Molecular Biology Commons^™

Exploring The Interactions Between Sars-Cov-2 And Host Proteins., Sojan Shrestha

School of Biological Sciences: Dissertations, Theses, and Student Research

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current pandemic, Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 is considered to be of zoonotic origin; it originated in non-human animals and was transmitted to humans. Since the early stage of the pandemic, however, the evidence of transmissions from humans to animals (reverse zoonoses) has been found in multiple animal species including mink, white-tailed deer, and pet and zoo animals. Furthermore, secondary zoonotic events of SARS-CoV-2, transmissions from animals to humans, have been also reported. It is suggested that non-human hosts can act as SARS-CoV-2 reservoirs where accumulated …

Synthesis And Study Of High-Spin Stable Organic Radicals For Electrical Conductors And Mannosamine Nitroxide For Mri Contrast Agents, Shuyang Zhang

Department of Chemistry: Dissertations, Theses, and Student Research

In the first project, we describe the synthesis of an ambient stable high spin organic diradical 4 based on the Blatter moiety. The high-spin (S = 1) organic diradical 4, which consists of two Blatter radical moieties in a conjugated structure, exhibits a nearly exclusive population (88%) on triplet ground state at room temperature as a consequence of a large single-triplet energy gap (ΔEST = 0.5 kcal/mol). The target diradical molecule is synthesized over five steps with structural confirmation by single-crystal X-ray diffraction. The thermogravimetric analysis (TGA) shows the onset of decomposition at ~264 oC, indicating the diradical molecule has …

Optimization And Standardization Of Dms Chemical Mapping Experiments For Probing Rna 3d Structure, Sarah Brady

Honors Theses

RNA plays a significant and crucial role in biological processes. The properties of RNA are ultimately responsible for each molecule’s unique function. The configuration and structural integrity of RNA is important for its functionality. Chemical mapping detailed in this thesis can be used to analyze the 3D structure of an RNA sequence. RNA is modified via methylation of adenine and cytosine bases using dimethyl sulfate, then reverse transcribed to DNA, then sequenced. The sites where the bases were methylated become mutations in the DNA sequence, allowing for identification of these locations when analyzing sequencing data. Conditions for modification can be …

Development Of High Value Oil Traits Using The Model Oilseed Crop Camelina Sativa, Evan Updike

Department of Biochemistry: Dissertations, Theses, and Student Research

Plant oils are an important source of food, fuel, and feed in our society today. The oil found in the seeds of plants is composed almost entirely of triacylglycerol (TAG) molecules, which consist of three fatty acids esterified to a glycerol backbone. As crude oil supplies decline, vegetable oils are gaining traction as a renewable substitute to petroleum-based materials in fuels, lubricants, and specialty oleochemicals. However, as it currently stands vegetable oils do not possess the properties necessary to fill the void of a petroleum free world.

To address this problem, plant biotechnologists have done extensive work on genetic engineering …

Mutagenesis Of Claudins To Probe In Vivo Interactions And Assemblies, Currey Zalman, Alex J. Vecchio

UCARE Research Products

Paracellular transport of solutes and the control of the flow of molecules through the intracellular space in vertebrate epithelia is directed by tight junctions (TJs). Claudins form paracellular barriers and pores that determine tight junction permeability. This investigation attempts to explain the molecular bases for destruction and reconstruction of tight junctions within epithelial cells, occurring via both natural and disease-causing mechanisms. This interdisciplinary research is important in the advancement of our understanding of human biology and health, as different disruptions to epithelial tight junctions are hallmarks of many human diseases. The overall objective was to take previously made Claudin containing …

Dgts Production As A Phosphate Starvation Response In The Human Fungal Pathogen Candida Albicans, Caleb Wehling

School of Biological Sciences: Dissertations, Theses, and Student Research

Betaine lipids are a class of membrane lipids with betaine head groups. Three betaine lipids are known - diacylglyceryltrimethylhomoserine (DGTS), diacylglycerylhydroxymethylalanine (DGTA), and diacylglycerylcarboxymethylcholine (DGCC). Betaine lipids are most common in algae, although DGTS, the most common betaine lipid, is also found in many bacteria and fungi. Organisms which produce betaine lipids (especially DGTS) often don’t produce phosphatidylcholine (PtdCho), and DGTS structure resembles PtdCho structure without any phosphorous, leading to the hypothesis that betaine lipids may substitute for phospholipids in some organisms. This has been confirmed by discoveries that some organisms are capable of switching their membrane composition from PtdCho …

