Genetics and Genomics Commons^™

Genetic Regulation Of The Elicitation Of Glyceollin Biosynthesis In Soybean, Md. Asraful Jahan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Glyceollin phytoalexins are the pathogen-elicited defense metabolites that belong to the isoflavonoid family of molecules of soybean (Glycine max L. Merr). Phytophthora root and stem rot of soybean caused by Phytophthora sojae is a destructive disease throughout the soybean-growing regions worldwide causing devastating economic damages (globally $1-2 billion and over $250 million in the USA) every year. Engineering soybean plants that produce higher levels of glyceollins could confer resistance against this pathogen. Glyceollins also show anticancer and neuroprotective activities in mammals, therefore they are important for agriculture and medical research. Firstly, we were interested in understanding how biotic and …

Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer

College of Graduate Studies: Theses & Dissertations

The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …

Association Genetics And Local Adaptation Of Populus Trichocarpa Torr. & Gray, Hari Bahadur Chhetri

Graduate Theses, Dissertations, and Problem Reports (ETD)

A major goal in plant science is overcoming the recalcitrance of plant biomass to cellulose extraction, to enable efficient production of cellulosic biofuel. We have started to understand the genetic basis of some important traits such as cell wall chemistry, but we do not know anything about the key structural and functional traits such as wood anatomy that greatly affect plant biomass recalcitrance. Furthermore, biofuel feedstocks have to be adapted to varied environmental conditions to ensure high productivity in plantations, but little is known about the molecular mechanisms underlying local adaptation. With the advancement in sequencing and genotyping technologies, association …

Glial Cell Expansion And Intercellular Signaling In The Developing Medial Nucleus Of The Trapezoid Body (Mntb), Ashley N. Brandebura

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neural circuit formation is a complex process involving coordinated communication between neurons, glia and vascular-associated cells (VACs). Each cell type is responsible for a unique transcriptional and translational contribution to tissue maturation. Deciphering the intercellular signaling patterns which guide neural circuit formation during normal development is thus an essential step in understanding which components of neural circuit formation go awry in neurodevelopmental disorders. The medial nucleus of the trapezoid body (MNTB), located in the auditory brainstem, was used as a model system to study the dynamics of neural circuit formation because it contains a mostly homogeneous population of postsynaptic neurons …

Enhancing Water Stress Tolerance In Floriculture Crops, Suejin Park

Graduate Theses, Dissertations, and Problem Reports (ETD)

Water deficit is one of the major constraints on plant growth and development, causing reduction of crop productivity. To minimize water loss, among many adaptation strategies, plants close their stomata to reduce transpiration. The stomatal closure is regulated by light, internal CO2 concentration, and plant hormones, mainly abscisic acid. Plants’ response mechanisms to water deficit are complex processes involving numerous genes and various signaling pathways. Floriculture crops are often exposed to water deficit during shipping and retailing, and these periods often result in damaged crops and profit loss. Understanding of plant responses to water deficit stress will provide us an …

Effects Of Commercial Formulations Of Glyphosate On Saccharomyces Cerevisiae, Apoorva Ravi Shankar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Commercial formulations of glyphosate are among the most extensively used herbicides around the world. The active ingredient, glyphosate, targets the aromatic amino acid pathway. This pathway is absent in mammals, resulting in low toxicity. Different formulations contain varying adjuvants and surfactants, whose synergistic effects are yet to be extensively studied at the cellular level. In this study, I tested multiple commercial formulations that showed a variation in growth phenotype among different yeast strains. To gain a better understanding of response and resistance mechanisms at the genome and transcriptome level, I carried out an in-lab evolution study, along with a transcriptome …

Phenotypic And Transcriptomic Characterization Of Colonial Phase Variation In The Cholera Pathogen Reveals A Novel Smooth Biofilm-Defective Form, Bliss Nicole Lambert

