Genetics and Genomics 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 …

Genomic And Ecological Dimensions Of Malagasy Reptile And Amphibian Biodiversity, Arianna L. Kuhn

Dissertations, Theses, and Capstone Projects

A long history of isolation coupled with complex topographic and ecological landscapes makes Madagascar ideal for exploring the historical factors that have shaped patterns of population diversity and endemism. Many species-level studies have suggested Late Quaternary climate change may have influenced population dynamics in the tropics, but Madagascar’s ecologically unique biomes or individual species properties may have driven idiosyncratic responses to these shifts. Using community-scale population genetic data I implement a hierarchical approximate Bayesian computation (hABC) approach to evaluate the degree of synchronous population expansion during glacial cycles across herpetofaunal assemblages both within and across discrete biomes and taxonomic groups. …

Dna Barcoding Of The High-Altitude Artemisia And Nepeta Species, Vyacheslav Dushenkov, Csanad Gurdon, Shukhratdzhon Satorov

Publications and Research

DNA barcoding was performed for four medicinal plant species from the mountain region of Tajikistan. The nucleotide sequences for Artemisia sieberi, Artemisia scoparia, Artemisia vulgaris, and Nepeta glutinosa were deposited into the GenBank at the National Center for Biotechnology Information.

Molecular Mechanisms Underlying Cell Fate Choice Within Specific Retinal Lineages, Estie Schick

Dissertations, Theses, and Capstone Projects

During development, retinal progenitor cells (RPCs) divide to form all of the cell types that make up the retina. Multipotent RPCs are competent to generate all retinal cell types, while restricted RPCs form specific lineages of cells. In particular, one genetically-defined RPC type preferentially gives rise to cone photoreceptors and horizontal cells. Many of the mechanisms that are responsible for directing cell fate choice within this lineage are unknown. This thesis largely focuses on examining the development of specific cell types and subtypes from restricted RPCs and on investigating the gene regulatory events that underlie cone photoreceptor and horizontal cell …

The Role Of Placental Genes On Intellectual Disability And Developmental Delay, Maedot A. Yidenk

Dissertations, Theses, and Capstone Projects

The complex interaction between gene expressions and environmental factors plays a key role in the pathogenesis of various diseases, including neurodevelopmental disorders (Lenroot & Giedd, 2008). This study aimed to evaluate first, the magnitude of association between placental gene Methyl-CpG Binding Protein 2 (MeCP2) and intellectual disability (ID) in the offspring and second, the synergy between placental gene Forkhead box protein 1(FOXP1) and developmental delay (DD) in the offspring. We focused on assessing two specific paradigms, i) placental gene expressions of MeCP2 among children that have ID vs. children without ID; and ii) placental gene expression of …

Evolution And Development Of The Seed Coat In Gymnosperms, Cecilia Zumajo

Dissertations, Theses, and Capstone Projects

Gymnosperms and angiosperms are the most abundant plant lineages on earth and constitute a turning point in the evolution of plants because they are at the origin of the seed, a key morphological and developmental novelty in the evolution of land plant. Although the morphological variation of the seed, across seed plants, may on its own, explain the complexity of this structure, the origin, and evolution are even more, the understanding of these topics is still under discussion. Evidence shows that previous studies have often lacked the component of gene expression, particularly in species that are not model species. The …

Dynamic Observers For Unknown Populations, Chris Guiver, Nathan Poppelreiter, Richard Rebarber, Brigitte Tenhumberg, Stuart Townley

Brigitte Tenhumberg Papers

Dynamic observers are considered in the context of structuredpopulation modeling and management. Roughly, observers combine a known measured variable of some process with a model of that process to asymptotically reconstruct the unknown state variable of the model. We investigate the potential use of observers for reconstructing population distributions described by density-independent (linear) models and a class of density-dependent (nonlinear) models. In both the density-dependent and -independent cases, we show, in several ecologically reasonable circumstances, that there is a natural, optimal construction of these observers. Further, we describe the robustness these observers exhibit with respect to disturbances and uncertainty in …

