Genetics and Genomics Commons^™

Genetic Underpinnings Of Novel Trait Development In A Euwallacea-Fusarium Mutualism, Elaina J. Spahr

Graduate Theses, Dissertations, and Problem Reports (ETD)

Evolutionary Developmental Biology seeks to answer fundamental questions about the mechanisms underlying the evolution and innovation towards increasing structural complexity within the body plan. The ambrosia symbiosis, a polyphyletic group of xylem-feeding beetles, provides a wealth of diversity in novel pouch-like structures called mycangia. This diversity could serve as a rich model for understanding how mutualisms may prompt structural innovation and diversification in a host organism. The ambrosia symbiosis has become a fast-growing research subject in entomology and forest pathology but has yet to experience the same attention under the lens of evolutionary developmental genetics.

Development of mycangia was examined …

Applying Conservation Genomic Techniques To Guide Management Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi), Miranda Gaupp

College of Graduate Studies: Theses & Dissertations

The Reticulated flatwoods salamander (Ambystoma bishopi) is a federally endangered amphibian endemic to the longleaf-pine ecosystem of the southeastern U.S. This study used analyses of single-nucleotide polymorphism (SNP) data, collected from 2,255 unique individuals across 5 breeding seasons, spread across the known extant range of A. bishopi, to characterize the genetic diversity and demographics of populations, genetic relationships among populations, and patterns and spatial extents of gene flow, and to evaluate potential effects of management on A. bishopi’s resiliency. Population structure was strongly hierarchical, with individual breeding ponds (n = 38) acting as semi-connected subpopulations …

Florida Sand Skink And Blue-Tailed Mole Skink: Expanding Geographic Coverage Of Genetic Analysis For Conservation, Emma Simpson

College of Graduate Studies: Theses & Dissertations

The Lake Wales Ridge is important scrub habitat that has been increasingly altered since the post-Columbian settlement in Florida. This loss of habitat has caused extreme anthropogenic fragmentation within the Lake Wales Ridge resulting in isolation among extant scrub patches. To expand the geographic scope of previous studies and answer questions concerning population connectivity, we characterized genetic diversity and differentiation using cytochrome-b and microsatellite genetic markers for two endemic skink species: the Florida Sand Skink (Plestiodon reynoldsi) and Blue-tailed Mole Skink (Plestiodon egregius lividus). Both species display historical isolation between central and southern Lake Wales Ridge …

Population Genomics Of Redbreast Sunfish (Lepomis Auritus): Exploring Gene Flow And Local Adaptation In A Widely Distributed Freshwater Fish, Garret J. Strickland

College of Graduate Studies: Theses & Dissertations

Little information is available concerning the distribution of genetic diversity in non-salmonid, non-imperiled, freshwater fish. In order to fill in this knowledge gap, I conducted a population genomics survey in Redbreast Sunfish (Lepomis auritus; RBS), a widespread, generalist species distributed along the Atlantic slope rivers of eastern North America. I sampled four basins (ACF, Savannah, Roanoke, and James) at eight sites each with a factorial experimental design. Sites were distributed among coastal plain, Piedmont, or mountain ecoregions in order to capture the greatest range of environmental states experienced by RBS, with the intention of finding evidence for local adaptation to …

Factors Impacting Genomic Testing Rates Among Epithelial Ovarian Cancer Patients Across A Large Community-Based Healthcare System, Nicole M. Kretzer, Christopher J. Darus, Nancy Biery, Roshanthi Weerasinghe, Grace Li, Ann Vita, Shwetha Pindikuri, Amy S. Parrish, Charles W Drescher, Fernanda B. Musa

All Podium Presentations

Background: Epithelial ovarian cancer (EOC) accounts for the highest mortality of all gynecological cancers. NCCN guidelines recommend germline and somatic testing for all women with invasive EOC. Despite this recommendation, there is a large diversity in the types of testing patients receive even within a single healthcare system. Reported data of genetic testing for epithelial ovarian cancer (EOC) patients is largely based on patients treated at academic medical centers or patients who participate in clinical trials.

Purpose: This study sought to determine the rates of germline and somatic testing for epithelial ovarian cancer patients and identify factors that impact testing …

Patterns Of Genomic Testing For Epithelial Ovarian Cancer Across A Large Community-Based Health Care Network- A Real World Experience, Nicole M. Kretzer, Fernanda B. Musa, Christopher Darus, Nancy Biery, Roshanthi Weerasinghe, Grace Li, Ann Vita, Shwetha Pindikuri, Amy S. Parrish, Charles W Drescher

All Podium Presentations

Background: NCCN guidelines recommend germline and somatic tumor testing for all women with invasive epithelial ovarian cancer (EOC). Despite this recommendation, testing rates remain low and an optimal strategy to achieve the recommended testing has not been defined.

Purpose: We elected to review the patterns of germline and somatic tumor testing for patients with EOC across a large health care network to identify barriers to testing.

Methods: Clinical, pathologic, demographic and genomic testing (GT) information including involvement of a genetic counselor, specific test(s) ordered, test vendor, test turn-around time, and test results were obtained from the diverse dataset within the …

Identifying The Role Of Cholesterol And The Cholesterol Transfer Protein, Ysp1-2, In Cell-Cell Fusion In Tetrahymena Thermophila, Natasha D. Kusibab

Honors Program Theses

A cell’s shape directly affects how it behaves as one’s structure directly correlates to its function. The shape of cells and organelles is driven in part by the lipid bilayer that makes up their membranes. The process by which cells systematically adjust the types of lipids in membranes to facilitate changes in membrane shape remain uncertain. In our research, we aimed to address this issue by studying the role of lipid transfer proteins in the ciliate, Tetrahymena thermophilia. Specifically, we focus on the process of cell-cell fusion during mating in Tetrahymena as this requires a drastic change in membrane shape …

Protein Charge Parameters That Influence Stability And Cellular Internalization Of Polyelectrolyte Complex Micelles, Rachel A. Kapelner, Rachel S. Fisher, Shana Elbaum-Garfinkle, Allie C. Obermeyer

Advanced Science Research Center

Proteins are an important class of biologics, but there are several recurring challenges to address when designing protein-based therapeutics. These challenges include: the propensity of proteins to aggregate during formulation, relatively low loading in traditional hydrophobic delivery vehicles, and inefficient cellular uptake. This last criterion is particularly challenging for anionic proteins as they cannot cross the anionic plasma membrane. Here we investigated the complex coacervation of anionic proteins with a block copolymer of opposite charge to form polyelectrolyte complex (PEC) micelles for use as a protein delivery vehicle. Using genetically modified variants of the model protein green fluorescent protein (GFP), …

Increasing Detection Sensitivity For Rare And Endangered Species In Kansas Through Development Of An Aquatic Environmental Dna Sampling Protocol, Sarah Hallyburton

Master's Theses or Doctor of Nursing Practice

Anthropogenic global climate change is forcing the mass extinction of wildlife across the globe. Humans depend on freshwater ecosystems for many aspects of life including agricultural production, sanitation, and recreation. Healthy levels of biodiversity in freshwater environments ensure economically beneficial ecosystem services are maintained. Freshwater ecosystems are hotspots for biodiversity and have higher levels of imperiled organisms compared to terrestrial and marine systems. Within freshwater systems, freshwater mussels (Family: Unionidae) are the most imperiled with over 70% of North American species assigned to a conservation class as judged by state or federal management agencies. The objective of this study was …

Efficacy Of Non-Lethal Molecular Methods In Elucidating Distribution Of Gray Treefrog Complex (Hyla Chrysoscelis/Versicolor) In Kansas, Nora K. Lazerus

Master's Theses or Doctor of Nursing Practice

Globally, amphibians are the most imperiled vertebrate taxa in part because they rely on both aquatic and terrestrial ecosystems. Specifically, their permeable skin makes them uniquely susceptible to habitat degradation and alteration. Cope’s Gray Treefrog (Hyla chrysoscelis) and the Gray Treefrog (Hyla versicolor) are a diploid-tetraploid, morphologically indistinguishable sister pair of cryptic anurans native to Kansas. Since 1987, the distribution of gray treefrogs in Kanas has extended west but the status of each species in the complex in Kansas is not known beyond its documented combined western expansion. Currently, species identification cannot be determined by nonlethal …

Genomic Degeneration And Reduction In The Fish Pathogen Mycobacterium Shottsi, David T. Gauthier, Janis H. Doss, M. Lagatta, T. Gupta, R.K. Karls, F. D. Quinn

Biological Sciences Faculty Publications

Mycobacterium shottsii is a dysgonic, nonpigmented mycobacterium originally isolated from diseased striped bass (Morone saxatilis) in the Chesapeake Bay, USA. Genomic analysis reveals that M. shottsii is a Mycobacterium ulcerans/Mycobacterium marinum clade (MuMC) member, but unlike the superficially similar M. pseudoshottsii, also isolated from striped bass, it is not an M. ulcerans ecovar, instead belonging to a transitional group of strains basal to proposed “Aronson” and “M” lineages. Although phylogenetically distinct from the human pathogen M. ulcerans, the M. shottsii genome shows parallel but nonhomologous genomic degeneration, including massive accumulation of pseudogenes accompanied by proliferation of …

Rickettsial Pathogen Perturbs Tick Circadian Gene To Infect The Vertebrate Host, Supreet Khanal, Vikas Taank, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ixodes scapularis is a medically important tick that transmits several microbes to humans, including rickettsial pathogen Anaplasma phagocytophilum. In nature, these ticks encounter several abiotic factors including changes in temperature, humidity, and light. Many organisms use endogenously generated circadian pathways to encounter abiotic factors. In this study, we provide evidence for the first time to show that A. phagocytophilum modulates the arthropod circadian gene for its transmission to the vertebrate host. We noted a circadian oscillation in the expression of arthropod clock, bmal1, period and timeless genes when ticks or tick cells were exposed to alternate 12 h …

Genomic Analysis Of Acetoanaerobium Sp. Vlb-1, An Anaerobic Bacterium Isolated From Nebraska's Eastern Saline Wetlands, Claire Martin

Honors Program: Senior Projects (Public)

Through the analysis of genetic code, the genomic and physiological characteristics of an environmental anaerobic bacterial isolate, Acetoanaerobium sp. strain VLB-1, can be determined and significant pathways can be identified in its significance to the environment. This particular organism was isolated from the Eastern Saline Wetlands in Lincoln, NE. With this isolate, an investigation into elemental and amino acid cycling via the Stickland reaction and the Wood-Ljungdahl pathway was conducted to determine possible metabolic products. The Stickland reaction is a relatively newly discovered pathway, observed in the genus Clostridium. A. sticklandii is the main model for this method of …

An Integrative Investigation Of The Synechococcus A/B Clade During Adaptive Radiation At The Upper Thermal Limit Of Phototrophy, Christopher L. Pierpont

Graduate Student Theses, Dissertations, & Professional Papers

Thermophilic microorganisms have been scientifically observed since the early nineteenth century and have spurred many questions about the limits of life and the capacity of organisms to survive extreme conditions. Decades of research on thermophile proteins and genomes have yielded several proposed correlates of temperature that may contribute to adaptation of bacteria and archaea to high temperature. However, many of the generalizations reported are drawn from analyses of deeply divergent taxa or from individual case studies in isolation from mesophilic relatives. Members of the Synechococcus A/B (SynAB) group are the only cyanobacteria with members able to grow above 65 °C …

Genetic Variants Associated With Circulating Liver Injury Markers In Mexican Americans, A Population At Risk For Non-Alcoholic Fatty Liver Disease, Caroline M Sabotta, Suet-Ying Kwan, Lauren E Petty, Jennifer E Below, Aron Joon, Peng Wei, Susan P Fisher-Hoch, Joseph B Mccormick, Laura Beretta