LSU Doctoral Dissertations

Biofilm formation, through the production of Vibrio polysaccharide (VPS), greatly enhances the environmental fitness and pathogenic success of Vibrio cholerae. As a result of phase variation, V. cholerae can switch from a smooth form to rugose, whose cells produce excess VPS, resulting in highly structured biofilms and greater resistance to stress. To further characterize the reversible process of phase variation, we isolated three colonial lineages. Each lineage began with a smooth parent, N16961, and contained a rugose variant derived from the parent, N16961R, as well as a smooth revertant of the rugose, N16961SD. We found clear phenotypic and transcriptomic …

Harnessing The Anopheles Microbiome To Conditionally Express Anti-Plasmodial Effectors During The Blood Meal, Jackie Shane

Electronic Theses and Dissertations

The control of vector-borne diseases such as malaria has been an extremely important research subject for hundreds of years. Because of the complex lifecycles of the pathogens that cause these diseases, finding a comprehensive treatment or preventative strategy has proven extremely difficult. Malaria alone is responsible for almost half a million deaths annually, most of them children under 5 years old. This disease is caused by parasitic protists in the genus Plasmodium that are transmitted to humans from Anopheles sp. mosquitoes. Most preventative strategies that are in use today revolve around controlling the vectors, including bed nets, insecticides, and larval …

Identification And Functional Characterization Of Effectors From An Anther Smut Fungus, Microbotryum Lychnidis-Dioicae., Venkata Swathi Kuppireddy

Electronic Theses and Dissertations

Microbotryum lychnidis-dioicae causes anther smut fungus in its host plant, Silene latifolia. The goal of this work is to identify and characterize the virulence determinants of this pathogen to better understand the molecular basis behind this host-pathogen interaction. This work studied for the first time the key effectors in the mechanism of infection by this fungal species. Using, yeast two-hybrid screens, I have identified the host plant interaction partners for the effector, MVLG_01732. A second effector MVLG_05720, interacts with other fungal proteins that appear to facilitate the fungal establishment and colonization during the infection. Our findings indicate that a …

Dna Methylation By Restriction Modification Systems Affects The Global Transcriptome Profile In Borrelia Burgdorferi, Timothey Casselli, Yvonne Tourand, Adam Scheidegger, William K. Arnold, Anna Proulx, Brian Stevenson, Catherine A. Brissette

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Prokaryote restriction modification (RM) systems serve to protect bacteria from potentially detrimental foreign DNA. Recent evidence suggests that DNA methylation by the methyltransferase (MTase) components of RM systems can also have effects on transcriptome profiles. The type strain of the causative agent of Lyme disease, Borrelia burgdorferi B31, possesses two RM systems with N6-methyladenosine (m6A) MTase activity, which are encoded by the bbe02 gene located on linear plasmid lp25 and bbq67 on lp56. The specific recognition and/or methylation sequences had not been identified for either of these B. burgdorferi MTases, and it was not previously known whether these RM …

Floxed-Cassette Allelic Exchange Mutagenesis Enables Markerless Gene Deletion In Chlamydia Trachomatis And Can Reverse Cassette-Induced Polar Effects, Gabrielle Keb, Robert Hayman, Kenneth A. Fields

Microbiology, Immunology, and Molecular Genetics Faculty Publications

As obligate intracellular bacteria, Chlamydia spp. have evolved numerous, likely intricate, mechanisms to create and maintain a privileged intracellular niche. Recent progress in elucidating and characterizing these processes has been bolstered by the development of techniques enabling basic genetic tractability. Florescence-reported allelic exchange mutagenesis (FRAEM) couples chromosomal gene deletion with the insertion of a selection cassette encoding antibiotic resistance and green fluorescent protein (GFP). Similar to other bacteria, many chlamydial genes exist within polycistronic operons, raising the possibility of polar effects mediated by insertion cassettes. Indeed, FRAEM-mediated deletion of Chlamydia trachomatis tmeA negatively impacts the expression of tmeB. We …

The Role Of Tumor Suppressor Dear1 In The Acquisition Of Mammary Stem/Progenitor Cell Properties, Uyen Le

