Molecular Genetics Commons^™

Microbial-Host Dynamics And The Evolution Of Nearshore Diversity In Hippocampus Abdominalis, Jimiane L. Ashe

Dissertations, Theses, and Capstone Projects

Local adaptation is a fundamental concept at the core of evolutionary process. Devising means to break down larger concepts and systematically test internal mechanisms are key to understanding the driving forces behind the influence of environmental differences on biological systems. To understand dynamic processes in the natural world, we must strip away layers and confounding variables that may mask the signal we hope to understand. In this case seahorse species, Hippocampus abdominalis, or the pot-bellied seahorse, made an unlikely but ideal study system. The first layer to strip away was neutral genetic variation within the population. A multilocus genetic …

Creating A Protein Chimera To Study Regulation Of Muscle Diversity, Shannon Scarboro

Symposium of Student Scholars

Creating a protein chimera to study regulation of muscle diversity.

Body muscles are made of many individual super-cells, called muscle fibers, that have distinct properties and determine every individual’s strength and endurance. Initially all muscle fibers have identical characteristics, but become differentiated into specific types in adults. The mechanism of such transition is not well understood, despite its obvious importance for shaping human physicality.

Remarkable conservation of the muscle tissue enables us to use fruit flies to study the mechanisms of muscle fiber diversity. We hypothesized that the transcription factor Mef2 acts as a molecular switch that activates structural genes …

Identifying The Cell Composition And Clonal Diversity Of Supratentorial Ependymoma Using Single Cell Rna-Sequencing, James He

University Scholar Projects

Ependymoma is a primary solid tumor of the central nervous system. Supratentorial ependymoma (ST-EPN), a subtype of ependymomas, is driven by an oncogenic fusion between the ZFTA and RELA genes in 70% of cases. We introduced this fusion into neural progenitor cells of mice embryos via in utero electroporation of a non-viral binary piggyBac transposon system containing ZFTA-RELA. From preliminary data in the LoTurco lab, inducing the expression of ZFTA-RELA into different neural progenitor cells produces tumors of varying lethality and cellular composition. To define the cellular composition and subclonal diversity of ST-EPN tumors, we used single cell RNA-sequencing to …

Evolution Of Extreme Habitat Specialists In The Dark: Cavefishes And Anglerfishes, Pamela Hart

LSU Doctoral Dissertations

Extremophilic organisms are fascinating in that they thrive in physiologically demanding environments. Extreme habitats include subsurface caves and the deep sea, which share several qualities like low light and cold temperatures. Extremophiles have adapted bizarre characteristics that allow them to thrive in such harsh environments including eye and pigment loss (cavefishes) and development of a lure in anglerfishes. These traits are integral to the health and fitness of these organisms, yet the evolutionary history of these traits is unclear.

Cave adaptation has evolved repeatedly across the Tree of Life, famously leading to eye degeneration and loss, yet its macroevolutionary implications …

Molecular Characterization Of A Unique Population Of Human Cortical Interneurons; Implications For Primate-Specific Development, Crina Peterson

Biomedical Sciences ETDs

The human brain consists of 86 billion neurons compared to rodent brain, which consists of 75 million neurons, and the underlying mechanisms for the increased complexity of the primate cortex are not fully elucidated. However, an increase in specific cell populations, including calretinin-expressing (CALB2/CR) interneurons (INs), has been identified. In my thesis work, I demonstrate that human pluripotent stem cells (hPSCs) differentiated to neurons by default patterning give rise to this CR population in vitro, providing a method to study their development.

Chapter I reviews cortical development and hPSCs as an appropriate proxy for studying human cortical development. Chapter …

Germline Variants Associated With Cancer Predisposition And Bone Marrow Failure Are Common In Kmt2a-R Infant Acute Lymphoblastic Leukemia Patients, Sarah E. Mc Dermott

Research Days

Background: Infant acute lymphoblastic leukemia (ALL), is a particularly aggressive subtype of leukemia with an early onset and unfavorable clinical outcome. Most (~70%) cases of infant ALL involve chromosomal rearrangement of KMT2A (KMT2A- r) on chromosome 11q23, the strongest independent predictor of a poor prognosis. To date, genomics studies have consistently demonstrated KMT2A-r infant ALL to have a strikingly silent landscape of DNA mutations. Germline mutations in cancer predisposition genes are found in 8.6% of pediatric malignancies and 4.4% of pediatric leukemias, compared to 1.1% in persons in the 1000 Genomes Project.

Objectives/Goal: We hypothesized that germline variants may contribute …

Many Clinical Laboratories Performing Next-Generation Sequencing Have No Future Plans To Migrate To The Most Recent Human Reference Genome Build (Grch38), Lisa A. Lansdon

Research Days

Background: Analysis of clinical next-generation sequencing (NGS) data requires the Human Reference Genome (HRG) for alignment. Build GRCh38 was released in December 2013 and resolved ~1,000 issues from GRCh37, including erroneous calls within clinically-relevant genes.

