Genetics and Genomics Commons^™

T-Dna-Genome Junctions Form Early After Infection And Are Influenced By The Chromatin State Of The Host Genome, Shay Shilo, Pooja Tripathi, Cathy Melamed Bessudo, Oren Tzfadia, Theodore R. Muth, Avraham A. Levy

Publications and Research

Agrobacterium tumefaciens mediated T-DNA integration is a common tool for plant genome manipulation. However, there is controversy regarding whether T-DNA integration is biased towards genes or randomly distributed throughout the genome. In order to address this question, we performed high-throughput mapping of T-DNA-genome junctions obtained in the absence of selection at several time points after infection. T-DNA-genome junctions were detected as early as 6 hours post-infection. T-DNA distribution was apparently uniform throughout the chromosomes, yet local biases toward AT-rich motifs and T-DNA border sequence micro-homology were detected. Analysis of the epigenetic landscape of previously isolated sites of T-DNA integration in …

Tumor Necrosis Factor Dynamically Regulates The Mrna Stabilome In Rheumatoid Arthritis Fibroblast-Like Synoviocytes, Konstantinos Loupasakis, David Kuo, Upneet K. Sokhi, Christopher Sohn, Bethany Syracuse, Eugenia G. Giannopoulou, Sung Ho Park, Hyelim Kang, Gunnar Rätsch, Lionel B. Ivashkiv, George D. Kalliolias

Publications and Research

During rheumatoid arthritis (RA), Tumor Necrosis Factor (TNF) activates fibroblast-like synoviocytes (FLS) inducing in a temporal order a constellation of genes, which perpetuate synovial inflammation. Although the molecular mechanisms regulating TNF-induced transcription are well characterized, little is known about the impact of mRNA stability on gene expression and the impact of TNF on decay rates of mRNA transcripts in FLS. To address these issues we performed RNA sequencing and genome-wide analysis of the mRNA stabilome in RA FLS. We found that TNF induces a biphasic gene expression program: initially, the inducible transcriptome consists primarily of unstable transcripts but progressively switches …

Effect Assessment Of Tio2 Nanoparticles Exposure On Medicago By Monitoring Morphophysiology, Charles Towey

Mahurin Honors College Capstone Experience/Thesis Projects

In recent years titanium dioxide nanoparticles (TiO₂NPs) have been ingredients in everything from paints to cosmetics, and even in some kinds of food. This growth in use has resulted in a substantial increase in the amount of titanium released into the environment, which could have detrimental effects on nearby plant and animal life. Currently, the number of studies conducted on the effects of TiO₂NPs is quite small, especially when it comes to edible crops. Because of this lack of research data, this study has been designed to assess the effect of TiO₂ NPs exposure on …

A Linkage Map For The Newt Notophthalmus Viridescens: Insights In Vertebrate Genome And Chromosome Evolution, Melissa C. Keinath, S. Randal Voss, Panagiotis A. Tsonis, Jeramiah J. Smith

Biology Faculty Publications

Genetic linkage maps are fundamental resources that enable diverse genetic and genomic approaches, including quantitative trait locus (QTL) analyses and comparative studies of genome evolution. It is straightforward to build linkage maps for species that are amenable to laboratory culture and genetic crossing designs, and that have relatively small genomes and few chromosomes. It is more difficult to generate linkage maps for species that do not meet these criteria. Here, we introduce a method to rapidly build linkage maps for salamanders, which are known for their enormous genome sizes. As proof of principle, we developed a linkage map with thousands …

The Recycling Gtpase, Rab-10, Regulates Autophagy Flux In Caenorhabditis Elegans, Nicholas J. Palmisano

Dissertations, Theses, and Capstone Projects

Autophagy and endocytosis are two cellular pathways that are vital to cell growth and homeostasis. Autophagy is a dynamic and catabolic process involving the formation of a double-membrane vesicle called the autophagosome, which engulfs long-lived proteins and damaged organelles. Endocytosis involves the uptake of extracellular material into the cell through the formation of intracellular vesicles termed endosomes. Although both endocytosis and autophagy are interconnected processes, the extent to which endocytic proteins and/or compartments contribute to autophagy, and how these endocytic components do so, is still unknown. To improve our understanding of the connections that exist between autophagy and endocytosis, we …

