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Biological Sciences Faculty Publications

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Articles 1 - 30 of 31

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Dietary Protein Content And Digestibility Influences Discrimination Of Amino Acid Nitrogen Isotope Values In A Terrestrial Omnivorous Mammal, John P. Whiteman, Mauriel Rodriguez Curras, Kelli L. Feeser, Seth D. Newsome Jan 2021

Dietary Protein Content And Digestibility Influences Discrimination Of Amino Acid Nitrogen Isotope Values In A Terrestrial Omnivorous Mammal, John P. Whiteman, Mauriel Rodriguez Curras, Kelli L. Feeser, Seth D. Newsome

Biological Sciences Faculty Publications

RATIONALE: Ecologists increasingly determine the δ15N values of amino acids (AA) in animal tissue; "source" AA typically exhibit minor variation between diet and consumer, while "trophic" AA have increased δ15N values in consumers. Thus, trophic-source δ15N offsets (i.e., Δ15NT-S) reflect trophic position in a food web. However, even minor variation in δ15Nsource AA values may influence the magnitude of offset that represents a trophic step, known as the trophic discrimination factor (i.e., TDFT-S). Diet digestibility and protein content can influence the δ15N values …

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Scaling The Effects Of Ocean Acidification On Coral Growth And Coral-Coral Competition On Coral Community Recovery, Nicolas R. Evensen, Yves-Marie Bozec, Peter J. Edmunds, Peter J. Mumby Jan 2021

Scaling The Effects Of Ocean Acidification On Coral Growth And Coral-Coral Competition On Coral Community Recovery, Nicolas R. Evensen, Yves-Marie Bozec, Peter J. Edmunds, Peter J. Mumby

Biological Sciences Faculty Publications

Ocean acidification (OA) is negatively affecting calcification in a wide variety of marine organisms. These effects are acute for many tropical scleractinian corals under short-term experimental conditions, but it is unclear how these effects interact with ecological processes, such as competition for space, to impact coral communities over multiple years. This study sought to test the use of individual-based models (IBMs) as a tool to scale up the effects of OA recorded in short-term studies to community-scale impacts, combining data from field surveys and mesocosm experiments to parameterize an IBM of coral community recovery on the fore reef of Moorea, …

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Can The Carbon And Nitrogen Isotope Values Of Offspring Be Used As A Proxy For Their Mother's Diet? Using Foetal Physiology To Interpret Bulk Tissue And Amino Acid Δ15N Values, Nico Lübcker, John P. Whiteman, Seth D. Newsome, Robert P. Millar, P.J. Nico De Bruyn Jan 2020

Can The Carbon And Nitrogen Isotope Values Of Offspring Be Used As A Proxy For Their Mother's Diet? Using Foetal Physiology To Interpret Bulk Tissue And Amino Acid Δ15N Values, Nico Lübcker, John P. Whiteman, Seth D. Newsome, Robert P. Millar, P.J. Nico De Bruyn

Biological Sciences Faculty Publications

The measurement of bulk tissue nitrogen (δ15N) and carbon isotope values (δ13C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n = 1895 chronologically subsampled whisker segments for bulk …

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Coordination Of Different Ligands To Copper(Ii) And Cobalt(Iii) Metal Centers Enhances Zika Virus And Dengue Virus Loads In Both Arthropod Cells And Human Keratinocytes, Shovan Dutta, Michael J. Celestine, Supreet Khanal, Alexis Huddleston, Colin Simms, Jessa Faye Arca, Amlam Mitra, Loree Heller, Piotr Kraj, Michael Ledizet, John F. Anderson, Girish Neelakanta, Alvin A. Holder, Hameeda Sultana Jan 2018

