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2011

University of Nebraska - Lincoln

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Articles 1 - 30 of 31

Full-Text Articles in Biology

Abiotic Stress Responses In Photosynthetic Organisms, Joseph Msanne Dec 2011

Abiotic Stress Responses In Photosynthetic Organisms, Joseph Msanne

School of Natural Resources: Dissertations, Theses, and Student Research

Cellular and molecular aspects of abiotic stress responses in Arabidopsis thaliana subjected to cold, drought, and high salinity and in two photosynthetic green alga, Chlamydomonas reinhardtii and Coccomyxa sp. C-169, subjected to nitrogen deprivation were investigated. Cold, drought, and high salinity can negatively affect plant growth and crop production. The first research aimed at determining the physiological functions of the stress-responsive Arabidopsis thaliana RD29A and RD29B genes. Cold, drought, and salt induced both genes; the promoter of RD29Awas found to be more responsive to drought and cold stresses, whereas the promoter of RD29B was highly responsive to salt stress. …


Prey Selection By The Northern Watersnake, Nerodia Sipedon, Kyle O' Connell Dec 2011

Prey Selection By The Northern Watersnake, Nerodia Sipedon, Kyle O' Connell

Department of Environmental Studies: Undergraduate Student Theses

Prey selection and composition of the northern waternake, Nerodia sipedon was investigated between 8/2010 and 3/2011 by palpation of stomach contents in the field and conducting laboratory trials. 41 snakes were captured, five yielded prey contents. Fish parts, freshwater mussels, and an insect exoskeleton were found. No amphibians were found despite availability at study sites. Snakes in the laboratory underwent 22 trials, feeding on 11 occasions. Snakes fed on an equal number of both fish species, revealing no selection. Further research is needed to determine the rate of digestion of N. sipedon.


Gravesoil Microbial Community Structure During Carcass Decomposition, Amy E. Maile Nov 2011

Gravesoil Microbial Community Structure During Carcass Decomposition, Amy E. Maile

Department of Entomology: Dissertations, Theses, and Student Research

Dead bodies placed on soil represent unique challenges for investigators. Although processes in soils can be used to estimate postmortem interval, we know very little about how carcasses and insects affect gravesoil microbial communities.

To address this, the current project was composed of two experiments. Experiment one was conducted to investigate the effect of surface type on carcass decomposition and evaluate soil ecology methods. Experiment two was conducted to investigate the presence of an insect population (Lucilia sericata Meigen) on gravesoil microbial communities. Both experiments were conducted in a laboratory setting using freshly killed mouse carcasses. Mouse carcasses were …


Avian Influenza In Migratory Birds In The United States, 2007–2009, And Effects Of September Hunting Seasons On Survival, Harvest, And Recovery Rates Of Canada Geese Banded In Southeast Nebraska, Scott R. Groepper Aug 2011

Avian Influenza In Migratory Birds In The United States, 2007–2009, And Effects Of September Hunting Seasons On Survival, Harvest, And Recovery Rates Of Canada Geese Banded In Southeast Nebraska, Scott R. Groepper

School of Natural Resources: Dissertations, Theses, and Student Research

Highly-pathogenic avian influenza virus (HPAIV H5N1) poses risks to wild birds, poultry, and humans. Personnel with the United States Department of Agriculture-Animal Plant Health Inspection Service-Wildlife Services, state, and tribal wildlife agencies collected 168,940 samples from migratory birds from 2007 to 2009 to test for presence of HPAIV H5N1. No HPAIV was found, but other subtypes were discovered, including H5 and H7. I estimated prevalence of avian influenza virus by flyway and found prevalence was lowest each year in the Atlantic Flyway (6.7%–8.3%), highest in the Pacific Flyway in 2007 (13.3%) and 2008 (13.4%), and highest in the Mississippi Flyway …


Exploring Sources Of Selection On The Multimodal Courtship Displays Of Two Sister Species Of Wolf Spiders: Schizocosa Crassipalpata And Schizocosa Bilineata, Mitch Bern Jul 2011

Exploring Sources Of Selection On The Multimodal Courtship Displays Of Two Sister Species Of Wolf Spiders: Schizocosa Crassipalpata And Schizocosa Bilineata, Mitch Bern

