Molecular Biology Commons^™

Mechanisms By Which Xenorhabdus Nematophila Interacts With Hosts Using Integrated -Omics Approaches, Nicholas C. Mucci

Doctoral Dissertations

Nearly all organisms exist in proximity to microbes. These microbes perform most of the essential metabolic processes necessary for homeostasis, forming the nearly hidden support system of Earth. Microbial symbiosis, which is defined as the long-term physical association between host and microbes, relies on communication between the microbial community and their host organism. These interactions among higher order organisms (such as animals, plants, and fungi) and their bacteria links metabolic processes between interkingdom consortia. Many questions on microbial behavior within a host remain poorly understood, such as the colonization efficiency among different microbial species, or how environmental context changes their …

An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan

Dissertations & Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and is associated with significant morbidity and mortality. To date, the majority of work in the field has focused on genomic alterations such as mutations and copy number alterations. However, the clinical success of targeted therapies that exploit known genomic alterations, such as EGFR mutations, has remained mixed. Over the past decade, the importance of epigenetic regulators has come to the forefront, with the realization that many of these genes are mutated in cancer. Despite this realization, the role of epigenetics in regulating tumorigenesis, progression and …

Development Of In-Silico Pipelines For Identification And Characterization Of Biomarker Panels And Therapeutic Interventions In Gastro-Intestinal (Gi) Cancers, Pranita Atri

Theses & Dissertations

Gastro-intestinal (GI) malignancies, including gastric, colorectal, and pancreatic cancers, have maintained their high overall mortality due to a lack of prognostic and diagnostic biomarkers and potential therapeutic modalities. While efforts have been made to improve both early detection and therapeutic interventions in these cancers, failure of conventional approaches have proven to be a big challenge, and alternate approaches are needed. Computational biology approaches owing to lesser time and more per target success rate offer a unique solution here. The current study explored the use of computational biology techniques to study the various aspects relating to GI malignancies. First, we sought …

Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis

Graduate College Dissertations and Theses

The overall incidence of thyroid cancer has more than tripled over the past several decades, as has aggressive disease and mortality. The direct relationship between thyroid disease, thyroid hormone levels, and development of thyroid cancer is incomplete. Recent meta-analyses have indicated a higher risk of thyroid cancer for patients with thyroid diseases that reflect an altered thyroid-pituitary signaling axis, which can have profound impacts on the physiology of the thyroid gland. These largely unanswered questions regarding altered thyroid hormone signaling and its consequences for thyroid tumor growth present a significant clinical challenge. This dilemma may come from a lack of …

Molecular Genetic Analysis Of Drought Resistance And Productivity Traits Of Rice Genotypes, Yheni Dwiningsih

Graduate Theses and Dissertations

Rice (Oryza sativa L.) is the staple food for a majority of the world’s population, and uses 30% of the global fresh water during its life cycle. Drought at the reproductive stage is the most important abiotic stress factor limiting grain yield. The United States is the third largest exporter of rice, and Arkansas is the top rice-producing state. The Arkansas rice-growing region in the Lower Mississippi belt is among the 10 areas with the highest risk of water scarcity. Adapted U.S. rice cultivars were screened for drought resistant (DR) traits to find sources for breeding U.S. rice cultivars for …

A Bioinformatic Approach To Exploring Land Plant Evolution, Lauren Margaret Orton

Graduate Research Theses & Dissertations

Today, researchers are inundated with an overwhelming amount of data due to advances in DNA sequencing technologies. This has benefited the fields of both bioinformatics and phylogenomics substantially. With the ability to increase sampling at both the taxonomic and molecular levels, we are now able to produce robust phylogenomic reconstructions and better discern relationships between taxa.

The goals of this dissertation are in two distinct parts: 1) to advance the understanding of land plant terrestrialization and evolution through examination of the closest relative to the land plant lineage, a species of green algae; and 2) to explore evolution among a …

Characterization Of Epigenetic Plasticity And Chromatin Dynamics In Cancer Cell Models, Diana Lea Gerrard

Graduate College Dissertations and Theses

Cancer progression is driven by cumulative changes that promote and maintain the malignant phenotype. Epigenetic alterations are central to malignant transformation and to the development of therapy resistance. Changes in DNA methylation, histone acetylation and methylation, noncoding RNA expression and higher-order chromatin structures are epigenetic features of cancer, which are independent of changes in the DNA sequence. Despite the knowledge that these epigenetic alterations disrupt essential pathways that protect cells from uncontrolled growth, how these modifications collectively coordinate cancer gene expression programs remains poorly understood. In this dissertation, I utilize molecular and informatic approaches to define and characterize the genome-wide …

