Genetics and Genomics Commons^™

Shifting Patterns Of Natural Variation In The Nuclear Genome Of Caenorhabditis Elegans, Eleanne Solorzano, Kazufusa Okamoto, Pushpa Datla, Way Sung, R. D. Bergeron, W. Kelley Thomas

Hubbard Center for Genome Studies (HCGS)

Background: Genome wide analysis of variation within a species can reveal the evolution of fundamental biological processes such as mutation, recombination, and natural selection. We compare genome wide sequence differences between two independent isolates of the nematode Caenorhabditis elegans (CB4856 and CB4858) and the reference genome (N2). Results: The base substitution pattern when comparing N2 against CB4858 reveals a transition over transversion bias (1.32:1) that is not present in CB4856. In CB4856, there is a significant bias in the direction of base substitution. The frequency of A or T bases in N2 that are G or C bases in CB4856 …

Improving Gene Expression Data Interpretation By Finding Latent Factors That Co-Regulate Gene Modules With Clinical Factors, Tianwei Yu, Yun Bai

PCOM Scholarly Works

Background: In the analysis of high-throughput data with a clinical outcome, researchers mostly focus on genes/proteins that show first-order relations with the clinical outcome. While this approach yields biomarkers and biological mechanisms that are easily interpretable, it may miss information that is important to the understanding of disease mechanism and/or treatment response. Here we test the hypothesis that unobserved factors can be mobilized by the living system to coordinate the response to the clinical factors.Results: We developed a computational method named Guided Latent Factor Discovery (GLFD) to identify hidden factors that act in combination with the observed clinical factors to …

Robust Rnai-Based Resistance To Mixed Infection Of Three Viruses In Soybean Plants Expressing Separate Short Hairpins From A Single Transgene, Xiuchun Zhang, Shirley Sato, Xiaohong Ye, Anne E. Dorrance, Thomas Jack Morris, Thomas E. Clemente, Feng Qu

Nebraska Center for Virology: Faculty Publications

Transgenic plants expressing double-stranded RNA (dsRNA) of virus

origin have been previously shown to confer resistance to virus infections

through the highly conserved RNA-targeting process termed RNA silencing

or RNA interference (RNAi). In this study we applied this strategy to

soybean plants and achieved robust resistance to multiple viruses with a

single dsRNA-expressing transgene. Unlike previous reports that relied

on the expression of one long inverted repeat (IR) combining sequences

of several viruses, our improved strategy utilized a transgene designed to

express several shorter IRs. Each of these short IRs contains highly conserved

sequences of one virus, forming dsRNA of …

Kaposi Sarcoma-Associated Herpesvirus Degrades Cellular Toll-Interleukin-1 Receptor Domain-Containing Adaptor-Inducing Β-Interferon (Trif), Humera Ahmad, Rachel Gubbels, Florencia Meyer, Thomas Waterbury, Rongtuan Lin, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Kaposi sarcoma-associated herpesvirus (KSHV) is a human ƴ - herpesvirus associated with several human malignancies. The replication and transcription activator (RTA) is necessary and sufficient for the switch from KSHV latency to lytic replication. Toll-interleukin-1 receptor (TIR) domain-containing adaptorinducing β-interferon (TRIF, also called TIR-domain-containing adaptor molecule-1 (TICAM-1)) is a signaling adaptor molecule that is critically involved in the Toll-like receptor 3 (TLR-3) and TLR-4 signaling pathways for type I interferon (IFN) production, a key component of innate immunity against microbial infection. In this report, we find a new mechanism by which RTA blocks innate immunity by targeting cellular TRIF. RTA …

Human Papillomavirus 16 Variants From Zambian Women With Normal Pap Smears, Yan Jun Lei, Kgomotso Makhaola, Daraporn Pittayakhajonwut, Charles Wood, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomavirus (HPV) type 16 is the most prevalent high-risk viral genotype associated with cervical cancer. Six distinct phylogenetic clusters of HPVs have been identified and are distributed differently across five continents. HPV16 DNA was extracted from cervico-lavage samples from women with normal pap smears. The LCR regions were amplified in triplicate, cloned, sequenced, and analyzed from a total of 11 recovered HPV16 positive samples [Ng’andwe et al. (2007): BMC Infect Dis 7:77] were analyzed for sequence variation. The HPV16 LCR variants were assessed for promoter activity by use of a luciferase reporter gene. Six novel HPV16 variants with nucleotide …