Body Size Regulation Via Bmp Signaling In Caenorhabditis Elegans, Uday Madaan

Dissertations, Theses, and Capstone Projects

The body size of an organism can be a crucial determinant of access to nutrition, reproductive success and overall survival in the wild. However, how body size of an individual is determined is incompletely understood. Body size is a complex trait determined by multiple pathways and genes, making it difficult to understand the role of individual genes and pathways in determining overall size. In Caenorhabditis elegans, a homolog of Bone Morphogenetic Proteins (BMP) is a major regulator of body size; functional loss of DBL-1 leads to a small body size. Due to a drastic change in body size in dbl-1 …

Variation In Dna Methylation Is Not Consistently Reflected By Sociality In Hymenoptera, Karl M. Glastad, Samuel V. Arsenault, Kim L. Vertacnik, Scott M. Geib, Sasha Kay, Bryan N. Danforth, Sandra M. Rehan, Catherine R. Linnen, Sarah D. Kocher, Brendan G. Hunt

Biology Faculty Publications

Changes in gene regulation that underlie phenotypic evolution can be encoded directly in the DNA sequence or mediated by chromatin modifications such as DNA methylation. It has been hypothesized that the evolution of eusocial division of labor is associated with enhanced gene regulatory potential, which may include expansions in DNA methylation in the genomes of Hymenoptera (bees, ants, wasps, and sawflies). Recently, this hypothesis garnered support from analyses of a commonly used metric to estimate DNA methylation in silico, CpG content. Here, we test this hypothesis using direct, nucleotide-level measures of DNA methylation across nine species of Hymenoptera. In doing …

The 'Pseudomonas Aeruginosa' Psl Polysaccharide Is A Social But Noncheatable Trait In Biofilms, Yasuhiko Irie, Aled E. Roberts, Kasper N. Kragh, Vernita D. Gordon, Jaime B. Hutchison, Rosalind J. Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A. West, Stephen P. Diggle

Biology Faculty Publications

Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa. We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides populationlevel benefits in biofilms, for both growth and antibiotic …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

The Santa Ana Speckled Dace (Rhinichthys Osculus): Phylogeography And Molecular Evolution Of The Mitochondrial Dna Control Region, James Jay Vanmeter

Electronic Theses, Projects, and Dissertations

The purpose of this genetic study of the Santa Ana Speckled Dace Rhinichthys osculus was three-fold. The first goal was to characterize the molecular structure of the mtDNA control region of R. osculus. An 1143 base-pair region of the mitochondrial DNA genome, which included the complete control region was sequenced for all individuals. Analysis of the sequence data revealed that the molecular structure of the speckled dace control region was similar to the molecular structure described for other vertebrate taxa. The speckled dace control region contains three major domains, which vary in base frequency as well as in the frequency …

Isolation And Comparative Genomic Analysis Of Final Third Of Satis Genome, Kelly Hartigan, Nicole Curnutt, Matthew Mcdermut

Undergraduate Research Symposium Posters

A highly novel Streptomyces phage, Satis, was isolated from a direct environmental sample collected from outside Danforth House on the Washington University campus. Satis infects bacterial species Streptomyces lividans producing pinpoint, cloudy plaques less than 1mm in diameter. Electron microscope data shows rare atypical physical features. Rather than the common octahedral capsid shape, Satis has a prolate head with visible cross-linked hexagonal protein structure and average measurements of 285 nm by 47 nm with a long, flexible tail measuring 268 nm. Upon sequencing, it was found that Satis contains the longest phage genome discovered to date through the SEA-PHAGE program …

Identification Of The Potentiating Mutations And Synergistic Epistasis That Enabled The Evolution Of Inter-Species Cooperation, Sarah Douglas, Lon Chubiz, William Harcombe, Christopher Marx

Biology Department Faculty Works

Microbes often engage in cooperation through releasing biosynthetic compounds required by other species to grow. Given that production of costly biosynthetic metabolites is generally subjected to multiple layers of negative feedback, single mutations may frequently be insufficient to generate cooperative phenotypes. Synergistic epistatic interactions between multiple coordinated changes may thus often underlie the evolution of cooperation through overproduction of metabolites. To test the importance of synergistic mutations in cooperation we used an engineered bacterial consortium of an Escherichia coli methionine auxotroph and Salmonella enterica. S. enterica relies on carbon by-products from E. coli if lactose is the only carbon source. …