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

We examined multiple sources of selection on the multimodal courtship display of two sister species of wolf spiders, Schizocosa crassipalpata and Schizocosa bilineata. We first experimentally altered body condition in these two species by employing divergent diet treatments. We then tested for differences in adult male seismic courtship displays, visual courtship displays, and foreleg morphology; as well as adult female foreleg morphology. We then simultaneously examined both content and efficacy-based sources of selection on the visual and seismic multimodal courtship display of both species by conducting mate choice trials with high and low diet individuals across manipulated signaling environments …


The Effects Of Social Context & Cache Survival On Pinyon Jay Caching Behavior, Christine L. Keefe Jul 2011

The Effects Of Social Context & Cache Survival On Pinyon Jay Caching Behavior, Christine L. Keefe

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

I examined how pinyon jays (Gymnorhinus cyanocephalus) assess and determine the risk of pilferage to their caches. Jays were allowed to cache in an open room while alone or while being observed by a conspecific. In a counterbalanced design, jays cached in the opposite treatment once they had finished recovering their caches. I compared birds’ behaviors between treatments in order to determine whether jays consider the presence of an observer in measuring the local competitive environment. Once all jays had completed alone- and observed- treatments, I ran the experiment once more to determine if individuals were consistent in …


Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown May 2011

Natural Selection And Age-Related Variation In Morphology Of A Colonial Bird, Mary Bomberger Brown

School of Natural Resources: Dissertations, Theses, and Student Research

In May 1996, inclement weather led to the deaths of thousands of Cliff Swallows (Petrochelidon pyrrhonota) in Nebraska. Survivors had larger skeletons, shorter wings and tails, and less wing asymmetry than non-survivors. This population was followed for 10 years to study 1) whether natural selection events result in permanent microevolutionary changes, 2) if variation in climate affects the development of morphological traits, and 3) if morphological traits vary systematically with age.

Patterns in morphology exhibited by swallows following the selection event were studied by measuring yearling birds. Wing and middle tail lengths decreased, beak length and width increased, …


Functional Classification Of Divergent Protein Sequences And Molecular Evolution Of Multi-Domain Proteins, Pooja K. Strope May 2011

Functional Classification Of Divergent Protein Sequences And Molecular Evolution Of Multi-Domain Proteins, Pooja K. Strope

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

Transmembrane proteins and multi-domain proteins together make up more than 80% of the total proteins in any eukaryotic proteome. Therefore accurately classifying such proteins into functional classes is an important task. Furthermore, understanding the molecular evolution of multi-domain proteins is important because it shows how various domains fuse to form more complex proteins, and acquire new functions possibly affecting the organismal level of evolution. In this thesis, I first investigated the performance of several protein classifiers using one of the most divergent transmembrane protein families, the G-protein-coupled receptor (GPCR) superfamily, as an example. Alignment-free classifiers based on support vector machines …


Multilocus And Parametric Analyses Of The Evolutionary History Of The Amazonian Peacock Cichlids, The Genus Cichla (Teleostei: Cichlidae), Stuart Willis Apr 2011

Multilocus And Parametric Analyses Of The Evolutionary History Of The Amazonian Peacock Cichlids, The Genus Cichla (Teleostei: Cichlidae), Stuart Willis

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

Accurate knowledge of species boundaries and species phylogeny are fundamental to testing hypotheses of recent evolutionary processes, but the estimation of these partitions is challenging due both to inherent confusion about what is being estimated as well as the data available to estimate them. Using multilocus data from mtDNA, microsatellites, and nuclear locus sequences of over 1100 individuals, we delimited eight separately evolving species of Cichla rather than the 15 described. Among species we found evidence of rare but widespread introgressive hybridization, while within these species we observed evidence of long-term gene exchange and constrained evolutionary trajectories. In most cases …


Protection Against Divergent Influenza H1n1 Virus By A Centralized Influenza Hemagglutinin, Eric A. Weaver, Adam M. Rubrum, Richard J. Webby, Michael A. Barry Mar 2011

Protection Against Divergent Influenza H1n1 Virus By A Centralized Influenza Hemagglutinin, Eric A. Weaver, Adam M. Rubrum, Richard J. Webby, Michael A. Barry