Coordination Of Different Ligands To Copper(Ii) And Cobalt(Iii) Metal Centers Enhances Zika Virus And Dengue Virus Loads In Both Arthropod Cells And Human Keratinocytes, Shovan Dutta, Michael J. Celestine, Supreet Khanal, Alexis Huddleston, Colin Simms, Jessa Faye Arca, Amlam Mitra, Loree Heller, Piotr Kraj, Michael Ledizet, John F. Anderson, Girish Neelakanta, Alvin A. Holder, Hameeda Sultana

Biological Sciences Faculty Publications

Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex …

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Human Rickettsial Pathogen Modulates Arthropod Organic Anion Transporting Polypeptide And Tryptophan Pathway For Its Survival In Ticks, Vikas Taank, Shovan Dutta, Amrita Dasgupta, Durland Fish, John F. Anderson, Hameeda Sultana, Girish Neelakanta Oct 2017

Human Rickettsial Pathogen Modulates Arthropod Organic Anion Transporting Polypeptide And Tryptophan Pathway For Its Survival In Ticks, Vikas Taank, Shovan Dutta, Amrita Dasgupta, Durland Fish, John F. Anderson, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

The black-legged tick Ixodes scapularis transmits the human anaplasmosis agent, Anaplasma phagocytophilum. In this study, we show that A. phagocytophilum specifically up-regulates I. scapularis organic anion transporting polypeptide, isoatp4056 and kynurenine amino transferase (kat), a gene involved in the production of tryptophan metabolite xanthurenic acid (XA), for its survival in ticks. RNAi analysis revealed that knockdown of isoatp4056 expression had no effect on A. phagocytophilum acquisition from the murine host but affected the bacterial survival in tick cells. Knockdown of the expression of kat mRNA alone or in combination with isoatp4056 mRNA significantly affected A. phagocytophilum survival …

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Ticks Elicit Variable Fibrinogenolytic Activities Upon Feeding On Hosts With Different Immune Backgrounds, Ashish Vora, Vikas Taank, John F. Anderson, Durland Fish, Daniel E. Sonenshine, John D. Catravas, Hameeda Sultana, Girish Neelakanta Mar 2017

Ticks Elicit Variable Fibrinogenolytic Activities Upon Feeding On Hosts With Different Immune Backgrounds, Ashish Vora, Vikas Taank, John F. Anderson, Durland Fish, Daniel E. Sonenshine, John D. Catravas, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several anti-hemostatic factors in their saliva to suppress the host innate and acquired immune defenses against infestations. Using Ixodes scapularis ticks and age-matched mice purchased from two independent commercial vendors with two different immune backgrounds as a model, we show that ticks fed on immunodeficient animals demonstrate decreased fibrinogenolytic activity in comparison to ticks fed on immunocompetent animals. Reduced levels of D-dimer (fibrin degradation product) were evident in ticks fed on immunodeficient animals in comparison to ticks fed on immunocompetent animals. Increased engorgement weights were noted for ticks fed on immunodeficient animals in comparison to ticks fed on …

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Exosomes Serve As Novel Modes Of Tick-Borne Flavivirus Transmission From Arthropod To Human Cells And Facilitates Dissemination Of Viral Rna And Proteins To The Vertebrate Neuronal Cells, Wenshuo Zhou, Michael Woodson, Biswas Neupane, Fengwei Bai, Michael B. Sherman, Kyung H. Choi, Girish Neelakanta, Hameeda Sultana Jan 2017

Exosomes Serve As Novel Modes Of Tick-Borne Flavivirus Transmission From Arthropod To Human Cells And Facilitates Dissemination Of Viral Rna And Proteins To The Vertebrate Neuronal Cells, Wenshuo Zhou, Michael Woodson, Biswas Neupane, Fengwei Bai, Michael B. Sherman, Kyung H. Choi, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Molecular determinants and mechanisms of arthropod-borne flavivirus transmission to the vertebrate host are poorly understood. In this study, we show for the first time that a cell line from medically important arthropods, such as ticks, secretes extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Our study shows that tick-borne Langat virus (LGTV), a model pathogen closely related to tick-borne encephalitis virus (TBEV), profusely uses arthropod exosomes for transmission of viral RNA and proteins to the human- skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed the presence of purified arthropod/neuronal exosomes …