Dissertations and Theses (Open Access)

Breast cancer is the most commonly diagnosed cancer in women in America. Ductal carcinoma in situ (DCIS), one of the earliest pre-invasive forms of invasive ductal carcinoma (IDC), has a 30-50% risk of progressing to IDC. Understanding the mechanisms regulating progression from DCIS to IDC would help identify biomarkers to stratify patients at higher risk of progression or metastasis. Cumulative literature suggests the earliest phase of dissemination from the primary tumor is driven by the epithelial-mesenchymal transition (EMT) program. DEAR1 is a tumor suppressor gene which is mutated, undergoes loss of heterozygosity in breast cancer, and is downregulated in DCIS …

Sip-428, A Sir2 Deacetylase Enzyme And Its Role In Biotic Stress Signaling Pathway, Bal Krishna Chand Thakuri

Electronic Theses and Dissertations

SABP2 (Salicylic Acid Binding Protein 2) plays a vital role in the salicylic acid signaling pathway of plants both regarding basal resistance and systemic acquired resistance against pathogen infection. SIP-428 (SABP2 Interacting Protein-428) is a Silent information regulator 2 (SIR2) like deacetylase enzyme that physically interacts with SABP2 in a yeast two-hybrid interaction and confirmed independently by a GST pull-down assay. We demonstrated that SIP- 428 is an NAD+ dependent SIR2 deacetylase enzyme. Transgenic tobacco plants silenced in SIP- 428 expression via RNAi showed enhanced basal resistance to microbial pathogens. Moreover, these SIP-428-silenced lines also exhibited a robust induction of …

Investigating Autophagy Dysfunction Induced By A Parkinson's Disease-Causing Mutation In Vps35, Abir Ashfakur Rahman

Boise State University Theses and Dissertations

Parkinson’s Disease (PD) is an idiopathic disorder with no known cure. With number of cases steadily rising around the world, it is imperative to turn to the underlying cellular and molecular mechanisms of the disease manifestation and neurodegeneration to craft novel modes of therapy. VPS35 is one of the few genes that have identified and definitively linked to familial PD. The particular mutation that has been associated is known to cause dysfunction of a key cellular process known as autophagy. This process is primarily responsible for clearance of unwanted, damaged or misfolded proteins, among other things. Our study reveals an …

Synergistic Effects Of Temperature And Salinity On The Gene Expression And Physiology Of Crassostrea Virginica, Hollis Jones

LSU Master's Theses

Crassostrea virginica, the eastern oyster, forms reefs that provide critical services and benefits to the resiliency of the surrounding ecosystem. Changes in environmental conditions, including salinity and temperature, can dramatically alter the services oysters provide by affecting their population dynamics. Climate warming may further exacerbate the effects of salinity changes as precipitation events increase in frequency, intensity, and duration. Temperature and salinity independently and synergistically influence gene expression and physiology in marine organisms. We used comparative transcriptomics, physiology, and a field assessment experiment to investigate whether Louisianan oyster are changing their phenotypes to cope with increased temperature and salinity …

Antibody Epitope Specificity For Dsdna Phosphate Backbone Is An Intrinsic Property Of The Heavy Chain Variable Germline Gene Segment Used, Tatjana Srdic-Rajic, Heinz Kohler, Vladimir Jurisic, Radmila Metlas

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Analysis of protein sequences by the informational spectrum method (ISM) enables characterization of their specificity according to encoded information represented with defined frequency (F). Our previous data showed that F(0.367) is characteristic for variable heavy chain (VH) domains (a combination of variable (V), diversity (D) and joining (J) gene segments) of the anti-phosphocholine (PC) T15 antibodies and mostly dependent on the CDR2 region, a site for PC phosphate group binding. Because the T15 dsDNA-reactive U4 mutant also encodes F(0.367), we hypothesized that the same frequency may also be characteristic for anti-DNA antibodies. Data obtained from an analysis of 60 spontaneously …