School of Biological Sciences: Faculty Publications

Influenza poses a persistent worldwide threat to the human population. As evidenced by the 2009 H1N1 pandemic, current vaccine technologies are unable to respond rapidly to this constantly diverging pathogen. We tested the utility of adenovirus (Ad) vaccines expressing centralized consensus influenza antigens. Ad vaccines were produced within 2 months and protected against influenza in mice within 3 days of vaccination. Ad vaccines were able to protect at doses as low as 107 virus particles/kg indicating that approximately 1,000 human doses could be rapidly generated from standard Ad preparations. To generate broadly cross-reactive immune responses, centralized consensus antigens were constructed …


Assessment Of Pathways For The Introduction And Spread Of Mycobacterium Bovis In The United States, Katie Portacci, Jason Lombard, Lauren Abrahamsen, Eric Bush, Charles Fossler, Robert Harris, Kamina Johnson, Ryan S. Miller, Dianna Mitchell, Randy Pritchard, Steven Sweeney, Todd Weaver Mar 2011

Assessment Of Pathways For The Introduction And Spread Of Mycobacterium Bovis In The United States, Katie Portacci, Jason Lombard, Lauren Abrahamsen, Eric Bush, Charles Fossler, Robert Harris, Kamina Johnson, Ryan S. Miller, Dianna Mitchell, Randy Pritchard, Steven Sweeney, Todd Weaver

Other Publications in Zoonotics and Wildlife Disease

Bovine tuberculosis (TB) was responsible for more losses among U.S. farm animals in the early 20th century than all other infectious diseases combined. The Cooperative State-Federal Tuberculosis Eradication Program (established in 1917 and administered by APHIS, State animal health agencies, and U.S. livestock producers) has nearly eradicated bovine TB from the nation’s livestock population. However, despite the many accomplishments of the program, bovine TB remains a serious and costly disease of livestock in the United States. In 1992, VS conducted an assessment to identify pathways for the introduction and spread of bovine TB, in order to develop the most effective …


Real-Time Dynamic Imaging Of Virus Distribution In Vivo, Sean E. Hofherr, Kristen E. Adams, Christopher Y. Chen, Shannon May, Eric A. Weaver, Michael A. Barry Feb 2011

Real-Time Dynamic Imaging Of Virus Distribution In Vivo, Sean E. Hofherr, Kristen E. Adams, Christopher Y. Chen, Shannon May, Eric A. Weaver, Michael A. Barry

School of Biological Sciences: Faculty Publications

The distribution of viruses and gene therapy vectors is difficult to assess in a living organism. For instance, trafficking in murine models can usually only be assessed after sacrificing the animal for tissue sectioning or extraction. These assays are laborious requiring whole animal sectioning to ascertain tissue localization. They also obviate the ability to perform longitudinal or kinetic studies in one animal. To track viruses after systemic infection, we have labeled adenoviruses with a near-infrared (NIR) fluorophore and imaged these after intravenous injection in mice. Imaging was able to track and quantitate virus particles entering the jugular vein simultaneous with …


Maize Cellulosic Biofuels: Soil Carbon Loss Can Be A Hidden Cost Of Residue Removal, Amy Kochsiek, Johannes Knops Jan 2011

Maize Cellulosic Biofuels: Soil Carbon Loss Can Be A Hidden Cost Of Residue Removal, Amy Kochsiek, Johannes Knops

School of Biological Sciences: Faculty Publications

Second generation biofuels, like cellulosic ethanol, have potential as important energy sources that can lower fossil fuel carbon emissions without affecting global food commodity prices. Agricultural crop residues, especially maize, have been proposed for use as biofuel, but the net greenhouse warming effect of the gained fossil fuel carbon offset needs to account for any ecosystem carbon losses caused by the large-scale maize residue removal. Using differential 13C isotopic ratios between residue and soil in an incubation experiment, we found that removal of residue increased soil organic matter decomposition by an average of 16%, or 540–800 kg carbon ha -1. …


Aphids: A Model For Polyphenism And Epigenetics, Dayalan G. Srinivasan, Jennifer A. Brisson Jan 2011

Aphids: A Model For Polyphenism And Epigenetics, Dayalan G. Srinivasan, Jennifer A. Brisson