Transcriptomic Analyses And Computational Modeling Reveal That Fatty Acid Transport Protein 2 (Fatp2) Impacts The Transcriptional Activity Of Pparα Thus Altering The Lipid Metabolic Landscape, Vincent M. Perez

Department of Biochemistry: Dissertations, Theses, and Student Research

Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the uptake of exogenous long chain fatty acids (LCFAs) and in the activation of very long chain fatty acids (VLCFAs). Here we address the phenotypic impacts of deleting FATP2 with the following three separate approaches: [1] Utilizing an unbiased next-generation sequencing analysis of FATP2-null (fatp2-/-) mice fed a standard chow diet; [2] Utilizing an unbiased next-generation sequencing analysis of fatp2-null (fatp2-/-) mice fed a high-fat ketogenic diet (KD) and fasted for 24-hours [3] Building dynamic computer models built with data …

Gut Symbiont Viability In Honey Bees Exposed To Agrochemical Stressors, Bryant Justin Gabriel

Department of Entomology: Dissertations, Theses, and Student Research

The honey bee gut microbiome is essential for protecting this pollinator against abiotic and biotic stressors, including the prevention of harmful gut parasites and pathogens. Previous studies have not only demonstrated a linkage of bee gut dysbiosis to increased immunodeficiencies and pathogen sensitivities, but also report the maladaptation of the gut microbiome in bees exposed to agricultural and apicultural chemistries. There are few techniques available that allow for a simple and reliable analysis of the relative proportions of live and dead gut microbes in bees exposed to these chemistries. Previous techniques for measuring gut symbiont dysbiosis are temporally limited by …

Biology Of Exosomes And Their Microrna Cargos In Human And Bovine Milk, Amy Lynn Leiferman

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Exosomes are small, cargo-containing vesicles secreted by cells to facilitate intercellular communication. Of exosome cargos, microRNAs are especially interesting because of their involvement in gene regulation. Recently, our lab has shown that exosomes and their microRNA cargo are absorbed through the diet and elicit effects exogenously. Human and animal milk contain exosomes, which may have implications in infant and adult nutrition. There is evidence that bovine milk exosomes enhance growth of murine C2C12 myotube cell cultures, but whether this translates to muscle in vivo is unknown. The USDA National Nutrient Database for Standard Reference is lacking up-to-date information about human …

Copy Number Variation In The Porcine Genome Detected From Whole-Genome Sequence, Rebecca Anderson

Honors Theses

Copy number variations (CNVs) are large insertions, deletions, and duplications in the genome that vary between individuals in a species. These variations are known to impact a broad range of phenotypes from molecular-level traits to higher-order clinical phenotypes. CNVs have been linked to complex traits in humans such as autism, attention deficit hyperactivity disorder, nervous system disorders, and early-onset extreme obesity. In this study, whole-genome sequence was obtained from 72 founders of an intensely phenotyped experimental swine herd at the U.S. Meat Animal Research Center (USMARC) in Clay Center, Nebraska. This included 24 boars (12 Duroc and 12 Landrace) and …

Testing The Independence Hypothesis Of Accepted Mutations For Pairs Of Adjacent Amino Acids In Protein Sequences, Jyotsna Ramanan, Peter Revesz

School of Computing: Faculty Publications

Evolutionary studies usually assume that the genetic mutations are independent of each other. However, that does not imply that the observed mutations are independent of each other because it is possible that when a nucleotide is mutated, then it may be biologically beneficial if an adjacent nucleotide mutates too. With a number of decoded genes currently available in various genome libraries and online databases, it is now possible to have a large-scale computer-based study to test whether the independence assumption holds for pairs of adjacent amino acids. Hence the independence question also arises for pairs of adjacent amino acids within …

Organ-Specific Transcriptome Profiling Of Metabolic And Pigment Biosynthesis Pathways In The Floral Ornamental Progenitor Species Anthurium Amnicola Dressler, Jon Suzuki, Teresita D. Amore, Bernarda Calla, Nathan A. Palmer, Erin D. Scully, Scott E. Sattler, Gautam Sarath, Joanne S. Lichty, Roxanna Y. Myers, Lisa M. Keith, Tracie K. Matsumoto, Scott M. Geib