Dna Sequences Of The Mitochondrial Cytochrome C Oxidase I (Coi) Genes From Deep Sea Fishes. Cruises Dp01 And Dp02 From May 2015 - August 2015, Andrea Bernard, Max Weber, Kimberly A. Finnegan, Mahmood S. Shivji, Ron Eytan

DEEPEND Datasets

The deep sea ecosystem is believed to contain the highest biomass of fish in the oceans. However, the taxonomic diversity in this ecosystem is incompletely described and likely to be vastly underestimated. DNA sequence data (barcodes) have become a key tool to discover hidden biodiversity. We generated mitochondrial DNA barcode datasets based on the Cytochrome c oxidase I (COI) gene from deep sea fishes. These data were analyzed using phylogenetic and statistical methods to reveal cryptic species and make taxonomic linkages between adult fishes and their early life stages. These datasets were generated from fishes collected in the Northern Gulf …

Differentiating The Neches River Rose Mallow (Hibiscus Dasycalyx) From Its Congeners By Means Of Phylogenetics And Population Genetics, Julia Norrell

Biology Theses

This study used molecular phylogenetic methods to attempt to resolve the taxonomic status of the federally threatened East Texas-endemic wildflower, the Neches River Rose Mallow (Hibiscus dasycalyx). Hibiscus dasycalyx co-occurs with two other closely related congeners that are currently not of conservation concern: the halberdleaf rose mallow (H. laevis); and the crimson-eyed rose mallow (H. moscheutos). This study assessed the phylogeny of these three Hibiscus species, and attempted to determine if there is possible hybridization occurring between them. To this end, Restriction Site Associated DNA Sequencing (RAD-Seq), a Next Generation Sequencing method, was used …

Chromatin-Modifying Agents Convert Fibroblasts To Oct4+ And Vegfr-2+ Capillary Tube-Forming Cells, Anita Wary, Neil Wary '18, Jugajyoti Baruah, Victoria Mastej, Kishore K. Wary

Student Publications & Research

Rationale
The human epigenome is plastic. The goal of this study was to address if fibroblast cells can be epigenetically modified to promote neovessel formation.

Methods and results
Here, we used highly abundant human adult dermal fibroblast cells (hADFCs) that were treated with the chromatin-modifying agents 5-aza-2'-deoxycytidine and trichostatin A, and subsequently subjected to differentiation by activating Wnt signaling. Our results show that these epigenetically modified hADFCs increasingly expressed β-catenin, pluripotency factor octamer-binding transcription factor-4 (OCT4, also known as POU5F1), and endothelial cell (EC) marker called vascular endothelial growth factor receptor-2 (VEGFR-2, also known as Fetal Liver Kinase-1). In microscopic …

From Sexless To Sexy: Why It Is Time For Human Genetics To Consider And Report Analyses Of Sex, Matthew S. Powers, Phillip H. Smith, Sherry A. Mckee, Marissa A. Ehringer

Publications and Research

Science has come a long way with regard to the consideration of sex differences in clinical and preclinical research, but one field remains behind the curve: human statistical genetics. The goal of this commentary is to raise awareness and discussion about how to best consider and evaluate possible sex effects in the context of large-scale human genetic studies. Over the course of this commentary, we reinforce the importance of interpreting genetic results in the context of biological sex, establish evidence that sex differences are not being considered in human statistical genetics, and discuss how best to conduct and report such …

Modeling 3d Retinogenesis In Mouse Embryonic Stem Cells Following Crispr-Mediated Crx Knockdown, Pooja Prasad

Dissertations, Masters Theses, Capstones, and Culminating Projects

An emerging technology known as three-dimensional (3D) tissue engineering has allowed scientists to mimic tissues found in vivo. Previous studies indicate that it is possible to differentiate dissociated mouse embryonic stem cells (mESCs) into 3D retinal tissues in vitro (Bertacchi, 2015; Eiraku, 2012). The newly differentiated retinal tissues are said to encompass all of the major components found in retinal tissues. The generation of in vitro 3D tissues holds great potential in terms of patient-specific disease modeling. Although various diseases have been well-studied in animal models, there are limitations with regards to patient-specificity. The generation of animal models to study …

Function Of The Enterobactin Operon Of A. Actinomycetemcomitans In The Presence Of Catecholmines And Iron., Taylor Johnson

