Genomics Commons^™

Plastic And Evolved Responses In The Eastern Oyster, Crassostrea Virginica, To Environmental Variation In The Northern Gulf Of Mexico, Kyle Sirovy

LSU Doctoral Dissertations

Climate change and other anthropogenic impacts are causing rapid alterations to many of the world’s most productive coastal ecosystems and there is an urgent need to understand how species will respond to these environmental changes. Organisms may respond through plasticity, evolution, or the evolution of plasticity. In this dissertation, I evaluate the role of plastic and evolved responses in the eastern oyster, Crassostrea virginica, to environmental variation in the northern Gulf of Mexico. I use comparative transcriptomics, physiology, and morphology to examine the relative contribution of plastic and evolved responses for oysters exposed to low salinity and outplant sites …

Genetic Variations In The Myostatin Gene Among Irish Cattle Breeds, Cliona Ann Ryan

ORBioM (Open Research BioSciences Meeting)

No abstract provided.

Characterizing Endogenous Dicer Products To Unravel Novel Rnai Biogenesis Pathways, Jacob Oche Peter

Dissertations

ABSTRACT

RNA interference (RNAi) is a pervasive gene regulatory mechanism in eukaryotes based on the action of multiple classes of small RNA (sRNA). Exploiting RNAi pathways in non-model systems have great potential for creating potent RNAi technologies. Here, we accessed RNAi-mediated control of gene expression in the two-spotted spider mite, Tetranychus urticae (T. urticae) using engineered dsRNA designed to modulate the host RNAi pathway and increase RNAi efficacy. Analysis of Dicer (Dcr) generated fragments revealed how exogenous RNAs access the host RNAi pathway in this animal, opening avenues for designing RNAi technology for their control. Further, some organisms …

Genomic Insights Into Mechanisms Of Microbial Evolution And Evolution-Inspired Strategies To Combat Pathogen Diversity, Saymon Akther

Dissertations, Theses, and Capstone Projects

We live in an era of emerging infectious diseases that are increasingly common, rapidly spreading, and gravely devastating. Lyme disease, caused by bacteria belonging to the genus Borreliella, is rapidly rising in the Northern Hemisphere because of geographic range expansion of both the tick vectors and the pathogens. Evolutionary comparative analysis of Borreliella genomes is a key to understanding the phylogeographic history and mechanisms of their global diversification. Moreover, genomic variations in Borreliella associated with human pathogenicity, e.g., at loci encoding cell-surface antigens interacting with the vertebrate hosts, have not been fully identified. Similarly, the ongoing COVID-19 pandemic, caused …

Noxious Cellular Injury Triggers An Oxidative Stress Gene Response, Shawyun Khoshneviszadeh

Master of Science in Integrative Biology Theses

Wound and regeneration involves a series of complex processes that can induce oxidative stress by elevating intracellular reactive oxygen species (ROS) levels. In this study, we used RNA-seq and qPCR to examine the molecular signature of Human Embryonic Kidney cells (HEK-293T) stimulated with Crotalus atrox (CA) venom. NGS data was assembled and annotated utilizing the Illumina paired-end RNA-seq approach with software packages HISAT2 and StringTie. Results showed 243 genes were differentially expressed (106 upregulated, 137 downregulated) between CA venom stimulated and non-stimulated cells (p<0.05). HEK-293T stimulated with CA venom for 4 hours showed an increase in the expression of oxidative stress response genes (e.g., TOMM6, EGR (1,2,3), HSP70 (1A, 1B), SPRY4, ETV5, and EMP1) (Fold-Change (fc) >2.0). Significantly downregulated genes were associated with many novel transcripts/proteins such as AC117378, AD000671, and AC023509. …

Repeated Targets Of Natural Selection During Ecological Transitions Of Fish Across Salinity Boundaries, Jonathan P. Velotta, Stephen D. Mccormick, Andrew Whitehead, Catherine S. Durso, Eric T. Schultz

EEB Articles

Ecological transitions across salinity boundaries have led to some of the most important diversification events in the animal kingdom, especially among fishes. Adaptations accompanying such transitions include changes in morphology, diet, whole-organism performance, and osmoregulatory function, which may be particularly prominent since divergent salinity regimes make opposing demands on systems that maintain ion and water balance. Research in the last decade has focused on the genetic targets underlying such adaptations, most notably by comparing populations of species that are distributed across salinity boundaries. Here, we synthesize research on the targets of natural selection using whole-genome approaches, with a particular emphasis …