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Adenovirus Entry From The Apical Surface Of Polarized Epithelia Is Facilitated By The Host Innate Immune Response, Poornima L.N. Kotha, Priyanka Sharma, Abimbola O. Kolawole, Ran Yan, Mahmoud Alghamri, Trisha L. Brockman, Julian Gomez-Cambronero, Julian Cambronero Mar 2015

Adenovirus Entry From The Apical Surface Of Polarized Epithelia Is Facilitated By The Host Innate Immune Response, Poornima L.N. Kotha, Priyanka Sharma, Abimbola O. Kolawole, Ran Yan, Mahmoud Alghamri, Trisha L. Brockman, Julian Gomez-Cambronero, Julian Cambronero

Biological Sciences Faculty Publications

Prevention of viral-induced respiratory disease begins with an understanding of the factors that increase or decrease susceptibility to viral infection. The primary receptor for most adenoviruses is the coxsackievirus and adenovirus receptor (CAR), a cell-cell adhesion protein normally localized at the basolateral surface of polarized epithelia and involved in neutrophil transepithelial migration. Recently, an alternate isoform of CAR, CAREx8, has been identified at the apical surface of polarized airway epithelia and is implicated in viral infection from the apical surface. We hypothesized that the endogenous role of CAREx8 may be to facilitate host innate immunity. We show that IL-8, …

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Altered Connexin 43 Expression Underlies Age-Dependent Decrease Of Regulatory T Cell Suppressor Function In Nonobese Diabetic Mice, Michel Kuczma, Cong-Yi Wang, Leszek Ignatowicz, Robert Gourdi, Piotr Kraj Jan 2015

Altered Connexin 43 Expression Underlies Age-Dependent Decrease Of Regulatory T Cell Suppressor Function In Nonobese Diabetic Mice, Michel Kuczma, Cong-Yi Wang, Leszek Ignatowicz, Robert Gourdi, Piotr Kraj

Biological Sciences Faculty Publications

Type 1 diabetes is one of the most extensively studied autoimmune diseases, but the cellular and molecular mechanisms leading to T cell–mediated destruction of insulin-producing β cells are still not well understood. In this study, we show that regulatory T cells (Tregs) in NOD mice undergo age-dependent loss of suppressor functions exacerbated by the decreased ability of activated effector T cells to upregulate Foxp3 and generate Tregs in the peripheral organs. This age-dependent loss is associated with reduced intercellular communication mediated by gap junctions, which is caused by impaired upregulation and decreased expression of connexin 43. Regulatory …

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Design And Study Of The Efflux Function Of The Egfp Fused Mexab-Oprm Membrane Transporter In Pseudomonas Aeruginosa Using Spectroscopy, Feng Ding, Kerry J. Lee, Ardeschir Vahedi-Faridi, Hiroshi Yoneyama, Christopher J. Osgood, Xiao-Hong Nancy Xu Jan 2014

Design And Study Of The Efflux Function Of The Egfp Fused Mexab-Oprm Membrane Transporter In Pseudomonas Aeruginosa Using Spectroscopy, Feng Ding, Kerry J. Lee, Ardeschir Vahedi-Faridi, Hiroshi Yoneyama, Christopher J. Osgood, Xiao-Hong Nancy Xu

Biological Sciences Faculty Publications

Multidrug membrane transporters (efflux pumps) can selectively extrude a variety of structurally and functionally diverse substrates (e.g., chemotoxics, antibiotics), leading to multidrug resistance (MDR) and ineffective treatment of a wide variety of diseases. In this study, we have designed and constructed a fusion gene (egfp-mexB) of N-terminal mexB with C-terminal egfp, inserted it into a plasmid vector (pMMB67EH), and successfully expressed it in the Δ MexB (MexB deletion) strain of Pseudomonas aeruginosato create a new strain that expresses MexA-(EGFP-MexB)-OprM. We characterized the fusion gene using gel electrophoresis and DNA sequencing, and determined its expression in live …