Involvement Of Jak/Stat Signaling And A Basement Membrane-Associated Protein During Air Sac Primordium Development In Drosophila Melanogaster, Nathan Anthony Powers

Masters Theses & Specialist Projects

Tumor metastasis currently presents the greatest obstacle for effective cancer remediation. Metastatic growth necessitates both degradation of a specialized form of extracellular matrix (ECM) known as the basement membrane (BM) and the invasion of surrounding tissues thereafter. The thoracic air sacs of fruit flies (Drosophila melanogaster), which develop and operate in a fashion comparable to the human lung, provide a unique model for identifying and characterizing factors that contribute to its own development as well as tumoral invasion. We investigated the involvement of both Janus kinase (JAK)/Signal transducer and activator of transcription (STAT) signaling and a BMassociated protein during the …

Confirming World-Wide Distribution Of An Agriculturally Important Lacewing, Chrysoperla Zastrowi Sillemi, Using Songs, Morphology, Mitochondrial Gene Sequencing, And Phylogenetic Reconstruction, Zoe Mandese

Honors Scholar Theses

The Chrysoperla carnea-group of green lacewings is a cryptic species complex. Species within the group are morphologically similar, yet isolated from one another via reproductive mating song. Chrysoperla zastrowi, a species within the carnea-group, is currently described with a distribution ranging from South Africa to the Middle East and India. However, recent collections of carnea-group lacewings from Guatemala and California were preliminarily identified as Chrysoperla zastrowi based upon similarities in their vibrational courtship songs. This analysis aims to place six specimens, collected by collaborators in Guatemala, Armenia, Iran, and California, into a pre-existing phylogeny of the …

Transcriptomic Insights On The Virulence-Controlling Csra, Badr, Rpon, And Rpos Regulatory Networks In The Lyme Disease Spirochete, William K. Arnold, Christina R. Savage, Kathryn G. Lethbridge, Trever C. Smith, Catherine A. Brisette, Janakiram Seshu, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Borrelia burgdorferi, the causative agent of Lyme disease, survives in nature through a cycle that alternates between ticks and vertebrates. To facilitate this defined lifestyle, B. burgdorferi has evolved a gene regulatory network that ensures transmission between those hosts, along with specific adaptations to niches within each host. Several regulatory proteins are known to be essential for the bacterium to complete these critical tasks, but interactions between regulators had not previously been investigated in detail, due to experimental uses of different strain backgrounds and growth conditions. To address that deficit in knowledge, the transcriptomic impacts of four critical …

Gain-Of-Function Experiments With Bacteriophage Lambda Uncover Residues Under Diversifying Selection In Nature, Rohan Maddamsetti, Daniel T. Johnson, Stephanie J. Spielman, Katherine L. Petrie, Debora S. Marks, Justin R. Meyer

College of Science & Mathematics Departmental Research

Viral gain‐of‐function mutations frequently evolve during laboratory experiments. Whether the specific mutations that evolve in the lab also evolve in nature and whether they have the same impact on evolution in the real world is unknown. We studied a model virus, bacteriophage λ, that repeatedly evolves to exploit a new host receptor under typical laboratory conditions. Here, we demonstrate that two residues of λ’s J protein are required for the new function. In natural λ variants, these amino acid sites are highly diverse and evolve at high rates. Insertions and deletions at these locations are associated with phylogenetic patterns indicative …

Regulated Capture Of Vκ Gene Topologically Associating Domains By Transcription Factories, Sophiya Karki, Domenick E. Kennedy, Kaitlin Mclean, Adrian T. Grzybowski, Mark Maienschein-Cline, Shiladitya Banerjee, Heping Xu, Elizabeth Davis, Malay Mandal, Christine Labno, Sarah E. Powers, Michelle M. Le Beau, Aaron R. Dinner, Harinder Singh, Alexander J. Ruthenburg, Marcus R. Clark