School of Biological Sciences: Faculty Publications

Environmental conditions can alter the form, function, and behavior of organisms over short and long timescales, and even over generations. Aphid females respond to specific environmental cues by transmitting signals that have the effect of altering the development of their offspring. These epigenetic phenomena have positioned aphids as a model for the study of phenotypic plasticity. The molecular basis for this epigenetic inheritance in aphids and how this type of inheritance system could have evolved are still unanswered questions. With the availability of the pea aphid genome sequence, new genomics technologies, and ongoing genomics projects in aphids, these questions can …


Analyses Of Fruit Flies That Do Not Express Selenoproteins Or Express The Mouse Selenoprotein, Methionine Sulfoxide Reductase B1, Reveal A Role Of Selenoproteins In Stress Resistance, Valentina A. Shchedrina, Hadise Kabil, Gerd Vorbruggen, Byung Cheon Lee, Anton A. Turanov, Mitsuko Hirosawa- Takamori, Hwa- Young Kim, Lawrence G. Harshman, Dolph L. Hatfield, Vadim N. Gladyshev Jan 2011

Analyses Of Fruit Flies That Do Not Express Selenoproteins Or Express The Mouse Selenoprotein, Methionine Sulfoxide Reductase B1, Reveal A Role Of Selenoproteins In Stress Resistance, Valentina A. Shchedrina, Hadise Kabil, Gerd Vorbruggen, Byung Cheon Lee, Anton A. Turanov, Mitsuko Hirosawa- Takamori, Hwa- Young Kim, Lawrence G. Harshman, Dolph L. Hatfield, Vadim N. Gladyshev

School of Biological Sciences: Faculty Publications

Selenoproteins are essential in vertebrates because of their crucial role in cellular redox homeostasis, but some invertebrates that lack selenoproteins have recently been identified. Genetic disruption of selenoprotein biosynthesis had no effect on lifespan and oxidative stress resistance of Drosophila melanogaster. In the current study, fruit flies with knock-out of the selenocysteine-specific elongation factor were metabolically labeled with 75Se; they did not incorporate selenium into proteins and had the same lifespan on a chemically defined diet with or without selenium supplementation. These flies were, however, more susceptible to starvation than controls, and this effect could be ascribed to the …


Characterization Of A Dipartite Iron Uptake System From Uropathogenic Escherichia Coli Strain, Doreen Koch, Anson C. K. Chan, Michael E.P. Murphy, Hauke Lilie, Gregor Grass, Dietrich H. Nies Jan 2011

Characterization Of A Dipartite Iron Uptake System From Uropathogenic Escherichia Coli Strain, Doreen Koch, Anson C. K. Chan, Michael E.P. Murphy, Hauke Lilie, Gregor Grass, Dietrich H. Nies

School of Biological Sciences: Faculty Publications

In the uropathogenic Escherichia coli strain F11, in silico genome analysis revealed the dicistronic iron uptake operon fetMP, which is under iron-regulated control mediated by the Fur regulator. The expression of fetMP in a mutant strain lacking known iron uptake systems improved growth under iron depletion and increased cellular iron accumulation. FetM is a member of the iron/lead transporter superfamily and is essential for iron uptake by the Fet system. FetP is a periplasmic protein that enhanced iron uptake by FetM. Recombinant FetP bound Cu(II) and the iron analog Mn(II) at distinct sites. The crystal structure of the …


Evolution And Personal Religious Belief: Christian University Biology-Related Majors’ Search For Reconciliation, Mark Winslow, John Staver, Lawrence C. Scharmann Jan 2011

Evolution And Personal Religious Belief: Christian University Biology-Related Majors’ Search For Reconciliation, Mark Winslow, John Staver, Lawrence C. Scharmann

Department of Teaching, Learning, and Teacher Education: Faculty Publications

The goal of this study was to explore Christian biology-related majors’ perceptions of conflicts between evolution and their religious beliefs. This naturalistic study utilized a case study design of 15 undergraduate biology-related majors at or recent biology-related graduates from a mid-western Christian university. The broad sources of data were interviews, course documents, and observations. Outcomes indicate that most participants were raised to believe in creationism, but came to accept evolution through evaluating evidence for evolution, negotiating the literalness of Genesis, recognizing evolution as a non-salvation issue, and observing professors as Christian role models who accept evolution. This study lends heuristic …


Crystallization Of Chlorella Deoxyuridine Triphosphatase, Laura Badalucco, Ishwari Poudel, Mamoru Yamanishi, Chandrasekhar Natarajan, Hideaki Moriyama Jan 2011