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Lineage-Specific Transcriptional Profiles Of Symbiodinium Spp. Unaltered By Heat Stress In A Coral Host, Daniel J. Barshis, Jason T. Ladner, Thomas A. Oliver, Stephen R. Palumbi Jan 2014

Lineage-Specific Transcriptional Profiles Of Symbiodinium Spp. Unaltered By Heat Stress In A Coral Host, Daniel J. Barshis, Jason T. Ladner, Thomas A. Oliver, Stephen R. Palumbi

Biological Sciences Faculty Publications

Dinoflagellates of the genus Symbiodinium form an endosymbiosis with reef building corals, in which photosynthetically derived nutrients comprise the majority of the coral energy budget. An extraordinary amount of functional and genetic diversity is contained within the coral-associated Symbiodinium, with some phylotypes (i.e., genotypic groupings), conferring enhanced stress tolerance to host corals. Recent advances in DNA sequencing technologies have enabled transcriptome-wide profiling of the stress response of the cnidarian coral host; however, a comprehensive understanding of the molecular response to stress of coral-associated Symbiodinium, as well as differences among physiologically susceptible and tolerant types, remains largely unexplored. Here, …

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Adenosine Triphosphate (Atp) Is A Candidate Signaling Molecule In The Mitochondria-To-Nucleus Retrograde Response Pathway, Feng Zhang, Tammy Pracheil, Janet Thornton, Zhengchang Liu Mar 2013

Adenosine Triphosphate (Atp) Is A Candidate Signaling Molecule In The Mitochondria-To-Nucleus Retrograde Response Pathway, Feng Zhang, Tammy Pracheil, Janet Thornton, Zhengchang Liu

Biological Sciences Faculty Publications

Intracellular communication from the mitochondria to the nucleus is achieved via the retrograde response. In budding yeast, the retrograde response, also known as the RTG pathway, is regulated positively by Rtg1, Rtg2, Rtg3 and Grr1 and negatively by Mks1, Lst8 and two 14-3-3 proteins, Bmh1/2. Activation of retrograde signaling leads to activation of Rtg1/3, two basic helix-loop-helix leucine zipper transcription factors. Rtg1/3 activation requires Rtg2, a cytoplasmic protein with an N-terminal adenosine triphosphate (ATP) binding domain belonging to the actin/Hsp70/sugar kinase superfamily. The critical regulatory step of the retrograde response is the interaction between Rtg2 and Mks1. Rtg2 binds to …

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Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Muhammad A. Farooq, Tammy M. Pracheil, Zhejun Dong, Fei Xiao, Zhengchang Liu Jan 2013

Mitochondrial Dna Instability In Cells Lacking Aconitase Correlates With Iron Citrate Toxicity, Muhammad A. Farooq, Tammy M. Pracheil, Zhejun Dong, Fei Xiao, Zhengchang Liu

Biological Sciences Faculty Publications

Aconitase, the second enzyme of the tricarboxylic acid cycle encoded by ACO1 in the budding yeast Saccharomyces cerevisiae, catalyzes the conversion of citrate to isocitrate. aco1 Delta results in mitochondrial DNA (mtDNA) instability. It has been proposed that Aco1 binds to mtDNA and mediates its maintenance. Here we propose an alternative mechanism to account for mtDNA loss in aco1 Delta mutant cells. We found that aco1 Delta activated the RTG pathway, resulting in increased expression of genes encoding citrate synthase. By deleting RTG1, RTG3, or genes encoding citrate synthase, mtDNA instability was prevented in aco1 Delta mutant …