Electronic Theses and Dissertations

Background: Aggregatibacter actinomycetemcomitans (Aa) possesses a two-component system, QseBC, which is key in biofilm formation/virulence and is activated in the presence of iron-catecholamine complexes. Aa does not synthesize enterobactin, a catechol-based siderophore, yet possesses the machinery for recognition and uptake. We hypothesize that Aa is able to acquire iron by catecholamine mediation through the enterobactin receptor/transporter. Methods: By insertional mutation, we attempted to delete the enterobactin permease from the genome using suicide vector pJT1. A growth curve of truncated mutant ΔfepA was also conducted to observe growth in the presence of iron and catecholamines. Statistical significance was determined by ANOVA …

Role Of Ime4 And Pho92 Proteins In Pho5 Regulation, Krishna Shah

Senior Honors Theses

In the yeast Saccharomyces cerevisiae, m6A methylation regulates the stability and translation of mRNA. Ime4, which is highly active in meiotic cells, recognizes consensus methyl sites in pre-mRNA and adds methyl groups to a small fraction of adenosine residues, whereas Pho92 binds to such methylated sites and promotes subsequent degradation. PHO5 transcripts expression is upregulated when IME4 and PHO92 are deleted. In the PHO5 transcript, near the stop codon of the open reading frame (ORF), there is a potential consensus methyl site that is predicted to be methylated, based on its location and excellent match to the consensus methylation sequence …

Gene Expression Profiling In The Larval Fat Body Of Desiccation Selected Drosophila Melanogaster, Adriana Michelle Charles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drosophila melanogaster selected for resistance to desiccation (no food or water) display slower development and a higher body mass compared to fed controls due to an extended third larval instar. I hypothesize that desiccation selected D. melanogaster larvae will have a different gene expression profile compared to fed controls. Separate populations of D. melanogaster were subjected to desiccation (no food or water), starvation (no food) until 80-85% mortality, for 75 generations. mRNA from the larval fat body was collected at 88 hours, 96 hours, 112 hours and 120 hours post-hatching. Four replicate samples were used for each condition and time …

Proteomic Identification Of Histone Post-Translational Modifications Induced By Dna Double-Strand Breaks And Novel Proteins Involved In The Dna Damage Response, Pingping Wang

Dissertations and Theses (Open Access)

Inaccurate repair of DNA double-strand breaks (DSBs) can lead to DNA mutation and chromosome rearrangements, causing human diseases such as cancer. Although we know the basic mechanisms of DSB repair, the added complexities in the chromatin context are unclear. This is partially due to the lack of unbiased systems for identifying proteins and post-translational modifications (PTMs) involved in DSB repair. In this work, we established a novel method, termed DSB-ChAP-MS (Double Strand Break-Chromatin Affinity Purification with Mass Spectrometry), for the affinity purification of a sequence-specific single copy endogenous chromosomal locus containing a DSB, followed by the proteomic identification of enriched …

A Longitudinal Cline Characterizes The Genetic Structure Of Human Populations In The Tibetan Plateau, Choongwon Jeong, Benjamin M. Peter, Buddha Basnyat, Maniraj Neupane, Geoff Childs, Sienna Craig, John Novembre, Anna Di Rienzo

Dartmouth Scholarship

Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their de- mography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with world- wide genetic variation data. We found a clear signal of genetic stratification across the east- west axis within Tibetan samples. Samples from more eastern locations …

Accumulation And Expression Of Multiple Antibiotic Resistance Genes In Arcobacter Cryaerophilus That Thrives In Sewage, Jess A. Millar, Rahul Raghavan

Biology Faculty Publications and Presentations

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also …

Development Of Site Fidelity In The Nocturnal Amblypygid, Phrynus Marginemaculatus, Jacob M. Graving, Verner P. Bingman, Eileen Hebets, Daniel D. Wiegmann

Eileen Hebets Publications

Amblypygids are capable of navigation in the complex terrain of rainforests in near complete darkness. Path integration is unnecessary for successful homing, and the alternative mechanisms by which they navigate have yet to be elucidated. Here, our aims were to determine whether the amblypygid Phrynus marginemaculatus could be trained to reliably return to a target shelter in a laboratory arena—indicating goal recognition—and to document changes in behavior associated with the development of fidelity. We recorded nocturnal movements and space use by individuals over five nights in an arena in which subjects were provided with two shelters that differed in quality. …

Genetics Research Paper: The Inheritance Of Schizophrenia, Kolbi Holmes

Academic Symposium of Undergraduate Scholarship

Schizophrenia is a spectrum of disorders defined by abnormalities in one or more areas including delusions, hallucinations, disorganized thinking or speech, grossly disorganized or abnormal motor behaviors including catatonia and other negative symptoms (American Psychology Association, 2013). Schizophrenia is inherited on autosomal chromosome 8p12. Neuregulin 1 (NRG1), an epithelial growth factor protein, located at 8p12, has been identified as being a nucleotide variation of the single-nucleotide polymorphism (SNP), rs833497 located on chromosome 18q21.1 that is associated with schizophrenia.