Crystallization Of Chlorella Deoxyuridine Triphosphatase, Laura Badalucco, Ishwari Poudel, Mamoru Yamanishi, Chandrasekhar Natarajan, Hideaki Moriyama

School of Biological Sciences: Faculty Publications

Deoxyuridine triphosphatase (dUTPase) is a ubiquitous enzyme that has been widely studied owing to its function and evolutionary significance. The gene coding for the dUTPase from the Chlorella alga was codon-optimized and synthesized. The synthetic gene was expressed in Escherichia coli and recombinant core Chlorella dUTPase (chdUTPase) was purified. Crystallization of chdUTPase was performed by the repetitive hanging-drop vapor-diffusion method at 298 K with ammonium sulfate as the precipitant. In the presence of 2'-deoxyuridine-5'-[(α,β)-imido]triphosphate and magnesium, the enzyme produced die-shaped hexagonal R3 crystals with unit-cell parameters a = b = 66.9, c = 93.6 A, ƴ = 120°. X-ray diffraction …


Interferon Regulatory Factor 4 (Irf-4) Targets Irf-5 To Regulate Epstein-Barr Virus Transformation, Dongsheng Xu, Florencia Meyer, Erica Ehlers, Laura Blasnitz, Luwen Zhang Jan 2011

Interferon Regulatory Factor 4 (Irf-4) Targets Irf-5 To Regulate Epstein-Barr Virus Transformation, Dongsheng Xu, Florencia Meyer, Erica Ehlers, Laura Blasnitz, Luwen Zhang

School of Biological Sciences: Faculty Publications

The cellular interferon regulatory factor-4 (IRF-4), which is a member of IRF family, is involved in the development of multiple myeloma and Epstein-Barr virus (EBV)-mediated transformation of B lymphocytes. However, the molecular mechanism of IRF-4 in cellular transformation is unknown. We have found that knockdown of IRF-4 leads to high expression of IRF-5, a pro-apoptotic member in the IRF family. Overexpression of IRF-4 represses IRF-5 expression. Reduction of IRF-4 leads to growth inhibition, and the restoration of IRF-4 by exogenous plasmids correlates with the growth recovery and reduces IRF-5 expression. In addition, IRF-4 negatively regulates IRF-5 promoter reporter activities and …


Epigenetic Regulatory Mechanisms In Plants, Zoya Avramova Jan 2011

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 Jan 2011

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 …


Arabidopsis G-Protein Interactome Reveals Connections To Cell Wall Carbohydrates And Morphogenesis, Karsten Klopffleisch, Nguyen Phan, Kelsey Augustin, Robert S. Bayne, Katherine S. Booker, Jose R. Botella, Nicholas C. Carpita, Tyrell Carr, Jin-Gui Chen, Thomas Ryan Cooke, Arwen Frick-Cheng, Erin J. Friedman, Brandon Fulk, Michael G. Hahn, Kun Jiang, Lucia Jorda, Lydia Kruppe, Chenggang Liu, Justine Lorek, Maureen C. Mccann, Antonio Molina, Etsuko N. Moriyama, M. Shahid Mukhtar, Yashwanti Mudgil, Sivakumar Pattathil, John Schwarz, Steven Seta, Matthew Tan, Ulrike Temp, Yuri Trusov, Daisuke Urano, Bastian Welter, Jing Yang, Ralph Panstruga, Joachim F. Uhrig, Alan M. Jones Jan 2011

Arabidopsis G-Protein Interactome Reveals Connections To Cell Wall Carbohydrates And Morphogenesis, Karsten Klopffleisch, Nguyen Phan, Kelsey Augustin, Robert S. Bayne, Katherine S. Booker, Jose R. Botella, Nicholas C. Carpita, Tyrell Carr, Jin-Gui Chen, Thomas Ryan Cooke, Arwen Frick-Cheng, Erin J. Friedman, Brandon Fulk, Michael G. Hahn, Kun Jiang, Lucia Jorda, Lydia Kruppe, Chenggang Liu, Justine Lorek, Maureen C. Mccann, Antonio Molina, Etsuko N. Moriyama, M. Shahid Mukhtar, Yashwanti Mudgil, Sivakumar Pattathil, John Schwarz, Steven Seta, Matthew Tan, Ulrike Temp, Yuri Trusov, Daisuke Urano, Bastian Welter, Jing Yang, Ralph Panstruga, Joachim F. Uhrig, Alan M. Jones