Halodash: The Deep And Shallow History Of Aquatic Life's Passages Between Marine And Freshwater Habitats, Eric T. Schultz, Lisa Park Boush

EEB Articles

This series of papers highlights research into how biological exchanges between salty and freshwater habitats have transformed the biosphere. Life in the ocean and in freshwaters have long been intertwined; multiple major branches of the tree of life originated in the oceans and then adapted to and diversified in freshwaters. Similar exchanges continue to this day, including some species that continually migrate between marine and fresh waters. The series addresses key themes of transitions, transformations, and current threats with a series of questions: When did major colonizations of fresh waters happen? What physiographic changes facilitated transitions? What organismal characteristics facilitate …

Unraveling The Genetic Architecture Of Somatic Embryogenesis In Upland Cotton, Adam M. Canal

All Theses

Somatic embryogenesis is the de novo development of asexual embryos because of the plasticity of the plant cell. In tissue culture, the biochemical and genetic mechanisms of dedifferentiated callus tissues can be reprogrammed to transdifferentiate into developed, polarized embryos, which can ultimately regenerate into whole plants. Although this rarely occurs in nature, scientists have exploited this process for decades to regenerate whole plants following gene transformation or for micropropagation. While some species are amenable to in vitro regeneration, upland cotton is particularly recalcitrant, with regenerative potential being confined to only several genotypes. The lack of elite, regenerable genotypes greatly restricts …

Functional Role Of Ppal And Potential For Moss In Industrial Applications., Susana Perez Martinez

Electronic Theses and Dissertations

This dissertation is an examination and characterization of the functional roles of PPAL. PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) is a recently discovered gene. PPAL homologs are present in all plants and many animals, where its function is largely unknown. It is possible that PPAL could participate in prenylation processes since it shares similarity to the α subunits of known prenylation enzymes. Prenylation is a post-translational modification of proteins that involves the addition of a lipid moiety to proteins to facilitate membrane targeting and association and promote protein-protein interactions. Prenylation has important roles in plant growth and development, including …

Exploration Of Genes Controlling Grain Yield Heterosis In Hybrid Wheat (Triticum Aestivum L.) Utilizing 3ʹ Rna Sequencing, Nichole Lynn Miller

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The implementation and future success of hybrid wheat (Triticum aestivum L.) is impacted by breeders’ inability to create consistent high yielding, high heterosis hybrids. This research addresses this problem by conducting an exploration of transcriptomes from hybrids and parent lines to determine what genes are active in heterotic or non-heterotic hybrids and how their level of expression can explain the phenotype of grain yield heterosis. Using hybrids that showed positive mid-parent heterosis (MPH), classified as heterotic in our study, and negative or no difference MPH hybrids, classified as non-heterotic, differentially expressed genes (DEGs) potentially related to heterosis and hybrid …

Genomic Tools And Models For Investigating The Role Of Germline Diversity In Mouse Antibody Repertoire Development., Justin T. Kos

Electronic Theses and Dissertations

Given the diversity and complexity within immunoglobulin (IG) loci, effective mouse models first require characterization of intra-strain differences and construction of high-quality reference assemblies for IG loci in several representative strains. To understand light chain germline diversity across biomedically significant mouse strains, we profiled the expressed IGK and IGL repertoires of 18 commonly used laboratory mouse strains using AIRR-seq. Across strains, we observed germline IGKV sequences shared by three different IGK haplotypes and a more conserved IGLV germline repertoire among common laboratory strains. Pacific Biosciences (PacBio) Single-Molecule Real-Time (SMRT) sequencing was used to sequence and assemble bacterial artificial chromosomes (BAC) …

Investigating The Ecology And Evolution Of Normal Breast Tissues And Breast Cancer With Single Cell Genomics, Tapsi Kumar, Tapsi Kumar

Dissertations and Theses (Open Access)