Hiv-1 Clade B And C Isolates Exhibit Differential Replication: Relevance To Macrophage-Mediated Neurotoxicity, Agnes A. Constantino, Yunlong Huang, Hong Zhang, Charles Wood, Jialin C. Zheng

Nebraska Center for Virology: Faculty Publications

HIV-associated neurocognitive disorders (HAND) continue to be a consequence of HIV-1 infection among clade B-infected individuals. In contrast, the incidence of severe neurological impairment is lower among clade C-infected patients in regions of Sub-Saharan Africa and India. Biological aspects such as replication, cytopathicity, inflammatory response, and neurotoxicity unique to each clade influence neuropathogenicity and ultimately affect the clinical outcome of the disease. We hypothesize that productive infection by clade C isolates leads to macrophagemediated neurotoxicity, although to a lesser extent than clade B isolates. Using a panel of primary isolates of clades B and C we demonstrated that clade B …

The Zambia Children's Ks-Hhv8 Study: Rationale, Study Design, And Study Methods, Veenu Minhas, Kay L. Crabtree, Ann Chao, Janet M. Wojcicki, Adrian M. Sifuniso, Catherine Nkonde, Chipepo Kankasa, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

The epidemic of human immunodeficiency virus in Zambia has led to a dramatic rise in the incidence of human herpesvirus-8 (HHV-8)–associated Kaposi's sarcoma in both adults and children. However, there is a paucity of knowledge about the routes of HHV-8 transmission to young children. The Zambia Children's KS-HHV8 Study, a large, prospective cohort study in Lusaka, Zambia, was launched in 2004 to investigate the role of household members as a source of HHV-8 infection in young children and social behaviors that may modify the risk of HHV-8 acquisition. This cohort is distinct from other epidemiologic studies designed to investigate HHV-8 …

Prevalence Of Human Herpesvirus 8 (Hhv8) And Hepatitis C Virus (Hcv) In A Rural Community With High Risk For Blood Borne Infections In Central China, Tiejun Zhang, Na He, Yingying Ding, Kay L. Crabtree, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

Former illegal blood donation in the past decade has caused HIV outbreaks in some rural areas in China. Other HIV associated virus infections, such as human herpesvirus 8 (HHV8) in such areas are still not well defined. In order to explore HHV8 and HCV seroprevalence and potential risk factors in such areas, a cross-sectional study with 305 HIV positive and 315 HIV negative subjects recruited from a rural county in Shanxi province was conducted, where illegal blood collection was reported. Interview questionnaires and serum testing were carried out with these participants. HCV and HHV8 seroprevalence were found to be higher …

Comparison Of Adenoviruses As Oncolytics And Cancer Vaccines In An Immunocompetent B Cell Lymphoma Model, Eric A. Weaver, Christopher Y. Chen, Shannon M. May, Mary E. Barry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

We have screened human adenoviruses (Ads) for oncolytic activity against a variety of mouse and hamster cell lines and have found a number that are susceptible to a variety of Ad serotypes. A20 lymphoma is derived from BALB/c mice and is susceptible to infection and killing by a variety of human Ads. A20 is also a suitable cancer vaccine model, because these cells express a unique immunoglobulin variable region that can be targeted by vaccination. To compare Ads as cancer vaccines versus Ads as oncolytics, A20 tumors were initiated in im- munocompetent BALB/c mice. Mice immunized with first-generation Ad5 expressing …

Advances And Future Challenges In Adenoviral Vector Pharmacology And Targeting, Reeti Khare, Christopher Y. Chen, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Adenovirus is a robust vector for therapeutic applications, but its use is limited by our understanding of its complex in vivo pharmacology. In this review we describe the necessity of identifying its natural, widespread, and multi-faceted interactions with the host since this information will be crucial for efficiently redirecting virus into target cells. In the rational design of vectors, the notion of overcoming a sequence of viral “sinks” must be combined with re-targeting to target populations with capsid as well as shielding the vectors from pre-existing or toxic immune responses. It must also be noted that most known adenoviral pharmacology …