School of Biological Sciences: Faculty Publications

The heterotrimeric G-protein complex is minimally composed of Ga, Gb, and Gc subunits. In the classic scenario, the G-protein complex is the nexus in signaling from the plasma membrane, where the heterotrimeric G-protein associates with heptahelical G-protein-coupled receptors (GPCRs), to cytoplasmic target proteins called effectors. Although a number of effectors are known in metazoans and fungi, none of these are predicted to exist in their canonical forms in plants. To identify ab initio plant G-protein effectors and scaffold proteins, we screened a set of proteins from the G-protein complex using two-hybrid complementation in yeast. After deep and exhaustive interrogation, we …


Environmental And Genetic Perturbations Reveal Different Networks Of Metabolic Regulation, Anthony J. Greenberg, Sean R. Hacket, Lawrence G. Harshman, Andrew G. Clark Jan 2011

Environmental And Genetic Perturbations Reveal Different Networks Of Metabolic Regulation, Anthony J. Greenberg, Sean R. Hacket, Lawrence G. Harshman, Andrew G. Clark

School of Biological Sciences: Faculty Publications

Progress in systems biology depends on accurate descriptions of biological networks. Connections in a regulatory network are identified as correlations of gene expression across a set of environmental or genetic perturbations. To use this information to predict system behavior, we must test how the nature of perturbations affects topologies of networks they reveal. To probe this question, we focused on metabolism of Drosophila melanogaster. Our source of perturbations is a set of crosses among 92 wild-derived lines from five populations, replicated in a manner permitting separate assessment of the effects of genetic variation and environmental fluctuation. We directly assayed activities …


Sex Chromosome-Specific Regulation In The Drosophila Male Germline But Little Evidence For Chromosomal Dosage Compensation Or Meiotic Inactivation, Colin D. Meiklejohn, Emily L. Landeen, Jodi M. Cook, Sarah B. Kingan, Daven C. Presgraves Jan 2011

Sex Chromosome-Specific Regulation In The Drosophila Male Germline But Little Evidence For Chromosomal Dosage Compensation Or Meiotic Inactivation, Colin D. Meiklejohn, Emily L. Landeen, Jodi M. Cook, Sarah B. Kingan, Daven C. Presgraves

School of Biological Sciences: Faculty Publications

The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females) has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation—the equalization of X chromosome gene expression in males and females— and meiotic sex chromosome inactivation (MSCI)—the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female) germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from …


Normalization And Centering Of Array-Based Heterologous Genome Hybridization Based On Divergent Control Probes, Brian J. Darby, Kenneth L. Jones, David Wheeler, Michael A. Herman Jan 2011

Normalization And Centering Of Array-Based Heterologous Genome Hybridization Based On Divergent Control Probes, Brian J. Darby, Kenneth L. Jones, David Wheeler, Michael A. Herman

School of Biological Sciences: Faculty Publications

Background: Hybridization of heterologous (non-specific) nucleic acids onto arrays designed for model-organisms has been proposed as a viable genomic resource for estimating sequence variation and gene expression in nonmodel organisms. However, conventional methods of normalization that assume equivalent distributions (such as quantile normalization) are inappropriate when applied to non-specific (heterologous) hybridization. We propose an algorithm for normalizing and centering intensity data from heterologous hybridization that makes no prior assumptions of distribution, reduces the false appearance of homology, and provides a way for researchers to confirm whether heterologous hybridization is suitable.

Results: Data are normalized by adjusting for Gibbs free energy …


Dtorsin, The Drosophila Ortholog Of The Early-Onset Dystonia Tor1a (Dyt1), Plays A Novel Role In Dopamine Metabolism, Noriko Wakabayashi-Ito, Olugbenga M. Doherty, Hideaki Moriyama, Xandra O. Breakefield, James F. Gusella, Janis M. O’Donnell, Naoto Ito Jan 2011

Dtorsin, The Drosophila Ortholog Of The Early-Onset Dystonia Tor1a (Dyt1), Plays A Novel Role In Dopamine Metabolism, Noriko Wakabayashi-Ito, Olugbenga M. Doherty, Hideaki Moriyama, Xandra O. Breakefield, James F. Gusella, Janis M. O’Donnell, Naoto Ito