Objectives/Goal: Despite this new release becoming available over seven years ago, most clinical laboratories continue to use build GRCh37. We were interested to learn other clinical laboratory’s plans for migration to GRCh38, including their proposed timelines and related concerns; therefore, we conducted a survey to define the current landscape of genome alignment in clinical NGS.

Methods/Design: Seventy-one clinical laboratories performing constitutional NGS testing were invited …

The Effects Of Mapk Signaling On The Development Of Cerebellar Granule Cells, Kerry Morgan

University Scholar Projects

The granule cells are the most abundant neuronal type in the human brain. Rapid proliferation of granule cell progenitors results in dramatic expansion and folding of the cerebellar cortex during postnatal development. Mis-regulation of this proliferation process causes medulloblastoma, the most prevalent childhood brain tumor. In the developing cerebellum, granule cells are derived from Atoh1-expressing cells, which arise from the upper rhombic lip (the interface between the roof plate and neuroepithelium). In addition to granule cells, the Atoh1 lineage also gives rise to different types of neurons including cerebellar nuclei neurons. In the current study, I have investigated the …

The Effects Of Mapk Signaling On The Development Of Cerebellar Granule Cells, Kerry Morgan

Honors Scholar Theses

The granule cells are the most abundant neuronal type in the human brain. Rapid proliferation of granule cell progenitors results in dramatic expansion and folding of the cerebellar cortex during postnatal development. Mis-regulation of this proliferation process causes medulloblastoma, the most prevalent childhood brain tumor. In the developing cerebellum, granule cells are derived from Atoh1-expressing cells, which arise from the upper rhombic lip (the interface between the roof plate and neuroepithelium). In addition to granule cells, the Atoh1 lineage also gives rise to different types of neurons including cerebellar nuclei neurons. In the current study, I have investigated the …

Evolutionary Conservation Of The Heterochronic Pathway In C. Elegans And C. Briggsae, Maria Ivanova, Eric G. Moss

Rowan-Virtua Research Day

Heterochronic genes control the sequence and timing of developmental events during four larval stages of Caenorhabitis nematodes. Mutations in these genes may cause skipping or reiteration of developmental events.

C. briggsae is a close relative of C. elegans. These species have similar morphology and share the same ecological niche. C. briggsae undergoes the same developmental pathway consisting of four larval stages before reaching adulthood. It also has the same set of heterochronic genes.

Lin-28 is one of the heterochronic genes that also exists in other animals from flies to humans. It conservatively blocks the maturation of let-7 miRNA, the process …

Implementing Crispr-Cas9 Gene Editing System In Microbotryum., Stevana Reese Schauer

College of Arts & Sciences Senior Theses

Microbotryum dianthorum is a species of smut fungus which causes infection in plants in the Dianthus genus. The infection process is aided by small-secreted proteins known as effectors. Effectors may aid in the infection process because they are secreted by the fungus and can enter plant tissue, possibly to facilitate infection and/or manipulate the host. Thus, it is of interest to investigate the genes for these effectors to determine their role in the infection process. One method to study genes is through gene disruption, via the CRISPR/Cas9 gene editing system, but this has not yet been implemented in Microbotryum dianthorum …

Mapping The Domain Of Rna Helicase Ddx1 That Interacts With The Ns1 Of Influenza A Viruses, Elise Wyatt

Biomedical Engineering Undergraduate Honors Theses

Of the known influenza virus strains, influenza A viruses (IAVs) are the most catastrophic due to their highly contagious nature and possibly life-threatening symptoms. IAVs invade a host cell and enter the nucleus where they use the cell’s nuclear machinery for replication of their viral RNA genome which is then exported to neighboring cells to establish a productive infection. Host pathogen recognition receptors (PRRs) respond to viral infection by signaling the cell to produce type I interferons (IFNs) to fight the foreign invader. Non-structural protein 1 (NS1) of IAVs, a major component in the regulation of viral replication, opposes host …

Identification Of Proteins That Contribute To Yeast Heat Stress By Lysine Acetylation, Weijia Shi

Biological Sciences Undergraduate Honors Theses

Evidence is emerging that protein lysine acetylation may be a novel type of post-translational modification (PTM) contributing to the mechanisms of yeast heat stress responses. Proteomics studies including ours have identified over 1,000 acetylated proteins in the yeast proteomes that are composed of about 6,000 proteins. Our lab recently identified 596 proteins that underwent acetylation changes during heat shock by mass spectrometry. However, the role of lysine acetylation on specific residues of specific proteins in yeast thermotolerance remains largely unknown. This study selected 43 proteins from our lab’s previous work and examined their possible contributions to yeast heat stress responses. …

Production, Evaluation, And Selection Of Elite Quality Protein Popcorn (Qpp) Hybrids, Leandra Marshall Parsons