Species D Adenoviruses As Oncolytics Against B-Cell Cancers, Christopher Y. Chen, Julien S. Senac, Eric A. Weaver, Shannon M. May, Diane F. Jelinek, Philip Greipp, Thomas Witzig, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Purpose: Oncolytic viruses are self-amplifying anticancer agents that make use of the natural ability of viruses to kill cells. Adenovirus serotype 5 (Ad5) has been extensively tested against solid cancers, but less so against B-cell cancers because these cells do not generally express the coxsackie and adenoviral receptor (CAR). To determine whether other adenoviruses might have better potency, we "mined" the adenovirus virome of 55 serotypes for viruses that could kill B-cell cancers.

Experimental Design: Fifteen adenoviruses selected to represent Ad species B, C, D, E, and F were tested in vitro against cell lines and primary patient B-cell cancers …

Regulation Of The Latency–Reactivation Cycle By Products Encoded By The Bovine Herpesvirus 1 (Bhv-1) Latency-Related Gene, Clinton Jones, Leticia Frizzo Da Silva, Devis Sinani

School of Veterinary and Biomedical Sciences: Faculty Publications

Like other α-herpesvirinae subfamily members, the primary site for bovine herpesvirus 1 (BHV-1) latency is ganglionic sensory neurons. Periodically BHV-1 reactivates from latency, virus is shed, and consequently virus transmission occurs. Transcription from the latency-related (LR) gene is readily detected in neurons of trigeminal ganglia (TG) of calves or rabbits latently infected with BHV-1. Two micro-RNAs and a transcript encompassing a small open reading frame (ORF-E) located within the LR promoter can also be detected in TG of latently infected calves. A BHV-1 mutant that contains stop codons near the beginning of the first open reading frame (ORF2) within the …

Epigenetic Regulatory Mechanisms In Plants, Zoya Avramova

School of Biological Sciences: Faculty Publications

Genomes are defined by their primary sequence, which provides the genetic blueprint of a species. Eukaryotic DNA functions within the context of chromatin, which provides additional layers of gene regulation referred to as “epigenetic.” The commonly found definition of epigenetics is that of a “study of heritable changes in genome function that occur without a change in DNA sequence.” However, evidence that neuronal gene-expression states are also regulated by epigenetic mechanisms, despite evidence that neuronal cells do not divide, has opened space for a broader unifying definition that keeps “the sense of prevailing usage but avoids constraints imposed by stringently …

The Arabidopsis Trithorax-Like Factor Atx1 Functions In Dehydration Stress Responses Via Aba-Dependent And Aba-Independent Pathways, Yong Ding, Zoya Avramova, Michael Fromm

School of Biological Sciences: Faculty Publications

Emerging evidence suggests that the molecular mechanisms driving the responses of plants to environmental stresses are associated with specific chromatin modifications. Here, we demonstrate that the Arabidopsis trithorax-like factor ATX1, which trimethylates histone H3 at lysine 4 (H3K4me3), is involved in dehydration stress signaling in both abscisic acid (ABA)-dependent and ABA-independent pathways. The loss of function of ATX1 results in decreased germination rates, larger stomatal apertures, more rapid transpiration and decreased tolerance to dehydration stress in atx1 plants. This deficiency is caused in part by reduced ABA biosynthesis in atx1 plants resulting from decreased transcript levels from NCED3, which …

Copper Tolerance Of Saccharomyces Cerevisiae Nonsense-Mediated Mrna Decay Mutants, Rafael Deliz-Aguirre, Audrey L. Atkin, Bessie W. Kebaara

School of Biological Sciences: Faculty Publications

The eukaryotic nonsense-mediated mRNA (NMD) is a specialized pathway that leads to the recognition and rapid degradation of mRNAs with premature termination codons, and importantly some natural mRNAs as well. Natural mRNAs with atypically long 3′-untranslated regions (UTRs) are degraded by NMD in Saccharomyces cerevisiae. A number of S. cerevisiae mRNAs undergo alternative 3′-end processing producing mRNA isoforms that differ in their 3′-UTR lengths. Some of these alternatively 3′-end processed mRNA isoforms have atypically long 3′-UTRs and would be likely targets for NMD-mediated degradation. Here, we investigated the role NMD plays in the regulation of expression of CTR2, …

Developmental Regulation Of Hemoglobin Synthesis In The Green Anole Lizard Anolis Carolinensis, Jay F. Storz, Federico G. Hoffmann, Juan C. Opazo, Thomas J. Sanger, Hideaki Moriyama

Jay F. Storz Publications

Tetrapod vertebrates possess multiple alpha- and beta-like globin genes that are ontogenetically regulated, such that functionally distinct hemoglobin (Hb) isoforms are synthesized during different stages of development. The alpha- and beta-like globin genes of amphibians, birds and mammals are differentially expressed during embryonic development and postnatal life, but little is known about the developmental regulation of globin gene expression in non-avian reptiles. Here we report an investigation into the developmental regulation of Hb synthesis in the green anole lizard Anolis carolinensis. We tested two hypotheses derived from comparative genomic studies of the globin gene clusters in tetrapod vertebrates. First, …

Evolutionary Origins Of Oxygen Sensing In Animals, Kalle T. Rytkönen, Jay F. Storz

Jay F. Storz Publications

All animal life requires molecular oxygen as the terminal electron acceptor in aerobic energy production. A lack of oxygen can reduce the rate of energy production, whereas an excess of oxygen leads to the accumulation of toxic reactive oxygen species. Hence, animals have evolved sophisticated mechanisms with which to monitor and respond to fluctuations in oxygen availability, in order to maintain cellular homeostasis. In all animal taxa examined so far, the maintenance of physiological oxygen homeostasis is mediated by the oxygen-dependent post-translational hydroxylation of a heterodimeric transcription factor, termed hypoxia-inducible factor (HIF; Kaelin & Ratcliffe, 2008). The hydroxylation reaction is …

Differential Loss And Retention Of Cytoglobin, Myoglobin, And Globin-E During The Radiation Of Vertebrates, Federico G. Hoffmann, Juan C. Opazo, Jay F. Storz

Jay F. Storz Publications

If rates of postduplication gene retention are positively correlated with levels of functional constraint, then gene duplicates that have been retained in a restricted number of taxonomic lineages would be expected to exhibit relatively low levels of sequence conservation. Paradoxical patterns are presented by gene duplicates that have been retained in a small number of taxa but which are nonetheless subject to strong purifying selection relative to paralogous members of the same multigene family. This pattern suggests that such genes may have been co-opted for novel, lineage-specific functions. One possible example involves the enigmatic globin-E gene (GbE), which …

Experimental Approaches To Evaluate The Contributions Of Candidate Protein-Coding Mutations To Phenotypic Evolution, Jay F. Storz, Anthony J. Zera

Jay F. Storz Publications

Identifying mechanisms of molecular adaptation can provide important insights into the process of phenotypic evolution, but it can be exceedingly difficult to quantify the phenotypic effects of specific mutational changes. To verify the adaptive significance of genetically based changes in protein function, it is necessary to document functional differences between the products of derived and wild-type alleles and to demonstrate that such differences impinge on higher-level physiological processes (and ultimately, fitness). In the case of metabolic enzymes, this requires documenting in vivo differences in reaction rate that give rise to differences in flux through the pathway in which the enzymes …

Role Of Hydrodynamic Behavior Of Dna Molecules In Dielectrophoretic Polarization Under The Action Of An Electric Field, Hui Zhao

Mechanical Engineering Faculty Research

A continuum model is developed to predict the dielectrophoretic polarizability of coiled DNA molecules under the action of an alternating current electric field. The model approximates the coiled DNA molecule as a charged porous spherical particle. The model explains the discrepancies among scaling laws of polarizability of different-sized DNA molecules with contour length and such discrepancies are attributed to different hydrodynamic behavior. With zero or one fitting parameter, theoretical predictions are in good agreement with various experimental data, even though in experiments there are some uncertainties in regard to certain parameters.