Biology Department Faculty Articles

Expression of vast repertoires of antigen receptors by lymphocytes, with each cell expressing a single receptor, requires stochastic activation of individual variable (V) genes for transcription and recombination. How this occurs remains unknown. Using single-cell RNA sequencing (scRNA-seq) and allelic variation, we show that individual pre-B cells monoallelically transcribe divergent arrays of Vκ genes, thereby opening stochastic repertoires for subsequent Vκ-Jκ recombination. Transcription occurs upon translocation of Vκ genes to RNA polymerase II arrayed on the nuclear matrix in transcription factories. Transcription is anchored by CTCF-bound sites or E2A-loaded Vκ promotors and continues over large genomic distances delimited only by …

N-Terminal Domain Of Human Uracil Dna Glycosylase (Hung2) Promotes Targeting To Uracil Sites Adjacent To Ssdna-Dsdna Junctions, Brian P Weiser, Gaddiel Rodriguez, Philip A Cole, James T Stivers

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The N-terminal domain (NTD) of nuclear human uracil DNA glycosylase (hUNG2) assists in targeting hUNG2 to replication forks through specific interactions with replication protein A (RPA). Here, we explored hUNG2 activity in the presence and absence of RPA using substrates with ssDNA-dsDNA junctions that mimic structural features of the replication fork and transcriptional R-loops. We find that when RPA is tightly bound to the ssDNA overhang of junction DNA substrates, base excision by hUNG2 is strongly biased toward uracils located 21 bp or less from the ssDNA-dsDNA junction. In the absence of RPA, hUNG2 still showed an 8-fold excision bias …

Double-Stranded Rna Binding Protein, Staufen, Is Required For The Initiation Of Rnai In Coleopteran Insects, June-Sun Yoon, Kanakachari Mogilicherla, Dhandapani Gurusamy, Xien Chen, Shankar C. R. R. Chereddy, Subba R. Palli

Entomology Faculty Publications

RNA interference (RNAi) is being used to develop methods to control pests and disease vectors. RNAi is robust and systemic in coleopteran insects but is quite variable in other insects. The determinants of efficient RNAi in coleopterans, as well as its potential mechanisms of resistance, are not known. RNAi screen identified a double-stranded RNA binding protein (StaufenC) as a major player in RNAi. StaufenC homologs have been identified in only coleopteran insects. Experiments in two coleopteran insects, Leptinotarsa decemlineata and Tribolium castaneum, showed the requirement of StaufenC for RNAi, especially for processing of double-stranded RNA (dsRNA) to small interfering …

The Transcriptome Of The Bermuda Fireworm Odontosyllis Enopla (Annelida: Syllidae): A Unique Luciferase Gene Family And Putative Epitoky-Related Genes, Mercer R. Brugler, M. Teresa Aguado, Michael Tessler, Mark Siddall

Publications and Research

The Bermuda fireworm Odontosyllis enopla exhibits an extremely tight circalunar circadian behavior that results in an impressive bioluminescent mating swarm, thought to be due to a conventional luciferase-mediated oxidation of a light-emitting luciferin. In addition, the four eyes become hypertrophied and heavily pigmented, and the nephridial system is modified to store and release gametes and associated secretions. In an effort to elucidate transcripts related to bioluminescence, circadian or circalunar periodicity, as well as epitoky-related changes of the eyes and nephridial system, we examined the transcriptomic profile of three female O. enopladuring a bioluminescent swarm in Ferry Reach, Bermuda. …

Inhibition Of Ribosome Biogenesis Through Genetic And Chemical Approaches, Leonid Anikin

Graduate School of Biomedical Sciences Theses and Dissertations

In order to maintain the ability to generate proteins, proliferating cells must continuously generate ribosomes, designating up to 80% of their energy to ribosome biogenesis (RBG). RBG involves transcription of rDNA by RNA polymerases I (Pol I) and III (Pol III), expression of approximately 80 ribosomal proteins, and assembly of these components in a process referred to as ribosome maturation. During maturation, the Pol I transcribed 47S pre-rRNA undergoes a number of processing events, while simultaneously interacting with processing factors and ribosomal proteins that drive pre-ribosome assembly. Inhibition of RBG has become one of the pursued targets for cancer therapy …