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Anthurium amnicola Dressler possesses a number of desirable and novel ornamental traits such as a purple-colored upright spathe, profuse flowering, and floral scent, some of which have been introgressed into modern Anthurium cultivars. As a first step in identifying genes associated with these traits, the transcriptome from root, leaf, spathe, and spadix from an accession of A. amnicola was assembled, resulting in 28,019 putative transcripts representing 19,458 unigenes. Genes involved in pigmentation, including those for the metabolism of chlorophyll and the biosynthesis of carotenoids, phenylpropanoids, and flavonoids were identified. The expression levels of one MYB transcription factor was highly …

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …

Assessing The Risk Of Resistance Evolution, Adult And Larval Susceptibility, And Sublethal Effects After Exposure Of Corn Rootworms To Vacuolar Atpase-A And Snf7 Dsrnas, Adriano Elias Pereira

Department of Entomology: Dissertations, Theses, and Student Research

Corn rootworms are Diabroticite beetles from the genus Diabrotica and include the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, and the northern corn rootworm, D. barberi Smith & Lawrence, as the most important pests in the U.S. Corn Belt. The southern corn rootworm (SCR), D. undecimpunctata howardi Barber, is considered a polyphagous plant pest and feeds in a wide variety of plants including peanuts, cucurbits, soybeans, and especially corn. Resistance to control methods including behavioral resistance to crop rotation and to corn hybrids expressing Bacillus thuringiensis Berliner toxins in WCR has frequently been reported. SCR has been considered a …

Study Of Autoxidation In Hemoglobin In The Presence Of Alcohol, Mckayla A. Wieczorek, Hideaki Moriyama

UCARE Research Products

In order to learn more about the effects alcohol has on the body, we investigated its effects on the circulatory system. Our bodies’ circulatory systems are the main way that we transport chemicals to where they are needed. One of the major roles of the blood, is the role of the red blood cells, which bind to and transport oxygen molecules to our cells where they can be used for cellular respiration. Without the transfer of oxygen, cellular respiration would not be possible, and without cellular respiration, our cells cannot produce adequate amounts of energy.

Hemoglobin proteins in the red …

The Nmr Solution Structure And Function Of Rpa3313: A Hypothetical Protein From R. Palustris, Austin J. Lowe, Jonathan Catazaro, Cheryl Arrowsmith, Robert Powers

UCARE Research Products

Protein function elucidation often relies heavily on amino acid sequence analysis and other bioinformatics approaches. The reliance is further extended to structure homology modeling for ligand docking and protein-protein interaction mapping. However, sequence analysis of RPA3313 exposes a large, unannotated class of hypothetical proteins mostly from the Rhizobiales order. In the absence of sequence and structure information, further functional elucidation of this class of proteins has been significantly hindered. A high quality NMR structure of RPA3313 reveals that the protein forms a novel split βαβ fold with a conserved ligand binding pocket between the first β-strand and the N-terminus of …

Defining The Roles Of Serine Palmitoyltransferase-Interacting Proteins In The Regulation Of Sphingolipid Homeostasis, Athen N. Kimberlin

Department of Biochemistry: Dissertations, Theses, and Student Research

Sphingolipids are major structural components of the plasma membrane and endomembrane system. Research suggests that sphingolipids are involved with the formation of lipid microdomains, also known as lipid rafts, which may help to organize proteins within the membrane and may be important for membrane trafficking. Aside from their structural roles in membranes, sphingolipids and their metabolic products have been implicated in several cellular signaling responses like programmed cell death (PCD). Because of this, maintenance of sphingolipid homeostasis is critical for eukaryotic cell growth and development. Serine palmitoyltransferase (SPT) catalyzes the first step in sphingolipid biosynthesis and is the primary regulatory …

Molecular Analysis Confirming The Introduction Of Nile Crocodiles, Crocodylus Niloticus Laurenti 1768 (Crocodylidae), In Southern Florida, With An Assessment Of Potential For Establishment, Spread, And Impacts., Michael R. Rochford, Kenneth L. Krysko, Frank J. Mazzotti, Matthew W. Shirley, Mark W. Parry, Joseph A. Wasilewski, Jeffrey S. Beauchamp, Christpher R. Gillette, Edward F. Metzger Iii, Michiko A. Squires, Louis A. Somma

Papers in Herpetology

The state of Florida, USA, has more introduced herpetofauna than any other governmental region on Earth. Four species of nonnative crocodilians have been introduced to Florida (all since 1960), one of which is established. Between 2000–2014 we field-collected three nonnative crocodilians in Miami-Dade County, Florida, and one in Hendry County, Florida. We used DNA barcoding and molecular phylogenetics to determine species identification and native range origin. Also, we described diet, movement, and growth for one crocodile. Our molecular analyses illustrated that two of the crocodiles we collected are most closely related to Nile Crocodiles (Crocodylus niloticus) from South Africa, suggesting …

