Molecular Biology Commons^™

Dopaminergic Innervation Of The Subventricular Zone In The Murine Brain, Linda Beth Drozdowicz

Honors Scholar Theses

The subventricular zone (SVZ) is one of two areas in the brain that, in a healthy mouse, continually generate neurons throughout adulthood. While it was previously thought that only the A9 neurons of the substantia nigra sent dopaminergic afferents to the SVZ, recent studies suggest that the A10 neurons of the ventral tegmental area may innervate this area. This project has aimed to discover which, if either, model is correct.

Examination of the Aphakia (AK) mouse was used to determine the role of distinct midbrain regions in SVZ regulation. Additionally, intraperitoneal injections of the chemical MPTP were used to deduce …

Characterization Of The Putative Xyloglucan Glycosyltransferase Gt14 In Arabidopsis Thaliana, Najam R. Syed

Honors Scholar Theses

Plant cell walls largely consist of matrix polysaccharides that are linked to cellulose microfibrils. Xyloglucan, the primary hemicellulose of the cell wall matrix, consists of a repeating glucose tetramer structure with xylose residues attached to the first three units ('XXXG'). In Arabidopsis thaliana, the core XXXG structure is further modified by enzymatic addition of galactose and fucose residues to the xylose side chains to produce XLXG, XXLG, XLLG and XLFG structures. GT14 is a putative glycosyltransferase in the GT47 gene family. Initial predictions of GT14's hydrophobic regions, based on its translated amino acid sequence, are almost identical to its Arabidopsis …

Alkylphenol Contamination In Homarus Americanus, Jennifer Renee Urban

Honors Scholar Theses

Alkylphenols are pollutants that are present in marine sediments and fishes. In earlier work it has been discovered that alkylphenols are present in the Homarus americanus, or the American lobster. Research suggests that alkylphenols could behave as endocrine disruptors as they have been found to affect juvenile hormone activity. It has been hypothesized that lobsters may be able to rid themselves of alkylphenol contamination through secreting these compounds into the environment or sequestering them in their tissues. In this study, I address the question of how lobsters may rid themselves of alkylphenols by analyzing hemolymph, muscle, gill, and shell samples …

Determination Of The Myogenic Potential Of Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells, Rory Coleman

Honors Scholar Theses

Human embryonic stem cells (hESCs) have the potential to

differentiate to all adult somatic cells. This property makes hESCs a very promising area of research for the treatment of disorders in which specific cell populations need to be restored. Despite this potential, research that focuses on producing mesodermally derived cell populations from hESCs is decidedly limited, notwithstanding the prevalence of disorders involving mesodermal tissues for which treatment options are limited. Skeletal muscle myoblasts are derivatives of mesodermal cells and are characterized by the expression of the MyoD gene. These cells are difficult to obtain from hESCs in a reproducible and …

Dynamics Of The Toc Gtpases: Modulation By Nucleotides And Transit Peptides Reveal A Mechanism For Chloroplast Protein Import, Lovett Evan Reddick

Doctoral Dissertations

The chloroplast is the green organelle in the plant cell responsible for harvesting energy from sunlight and converting it into sugars and ATP. Origins of this organelle can be traced back to an endosymbiotic event in which a primitive eukaryotic cell capable of oxidative phosphorylation engulfed a free-living cyanobacterium capable of photosynthetic respiration (1). Immediately following this event the details are not clear, however what is known is that over the course of evolution, the engulfed cyanobacteria relinquished approximately 97% of its protein coding sequences to the host cell nucleus, thus making the newly formed chloroplast reliant on its host …

Functional Analysis Of Chromodomain Helicase Dna Binding Protein 2(Chd2) Mediated Genomic Stability, Sangeetha Rajagopalan

Doctoral Dissertations

Histone modifying enzymes and chromatin remodeling complexes play an important regulatory role in chromatin dynamics that dictate the interaction of regulatory factors involved in processes such as DNA replication, recombination, repair and transcription, with DNA template. The CHD (Chromodomain Helicase DNA Binding Protein) family of proteins is known to be involved in the regulation of gene expression, recombination and chromatin remodeling via their chromatin specific interactions and activities. Phenotypic analysis of the Chd2 mutant mouse model developed by our laboratory indicates that the Chd2 protein plays a critical role in tumor suppression as the heterozygous mutant mice develop spontaneous lymphomas. …

Determining The Role Of Water And Proton Uptake/Release Upon Binding Of Substrate Dhf And Cofactor Nadph To The Enzyme Dihydrofolate Reductase's Active Site, Sharghi Rahmanian

Chancellor’s Honors Program Projects

No abstract provided.