Editorial: Genetics, Genomics And –Omics Of Thermophiles, Kian Mau Goh, Kok-Gan Chan, Rajesh Kumar Sani, Edgardo Ruben Donati, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

Thermophilic Archaea and Bacteria occupy heated environments. Advancement of next-generation sequencing (NGS), single-cell analyses, and combinations of –omics and microscopic technologies have resulted in the discovery of new thermophiles. This e-book consists of a review, and 10 original articles authored by 94 authors. The main aim of this Research Topic of Frontiers in Microbiology was to provide a platform for researchers to describe recent findings on the ecology of thermophiles using NGS, functional genomics, comparative genomics, gene evolution, and extremozyme discovery.

Phylogenetic Studies Of The Madagascan Freshwater Crabs (Potamoidea, Potamonautidae, Deckeniinae), Rainee Stevens

All NMU Master's Theses

Relationships within the Madagascan freshwater crab fauna were examined based on unstudied specimens from all parts of Madagascar. This study allowed the examination of the validity of existing genera and species, and identified potential new taxa. The new specimens provided phylogenetic and evolutionary data, as well as new insights into the distribution patterns of the Malagasy freshwater crab fauna. In addition, the large number of new localities from previously unsurveyed areas of Madagascar allowed the construction of updated distribution maps.

The present analysis included 62 unidentified specimens plus 13 identified species of Malagasy freshwater crab taxa that had already been …

Demethylated Hsatii Dna And Hsatii Rna Foci Sequester Prc1 And Mecp2 Into Cancer-Specific Nuclear Bodies, L. L. Hall, M. Byron, Dawn M. Carone, T. W. Whitfield, G. P. Pouliot, A. Fischer, P. Jones, J. B. Lawrence

Biology Faculty Works

This study reveals that high-copy satellite II (HSATII) sequences in the human genome can bind and impact distribution of chromatin regulatory proteins and that this goes awry in cancer. In many cancers, master regulatory proteins form two types of cancer-specific nuclear bodies, caused by locus-specific deregulation of HSATII. DNA demethylation at the 1q12 mega-satellite, common in cancer, causes PRC1 aggregation into prominent Cancer-Associated Polycomb (CAP) bodies. These loci remain silent, whereas HSATII loci with reduced PRC1 become derepressed, reflecting imbalanced distribution of UbH2A on these and other PcG-regulated loci. Large nuclear foci of HSATII RNA form and sequester copious MeCP2 …

P02. Production Of A Protein Subunit Vaccine For Mannheimia Haemolytica In Lettuce Chloroplasts, Coby K. Martin

Western Research Forum

The cattle industry worldwide is ravaged by bovine respiratory disease (BRD), a bacterial disease caused by Mannheimia haemolytica. We have designed a chimeric protein subunit vaccine against M. haemolytica based on recent evidence demonstrating the protective potential of antigens against a virulence factor, leukotoxin, in addition to a surface lipoprotein. Plant-based production of this protein vaccine provides a safe and inexpensive alternative to traditional production methods. Plant-base production also supports the use of an edible vaccine that will deliver antigens to pharyngeal tissues to provide local immunization against M. haemolytica to prior to its progression into the lungs. Chloroplasts …

Taxonomic Placement Of The Nidulariaceae Of Nebraska And Iowa Based On Molecular And Morphological Data, Goodmond H. Danielsen Iv

UNO Student Research and Creative Activity Fair

Proper taxonomic and molecular study is necessary to better organize closely related species that may not only be used for human needs, but also in the quest for knowledge of how the world around us works. Though important, the taxonomic placement of Nebraskan and Iowan bird’s nest fungi (Nidulariaceae) is not well documented. Here, phylogenetic analysis is used to place the Nidulariaceae of Nebraska and Iowa in the tree of life using molecular and morphological techniques. Based on these results and results of further work done on these specimens, it will be possible to better place the Nidulariaceae of Nebraska …