School of Biological Sciences: Faculty Publications

Dystonia represents the third most common movement disorder in humans. At least 15 genetic loci (DYT1-15) have been identified and some of these genes have been cloned. TOR1A (formally DYT1), the gene responsible for the most common primary hereditary dystonia, encodes torsinA, an AAA ATPase family protein. However, the function of torsinA has yet to be fully understood. Here, we have generated and characterized a complete loss-of-function mutant for dtorsin, the only Drosophila ortholog of TOR1A. Null mutation of the X-linked dtorsin was semi-lethal with most male flies dying by the prepupal stage and the few surviving …


Composite Effects Of Polymorphisms Near Multiple Regulatory Elements Create A Major-Effect Qtl, Ryan D. Bickel, Artyom Kopp, Sergey V. Nuzhdin Jan 2011

Composite Effects Of Polymorphisms Near Multiple Regulatory Elements Create A Major-Effect Qtl, Ryan D. Bickel, Artyom Kopp, Sergey V. Nuzhdin

School of Biological Sciences: Faculty Publications

Many agriculturally, evolutionarily, and medically important characters vary in a quantitative fashion. Unfortunately, the genes and sequence variants accounting for this variation remain largely unknown due to a variety of biological and technical challenges. Drosophila melanogaster contains high levels of sequence variation and low linkage disequilibrium, allowing us to dissect the effects of many causative variants within a single locus. Here, we take advantage of these features to identify and characterize the sequence polymorphisms that comprise major effect QTL alleles segregating at the bric-a-brac locus. We show that natural bric-a-brac alleles with large effects on cuticular pigmentation reflect a cumulative …


Copper Tolerance Of Saccharomyces Cerevisiae Nonsense-Mediated Mrna Decay Mutants, Rafael Deliz-Aguirre, Audrey L. Atkin, Bessie W. Kebaara Jan 2011

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, …


Some Laelapine Mites (Acari: Laelapidae) Ectoparasitic On Small Mammals In The Galapagos Islands, Including A New Species Of Gigantolaelaps From Aegialomys Galapagoensis, Donald D. Gettinger, Fernanda Martins-Hatano, Scott Lyell Gardner Jan 2011

Some Laelapine Mites (Acari: Laelapidae) Ectoparasitic On Small Mammals In The Galapagos Islands, Including A New Species Of Gigantolaelaps From Aegialomys Galapagoensis, Donald D. Gettinger, Fernanda Martins-Hatano, Scott Lyell Gardner

Scott L. Gardner Publications

A collection of laelapine mites from small mammals in the Galapagos Islands are identified and their host distributions reviewed. Two species of native rodents, Aegialomys galapagoensis and Nesoryzomys narboroughii, were infested only with species typical of Neotropical oryzomyine rodents; Rattus rattus was infested with Laelaps nuttalli, a host-specific ectoparasite to Old World Rattus. A synopsis of Gigantolaelaps Fonseca is provided and we describe a new laelapine mite, Gigantolaelaps aegialomys n. sp., from the pelage of the rodent A. galapagoensis on Santa Fe Island. The new species has strong morphological affinities with a subgroup of Gigantolaelaps associated with …


Survival Rates Of Planidial Larvae Of The Parasitoid Fly Ormia Ochracea (Diptera: Tachinidae), Oliver M. Beckers, Cassandra M. Martin, William E. Wagner Jr. Jan 2011

Survival Rates Of Planidial Larvae Of The Parasitoid Fly Ormia Ochracea (Diptera: Tachinidae), Oliver M. Beckers, Cassandra M. Martin, William E. Wagner Jr.

School of Biological Sciences: Faculty Publications

The tachinid fly, Ormia ochracea Bigot 1889, is a major parasitoid of field crickets in North America. The fly ranges from Florida to California, and it has also been introduced to Hawaii. Across this range, O. ochracea uses at least 6 different Gryllus species as hosts for its larvae (Cade, 1975; Walker, 1986; Walker and Wineriter, 1991; Zuk et al., 1993; Wagner, 1996; Hedrick and Kortet, 2006). O. ochracea finds it hosts by eavesdropping on male mating songs (Cade, 1975). The fly deposits up to 3 planidial larvae (Adamo et al., 1995a) directly on the male and these …