Mutations Of Adjacent Amino Acid Pairs Are Not Always Independent, Jyotsna Ramanan, Peter Revesz

CSE Conference and Workshop Papers

Evolutionary studies usually assume that the genetic mutations are independent of each other. This paper tests the independence hypothesis for genetic mutations with regard to protein coding regions. According to the new experimental results the independence assumption generally holds, but there are certain exceptions. In particular, the coding regions that represent two adjacent amino acids seem to change in ways that sometimes deviate significantly from the expected theoretical probability under the independence assumption.

Investigations Into The Molecular Mechanisms Of Bacterial Pathogen-Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber

Department of Chemistry: Dissertations, Theses, and Student Research

A dual plasmid system for the incorporation of unnatural amino acids into plant pathogen, Pseudomonas syringae pv. tomato DC3000, has been designed. This invention is expected to allow (a) mutations of proteins synthesized by the bacterium, P. syringae pv. tomato DC3000, that can capture molecular targets, especially for such modified proteins secreted by the phytopathogen into the host plant cells of A. thaliana and S. lycopersicum, (b) expression of biological probes in the bacterial species to monitor changes in redox, nutritional, and other small molecule states over pre-, post- and in situ disease stages, and (c) secretion of such …

Oxygenation Properties And Isoform Diversity Of Snake Hemoglobins, Jay F. Storz, Chandrasekhar Natarajan, Hideaki Moriyama, Federico G. Hoffmann, Tobias Wang, Angela Fago, Hans Malte, Johannes Overgaard, Roy E. Weber

Jay F. Storz Publications

Available data suggest that snake hemoglobins (Hbs) are characterized by a combination of unusual structural and functional properties relative to the Hbs of other amniote vertebrates, including oxygenation-linked tetramer-dimer dissociation. However, standardized comparative data are lacking for snake Hbs, and the Hb isoform composition of snake red blood cells has not been systematically characterized. Here we present the results of an integrated analysis of snake Hbs and the underlying α- and β-type globin genes to characterize 1) Hb isoform composition of definitive erythrocytes, and 2) the oxygenation properties of isolated isoforms as well as composite hemolysates. We used species from …

Parental Rna Interference Of Genes Involved In Embryonic Development Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera Leconte, Chitvan Khajuria, Ana Maria Vélez, Murugesan Rangasamy, Haichuan Wang, Elane Fishilevich, Meghan L.F. Frey, Newton Portilho Carneiro, Premchand Gandra, Kenneth E. Narva, B. D. Siegfried

Department of Entomology: Faculty Publications

RNA interference (RNAi) is being developed as a potential tool for insect pest management and one of the most likely target pest species for transgenic plants that express double stranded RNA (dsRNA) is the western corn rootworm. Thus far, most genes proposed as targets for RNAi in rootworm cause lethality in the larval stage. In this study, we describe RNAi-mediated knockdown of two developmental genes, hunchback (hb) and brahma (brm), in the western corn rootworm delivered via dsRNA fed to adult females. dsRNA feeding caused a significant decrease in hb and brm transcripts in the adult …

Regulation Of Phialide Morphogenesis In Aspergillus Nidulans, Hu Yin

School of Biological Sciences: Dissertations, Theses, and Student Research

Filamentous fungi have two distinctive life cycles, vegetative growth and development for sexual or asexual spore formation. The asexual reproduction in development as conidiation in A. nidulans is the dominant form of producing spores effectively. A complex conidiophore structure is developed during asexual reproduction process. The conidiophore is formed from hyphal cell and consists of stalk, vesicle, metulae, phialide and conidial spores. Phialides are essential sporogenous cells in the conidiophore structure. The growth pattern is switched from acropetal to basipetal between phialide and spores, which makes phialide a unique cell type in A. nidulans and other phialide producing fungi. Study …

The Mechanism Of Small Rna Biogenesis, Degradation, And Function In Arabidopsis, Meng Xie

