Life Sciences Commons^™

Molecular Analysis Of Epigenetic Memory Of Stress Establishment And Long-Term Maintenance In A Perennial Woody Plant, Jia Wen Tan

Theses and Dissertations--Plant and Soil Sciences

Plants adapt to extreme environmental conditions through physiological adaptations, which are usually transient. Recent research has suggested that environmental conditions can activate a memory of stress that can result in a primed response to subsequent stress events. While the effect of priming has been observed in many plants, the underlying mechanisms are puzzling and seldom studied. A large body of research has been developed in the last decade linking response to stress, stress priming, and memory of stress with epigenetic mechanisms. This understanding of plant epigenetics has opened the door to the application of epigenetics to crop improvement, such as …

Deciphering Medicago Truncatula Nodulation Using Time-Series Transcriptomic Data At Multiple Levels Of Resolution: Organ, Tissue, And Single-Cell, Yueyao Gao

All Dissertations

Use of chemical nitrogen fertilizers has environmental repercussions such as global warming, soil contamination, and aquatic eutrophication. Legumes form a symbiotic association with nitrogen-fixing bacteria (rhizobia sp.) to obtain atmospheric nitrogen through the formation of a specialized root structure called a nodule. Understanding the transcriptional reprogramming during nodulation is a powerful approach to decipher the genetic control of nodulation, with the goal of engineering nitrogen-fixing symbiosis into non-leguminous crops. This dissertation focuses on the analytics of bulk, tissue-specific, and single-cell RNA-seq technologies and how I utilized them to discover a collection of genes to aid in deciphering nodulation mechanisms in …

Effects Of Continuous In Situ Low-Dose Ionizing Radiation On Microorganisms, Molly E. Wintenberg

All Dissertations

Precise detection and monitoring of nuclear fuel cycle, enrichment, and weapon development activities are critical for supporting warfighter preparation in chemical, biological, radiological, nuclear, and explosives (CBRNE) operations, clandestine activities, and nuclear compliance. A biological sensing system could serve as an alternative to traditional detection methods by using organic material naturally present in the environment to discreetly detect residual trace nuclear material. Microorganisms provide an optimal platform for an alternative sensing system; however, their response to low levels of ionizing radiation is poorly characterized. Combining the power of next-generation sequencing and transcriptomic analysis, this dissertation takes an approach to obtain …

Analysis Of Post-Traumatic Stress Disorder Gene Expression Profiles In A Prospective, Community-Based Cohort, Jan Dahrendorff

USF Tampa Graduate Theses and Dissertations

Post-traumatic stress disorder (PTSD) is a common and debilitating psychiatric disorder that may occur in individuals exposed to traumatic events such as accidents, interpersonal violence, war, combat-exposures or natural disasters. PTSD is a significant public health issue with a high disease burden associated with substantial health care costs and several comorbidities negatively affecting an individual’s quality of life. The biological underpinnings of the disorder are not well understood. Gene expression studies can shed light into the complex physiology of PTSD. However, to date, studies employing a hypothesis-free approach examining the whole transcriptome are scarce and are limited to assessment of …

The Origin Of Novel Trait Inferred From Transcriptomic Analysis And A Targeted Gene Approach In The Beetle Horns., Naureen Fatima

Graduate Theses, Dissertations, and Problem Reports

The origin of the evolutionary new trait (evolutionary novelty) and its subsequent evolution is of great interest for biologists in various fields, and beetle horns have been used to address this fundamental biological question. Previous studies on one of the horned beetle species, Onthophagus taurus, that utilized comparative gene expression analyses, suggested legs to be a strong candidate of the origin of horns. At the same time, their horns are secondary sexual traits whose development is regulated by the same gene (doublesex) as genitalia, which also originates from paired appendages such as legs. However, little is known …

Initial And Advanced Stages Of Microbiota Establishment Within The Tsetse Fly, Miguel Eduardo Medina Munoz

Graduate Theses, Dissertations, and Problem Reports

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and …

The Transcriptome Response Of The White-Rot Fungus Trametes Versicolor To Wild-Type And Lignin-Modified Hybrid Poplar, Anbarah Alzabaidi

Masters Theses

Plant biomass is a renewable and sustainable feedstock for biofuel production that can reduce societal dependence on fossil fuels. However, the production of liquid biofuels from the non-starch (i.e. lignocellulosic) material through fermentation technology is limited due to the complexity of the cell wall structure. This necessitates the use of chemical, thermal, and/or mechanical pretreatment technologies, which adds significant capital, operational, and environmental costs. Biological pretreatment strategies have the potential to mitigate these expenses by harnessing the innate ability of specialized bacteria and fungi to deconstruct lignocellulose. White-rot fungi (e.g. Trametes versicolor) have been shown to be …

An Evolving Epigenome That Determines Tissue And Cell Specificity, Renee Louise Sears

Arts & Sciences Electronic Theses and Dissertations

Understanding the mechanisms driving phenotypic variation is a major goal of biology that unifies classical genetics with the emerging fields of genomics and epigenomics. Human and mouse share over 90% of genes and global tissue-specific patterns of expression are maintained between the species. Thus, it is hypothesized that gene expression is influenced through distinctive regulation among species in order to account for the unmistakable phenotypic divergence. DNA methylation, histone modifications, open chromatin patterns, transcription factor binding, and other epigenetic factors are all associated with shaping, maintaining, and repressing regulatory regions which in turn coordinate gene expression. It is vital to …

Unraveling The Neurogenin/Ngn-1 Gene Regulatory Network Of C. Elegans Using Classical Genetics And Comparative Transcriptomics, Elyse Christensen

Master of Science in Integrative Biology Theses

Proper nervous system development is required for an organism’s survival and function. Defects in neurogenesis have been linked to neurodevelopmental disorders such as schizophrenia and autism spectrum disorders. Understanding the gene regulatory networks that orchestrate neural development, specifically cascades of proneural transcription factors, can better elucidate which genes are most essential in governing early neurogenesis. Neurogenins are a family of such factors that are both sufficient and necessary for the development of neural sub-types in mice, primarily through the regulation of other factors, particularly NeuroD. The objective of this study was to evaluate previously established regulatory targets of neurogenin(ngn-1 …

Synergistic Effects Of Temperature And Salinity On The Gene Expression And Physiology Of Crassostrea Virginica, Hollis Jones

LSU Master's Theses

Crassostrea virginica, the eastern oyster, forms reefs that provide critical services and benefits to the resiliency of the surrounding ecosystem. Changes in environmental conditions, including salinity and temperature, can dramatically alter the services oysters provide by affecting their population dynamics. Climate warming may further exacerbate the effects of salinity changes as precipitation events increase in frequency, intensity, and duration. Temperature and salinity independently and synergistically influence gene expression and physiology in marine organisms. We used comparative transcriptomics, physiology, and a field assessment experiment to investigate whether Louisianan oyster are changing their phenotypes to cope with increased temperature and salinity …

Transcriptional Signatures Of Host Susceptibility In Urinary Tract Infections, Lu Yu

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli (UPEC) are common and highly recurrent. Two important non-behavioral risk factors for UTI in women are genetics and history of two or more episodes of previous UTI. However, specific mechanisms of how these two factors modulate host susceptibility to UTI remain unclear. Concordantly, inbred mice of various genotypes and with different infection histories exhibit different susceptibilities to acute and chronic bladder infection (cystitis), which recapitulates a range of clinical UTI outcomes observed in women. Early host-pathogen interactions have been shown to determine UTI outcomes in mouse models. Here, we used two …

Gene Expression Changes In The Mushroom Body Of Drosophila Melanogaster During A Time Course Of Long-Term Memory Formation And Maintenance, Spencer G. Jones

Electronic Thesis and Dissertation Repository

Long-term memory (LTM) requires gene transcription. However, there is still much to learn about which genes are transcriptionally regulated during LTM and the biological roles they play. Here, gene expression changes were characterized in Drosophila melanogaster over a time course of LTM formation and maintenance in neurons of the mushroom body (MB), a structure required for normal learning and memory. I identified 120 genes differentially expressed (q < 0.2, fold change > 1.3) 24h after LTM induction. Among these were 13 potential downstream targets for RNA localization by the known memory genes pumilo, staufen and oskar, several genes encoding chromatin regulators and seven genes with …

Differential Activity And Content Of High-Affinity Glutamate Transporters, Content Of Their Regulatory Proteins, And Capacity For Glutamine And Glutathione Synthesis In Tissues Of Finished Versus Growing Steers, Jing Huang

Theses and Dissertations--Animal and Food Sciences

Improvement of feeding regimens for production animals has been hindered by a lack of fundamental knowledge about how the capacity to regulate nutrient absorption across cell membranes affects the function of nutrient metabolizing enzymes. The objective is to determine if the activities and protein content of system X^-_AG glutamate transporter, its regulatory protein (GTRAP3-18 and ARL6IP1), glutamine synthetase (GS) and glutathione (GSH) content, changes in liver (Experiment 1), longissimus dorsi (LM) and subcutaneous adipose tissue (SF) (Experiment 2) as beef steers transitioned from predominantly-lean (growing) to -lipid (finished) tissue accretion phases. In liver (Experiment 1), system X^{- …}

Novel Computational Methods For Transcript Reconstruction And Quantification Using Rna-Seq Data, Yan Huang

Theses and Dissertations--Computer Science

The advent of RNA-seq technologies provides an unprecedented opportunity to precisely profile the mRNA transcriptome of a specific cell population. It helps reveal the characteristics of the cell under the particular condition such as a disease. It is now possible to discover mRNA transcripts not cataloged in existing database, in addition to assessing the identities and quantities of the known transcripts in a given sample or cell. However, the sequence reads obtained from an RNA-seq experiment is only a short fragment of the original transcript. How to recapitulate the mRNA transcriptome from short RNA-seq reads remains a challenging problem. We …

Transcriptome Analysis Of Sea Lamprey Embryogenesis, Zakary Ilya Yermolenko

Seton Hall University Dissertations and Theses (ETDs)

The sea lamprey (Petromyzon marinus) has survived throughout evolution for hundreds of millions of years. It is considered an invasive species to the Great Lakes that has caused dramatic changes in the ecosystem for fish communities resulting in the collapse of a fishing industry that was previously valued at billions of dollars. Successful management of the sea lamprey is essential to a sustainable fishing industry and biodiversity. Therefore sea lamprey embryos were studied at various stages of development by growing them in a simulated habitat. RNAs from adult female ovaries and embryos at different time points during embryogenesis …

Neurodevelopmental Consequences Of Prenatal Alcohol Exposure: Behavioural And Transcriptomic Alterations In A Mouse Model, Katarzyna Mantha

Electronic Thesis and Dissertation Repository

Fetal Alcohol Spectrum Disorder (FASD) is an umbrella term referring to a range of physical, behavioural, and cognitive deficits resulting from prenatal alcohol exposure. The resulting abnormalities are heterogeneous and often attributed to timing and dosage of alcohol exposure. However, the specific effects of developmental timing are not well-known.

This research used C57BL/6J (B6) as an animal model for early (human trimester one) and mid-gestation (human trimester two) alcohol exposure. Pregnant B6 mice were injected with 2.5 g/kg ethanol on gestational day (GD) 8 and 11 (trimester one equivalent), or on GD 14 and 16 (trimester two equivalent). Resulting pups …

Understanding Osmoregulation And Immunity In Heteromyid Rodents Through Insights Gained From Rna-Seq, Nicholas John Marra

Open Access Dissertations

Understanding the genetic basis of adaptation is one of the central questions of evolutionary genetics. In the face of selective pressure, individuals with adaptive phenotypes survive and pass on their beneficial alleles that conferred this fitness advantage. Over sufficient time scales and under strong selection, differences accumulate between taxa in the form of physical and/or behavioral traits that have been shaped differently. By looking at the transcriptomes of related taxa we can identify sequence and regulatory differences that represent molecular signatures of these different selection regimes. When we study these differences between taxa that have evolved under opposing selective forces …

Cellular And Molecular Aspects Of The Interaction Betwen Maize And The Anthracnose Pathogen Colletotrichum Graminicola, Maria F. Torres

Theses and Dissertations--Plant Pathology

Maize anthracnose, caused by the fungus Colletotrichum graminicola, is an economically important species contributing to major yield losses. C. graminicola is a hemibiotroph; initially it invades its host while it is alive, and then it switches to destructive necrotrophic growth and the host is killed. Establishment of compatible interactions by biotrophic pathogens is usually associated with suppression of host defenses and cell death, while necrotrophic pathogens typically secrete phytotoxic compounds and induce cell death. To understand the relationship of hemibiotrophy in C. graminicola to biotrophy and necrotrophy, I compared a compatible and an incompatible interaction, utilizing a non-pathogenic …

A Novel Computational Framework For Transcriptome Analysis With Rna-Seq Data, Yin Hu

Theses and Dissertations--Computer Science

The advance of high-throughput sequencing technologies and their application on mRNA transcriptome sequencing (RNA-seq) have enabled comprehensive and unbiased profiling of the landscape of transcription in a cell. In order to address the current limitation of analyzing accuracy and scalability in transcriptome analysis, a novel computational framework has been developed on large-scale RNA-seq datasets with no dependence on transcript annotations. Directly from raw reads, a probabilistic approach is first applied to infer the best transcript fragment alignments from paired-end reads. Empowered by the identification of alternative splicing modules, this framework then performs precise and efficient differential analysis at automatically detected …

Genomic Perspectives On Evolution In Bracken Fern, Joshua P. Der

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fern genus Pteridium comprises a number of closely related species distributed throughout the world. Collectively they are called bracken ferns and have historically been treated as a single species, Pteridium aquilinum. Bracken is notorious as a toxic weed that colonizes open fields and poisons livestock. Bracken is also easily cultured and has become one of the most intensively studied ferns. Bracken has been used as a model system for the study of the fern life cycle, fern gametophyte development, the pheromonal mechanism of sex determination, toxicology, invasion ecology, and climate change. This dissertation places bracken within a global …