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The Role Of P38 Mapk In The Aetiopathogenesis Of Psoriasis And Psoriatic Arthritis, Athanasios Mavropoulos, Eirini I. Rigopoulou, Christos Liaskos, Dimitrios P. Bogdanos, Lazaros I. Sakkas Jan 2013

The Role Of P38 Mapk In The Aetiopathogenesis Of Psoriasis And Psoriatic Arthritis, Athanasios Mavropoulos, Eirini I. Rigopoulou, Christos Liaskos, Dimitrios P. Bogdanos, Lazaros I. Sakkas

Biological Sciences Faculty Publications

The pathogenetic mechanisms responsible for the induction of immune-mediated disorders, such as psoriasis, remain not well characterized. Molecular signaling pathways are not well described in psoriasis, as well as psoriatic arthritis, which is seen in up to 40% of patients with psoriasis. Signaling pathway defects have long been hypothesized to participate in the pathology of psoriasis, yet their implication in the altered psoriatic gene expression still remains unclear. Emerging data suggest a potential pathogenic role for mitogen activated protein kinases p38 (p38 MAPK) extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK) in the development of psoriasis. The data …

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Molecular Characterization And Tissue-Specific Gene Expression Of Dermacentor Variabilis Α-Catenin In Response To Rickettsial Infection, Piyanate Sunyakumthorn, Natthida Petchampai, Michael T. Kearney, Daniel E. Sonenshine, Kevin R. Macaluso Jan 2012

Molecular Characterization And Tissue-Specific Gene Expression Of Dermacentor Variabilis Α-Catenin In Response To Rickettsial Infection, Piyanate Sunyakumthorn, Natthida Petchampai, Michael T. Kearney, Daniel E. Sonenshine, Kevin R. Macaluso

Biological Sciences Faculty Publications

Alpha catenin is a cytoskeleton protein that acts as a regulator of actin rearrangement by forming an E-cadherin adhesion complex. In Dermacentor variabilis, a putative α-catenin (Dvα-catenin) was previously identified as differentially regulated in ovaries of ticks chronically infected with Rickettsia montanensis. To begin characterizing the role(s) of Dvα-catenin during rickettsial infection, the full-length Dvα-catenin cDNA was cloned and analysed. Comparative sequence analysis demonstrates a 3069-bp cDNA with a 2718-bp open reading frame with a sequence similar to Ixodes scapularis α-catenin. A portion of Dvα-catenin is homologous to the vinculin-conserved domain containing a putative …

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Expansion Dating: Calibrating Molecular Clocks In Marine Species From Expansions Onto The Sunda Shelf Following The Last Glacial Maximum, Eric D. Crandall, Elizabeth J. Sbrocco, Timery S. Deboer, Paul H. Barber, Kent E. Carpenter Jan 2012

Expansion Dating: Calibrating Molecular Clocks In Marine Species From Expansions Onto The Sunda Shelf Following The Last Glacial Maximum, Eric D. Crandall, Elizabeth J. Sbrocco, Timery S. Deboer, Paul H. Barber, Kent E. Carpenter

Biological Sciences Faculty Publications

The rate of change in DNA is an important parameter for understanding molecular evolution and hence for inferences drawn from studies of phylogeography and phylogenetics. Most rate calibrations for mitochondrial coding regions in marine species have been made from divergence dating for fossils and vicariant events older than 1-2 My and are typically 0.5-2% per lineage per million years. Recently, calibrations made with ancient DNA (aDNA) from younger dates have yielded faster rates, suggesting that estimates of the molecular rate of change depend on the time of calibration, decaying from the instantaneous mutation rate to the phylogenetic substitution rate. aDNA …

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Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, John C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig Jan 2010

Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, John C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) are major determinants of verapamil (VP)-reversible CQ resistance (CQR). In the presence of mutant PfCRT, additional genes contribute to the wide range of CQ susceptibilities observed. It is not known if these genes influence mechanisms of chemosensitization by CQR reversal agents. Using quantitative trait locus (QTL) mapping of progeny clones from the HB3 x Dd2 cross, we show that the P. falciparum multidrug resistance gene 1 (pfmdr1) interacts with the South-East Asia-derived mutant pfcrt haplotype to modulate CQR levels. A novel chromosome 7 locus is predicted to contribute …

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Dc Electrokinetic Transport Of Cylindrical Cells In Straight Microchannels, Ye Ai, Ali Beskok, David T. Gauthier, Sang W. Joo, Shizhi Qian Jan 2009

Dc Electrokinetic Transport Of Cylindrical Cells In Straight Microchannels, Ye Ai, Ali Beskok, David T. Gauthier, Sang W. Joo, Shizhi Qian

Biological Sciences Faculty Publications

Electrokinetic transport of cylindrical cells under dc electric fields in a straight microfluidic channel is experimentally and numerically investigated with emphasis on the dielectrophoretic (DEP) effect on their orientation variations. A two-dimensional multiphysics model, composed of the Navier-Stokes equations for the fluid flow and the Laplace equation for the electric potential defined in an arbitrary Lagrangian-Eulerian framework, is employed to capture the transient electrokinetic motion of cylindrical cells. The numerical predictions of the particle transport are in quantitative agreement with the obtained experimental results, suggesting that the DEP effect should be taken into account to study the electrokinetic transport of …

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Comparative Efficacy Of Bioud To Other Commercially Available Arthropod Repellants Against The Ticks Amblyomma Americanum And Dermacentor Variabilis On Cotton Cloth, Brooke W. Bissinger, Jiwei Zhu, Charles S. Apperson, Daniel E. Sonenshine, D. Wesley Watson, R. Michael Roe Jan 2009

Comparative Efficacy Of Bioud To Other Commercially Available Arthropod Repellants Against The Ticks Amblyomma Americanum And Dermacentor Variabilis On Cotton Cloth, Brooke W. Bissinger, Jiwei Zhu, Charles S. Apperson, Daniel E. Sonenshine, D. Wesley Watson, R. Michael Roe

Biological Sciences Faculty Publications

BioUD is an arthropod repellent that contains the active ingredient 2-undecanone originally derived from wild tomato plants. Repellency of BioUD was compared with five commercially available arthropod repellents against the ticks Amblyomma americanum (L.) and Dermacentor variabilis Say in two-choice bioassays on treated versus untreated cotton cheesecloth. Overall mean percentage repellency against both species was greatest for and did not differ significantly between BioUD (7.75% 2-undecanone) and products containing 98.1% DEET, 19.6% IR3535, and 30% oil of lemon eucalyptus. Products containing 5% and 15% Picaridin and 0.5% permethrin were also repellent compared with untreated controls but to a lesser degree …

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Ancient Dna Identification Of Early 20th Century Simian T-Cell Leukemia Virus Type 1, Sebastien Calvignac, Jean-Michel Terme, Shannon M. Hensley, Pierre Jalinot, Alex D. Greenwood, Catherine Hanni Jan 2008

Ancient Dna Identification Of Early 20th Century Simian T-Cell Leukemia Virus Type 1, Sebastien Calvignac, Jean-Michel Terme, Shannon M. Hensley, Pierre Jalinot, Alex D. Greenwood, Catherine Hanni

Biological Sciences Faculty Publications

The molecular identification of proviruses from ancient tissues (and particularly from bones) remains a contentious issue. It can be expected that the copy number of proviruses will be low, which magnifies the risk of contamination with retroviruses from exogenous sources. To assess the feasibility of paleoretrovirological studies, we attempted to identify proviruses from early 20th century bones of museum specimens while following a strict ancient DNA methodology. Simian T-cell leukemia virus type 1 sequences were successfully obtained and authenticated from a Chlorocebus pygerythrus specimen. This represents the first clear evidence that it will be possible to use museum specimens to …