School of Biological Sciences: Dissertations, Theses, and Student Research

Eukaryotic small RNAs play important roles in many biological processes through sequence-specific RNA silencing. In plants, there are mainly two small RNAs triggering gene silencing: microRNAs (miRNAs) and small interfering RNAs (siRNAs). The biogenesis and precise regulation of small RNA abundance are crucial for plant growth, development, genomic stability, and the resistance to both abiotic and biotic stresses. In this study, we used Arabidopsis thaliana, the model plant, to study the mechanism of RNA-directed DNA methylation (RdDM), in which siRNAs can trigger DNA methylation and gene silencing. In addition, we investigated the mechanism of miRNA biogenesis and degradation. For …

Transcriptomic Analyses Of The Co2-Concentrating Mechanisms And Development Of Molecular Tools For Chlamydomonas Reinhardtii, Andrew J. Brueggeman

Department of Biochemistry: Dissertations, Theses, and Student Research

Microalgae, such as Chlamydomonas reinhardtii, account for a large percentage of photosynthesis that occurs on the planet. Many algae possess a Carbon-Concentrating Mechanism, or CCM, that actively transports inorganic carbon (C_i) into the cell to create artificially high internal levels of CO₂, enhancing their rate of carbon fixation. The production of biofuels from algal sources can serve as both a renewable and carbon-neutral energy source. This thesis details research in Chlamydomonas, in the effort to both better understand the CCM in algae and improve laboratory and industrial manipulations with algae.

In the first chapter of this …

Investigations Of Substrate Channeling In The Proline Oxidative Pathway, Nikhilesh Sanyal

Department of Biochemistry: Dissertations, Theses, and Student Research

In cell metabolism, substrate channeling is a phenomenon where the product of one reaction is transported to a second enzyme active site without equilibrating into bulk solvent. Chapter 1 reviews the rationale and evidence for substrate channeling with the specific example of proline metabolism. Oxidation of proline to glutamate is catalyzed in consecutive reactions by proline dehydrogenase (PRODH) and pyrroline-5-carboxylate dehydrogenase (P5CDH). The intermediate Δ¹-pyrroline-5-carboxylate reportedly tends to be labile and inhibitory towards several metabolic pathways.

One of the main objectives of this dissertation was to investigate substrate channeling between independent proline oxidative enzymes from Thermus thermophilus- …

Structure-Function Analysis Of A Protein Encoded By The Bhv-1 Latency Related Gene, Devis Sinani

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine herpes virus 1 (BHV-1) is a significant viral pathogen in cattle that induces a myriad of clinical symptoms. These symptoms include: conjunctivitis, upper respiratory tract infections, genital disorders, and abortions. BHV-1 infection can also lead to transient immune-suppression, which predisposes cattle to secondary bacterial infection leading to life-threatening pneumonia referred to as bovine respiratory disease (BRD). Following acute infection, BHV-1 establishes latency in sensory neurons within trigeminal ganglia. Reactivation of the virus can occur periodically, resulting in virus transmission. The latency-related (LR) RNA is the only abundantly expressed transcript in latently infected sensory neurons and it encodes several proteins, …

Studies On The Small Ubiquitin-Like Modifier (Sumo) E2 Conjugases Of The Sumoylation System In Chlamydomonas Reinhardtii And Their Role In Stress Physiology, Amy R. Knobbe

Department of Biochemistry: Dissertations, Theses, and Student Research

The eukaryotic protein post-translational modification by SUMOylation is involved in a diverse array of cellular processes, including various stress responses. A fully functional SUMOylation system is present in the unicellular green alga Chlamydomonas reinhardtii, and SUMOylation of multiple high molecular weight proteins is induced in response to abiotic stress in this organism. We report here the characterization of a SUMO E2 conjugase deletion mutant in C. reinhardtii, mut5. SUMO E2 conjugase enzymes are responsible for the conjugation of the protein SUMO to a lysine residue within a target protein. C. reinhardtii mutants in which the SUMO E2 …

Template-Based Structure Prediction And Classification Of Transcription Factors In Arabidopsis Thaliana, Tao Lu, Yuedong Yang, Bo Yao, Song Liu, Yaoqi Zhou, Chi Zhang

School of Biological Sciences: Faculty Publications

Transcription factors (TFs) play important roles in plants. However, there is no systematic study of their structures and functions of most TFs in plants. Here, we performed template-based structure prediction for all TFs in Arabidopsis thaliana, with their full-length sequences as well as C-terminal and N-terminal regions. A total of 2,918 model structures were obtained with a high confidence score. We find that TF families employ only a smaller number of templates for DNA-binding domains (DBD) but a diverse number of templates for transcription regulatory domains (TRD). Although TF families are classified according to DBD, their sizes have a significant …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

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

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …