. The FV3 genome is 105, 903 base pairs long excluding the terminal redundancy. The G+C content of FV3 genome is 55% and it encodes 98 non-overlappingpotential open reading frames (ORFs) containing 50 to 1293 amino acids. Eighty-four ORFs have significant homology to known proteins of other iridoviruses, whereas 14 are unique FV3 ORFs. …

The Glucose And Insulin Responsiveness Of The Rat Glucose-6-Phosphate Dehydrogenase Promoter, Daryl Arkwright-Keeler

Dissertations

The regulation of expression of some enzymes involved in glucose homeostasis and fat metabolism requires both insulin and glucose to elicit an effect, while the regulation of others requires only one. Glucose-6-phosphate dehydrogenase (G6PDH), an important enzyme involved in glucose homeostasis, has been shown to be transcriptionally regulated by carbohydrate feeding in rat liver, a diet regime that increases the levels of both glucose and insulin. Our lab had previously shown that insulin induces expression of G6PDH, thus we wanted to determine if glucose also induced G6PDH expression and if so, are the glucose and insulin responses mediated through identical …

Changes In Glial Cell Line Derived Neurotrophic Factor And Nerve Growth Factor Expression With Development, Age, Exercise And Hypertension, Bertha C. Rebimbas-Cohen

Dissertations

Neurotrophic factors are important for neuronal growth, survival, and maintenance of cell phenotype. Glial cell line-derived neurotrophic factor (GDNF) affects sensory, autonomic and somatic motor neurons and nerve growth factor (NGF) affects sensory and sympathetic neurons. NGF and GDNF are produced by cardiac muscle and have potent effects on sensory and autonomic neuronal innervation of blood vessels. Neural innervation plays a key role in blood vessel function. Since neural innervation of blood vessels may be regulated by growth factors, we wanted to determine what changes would occur to NGF and GDNF levels with maturity, exercise and hypertension.

Changes in GDNF …

Cellular Proliferation, Death And Histology In Gambusia Affinis Livers After Exposure To 2-Aminofluorene And Benzidine, Susan J. Lentz

Dissertations

A fundamental need exists for aquatic animals in the biomonitoring of aquatic ecosystems for environmental carcinogens. G. affinis, a small fish species, is selected for this study due to its hardiness, non-migratory nature, geographic diversity and ability to develop tumors. Molecular tools for cellular proliferation and death are examined for use with G. affinis. Additionally, these tools are used to investigate the early carcinogenic effects of 2-aminofluorene and benzidine, both individually and combined, on G. affinis livers.

Antibodies to proliferating cell nuclear antigen (PCNA), p53, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) were examined for use in G. …