Genetics and Genomics Commons^™

Native And European Haplotypes Of Phragmites Australis (Common Reed) In The Central Platte River, Nebraska, Diane L. Larson, Susan M. Galatowitsch, Jennifer L. Larson

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Phragmites australis (common reed) is known to have occurred along the Platte River historically, but recent rapid increases in both distribution and density have begun to impact habitat for migrating sandhill cranes and nesting piping plovers and least terns. Invasiveness in Phragmites has been associated with the incursion of a European genotype (haplotype M) in other areas; determining the genotype of Phragmites along the central Platte River has implications for proper management of the river system. In 2008 we sampled Phragmites patches along the central Platte River from Lexington to Chapman, NE, stratified by bridge segments, to determine the current …

Sequencing Of A Qtl-Rich Region Of The Theobroma Cacao Genome Using Pooled Bacs And The Identification Of Trait Specific Candidate Genes, Frank A. Feltus, Christopher Saski, Keithanne Mockaitis, Niina Haiminen, Laxmi Parida, Zachary Smith, James Ford, Margaret E. Staton, Stephen P. Ficklin, Barbara P. Blackmon, Chun-Huai Cheng, Raymond J. Schnell, David N. Kuhn, Juan-Carlos Motamayor

Publications

BAC-based physical maps provide for sequencing across an entire genome or a selected sub-genomic region of biological interest. Such a region can be approached with next-generation whole-genome sequencing and assembly as if it were an independent small genome. Using the minimum tiling path as a guide, specific BAC clones representing the prioritized genomic interval are selected, pooled, and used to prepare a sequencing library.

New Genomic Resources For Switchgrass: A Bac Library And Comparative Analysis Of Homoeologous Genomic Regions Harboring Bioenergy Traits, Christopher Saski, Zhigang Li, Frank A. Feltus, Hong Luo

Publications

Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18) to duodecaploid (12X = 108). Like in other large, repeat-rich plant genomes, this genomic complexity …

Beyond Structural Genomics: Computational Approaches For The Identification Of Ligand Binding Sites In Protein Structures, Dario Ghersi, Roberto Sanchez

Interdisciplinary Informatics Faculty Publications

t Structural genomics projects have revealed structures for a large number of proteins of unknown function. Understanding the interactions between these proteins and their ligands would provide an initial step in their functional characterization. Binding site identification methods are a fast and cost-effective way to facilitate the characterization of functionally important protein regions. In this review we describe our recently developed methods for binding site identification in the context of existing methods. The advantage of energy-based approaches is emphasized, since they provide flexibility in the identifi- cation and characterization of different types of binding sites

Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens

Biology Faculty Publications

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with …

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

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

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …

Phylogeography Of The Reef Fish Cephalopholis Argus(Epinephelidae) Indicates Pleistocene Isolation Across The Indo-Pacific Barrier With Contemporary Overlap In The Coral Triangle, Michelle R. Gaither, Brian W. Bowen, Tiana-Rae Bordenave, Luiz A. Rocha, Stephen J. Newman, Juan A. Gomez, Lynne Van Herwerden, Matthew T. Craig

Fisheries Research Articles

Background

The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein).

Results

Population structure was significant …

Generation Of A Kupffer Cell-Evading Adenovirus For Systemic And Liver-Directed Gene Transfer, Reeti Khare, Shannon M. May, Francesco Vetrini, Eric A. Weaver, Donna Palmer, Amanda Rosewell, Nathan Grove, Philip Ng, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

As much as 90% of an intravenously (i.v.) injected dose of adenovirus serotype 5 (Ad5) is absorbed and destroyed by liver Kupffer cells. Viruses that escape these cells can then transduce hepatocytes after binding factor X (FX). Given that interactions with FX and Kupffer cells are thought to occur on the Ad5 hexon protein, we replaced its exposed hypervariable regions (HVR) with those from Ad6. When tested in vivo in BALB/c mice and in hamsters, the Ad5/6 chimera mediated >10 times higher transduction in the liver. This effect was not due to changes in FX binding. Rather, Ad5/6 appeared to …

Bonobos Fall Within The Genomic Variation Of Chimpanzees, Anne Fischer, Kay Prüfer, Jeffrey M. Good, Michel Halbwax, Victor Wiebe, Claudine André, Rebeca Atencia, Lawrence Mugisha, Susan E. Ptak, Svante Pääbo

All Peer-Reviewed Publications

To gain insight into the patterns of genetic variation and evolutionary relationships within and between bonobos and chimpanzees, we sequenced 150,000 base pairs of nuclear DNA divided among 15 autosomal regions as well as the complete mitochondrial genomes from 20 bonobos and 58 chimpanzees. Except for western chimpanzees, we found poor genetic separation of chimpanzees based on sample locality. In contrast, bonobos consistently cluster together but fall as a group within the variation of chimpanzees for many of the regions. Thus, while chimpanzees retain genomic variation that predates bonobo-chimpanzee speciation, extensive lineage sorting has occurred within bonobos such that much …

A Bayesian Model Averaging Approach For Observational Gene Expression Studies, Xi Kathy Zhou, Fei Liu, Andrew J. Dannenberg

COBRA Preprint Series

Identifying differentially expressed (DE) genes associated with a sample characteristic is the primary objective of many microarray studies. As more and more studies are carried out with observational rather than well controlled experimental samples, it becomes important to evaluate and properly control the impact of sample heterogeneity on DE gene finding. Typical methods for identifying DE genes require ranking all the genes according to a pre-selected statistic based on a single model for two or more group comparisons, with or without adjustment for other covariates. Such single model approaches unavoidably result in model misspecification, which can lead to increased error …

Metagenomic Biomarker Discovery And Explanation, Nicola Segata, Jacques Izard, Levi Waldron, Dirk Gevers, Larisa Miropolsky, Wendy S. Garrett, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

This study describes and validates a new method for metagenomic biomarker discovery by way of class comparison, tests of biological consistency and effect size estimation. This addresses the challenge of finding organisms, genes, or pathways that consistently explain the differences between two or more microbial communities, which is a central problem to the study of metagenomics. We extensively validate our method on several microbiomes and a convenient online interface for the method is provided at http://huttenhower.sph.harvard.edu/lefse/.

Includes supplemental materials.

Component Extraction Of Complex Biomedical Signal And Performance Analysis Based On Different Algorithm, Hemant Pasusangai Kasturiwale

Johns Hopkins University, Dept. of Biostatistics Working Papers

Biomedical signals can arise from one or many sources including heart ,brains and endocrine systems. Multiple sources poses challenge to researchers which may have contaminated with artifacts and noise. The Biomedical time series signal are like electroencephalogram(EEG),electrocardiogram(ECG),etc The morphology of the cardiac signal is very important in most of diagnostics based on the ECG. The diagnosis of patient is based on visual observation of recorded ECG,EEG,etc, may not be accurate. To achieve better understanding , PCA (Principal Component Analysis) and ICA algorithms helps in analyzing ECG signals . The immense scope in the field of biomedical-signal processing Independent Component Analysis( …

Role Of Phosphoinositide 3-Kinase – Akt Signaling Pathway In The Age-Related Cytokine Dysregulation In Splenic Macrophages Stimulated Via Tlr-2 Or Tlr-4 Receptors, Mosoka Papa Fallah, R. Lakshman Chelvarajan, Beth A. Garvy, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Age-associated defects in both B-lymphocytes and macrophages in elderly result in a reduction in the efficacy of vaccines to many Gram positive bacteria like Streptococcus pneumoniae. Splenic macrophages from aged mice have been shown to have a defect in production of pro-inflammatory cytokines (IL-6, IL-12, IL-1β, TNF-α) but exhibit increased production of IL-10 upon TLR4 ligation. Here we showed that aged macrophages demonstrate similar cytokine dysregulation phenotype upon stimulation with TLR2 ligands, or killed S. pneumoniae. We hypothesized that an age-associated increase in activity of phosphatidyl inositol 3-kinase (PI3K)-Akt signaling pathway may be playing a causal role in …

Rna Interference In Marine And Freshwater Sponges: Actin Knockdown In Tethya Wilhelma And Ephydatia Muelleri By Ingested Dsrna Expressing Bacteria, Ajna S. Rivera, April L. Hill, Et. Al.

Biology Faculty Publications

Background: The marine sponge Tethya wilhelma and the freshwater sponge Ephydatia muelleri are emerging model organisms to study evolution, gene regulation, development, and physiology in non-bilaterian animal systems. Thus far, functional methods (i.e., loss or gain of function) for these organisms have not been available.

Results: We show that soaking developing freshwater sponges in double-stranded RNA and/or feeding marine and freshwater sponges bacteria expressing double-stranded RNA can lead to RNA interference and reduction of targeted transcript levels. These methods, first utilized in C. elegans, have been adapted for the development and feeding style of easily cultured marine and freshwater poriferans. …

The Human Gut Microbiome: Ecology And Recent Evolutionary Changes, Jens Walter, Ruth Ley

Department of Food Science and Technology: Faculty Publications

The human gastrointestinal tract is divided into sections, allowing digestion and nutrient absorption in the proximal region to be separate from the vast microbial populations in the large intestine, thereby reducing conflict between host and microbes. In the distinct habitats of the gut, environmental filtering and competitive exclusion between microbes are the driving factors shaping microbial diversity, and stochastic factors during colonization history and in situ evolution are likely to introduce intersubject variability. Adaptive strategies of microbes with different niches are genomically encoded: Specialists have smaller genomes than generalists, and microbes with environmental reservoirs have large accessory genomes. A shift …

Evolutionary Patterns In Deep-Sea Mollusks, Elizabeth Ellen Boyle

Graduate Doctoral Dissertations

The evolution of deep-sea fauna is poorly known. We know little about the scales of population differentiation, radiation and colonization of the deep sea. This dissertation explores evolution in the deep sea at the level of population differentiation on ocean-wide scales in a gastropod species Benthonella tenella and phylogeny of a deep-sea subfamily of protobranch bivalves, Ledellinae. While working on the phylogeny of the Ledellinae the presence of mitochondrial heteroplasmy was discovered.

Genetic variation was quantified within and among populations of deep-sea gastropod Benthonella tenella to identify the extent of population differentiation and potential mechanisms that might isolate gene pools. …

Removing Technical Variability In Rna-Seq Data Using Conditional Quantile Normalization, Kasper D. Hansen, Rafael A. Irizarry, Zhijin Wu

Johns Hopkins University, Dept. of Biostatistics Working Papers

The ability to measure gene expression on a genome-wide scale is one of the most promising accomplishments in molecular biology. Microarrays, the technology that first permitted this, were riddled with problems due to unwanted sources of variability. Many of these problems are now mitigated, after a decade’s worth of statistical methodology development. The recently developed RNA sequencing (RNA-seq) technology has generated much excitement in part due to claims of reduced variability in comparison to microarrays. However, we show RNA-seq data demonstrates unwanted and obscuring variability similar to what was first observed in microarrays. In particular, we find GC-content has a …

Recombination Phenotypes Of The Nci-60 Collection Of Human Cancer Cells, Dawn M. Stults, Michael W. Killen, Brent J. Shelton, Andrew J. Pierce

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: The NCI-60 is a collection of tumor cell lines derived from a variety of human adult cancer tissue types and is commonly used for genetic analysis and screening of potential chemotherapeutic agents. We wanted to understand the contributions of specific mechanisms of genomic instability to the etiology of cancers represented by the NCI-60.