Analysis Of The Genetic Structure Of Bithynia Tentaculata Snail Populations In Wisconsin And Minnesota, Sarah J. Whalen

All Graduate Theses, Dissertations, and Other Capstone Projects

In recent years, there have been tens of thousands of waterfowl mortalities in Wisconsin and Minnesota. An invasive species of snail, Bithynia tentaculata, is a host for the trematode parasites (Cyathocotyle bushiensis and Sphaeridiotrema globulus) that have caused these deaths. A microsatellite-enriched genomic library was detected using DNA from a B. tentaculata specimen from Lake Onalaska (Pool 7 of the Upper Mississippi River). Seven polymorphic microsatellite loci were used to genotype snails collected from Lake Butte des Morts, Shawano Lake, and Lake Onalaska in Wisconsin, as well as Lake Winnibigoshish in Minnesota. The genetic diversity of each population was measured …

Computational Network Analysis Of The Anatomical And Genetic Organizations In The Mouse Brain, Shuiwang Ji

Computer Science Faculty Publications

Motivation: The mammalian central nervous system (CNS) generates high-level behavior and cognitive functions. Elucidating the anatomical and genetic organizations in the CNS is a key step toward understanding the functional brain circuitry. The CNS contains an enormous number of cell types, each with unique gene expression patterns. Therefore, it is of central importance to capture the spatial expression patterns in the brain. Currently, genome-wide atlas of spatial expression patterns in the mouse brain has been made available, and the data are in the form of aligned 3D data arrays. The sheer volume and complexity of these data pose significant challenges …

From Dna To Protein: A Study Of Genomic Instability Candidate Genes During Zebrafish Development, Kristine Griffett

USF Tampa Graduate Theses and Dissertations

The zebrafish, Danio rerio, is a type of freshwater minnow often used to model human diseases including cancer, anxiety and aging diseases. The overall biology of zebrafish is strikingly similar to that of humans, allowing these fish to be used for drug discovery and toxicology studies for preclinical trials. In this study, zebrafish embryos were used to identify and characterize several candidate genes within two known regions of genomic instability on chromosome 18 and chromosome 4. This fish that were used in this study had been previously classified as genomic instability (gin) mutants due to increased incidence of somatic mutation …

Population Genetics Of Amphiuma Means And Siren Lacertina In Central Florida, Anna C. Deyle

USF Tampa Graduate Theses and Dissertations

Population structure can be defined as a difference in the frequencies of alleles among populations, and it is often caused by barriers to dispersal. I used mitochondrial DNA sequences to examine the population structure of two large, aquatic salamanders, Amphiuma means (the Two-Toed Amphiuma) and Siren lacertina (the Greater Siren), at two spatial scales in peninsular Florida. Both species appear to have similar life histories, including poor dry land dispersal capabilities, and I hypothesized that they would exhibit significant population structure at both broad and fine scales. Wetland loss and landscape fragmentation are certain to have caused decreases in abundance …

Capturing Changes In Gene Expression Dynamics By Gene Set Differential Coordination Analysis, Tianwei Yu, Yun Bai

PCOM Scholarly Works

Analyzing gene expression data at the gene set level greatly improves feature extraction and data interpretation. Currently most efforts in gene set analysis are focused on differential expression analysis - finding gene sets whose genes show first-order relationship with the clinical outcome. However the regulation of the biological system is complex, and much of the change in gene expression dynamics do not manifest in the form of differential expression. At the gene set level, capturing the change in expression dynamics is difficult due to the complexity and heterogeneity of the gene sets. Here we report a systematic approach to detect …

Population And Conservation Genetics Of Crawfish Frogs, Lithobates Areolatus, At Their Northeastern Range Limits, Schyler O. Nunziata

Online Theses and Dissertations

Crawfish Frogs (Lithobates areolatus) are state endangered in Indiana and Iowa, with populations in decline throughout their range. I studied populations of Crawfish Frogs on local and statewide scales at their northeastern range limits to (1) assess the level of genetic diversity within populations (2) estimate fine-scale genetic structure, and (3) estimate genetic differentiation between populations at the state level. Crawfish Frogs breed in temporary pools and wetlands, and have high breeding-pond fidelity; therefore I predicted to find genetic differences between ponds at small geographic scales. I used 10 microsatellite loci to genotype frogs collected from three primary populations in …