Overview Of The Microbiome Among Nurses Study (Micro-N) As An Example Of Prospective Characterization Of The Microbiome Within Cohort Studies, Christine Everett, Chengchen Li, Jeremy E. Wilkinson, Long H. Nguyen, Lauren J. Mciver, Kerry Ivey, Jacques Izard, Natalia Palacios, A. Heather Eliassen, Walter C. Willett, Alberto Ascherio, Qi Sun, Shelley S. Tworoger, Andrew T. Chan, Wendy S. Garrett, Curtis Huttenhower, Eric B. Rimm, Mingyang Song

Department of Food Science and Technology: Faculty Publications

A lack of prospective studies has been a major barrier for assessing the role of the microbiome in human health and disease on a population-wide scale. To address this significant knowledge gap, we have launched a large-scale collection targeting fecal and oral microbiome specimens from 20,000 women within the Nurses’ Health Study II cohort (the Microbiome Among Nurses study, or Micro-N). Leveraging the rich epidemiologic data that have been repeatedly collected from this cohort since 1989; the established biorepository of archived blood, urine, buccal cell, and tumor tissue specimens; the available genetic and biomarker data; the cohort’s ongoing follow-up; and …

Impact Of Intratumor Heterogeneity And The Tumor Microenvironment In Shaping Tumor Evolution And Response To Therapy, Akash Mitra

Dissertations and Theses (Open Access)

Intratumor heterogeneity (ITH) is a crucial challenge in cancer treatment. The genotypic and phenotypic heterogeneity underlying diverse cancer types leads to subclonal variation, which may result in mixed or failed response to therapy. The heterogeneity at the tumor level, along with the tumor microenvironment (TME), often shapes tumor evolution and ultimately clinical outcome. Given that modern treatment paradigms increasingly expose patients with metastatic disease to multiple treatment modalities through the course of their disease, there exists a need to characterize robust and predictive biomarkers of response to therapy. In order to accurately characterize tumor evolution, we need to account for …

Genome-Wide Association Study Of More Than 40,000 Bipolar Disorder Cases Provides New Insights Into The Underlying Biology, Niamh Mullins, Andreas J. Forstner, Kevin S. O’Connell, Brandon Coombes, Ney Alliey Rodriguez

School of Medicine Publications

Bipolar disorder is a heritable mental illness with complex etiology. We performed a genome-wide association study of 41,917 bipolar disorder cases and 371,549 controls of European ancestry, which identified 64 associated genomic loci. Bipolar disorder risk alleles were enriched in genes in synaptic signaling pathways and brain-expressed genes, particularly those with high specificity of expression in neurons of the prefrontal cortex and hippocampus. Significant signal enrichment was found in genes encoding targets of antipsychotics, calcium channel blockers, antiepileptics and anesthetics. Integrating expression quantitative trait locus data implicated 15 genes robustly linked to bipolar disorder via gene expression, encoding druggable targets …

Transcriptional Analysis Of The Response Of C. Elegans To Ethanol Exposure, Mark G. Sterken, Marijke H. Van Wijk, Elizabeth C. Quamme, Joost A. G. Riksen, Lucinda Carnell, Laura D. Mathies, Andrew G. Davies, Jan E. Kammenga, Jill C. Bettinger

Biology Faculty Scholarship

Ethanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome. Several genes that are known to be involved …

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …

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 …

Successful Atac-Seq From Snap-Frozen Equine Tissues, Sichong Peng, Rebecca Bellone, Jessica Lynn Petersen, Theodore S. Kalbfleisch, Carrie J. Finno

Department of Animal Science: Faculty Publications

An assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) has become an increasingly popular method to assess genome-wide chromatin accessibility in isolated nuclei from fresh tissues. However, many biobanks contain only snap-frozen tissue samples. While ATAC-seq has been applied to frozen brain tissues in human, its applicability in a wide variety of tissues in horse remains unclear. The Functional Annotation of Animal Genome (FAANG) project is an international collaboration aimed to provide high quality functional annotation of animal genomes. The equine FAANG initiative has generated a biobank of over 80 tissues from two reference female animals and experiments to begin …

Cnd-1/Neurod Is Required For Rme Head Neuron Cell Fate Specification In The Nematode Caenorhabditis Elegans., Genevieve Doxakis

Symposium of Student Scholars

cnd-1/NeuroD is required for RME head neuron cell fate specification in the nematode Caenorhabditis elegans.