RESULTS: We screened the NCI-60 for dysregulated homologous recombination by using the gene cluster instability (GCI) assay we pioneered, and for defects in base excision repair by sensitivity to 5-hydroxymethyl-2'-deoxyuridine (hmdUrd). We identified subsets of the NCI-60 lines that either displayed the characteristic molecular signature of …

Expression Analysis Of The Imprinted Gene Transketolase-Like 1 In Mouse And Human, Amy F. Friss

Master's Theses

Genomic imprinting is an epigenetic phenomenon resulting in differential gene expression based on parental origin. Recently, transketolase-like 1 (TKTL1) has been identified as an X-linked imprinted gene. TKTL1 functions in the nonoxidative branch of the pentose phosphate pathway (PPP), which maintains glutathione in a reduced state through the generation of NADPH. Previous studies on transaldolase, the other critical enzyme in the nonoxidative branch of the PPP, suggest that TKTL1 may affect the cell’s ability to reduce glutathione. This study provides evidence that TKTL1 overexpression inhibits glutathione reduction. Intriguingly, aberrant glutathione levels are associated with autism. Additionally, studies involving …

Phylogeography Of The Polychaete Phragmatopoma Californica (Family Sabellarididae) In The Southern California Bight (Scb), Praneeth Kamana

Student Theses and Dissertations

This study measured the genetic differentiation among populations of Phragmatopoma californica and compared this genetic structuring with another polychaete species (Neries grubei) having a different life history. A total of 234 samples from 13 populations of the sabelleriid polychaete Phragmatapoma californica (Fewkes) from six mainland sites along the southern California coast and two Channel Islands were studied by way of inter simple sequence repeats (ISSRs) to determine genetic diversity, divergence and to estimate gene flow among populations. The results were compared to another polycheate species, Neries grubei which has a shorter larval development than P. californica, reducing potential dispersal and …

Drosophila Model For Fetal Alcohol Syndrome Disorders: Role For The Insulin Pathway, Rachael L. French, K D. Mcclure, U Heberlein

Faculty Publications, Biological Sciences

Prenatal exposure to ethanol in humans results in a wide range of developmental abnormalities, including growth deficiency, developmental delay, reduced brain size, permanent neurobehavioral abnormalities and fetal death. Here we describe the use of Drosophila melanogaster as a model for exploring the effects of ethanol exposure on development and behavior. We show that developmental ethanol exposure causes reduced viability, developmental delay and reduced adult body size. We find that flies reared on ethanol-containing food have smaller brains and imaginal discs, which is due to reduced cell division rather than increased apoptosis. Additionally, we show that, as in mammals, flies reared …

Construction Of Papaya Male And Female Bac Libraries And Application In Physical Mapping Of The Sex Chromosomes, Andrea R. Gschwend, Qingyi Yu, Paul Moore, Christopher Saski, Cuixia Chen, Jianping Wang, Jong-Kuk Na, Ray Ming

Publications

Papaya is a major fruit crop in the tropics and has recently evolved sex chromosomes. Towards sequencing the papaya sex chromosomes, two bacterial artificial chromosome (BAC) libraries were constructed from papaya male and female genomic DNA. The female BAC library was constructed using restriction enzyme BstY I and consists of 36,864 clones with an average insert size of 104 kb, providing 10.3x genome equivalents. The male BAC library was constructed using restriction enzyme EcoR I and consists of 55,296 clones with an average insert size of 101 kb, providing 15.0x genome equivalents. The male BAC library was used in constructing …

Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, Bernadette Ferraro, Loree C. Heller, Yolmari L. Cruz, Siqi Guo, Amy Donate, Richard Heller

Bioelectrics Publications

Electroporation (EP) is a simple in vivo method to deliver normally impermeable molecules, such as plasmid DNA, to a variety of tissues. Delivery of plasmid DNA by EP to a large surface area is not practical because the distance between the electrode pairs, and therefore the applied voltage, must be increased to effectively permeabilize the cell membrane. The design of the multielectrode array (MEA) incorporates multiple electrode pairs at a fixed distance to allow for delivery of plasmid DNA to the skin, potentially reducing the sensation associated with in vivo EP. In this report, we evaluate the effects of field …

The Basis And Implications Of Genetic Counseling In Patient Testing Choice, Yanina Tovpeko

Renée Crown University Honors Thesis Projects - All

Perinatal genetic counseling is a health service provided to patients who carry risk factors for genetic abnormalities for their offspring. There are several non-invasive and invasive tests offered to patients in order to provide genetic information about possible disorders. The non-invasive screens calculate a percentage of risk relative to average population risk. If the non-invasive screens predict an elevated risk, a more invasive test can be offered to obtain definitive results about possible disorders in the pregnancy. The most commonly used invasive test is called amniocentesis and it carries a risk for pregnancy complications. After receiving abnormal results on the …