Software For Sequence Analysis Of Variants In Functional Screening Libraries And Personalized Genome Files, Jacklyn Michelle Newsome

UNLV Theses, Dissertations, Professional Papers, and Capstones

Detailed knowledge of protein function is critical for both the study of protein interactions and the development of drugs which target specific proteins. Currently, there are few techniques that directly examine protein function. The techniques that are available are time consuming and can only address one variant of a protein at a time. Our laboratory has designed 3 high throughput protein function screens. We hypothesize that these will address this shortfall.

The first screen is the Chimeric Minimotif Decoy (CMD) Assay. For this screen, we constructed red fluorescent proteins with one or more C-terminal minimotifs. Minimotifs are short, contiguous amino …

The Selective Survival Of Escherichia Coli In Freshwater Beach Sand, Natalie Ann Rumball

Theses and Dissertations

The quantification of Escherichia coli or E. coli is the most common method used to detect recent fecal pollution in recreational water, as this species is known for its high abundance in fecal matter and assumed host-associated nature. However, it has been determined that some strains are capable of long-term survival and potential propagation in non-host environments, such as the beach sand. These long-term environmental survivors are host-independent and are not associated with the same health risks as those E. coli from recent fecal pollution. However, they have been shown to impact how water quality is perceived as they are …

Modeling The Mechanism Underlying Environmental And Genetic Determinants Of Gene Expression And Complex Traits, Gregory Alan Moyerbrailean

Wayne State University Dissertations

Advances in next-generation sequencing technologies and functional genomics strategies have allowed researchers to identify both common and rare genetic variation, to deeply profile gene expression, and even to determine regions of active gene transcription.

While these technologies and strategies have contributed greatly to our understanding of complex traits and diseases, there are many biological questions and analytical issues to be addressed.

Genome-wide association studies (GWAS) have successfully identified large numbers of genetic variants associated with complex traits and diseases. However, in many cases the mechanistic link between the phenotype and associated variant remains unclear. This may be because most variants …

Genome-Scale Analyses Of Transcription And Transcriptional Regulation In Bacteria, Devon Marie Fitzgerald

Legacy Theses & Dissertations (2009 - 2024)

The textbook model of bacterial transcription regulation posits that promoters occur immediately upstream of genes and that transcription factors (TFs) modulate transcription through promoter-proximal binding. However, the recent application of unbiased genome-wide approaches, such as ChIP-seq and RNA-seq, has revealed a much more complex picture, including TF binding and transcription initiation occurring in unexpected locations. This dissertation describes the use of deep sequencing-based approaches to evaluate the genome-wide binding of transcription-related proteins and identify locations of transcription initiation. I have assessed the genome-wide binding of three Escherichia coli TFs and an alternative σ factor. Additionally, I have analyzed genome-wide patterns …

Lipid Uptake And Metabolism In The Parasitic Protozoan Giardia Lamblia., Mayte Yichoy

Open Access Theses & Dissertations

Giardia lamblia is a protozoan parasite that causes various intestinal syndromes, and it is a common cause of water-borne illness worldwide, both in developed and developing countries. Giardia attaches to the mucosal epithelia of the duodenum below the bile duct, where it is exposed to bile salts and dietary lipids. G. lamblia is unable to synthesize lipids de novo and must therefore scavenge necessary lipids from its extracellular environment and remodel them as needed. However, the current lipidomic analysis (presented in this Dissertation) has revealed that while the Giardia lipidome is rich in phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG), …

A Locus-Based Paradigm For Generating Systems Biological Inferences From Large Scale Functional Genomics Datasets, Ajish Dominic George

Legacy Theses & Dissertations (2009 - 2024)

Genomics data is growing at a exponential rate. The ability to integrate new results with existing knowledge about genomic biology is rapidly becoming the limiting factor as there no universal language with which to describe genomic functional elements. To integrate and compare new and existing genomic data, we define our basic functional unit of a genome to be a locus -- a set of positional coordinates along any genome with an arbitrary amount of functional annotations attached. The locus concept enables addressing genomic elements and annotations at any level of granularity from entire swaths of chromosomes to single base-positions. We …