Genevieve Doxakis (1), Illyana Weitzel (2), Amber Baldwin (1), Davron Hanley (1), and Martin L. Hudson (1)

(1) Department of Molecular and Cellular Biology, Kennesaw State University

(2) STEM Magnet Program, Wheeler High School

Transcription factors are proteins that control gene transcription. NeuroD is a deeply conserved transcription factor that regulates neuronal differentiation and pancreatic development. Mutations in this gene correlate with several neurological disorders, creating an imperative for further study. The nematode Caenorhabditis elegans has a NeuroD ortholog, cnd-1, which means we can use …

Detecting Bacterial Species From Ancient Human Skeletal Samples, Ariel Owens, Daisy Mcgrath, Tsai-Tien Tseng

Symposium of Student Scholars

This paleopathological study aims to identify Mycobacterium tuberculosis complex (MTBC), Mycobacterium avium complex (MAC) and other Mycobacterium species in silico from skeletal samples that belonged to 28 Polish individuals in the Neolithic period under PRJNA422903 from the Sequence Read Archive (SRA). After next-generation sequencing (NGS), bioinformatics methods are heavily relied upon for identification of pathogens from complex samples. We implemented a bioinformatics pipeline, with custom-built databases, utilizing the following software tools: Trim Galore! and Kraken2. After adapter trimming, Kraken2 was used for taxonomic classifications. We have found that Mycobacterium is present in all 28 individuals. The average percentage of MAC …

Identification And Comparison Of Arbuscular Mycorrhizal Fungi And Soil Microbiomes Between American Chestnuts And Surrounding Hardwoods, Sarah Andrews, Geoffrey Eger, Isabella Vahle

Symposium of Student Scholars

Background/Questions/Methods

The introduction of the Chinese chestnut blight in 1904 decimated native American chestnut (Castanea dentata (Marshall) Borkh.) populations. In this study we aim to: 1) document the location of individual chestnuts in our vicinity; 2) document healthy versus blight infected individuals; 3) characterize putative differences in the soil microbiome between infected and non-infected individuals, as well as between chestnuts and hardwood neighbors. With this information we hope to provide new insights into mechanisms that may enhance blight and fungal resistance in American chestnuts through the understanding of the interactions between the trees and their surrounding soil microbiome.

Soil …

A Forward Genetic Screen To Identify Human Genes Of Interest And Their Roles In Ovarian Cancer, Susan A. Ihejirika

Honors College Theses

Drosophila melanogaster, fruit flies, are very important for modeling and studying human diseases. This study identifies human genes of interest and their contributions to epithelial ovarian carcinogenesis and progression as well as the roles orthologs of these genes play in Drosophila melanogaster. This is important because ovarian cancer is the most common cause of death among the gynecological cancers. This identification of genes was carried out using a forward genetic screen employing the widely used GMR-Gal4 driver/UAS-transgene system. The GMR-Gal4 driver is commonly utilized to express transgenes in the developing eye of the fruit fly. Transgenes that are expressed using …

Sources Of Resistance To Common Bacterial Blight And Charcoal Rot Disease For The Production Of Mesoamerican Common Beans In The Southern United States, Daniel Ambachew, Jacqueline Joshua, Margaret T. Mmbaga, Matthew W. Blair

Agricultural and Environmental Sciences Faculty Research

The gene pool of Mesoamerican common beans (Phaseolus vulgaris L.) includes genotypes in the small-to-medium-size seeded dry beans, as well as some snap beans from hotter environments adapted to the Southeastern United States. However, the warm and humid climate of the Southeastern United States is conducive to diseases such as Common Bacterial Blight (CBB) and Charcoal Rot (CR). The pathogens for these two diseases can survive long periods in infested soil or on seeds and are difficult to control through pesticides. Hence, field-level resistance would be the best management strategy for these diseases. The goals of this study were (1) …

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 …

Splitting The Difference: Heterogeneous Soil Moisture Availability Affects Aboveground And Belowground Reserve And Mass Allocation In Trembling Aspen, Ashley T. Hart, Morgane Merlin, Erin Wiley, Simon M. Landhäusser