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Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig Jan 2007

Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) can result in verapamil-reversible CQ resistance and altered susceptibility to other antimalarials. PfCRT contains 10 membrane-spanning domains and is found in the digestive vacuole (DV) membrane of intraerythrocytic parasites. The mechanism by which PfCRT mediates CQ resistance is unclear although it is associated with decreased accumulation of drug within the DV. On the permissive background of the P. falciparum 106/1(K76) parasite line, we used single-step drug selection to generate isogenic clones containing unique pfcrt point mutations that resulted in amino acid changes in PfCRT transmembrane domains 1 (C72R, K76N, K76I …

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In Vivo Role Of 20-Hydroxyecdysone In The Regulation Of The Vitellogenin Mrna And Egg Development In The American Dog Tick, Dermacentor Variabilis (Say), Deborah M. Thompson, Sayed M.S. Khalil, Laura A. Jeffers, Usha Ananthapadadmanaban, Daniel E. Sonenshine, Robert D. Mitchell, Christopher J. Osgood, Charles S. Apperson, R. Michael Roe Jan 2005

In Vivo Role Of 20-Hydroxyecdysone In The Regulation Of The Vitellogenin Mrna And Egg Development In The American Dog Tick, Dermacentor Variabilis (Say), Deborah M. Thompson, Sayed M.S. Khalil, Laura A. Jeffers, Usha Ananthapadadmanaban, Daniel E. Sonenshine, Robert D. Mitchell, Christopher J. Osgood, Charles S. Apperson, R. Michael Roe

Biological Sciences Faculty Publications

Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not …

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Host Blood Proteins And Peptides In The Midgut Of The Tick Dermacentor Variabilis Contribute To Bacterial Control, Daniel E. Sonenshine, Wayne L. Hynes, Shane M. Ceraul, Robert Mitchell, Tiffany Benzine Jan 2005

Host Blood Proteins And Peptides In The Midgut Of The Tick Dermacentor Variabilis Contribute To Bacterial Control, Daniel E. Sonenshine, Wayne L. Hynes, Shane M. Ceraul, Robert Mitchell, Tiffany Benzine

Biological Sciences Faculty Publications

Antimicrobial midgut proteins and peptides that result from blood digestion in feeding American dog ticks Dermacentor variabilis (Say) were identified. Midgut extracts from these ticks showed antimicrobial activity against Micrococcus luteus, regardless of whether they were challenged with peptidoglycan, blood meal components, rabbit blood, Bacillus subtilis, Escherischia coli or Borrelia burgdorferi. However, no peptide band co-migrating with defensin was found in midgut extracts from the challenged ticks. Partial purification of the midgut extracts using C18 Sep Paks and gel electrophoresis showed the presence of 4 distinct bands with rMW 4.1, 5.3, 5.7 and 8.0 kDa identified …

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Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems Jan 2004

Dissecting The Loci Of Low-Level Quinine Resistance In Malaria Parasites, Michael T. Ferdig, Roland A. Cooper, Jianbing Mu, Bingbing Deng, Deirdre A. Joy, Xin-Zhuan Su, Thomas E. Wellems

Biological Sciences Faculty Publications

Quinine (QN) remains effective against Plasmodium falciparum, but its decreasing efficacy is documented from different continents. Multiple genes are likely to contribute to the evolution of QN resistance. To locate genes contributing to QN response variation, we have searched a P. falciparum genetic cross for quantitative trait loci (QTL). Results identify additive QTL in segments of chromosomes (Chrs) 13, 7 and 5, and pairwise effects from two additional loci of Chrs 9 and 6 that interact, respectively, with the QTL of Chrs 13 and 7. The mapped segments of Chrs 7 and 5 contain pfcrt, the determinant of …

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Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall Jan 2003

Algal Composition And Abundance In The Neuston Surface Micro Layer From A Lake And Pond In Virginia (U.S.A.), Lubomira Burchardt, Harold G. Marshall