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

In 2017, twelve Quality Protein Popcorn (QPP) inbred lines were developed and selected as premier dent by popcorn crosses fit for hybridization and testing. These QPP inbred lines were derived from specific Quality Protein dent Maize (QPM) by ConAgra Brands® popcorn line crosses to produce high lysine, vitreous popcorn lines capable of near-equal popping characteristics compared to the original popcorn parents. The QPP hybridization project commenced in the summer of 2018 utilizing these 12 inbred QPP lines and crossing them in a full diallel. Since then, the production of QPP hybrids has employed a diverse set of selection factors evaluating …

Using Crispr-Cas9 To Characterize The Role Of Gli-Similar 3 (Glis3) In Insulin Regulation, Pancreatic Development, And Type 2 Diabetes, Lilyanne Grieve

Honors College Theses

The prevalence of type 2 diabetes continues to rise nationally and internationally, impacting millions of people worldwide. Type 2 diabetes results from insulin resistance leading to chronic hyperinsulinemia and dysfunction of the insulin producing β cells of the pancreas. While environmental factors can influence the development of type 2 diabetes, research has shown genetics are also involved. Gli-similar 3 (Glis3), a Krüppel-like zinc finger transcription factor, has been identified as a novel regulator of insulin transcription. Evidence has shown that loss-of-function Glis3 mutations decrease insulin expression, implicating Glis3 in the development of type 2 diabetes. However, the distinct role Glis3 …

Determination Of Human Shedding Propensity Based On Str Results, Genevieve Trapani

Student Theses

Trace DNA evidence may be discovered at a crime scene after having been deposited by a person of interest via active or passive transfer. Based on previous studies, passive transfer of one’s DNA is influenced by their shedding propensity, or probability of depositing a detectable amount of DNA through touch. Determining the shedding propensity of a person of interest can aid in trace DNA interpretation in forensic casework. This study explored STR profile quality and the presence of a DNA mixture for different skin surface locations, including fingertips before and after handwashing. As expected, unwashed fingers showed a higher prevalence …

Functions Of Dcp2 And Ski7 In Mrna Degradation, Minseon Kim, Ambro Van Hoof

Dissertations and Theses (Open Access)

Posttranscriptional gene regulation is essential to maintain gene expression fidelity. This is partially achieved by mRNA decay. When no longer required, mRNA is degraded by two alternative pathways. The decapping enzyme Dcp2 removes the 5` <sup>m7</sup>G cap of mRNAs, allowing Xrn1 to degrade the mRNA from the 5` end. Alternatively, mRNA is degraded from the 3` end by the RNA exosome.

While decapping by Dcp2 is a critical step in mRNA decay, its physiological function has been unclear. Null mutations of Saccharomyces cerevisiae DCP2 have been reported to be lethal in some studies but slow-growing in others. In this …

Rare Variant Association Studies In Crohn’S Disease And Colorectal Cancer: Methods And Applications, Jiun-Sheng Chen

Dissertations and Theses (Open Access)

Genetic factors account for a substantial portion of Crohn’s disease and colorectal cancer (CRC) risk. Patients with Crohn’s disease, a condition that causes chronic inflammation of the gastrointestinal tract, are at increased risk of colorectal cancer morbidity and mortality. Genome-wide association studies using single marker approaches have identified loci responsible for these diseases, but disease susceptibility from rare variants is incompletely understood. This dissertation includes three chapters, two association studies for Crohn’s disease and CRC, and a statistical method to improve the power of statistical tests.

For Crohn’s disease, we performed targeted sequencing of 101 genes in 205 children with …

Examining The Role Of The Drosophila Melanogaster Unc13 Protein In Open Field Activity Using Rnai, Islam Orabi

Honors Theses

Unc13 are proteins in the presynaptic neurons essential in controlling synaptic vesicle fusion and synaptic transmission. Recently, the reduction of Drosophila melanogaster Unc13 proteins (Dunc13), were found to result in a resistance to alcohol, highly reminiscent of tolerance formation. I investigated whether genetically reducing Dunc13 activity in Drosophila brain regions leads to different forms of behavioral plasticity using an open field activity paradigm. In my approach, a Dunc13 RNAi transgene was expressed in the Drosophila brain within the mushroom body, the ellipsoid body, and in all neurons. The activities of the flies were examined in the open field paradigm to …

The Biodiversity Of Deadwood-Associated Arthropods In The Southern Appalachian Mountains, Isabelle Ong

Honors Theses

A biodiversity hotspot is a location that has significantly elevated levels of biodiversity including many species found nowhere else, and which is also in danger of losing much of this diversity. By identifying biodiverse regions, conservation efforts can be targeted to those locations where they are likely to have the most beneficial impacts. We looked at deadwood associated arthropods within the Southern Appalachian Mountains to examine centers of biodiversity. Nine logs were sampled, three of which were located in Bankhead National Forest and six were located in the Great Smoky Mountains. Polymerase chain reaction was used to amplify the mitochondrial …