Analysis Of Long-Term Selection (28 Generations) For Reproduction, Growth, And Carcass Traits In Swine, Wan-Ling Hsu

Department of Animal Science: Dissertations, Theses, and Student Research

The objectives were 1) to estimate responses from 28 generations of selection for increased pigs born alive (BA) with additional selection for increased 180 d weight (WT) and longissimus muscle area (LMA) and decreased backfat (BF) in the last eight generations, 2) to estimate genetic parameters for an array of traits, and 3) to investigate whether a plateau in response for BA has occurred. All lines were derived from the same Large White/Landrace composite population. Index selection for ovulation rate and embryo survival (G0-11) was initiated in L2 in 1981; L1 was selected randomly control line for L2 (G0-23). L2 …

Population Genetics Of The Western Bean Cutworm (Striacosta Albicosta Smith) Across The United States, Erica Lindroth

Department of Entomology: Dissertations, Theses, and Student Research

The western bean cutworm, Striacosta albicosta (Smith), is a secondary pest of maize (Zea mays L.) and dry beans (Phaseolus vulgaris L.) in the western United States. Recently, this insect has undergone a major territory expansion into the eastern US and has become a pest throughout much of the Corn Belt. This study was instigated to examine the population genetics of this pest to facilitate control and resistance management, as well as to shed light on the current habitat expansion. To this end, western bean cutworm individuals were collected from 28 different locations across the traditional and expanded …

Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell

Biology Faculty Publications

Background: Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.

Methods: The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the …

Endo-Porter–Mediated Delivery Of Phosphorodiamidate Morpholino Oligos (Pmos) In Erythrocyte Suspension Cultures From Cope's Gray Treefrog Hyla Chrysoscelis, Venkateshwar Mutyam, Matthew V. Puccetti, James Frisbie, David L. Goldstein, Carissa M. Krane

Biology Faculty Publications

Cope's gray treefrog, Hyla chrysoscelis, is a freeze-tolerant anuran that accumulates cryoprotective glycerol during cold acclimation. H. chrysoscelis erythrocytes express the aquaglyceroporin HC-3, which facilitates transmembrane glycerol and water movement. Aquaglyceroporins have no pharmacological inhibitors, and no genetic knockout tools currently exist for H. chrysoscelis. A phosphorodiamidate morpholino oligo (PMO)–mediated expression knockdown approach was therefore pursued to provide a model for testing the role of HC-3. We describe a novel procedure optimized for specific, efficient knockdown of HC-3 expression in amphibian erythrocyte suspensions cultured at nonmammalian physiological temperatures using Endo-Porter. Our protocol includes three critical components: pre-incubation at 37°C, …

Microarray Data Mining And Gene Regulatory Network Analysis, Ying Li

Dissertations

The novel molecular biological technology, microarray, makes it feasible to obtain quantitative measurements of expression of thousands of genes present in a biological sample simultaneously. Genome-wide expression data generated from this technology are promising to uncover the implicit, previously unknown biological knowledge. In this study, several problems about microarray data mining techniques were investigated, including feature(gene) selection, classifier genes identification, generation of reference genetic interaction network for non-model organisms and gene regulatory network reconstruction using time-series gene expression data. The limitations of most of the existing computational models employed to infer gene regulatory network lie in that they either suffer …

Expression And Purification Of Recombinant Hemoglobin In Escherichia Coli, Chandrasekhar Natarajan, Xiaoben Jiang, Angela Fago, Roy E. Weber, Hideaki Moriyama, Jay F. Storz

Jay F. Storz Publications

Background: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe a protocol for expressing Hbs with low intrinsic solubilities. Since the alpha- and beta-chain Hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing recombinant human HbA may often prove unsuitable for the recombinant expression of wildtype and mutant Hbs of other species.

Methodology/Principal Findings: As a test case …