Xenoestrogen-Specific Mechanisms Of Developmental Reprogramming Correlate With Gene Expression And Tumor Development, Kristen L. Greathouse

Dissertations & Theses (Open Access)

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. We have shown that neonatal exposure to the xenoestrogen diethylstilbestrol (DES) can developmentally reprogram the reproductive tract in genetically susceptible Eker rats giving rise to complete penetrance of uterine leiomyoma. Based on this, we hypothesized that xenoestrogens, including genistein (GEN) and bisphenol A (BPA), reprogram estrogen-responsive gene expression in the myometrium and promote the development of uterine leiomyoma. We proposed the mechanism that is responsible for the developmental reprogramming of gene expression was through …

The Development Of A Comprehensive Mechanism For Intracellular Calcium Oscillations: A Theoretical Approach And An Experimental Validation, Amanda A. Borges, Deanna Salter, Sandor Kadar, Steven B. Symington

Pell Scholars and Senior Theses

Calcium is an important second messenger for cellular communication. Theoretical models help scientists understand its signalling mechanism. A comprehensive model was developed in order to minimize any limitations in the models currently presented in the literature. Experimental results support the model and therefore the theoretical model provides a plausible explanation of the dynamics of the calcium-signaling mechanism. In the future, additional verification will be performed using various experimental configurations on PC12 cells. Further, the model will be used to predict the response of cells to environmental factors such as pesticides and heavy metals.

Physiological And Evolutionary Implications Of The Pattern Of Expression Of Oxygen-Binding Hemoproteins In Antarctic Notothenioid Fishes, Kimberly Borley

Electronic Theses and Dissertations

Antarctic icefish do not express hemoglobin (Hb). Icefishes possess cardiovascular modifications including increased densities of blood vessels, larger ventricles and increased blood volume compared to red-blooded relatives. In addition to delivering oxygen to tissues, Hb degrades nitric oxide (NO), a small signaling molecule. To investigate the mechanism driving development of icefish cardiovascular characteristics, I present and test the hypothesis that loss of Hb results in increased steady-state levels of NO, triggering downstream signaling pathways such as angiogenesis. I measured NO breakdown products, as a proxy for NO, and found that icefish have higher steady-state levels of NO metabolites in their …

Alteration Of Nucleotide Excision Repair By Estrogens: Implications For Carcinogenesis, Emily Glynn Notch

Electronic Theses and Dissertations

Estrogens and estrogen mimics represent a wide range of aquatic contaminants that elicit deleterious effects on exposed organisms. Despite well-characterized reproductive effects of environmental estrogens, less is known about non-reproductive impacts of exogenous estrogen exposure. Additionally, estrogens are known carcinogens, implicated in multiple human cancers. Little or no research has examined the effects of xenoestrogens on DNA repair despite being known carcinogens. The goal of this research was to test the hypothesis that aquatic estrogens enhance the effects of environmental mutagens by altering DNA repair. Of particular interest is nucleotide excision repair (NER), the only repair pathway to remove structurally …

A New Tumor Suppressor Gene Candidate Regulated By The Non-Coding Rna Pca3 In Human Prostate Cancer, Alessandro K. Lee

Dissertations & Theses (Open Access)

Prostate cancer is the second leading cause of cancer-related death and the most common non-skin cancer in men in the USA. Considerable advancements in the practice of medicine have allowed a significant improvement in the diagnosis and treatment of this disease and, in recent years, both incidence and mortality rates have been slightly declining. However, it is still estimated that 1 man in 6 will be diagnosed with prostate cancer during his lifetime, and 1 man in 35 will die of the disease.

In order to identify novel strategies and effective therapeutic approaches in the fight against prostate cancer, it …

Physiological And Molecular Function Of Hap3b In Flowering Time Regulation And Cold Stress Response, Mingxiang Liang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heme-activated proteins (HAPs) are transcription factors that have multiple roles in plant growth and development, such as embryogenesis, flowering time control, and drought tolerance.

In the present study I found that HAP3b was also involved in controlling response to cold stress. Transcript profiling and gene expression analyses indicated that HAP3b repressed the CBF3 regulon under normal growth conditions. As a result, plants with HAP3b-overexpressed showed decreased survival rates while plants homozygous for the null allele hap3b showed an improved freezing tolerance compared to wild-type plants.