There is vast cellular heterogeneity in human breast tissues, with different transcriptional programs in the stromal, epithelial, and immune components, however, it remains unclear how their reprogramming and interplay leads to the progression of invasive phenotypes such as Triple- Negative Breast cancer (TNBC). To do define the microenvironmental alterations that occur during cancer, we first established a human breast cell atlas, a reference of normal breast cell types from disease free women. We profiled 535,941 cells from 62 women and 124,024 nuclei from 20 women revealing 11 major cell types and 52 cell states that reflect different biological functions that …

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

Dissertations and 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 …

Computational Approaches To Understand Chemoresistance & Tumor Evolution Using Longitudinal Clinical Data And Lineage Tracing, Sahil Seth

Dissertations and Theses (Open Access)

Tumors are highly heterogeneous and dynamic, continually adapting and evolving in response to their microenvironment as well as external perturbations. Multi-region (spatial) and single cell sequencing has enabled us to anatomize the heterogeneity further and provide evidence of its association with chemo and drug resistance. To investigate this further we took two different approaches to understand the chemo-resistance, and functional heterogeneity in Triple negative breast cancer (TNBC) and Pancreatic ductal carcinoma in situ (PDAC) from an evolutionary perspective.

The first approach was to leverage tumor profiling from an ongoing randomized clinical trial in triple-negative breast cancer (ARTEMIS) to assess mechanisms …

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 …

Scalable Software Infrastructure For The Lab And A Specific Investigation Of The Yeast Transcription Factor Eds1, Chase Mateusiak

McKelvey School of Engineering Graduate Student Theses & Dissertations

Individual biology labs handle increasingly large data sets. Ensuring accurate data entry, consistent sample metadata, and ease of access to the data once it is stored, are critical for both the integrity of analysis as well as productivity of the lab. Chapter 1 one of this thesis describes three implementations of software meant to facilitate handling data and metadata in the lab as the size of the data and complexity of analysis scale. The first piece of software is a database and entry interface for storing a large and varied amount of data on biological samples. The second is a …

Novel And Extendable Genotyping System For Human Respiratory Syncytial Virus Based On Whole-Genome Sequence Analysis, Jiani Chen, Xueting Qiu, Vasanthi Avadhanula, Samuel S Shepard, Do-Kyun Kim, James Hixson, Pedro A Piedra, Justin Bahl

Faculty, Staff and Student Publications

BACKGROUND: Human respiratory syncytial virus (RSV) is one of the leading causes of respiratory infections, especially in infants and young children. Previous RSV sequencing studies have primarily focused on partial sequencing of G gene (200-300 nucleotides) for genotype characterization or diagnostics. However, the genotype assignment with G gene has not recapitulated the phylogenetic signal of other genes, and there is no consensus on RSV genotype definition.

METHODS: We conducted maximum likelihood phylogenetic analysis with 10 RSV individual genes and whole-genome sequence (WGS) that are published in GenBank. RSV genotypes were determined by using phylogenetic analysis and pair-wise node distances.

RESULTS: …

Development Of Cloning Vehicles For Expression Of Gc-Maf In Yeast, Tammy Tran, Seohyun Lee, Jane Yu, Wilson Wu

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Proteomic Analysis Of The Expression Of Masp1 Dragline Silk Protein In E. Coli, Sophie Rae Pazzo, Rajan Amit Patel, Kamrin Athwal, Edward Kim

Pacific Undergraduate Research and Creativity Conference (PURCC)

No abstract provided.

Spr-5; Met-2 Maternal Reprogramming Cooperates With The Dream Complex To Regulate Developmental Cell Fates, Jazmin Dozier, Sandra Nguyen, Brandon Carpenter

Symposium of Student Scholars

Histone methylation is a post-transcriptional modification to the N-terminal tails of histone core proteins that regulates DNA accessibility, and consequently, gene expression. Like DNA, histone methylation can be inherited between generations, and is highly regulated during embryonic development. At fertilization, histone methylation must undergo maternal reprogramming to reset the epigenetic landscape in the new zygote. During maternal reprogramming of histone methylation in the nematode, C. elegans, H3K4me (a modification associated with active transcription) is removed by the H3K4 demethylase, SPR-5, and H3K9me (a modification associated with transcriptional repression) is subsequently added by the histone methyltransferase, MET-2. Recently, it was …