Aspen Bibliography

When exploring the impact of resource availability on perennial plants, artificial treatments often apply conditions homogeneously across space and time, even though this rarely reflects conditions in natural systems. To investigate the effects of spatially heterogeneous soil moisture on morphological and physiological responses, trembling aspen (Populus tremuloides) saplings were used in a split-pot experiment. Following the division of the root systems, saplings were established for a full year and then subjected to either heterogeneous (portion of the root system exposed to non-lethal drought) or homogeneous (whole root system exposed to non-lethal drought or well-watered) treatments. Above- and belowground …

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 …

Genome Sequence Of A Virulent African Swine Fever Virus Isolated In 2020 From A Domestic Pig In Northern Vietnam, Quang Lam Truong, Thi Lan Nguyen, Thi Hoa Nguyen, Jishu Shi, Hiep Lai Xuan Vu, Thi Lan Huong Lai, Van Giap Nguyen

Nebraska Center for Virology: Faculty Publications

This study reports the genome sequence of an isolated African swine fever (ASF) virus (VNUA-ASFV-05L1/HaNam) obtained at the fourth passage on pulmonary alveolar macrophages. The virus was isolated during a typical acute ASF outbreak in pigs in a northern province of Vietnam in 2020.

Repurposing Potential Of Posaconazole And Grazoprevir As Inhibitors Of Sars-Cov-2 Helicase, Syed Hani Abidi, Nahlah Makki Almansour, Daulet Amerzhanov, Khaled S. Allemailem, Wardah Rafaqat, Mahmoud A A. Ibrahim, Philip La Fleur, Martin Lukac, Syed Ali

Department of Biological & Biomedical Sciences

As the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic engulfs millions worldwide, the quest for vaccines or drugs against the virus continues. The helicase protein of SARS-CoV-2 represents an attractive target for drug discovery since inhibition of helicase activity can suppress viral replication. Using in silico approaches, we have identified drugs that interact with SARS-CoV-2 helicase based on the presence of amino acid arrangements matching binding sites of drugs in previously annotated protein structures. The drugs exhibiting an RMSD of ≤ 3.0 Å were further analyzed using molecular docking, molecular dynamics (MD) simulation, and post-MD analyses. Using these approaches, we …

The Immune Microenvironment And Relation To Outcome In Patients With Advanced Breast Cancer Treated With Docetaxel With Or Without Gemcitabine, Elisabeth S. Stovgaard, Karama Asleh, Nazia Riaz, Samuel Leung, Dongxia Gao, Lise B. Nielsen, Anne-Vibeke Lænkholm, Eva Balslev, Maj-Britt Jensen, Dorte Nielsen, Torsten O. Nielsen

Centre for Regenerative Medicine & Stem Cell Research

Preclinical studies suggest that some effects of conventional chemotherapy, and in particular, gemcitabine, are mediated through enhanced antitumor immune responses. The objective of this study was to use material from a randomized clinical trial to evaluate whether patients with preexisting immune infiltrates responded better to treatment with gemcitabine + docetaxel (GD) compared to docetaxel alone. Formalin fixed, paraffin-embedded breast cancer tissues from SBG0102 phase 3 trial patients randomly assigned to treatment with GD or docetaxel were used. Immunohistochemical staining for CD8, FOXP3, LAG3, PD-1, PD-L1 and CD163 was performed. Tumor infiltrating lymphocytes (TILs) and tumor associated macrophages were evaluated. Prespecified …

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 …

Extraction Of Human Dna From Soil In A Simulated Clandestine Grave, Arely Joaly Parra Lopez

Honors Theses

Locard’s Exchange Principle states that “every contact leaves a trace.” The same principle applies when a perpetrator of a homicide decides to bury a victim in a clandestine grave. If a perpetrator originally buried a murder victim in haste to prevent discovery and then decided to later move the victim’s body to a remote location for disposal, decomposition fluids from the victim’s body (which contain cellular material and therefore DNA) would remain in the surrounding grave soil at the original burial site. It is possible that investigators could: 1) prove that a human body had once laid in that location …