Insight Into Translational Activation In Yeast Mitochondria, Julia Lynn Jones

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial function depends on over a thousand proteins, of which the majority are nuclear DNA-encoded and approximately one percent are mitochondrial DNA-encoded. The mitochondrial DNA of Saccharomyces cerevisiae contains eight protein-encoding genes, seven of which are required for proper function of the respiratory complexes and one encodes a ribosomal protein. The bigenomic nature of the oxidative phosphorylation complexes requires coordinated expression and regulation from both the nuclear and the mitochondrial genomes. It is currently unclear how this regulatory network operates. However, it is thought that nuclear genome-encoded messengers localized to the mitochondria aid in this coordination.

A family of proteins …

Grapevine Vein Clearing Virus: Epidemiological Patterns And Construction Of A Clone, Cory Von Keith

Graduate Theses/Dissertations

Grapevine vein clearing virus (GVCV) is a recently discovered virus belonging to the Badnavirus genus. Characteristic to its name, the virus is associated with a disease where symptoms manifest as pronounced vein-clearing, resulting in severe berry deformation and vine decline in susceptible grape varieties. Sustainable production of wine is dependent on healthy plants. The associated disease is mainly found in Midwest vineyards. Attempts were made in this thesis to provide evidence of causality of the virus to the associated disease and to infer the historical path and migration pattern of GVCV. Conclusions and discussions will provide grape producers with the …

The N-Terminal Methyltransferase Homologs Nrmt1 And Nrmt2 Exhibit Novel Regulation Of Activity Through Heterotrimer Formation., Jon David Faughn

Electronic Theses and Dissertations

Protein, DNA, and RNA methyltransferases have an ever-expanding list of novel substrates and catalytic activities. Even within families and between homologs, it is becoming clear the intricacies of methyltransferase specificity and regulation are far more diverse than originally thought. In addition to specific substrates and distinct methylation levels, methyltransferase activity can be altered through formation of complexes with close homologs. This work involves the N-terminal methyltransferase homologs NRMT1 and NRMT2. NRMT1 is a ubiquitously expressed distributive trimethylase. NRMT2 is a monomethylase expressed at low levels and in a tissue-specific manner. They are both nuclear methyltransferases with overlapping target consensus sequences …

Genomic Investigation Of Beta Agonist Supplementation And Heat Stress In Livestock Species, Rachel Marie Kubik

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

β-adrenergic agonists (β-AA), commonly fed to cattle during the last 20-40 days of the finishing period, improve muscle growth by decreasing adipose deposition and increasing muscle accretion. In most cases, final live weights, hot carcass weight and average daily gain have all been shown to increase when β-AA are feed while fed intake, back fat, and marbling all decrease. Two β-AA, Ractopamine HCl (β1-AA) and Zilpaterol HCl (β2-AA) are currently approved for use in beef cattle in the United States. Converse to the beneficial effects of β-AA, heat stress in livestock decreases production efficiency and growth. There have also been …

The Identification Of Interspecific Hybrids Between Jaeger 70 X Vignoles Grapes Using Ssr Markers, Carl William Knuckles Iv

Graduate Theses/Dissertations

Jaeger 70 cultivar is an interspecific hybrid of Vitis linececumii x Vitis rupestris, with an interesting past. It was created by Hermann Jaeger of Neosho, MO, who is most notable for saving the French wine industry by developing phylloxera resistant rootstocks in the mid-1800s. Traditionally the Jaeger 70 variety has been grafted to French wine grape cultivars to impart disease resistance and cold hardiness while retaining desirable wine characteristics. One interesting characteristic of Jaeger 70 is that it is a female-only plant, allowing for many interesting areas of study. Vitis interspecific hybrid Vignoles, is a cold hardy cultivar of largely …