Faculty, Staff and Student Publications

Objective: Mexican Americans are disproportionally affected by non-alcoholic fatty liver disease (NAFLD), liver fibrosis and hepatocellular carcinoma. Noninvasive means to identify those in this population at high risk for these diseases are urgently needed. Approach: The Cameron County Hispanic Cohort (CCHC) is a population-based cohort with high rates of obesity (51%), type 2 diabetes (28%) and NAFLD (49%). In a subgroup of 564 CCHC subjects, we evaluated 339 genetic variants previously reported to be associated with liver injury markers aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in United Kingdom and Japanese cohorts. Results: Association was confirmed for 86 variants. Among …

Robust Meta-Analysis For Large-Scale Genomic Experiments Based On An Empirical Approach, Sinjini Sikdar

Mathematics & Statistics Faculty Publications

BACKGROUND: Recent high-throughput technologies have opened avenues for simultaneous analyses of thousands of genes. With the availability of a multitude of public databases, one can easily access multiple genomic study results where each study comprises of significance testing results of thousands of genes. Researchers currently tend to combine this genomic information from these multiple studies in the form of a meta-analysis. As the number of genes involved is very large, the classical meta-analysis approaches need to be updated to acknowledge this large-scale aspect of the data.

METHODS: In this article, we discuss how application of standard theoretical null distributional assumptions …

Quantifying Contributions Of Climate, Geography, And Gene Flow To Divergence: A Case Study For Three North American Pines, Constance E. Bolte

Theses and Dissertations

Long-lived species of trees, especially conifers, often display weak patterns of reproductive isolation, but clear patterns of local adaptation and phenotypic divergence. Discovering the evolutionary history of these patterns is paramount to a generalized understanding of speciation and the processes that confer population persistence versus those that compromise adaptive potential under rapidly changing environments. Forest trees have long generation times and low migratory potential making them especially vulnerable to population fragmentation and reductions of genetic diversity due to insufficient tracking of niche optima and adaptational lags. Within clades of the genus Pinus, evolutionary histories appear to be riddled with hybridization …

Identifying Epidermal Enriched Genes Required For Planarian Regeneration- Sp. Schmidtea Mediterranea, Pallob Barai

Theses and Dissertations--Biology

The outer epithelial layer covering an organism, commonly known as the epidermis, is crucial for maintaining homeostasis and for the wound healing processes after injury. The planarian epidermis allows flatworms to heal their wounds and virtually restore any missing tissues. Immediately after amputation, planarians contract their muscle and stretch their epidermis to heal the wound area. However, how the planarian epidermis coordinates with other tissues and mechanisms after the initial wound healing processes begins is not understood in detail. I hypothesized that epidermal cell stretching upon wound healing induces transcriptional changes that are required for effective regeneration. To test this …

Determinants Of Virus Variation, Evolution, And Host Adaptation, Katherine Latourrette, Hernan Garcia-Ruiz

Nebraska Center for Virology: Faculty Publications

Virus evolution is the change in the genetic structure of a viral population over time and results in the emergence of new viral variants, strains, and species with novel biological properties, including adaptation to new hosts. There are host, vector, environmental, and viral factors that contribute to virus evolution. To achieve or fine tune compatibility and successfully establish infection, viruses adapt to a particular host species or to a group of species. However, some viruses are better able to adapt to diverse hosts, vectors, and environments. Viruses generate genetic diversity through mutation, reassortment, and recombination. Plant viruses are exposed to …

Immunogenicity And Protective Efficacy Of A Recombinant Pichinde Viral-Vectored Vaccine Expressing Influenza Virus Hemagglutinin Antigen In Pigs, Sushmita Kumari, Jayeshbhai Chaudhari, Qinfeng Huang, Phillip Gauger, Marcelo Nunes De Almeida, Yuying Liang, Hinh Ly, Hiep Vu

Nebraska Center for Virology: Faculty Publications

Influenza A virus of swine (IAV-S) is an economically important swine pathogen. The IAV-S hemagglutinin (HA) surface protein is the main target for vaccine development. In this study, we evaluated the feasibility of using the recombinant tri-segmented Pichinde virus (rPICV) as a viral vector to deliver HA antigen to protect pigs against IAV-S challenge. Four groups of weaned pigs (T01–T04) were included in the study. T01 was injected with PBS to serve as a non-vaccinated control. T02 was inoculated with rPICV expressing green fluorescence protein (rPICV-GFP). T03 was vaccinated with rPICV expressing the HA antigen of the IAV-S H3N2 strain …

Increased Signal Complexity Is Associated With Increased Mating Success, Noori Choi, Matt Adams, Kasey Fowler-Finn, Elise Knowlton, Malcolm Rosenthal, Aaron Rundus, Roger D. Santer, Dustin J. Wilgers, Eileen Hebets

Eileen Hebets Publications

The evolution of complex signals has often been explored by testing multiple functional hypotheses regarding how independent signal components provide selective benefits to offset the costs of their production. In the present study, we take a different approach by exploring the function of complexity per se. We test the hypothesis that increased vibratory signal complexity— based on both proportional and temporal patterning—provides selective benefits to courting male Schizocosa stridulans wolf spiders. In support of this hypothesis, all of our quantified metrics of vibratory signal complexity predicted the mating success of male S. stridulans. The rate of visual signalling, which is …

Description Of The Courtship And Copulation Behaviours Of The Wall Spider Oecobius Concinnus (Oecobiidae), Diego Solano-Brenes, Laura Segura-Hernández, Gilbert Barrantes

Eileen Hebets Publications

Courtship and copulation behaviours are yet scantily described in many spider families, and this lack of information limits our understanding of the evolution of such behaviours within and across families. Here, we provide a detailed description of both courtship and copulation behaviour for Oecobius concinnus Simon, 1893. A striking characteristic of the male courtship is the construction of a tubular web (mating web) in which most courtship and copulation occurs. This web likely functions to restrain the female in a reduced space and as a substrate for male pheromones. The courtship consists of a complex web of interactions between both …

Modeling The Evolution Of Herbicide Resistance In Weed Species With A Complex Life Cycle, K. Harrison Holmes, John L. Lindquist, Richard Rebarber, Rodrigo Werle, Melinda K. Yerka, Brigitte Tenhumberg

Brigitte Tenhumberg Papers

A growing number of weed species have evolved resistance to herbicides in recent years, which causes an immense financial burden to farmers. An increasingly popular method of weed control is the adoption of crops that are resistant to specific herbicides, which allows farmers to apply the herbicide during the growing season without harming the crop. If such crops are planted in the presence of closely related weed species, it is possible that resistance genes could transfer from the crop species to feral populations of the wild species via gene flow and become stably introgressed under ongoing selective pressure by the …

Genomic Approaches To Uncovering The Coevolutionary History Of Parasitic Lice [Review], Kevin P. Johnson

Harold W. Manter Laboratory of Parasitology: Library Materials

Next-generation sequencing technologies are revolutionizing the fields of genomics, phylogenetics, and population genetics. These new genomic approaches have been extensively applied to a major group of parasites, the lice (Insecta: Phthiraptera) of birds and mammals. Two louse genomes have been assembled and annotated to date, and these have opened up new resources for the study of louse biology. Whole genome sequencing has been used to assemble large phylogenomic datasets for lice, incorporating sequences of thousands of genes. These datasets have provided highly supported trees at all taxonomic levels, ranging from relationships among the major groups of lice to those among …

Population Structure Of The Lizard Ecpleopus Gaudichaudii Coincides With A Biogeographic Barrier - The Doce River, Alexander J. Garretson

Dissertations and Theses

Intraspecific genetic variation is an integral component of diversification and the accumulation of biodiversity. The degree to which isolated populations of the same species are genetically structured in geographical space is impacted by a variety of mechanisms. In this study, I document patterns and discuss possible drivers of genetic structure within Ecpleopus gaudichaudii, a lizard species endemic to the Atlantic Forest of Brazil. For that, I assembled ddRadseq sequences from 48 individuals across much of the range of the E. gaudichaudii and analyzed its population structure. I created an intraspecific phylogeny for this group utilizing RAxML and conducted a …

Opioid Medication Use And Blood Dna Methylation: Epigenome-Wide Association Meta-Analysis, Mikyeong Lee, Roby Joehanes, Daniel L. Mccartney, Minjung Kho, Anke Hüls, Annah B. Wyss, Chunyu Liu, Rosie M. Walker, Sharon L.R. Kardia, Thomas S. Wingo, Adam Burkholder, Jiantao Ma, Archie Campbell, Aliza P. Wingo, Tianxiao Huan, Sinjini Sikdar, Amena Keshawarz, David A. Bennett, Jennifer A. Smith, Kathryn L. Evans, Daniel Levy, Stephanie J. London

Mathematics & Statistics Faculty Publications

Aim: To identify differential methylation related to prescribed opioid use. Methods: This study examined whether blood DNA methylation, measured using Illumina arrays, differs by recent opioid medication use in four population-based cohorts. We meta-analyzed results (282 users; 10,560 nonusers) using inverse-variance weighting. Results: Differential methylation (false discovery rate <0.05) was observed at six CpGs annotated to the following genes: KIAA0226, CPLX2, TDRP, RNF38, TTC23 and GPR179. Integrative epigenomic analyses linked implicated loci to regulatory elements in blood and/or brain. Additionally, 74 CpGs were differentially methylated in males or females. Methylation at significant CpGs correlated with gene expression in blood and/or brain. Conclusion: This study identified DNA …

Cloning Of Root-Specific Promoters In Helianthus Annuus And Populus Trichocarpa, Jacob Murphy

Masters Theses

Tissue-specific promoters are a valuable tool in plant biotechnology because they allow for precise spatial control of transgene expression. To identify root-specific promoters in sunflower (Helianthus annuus), sunflower RNA sequence (RNA-seq) data were screened in silico by Pavlidis Template Matching (PTM) with a root-specific template. Eight root-specific genes were identified in sunflower. The 2.5kbp promoter regions of six of these root-specific sunflower genes (HaTOR1L3, HaGOXL3A, HaGOXL3B, HaAPA1, HaPOE1, and HaMOP10) were successfully cloned as well as the 3kbp promoter regions of four root-specific genes previously identified in poplar (Populus trichocarpa …

Course Portfolio For Bioc934: Genome Dynamics And Gene Expression, Nicole R. Buan

UNL Faculty Course Portfolios

A graduate degree in Biochemistry or any molecular life science field requires a strong foundation in molecular biology. BIOC934 Genome Dynamics and Gene Expression is a course designed to challenge graduate students whose research interests lie in the areas of biochemistry, molecular biology, synthetic biology, bioinformatics, and systems biology of prokaryote and eukaryote systems. Graduate students in these disciplines require a rigorous and thorough examination of core concepts in addition to practice applying theory to new observations while traversing unfamiliar disciplinary terrain. This portfolio describes the design of BIOC934, its implementation, and observed outcomes to identify strengths of the course …

Phylogenetic Origins And Age-Based Proportions Of Malacho (Elops Smithi) Relative To Ladyfish (Elops Saurus): Species On The Move In The Western Gulf Of Mexico, Damon Williford, Nicolette S. Beeken, Joel Anderson, Polly Hajovsky, Roberta Weixelman

Gulf and Caribbean Research

Two species of ladyfish occur in the Gulf of Mexico (GOM), Elops saurus and Elops smithi, that are morphologically indistinguishable except for vertebral counts but can also be identified by mitochondrial DNA haplotypes. Here we expand on previous work, most of which has occurred in Florida, and examine the demography, phylogenetics, geographic distribution, and age—structure of ladyfishes in Texas estuaries. Fishery—independent gill net data demonstrated that ladyfishes increase in abundance from north to south along the Texas coast. The abundance of ladyfishes also increased in Texas waters from 1982–2021, which coincides with recent trends of warmer winters. Genetic data …

Fathmm: Frameshift Aware Translated Hidden Markov Models, Genevieve Krause

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.