To understand the mechanism of HAP3b in Arabidopsis, i.e. whether it also acts …

Host Signaling Response To Adhesion Of Bifidobacterium Infantis, Reed N. Gann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations of the molecular binding partners of the probiotic bacterium Bifidobacterium longum subspecies infantis (B. infantis) and the pathogen Salmonella enterica subspecies enterica serovar Typhimurium LT2 (Salmonella ser. Typhimurium) found that these two very different bacteria bind gangliosides. However, these organisms lead to completely different host health outcomes when present in the gut. B. infantis is the founding microbial population in the intestinal tract of breast-fed infants. S. typhimurium is the most important food-borne pathogen that results in humans. This study used an in vitro gut epithelial cell model to examine the host cellular response to adhesion …

A Synthetic Biological Engineering Approach To Secretion- Based Recovery Of Polyhydroxyalkanoates And Other Cellular Products, Elisabeth Linton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The costs associated with cellular product recovery commonly account for as much as 80% of the total production expense. As a specific example, significant recovery costs limit commercial use of polyhydroxyalkanoates (PHA), which comprise a class of microbially-accumulated polyesters. PHAs are biodegradable compounds that are of interest as a sustainable alternative to petrochemically-derived plastics. Secretion-based recovery of PHAs was studied to decrease PHA production costs. Type I and II secretory pathways are commonly used for the translocation of recombinant proteins out of the cytoplasm of E. coli. Proteins were targeted for translocation using four signal peptides (HlyA, TorA, GeneIII, …

Role Of Protein Kinase C Isotypes In 1,25-Dihydroxyvitamin D3 Mediated Signal Transduction Through The 1,25d3 Membrane Associated, Rapid Response Steroid Binding Receptors In Chick Intestinal Cells, Sakara Tunsophon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is now accepted that 1,25(OH)2D3 mediates its rapid actions on the control of phosphate and calcium homeostasis through its membrane receptor termed the 1,25D3-MARRS (membrane associated rapid response steroid binding) protein. I determined the various PKC isotypes involved in the rapid regulation of phosphate uptake and calcium extrusion in chick intestinal cells. 1,25(OH)2D3-mediated phosphate uptake was stimulated within 1 min after addition of the hormone. Western blot analyses on isolated intestinal cells treated with steroid hormone resulted in dose-dependent increases in PKC alpha and PKC beta in postnuclear centrifugation fractions, but not in the low speed centrifugation fractions. The …

Genetic And Biochemical Studies Of Plasmid Pir52-1 In Lactobacillus Helveticus, Cody Alexander Tramp

Undergraduate Honors Capstone Projects

Lactobacillus helveticus is a species of lactic acid bacteria. These bacteria, which produce lactic acid as a major product of carbohydrate metabolism, are used industrially to produce cheese and other fermented dairy products (Ebringer et al., 2008). Many species of lactic acid bacteria also possess probiotic characteristics and when ingested potentially confer increased immune function, regulate gut microbiota, and improve digestion in the host (Reid, 2008). Genetic studies of these probiotic effects and other characteristics of L. helveticus and related species have been hindered by the lack of stably replicating plasmid vectors. Plasmid vectors for several Lactobacillus species have been …

Human Monocytes, Macrophages, And Dendritic Cells: Alcohol Treatment Methods, Gyongyi Szabo, Pranoti Mandrekar

Gyongyi Szabo

Both acute and chronic alcohol consumption have significant immunomodulatory effects of which alterations in innate immune functions contribute to impaired antimicrobial defense and inflammatory responses. Blood monocytes, macrophages, and dendritic cells play a central role in innate immune recognition as these cells recognize pathogens, respond with inflammatory cytokine production, and induce antigen-specific T-lymphocyte activation. All of these innate immune cell functions are affected in humans by alcohol intake. Here, we summarize the different effects of acute and chronic alcohol on monocyte, macrophage, and dendritic cell functions in humans and describe methods for separation and functional evaluation of these cell types.

Protein Evolution Via Amino Acid And Codon Elimination, Lise Goltermann, Marie Sofie Yoo Larsen, Ranat Banerjee, Andreas C. Joerger, Michael Ibba, Thomas Bentin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background
Global residue-specific amino acid mutagenesis can provide important biological insight and generate proteins with altered properties, but at the risk of protein misfolding. Further, targeted libraries are usually restricted to a handful of amino acids because there is an exponential correlation between the number of residues randomized and the size of the resulting ensemble. Using GFP as the model protein, we present a strategy, termed protein evolution via amino acid and codon elimination, through which simplified, native-like polypeptides encoded by a reduced genetic code were obtained via screening of reduced-size ensembles.

Methodology/Principal Findings
The strategy involves combining a sequential …

Determinants For Stop-Transfer And Post-Import Pathways For Protein Targeting To The Chloroplast Inner Envelope Membrane, Antonio A. B. Viana, Ming Li, Danny Schnell

Danny Schnell

he inner envelope membrane (IEM) of the chloroplast plays key roles in controlling metabolite transport between the organelle and cytoplasm and is a major site of lipid and membrane synthesis within the organelle. IEM biogenesis requires the import and integration of nucleus-encoded membrane proteins. Previous reports have led to the conclusion that membrane proteins are inserted into the IEM during protein import from the cytoplasm via a stop-transfer mechanism or are completely imported into the stroma and then inserted into the IEM in a post-import mechanism. In this study, we examined the determinants for each pathway by comparing the targeting …