Biological Sciences Faculty Publications

A comparative study was conducted that characterized the algae within the neuston, ca 2 mm below the surface, and the algae in the water column from two freshwater habitats. There were significant differences in total algal abundance and the abundance of diatoms, cyanoprokaryotes, and chlorophytes between the neuston and water column algae of these two regions during each season and at both sites. The pond neuston was dominated by chlorophytes, with total algal abundance ranging seasonally from 0.6 to 59.6 x 10-3 cells ml-1 compared to water column algal concentrations of 4.1 to 40.4 x 10-3 cells ml-1. …

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Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su Jan 2003

Multiple Transporters Associated With Malaria Parasite Responses To Chloroquine And Quinine, Jianbing Mu, Michael T. Ferdig, Xiaorong Feng, Deirdre A. Joy, Junhui Duan, Tetsuya Furuya, G. Subramanian, L. Aravind, Roland A. Cooper, John C. Wootton, Momia Xiong, Xin-Zhuan Su

Biological Sciences Faculty Publications

Mutations and/or overexpression of various transporters are known to confer drug resistance in a variety of organisms. In the malaria parasite Plasmodium falciparum, a homologue of P-glycoprotein, PfMDR1, has been implicated in responses to chloroquine (CO), quinine (ON) and other drugs, and a putative transporter, PfCRT, was recently demonstrated to be the key molecule in CO resistance. However, other unknown molecules are probably involved, as different parasite clones carrying the same pfcrt and pfmdr1 alleles show a wide range of quantitative responses to CO and ON. Such molecules may contribute to increasing incidences of ON treatment failure, the molecular basis …

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Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva Jan 2002

Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva

Biological Sciences Faculty Publications

We evaluated an artificial capillary feeding method to infect nymphal Ixodes scapularis (Say) ticks with Borrelia burgdorferi, the causative agent of Lyme disease. Thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. Capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. Capillary feeding also maintained natural vector competence patterns because I. scapularis ticks acquired infection unlike Dermacentor variablis (Say), which did not become infected. Capillary infected I. scapularis nymphs were capable of transmitting the infection to naive mice …

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Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe Jan 2000

Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe

Biological Sciences Faculty Publications

Synganglia, salivary gland, midgut, ovary, fat body and muscle alone and in combination from the ixodid tick, Dermacentor variabilis (Say), or the argasid tick, Ornithodoros parkeri Cooley, were incubated in vitro in separate experiments with L-[methyl-3H]methionine and farnesoic acid or with [1-14C]acetate. Life stages examined in D. variabilis were 3 and 72 h old (after ecdysis) unfed nymphs, partially fed nymphs (18 and 72 h after attachment to the host), fully engorged nymphs (2 d after detachment from host), 3 and 72 h old (after eclosion) unfed females, partially fed unmated females (12–168 …

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The Drosophila Melanogaster Rad54 Homolog, Dmrad54, Is Involved In The Repair Of Radiation Damage And Recombination, Rolf Kooistra, José B. M. Zonneveld, Anja De Jong, Jan C. J. Eeken, Chris J. Osgood, Jean-Marie Buerstedde, Paul H. M. Lohman, Albert Pastink Jan 1997

The Drosophila Melanogaster Rad54 Homolog, Dmrad54, Is Involved In The Repair Of Radiation Damage And Recombination, Rolf Kooistra, José B. M. Zonneveld, Anja De Jong, Jan C. J. Eeken, Chris J. Osgood, Jean-Marie Buerstedde, Paul H. M. Lohman, Albert Pastink

Biological Sciences Faculty Publications

The RAD54 gene of Saccharomyces cerevisiae plays a crucial role in recombinational repair of double-strand breaks in DNA. Here the isolation and functional characterization of the RAD54 homolog of the fruit fly Drosophila melanogaster, DmRAD54, are described. The putative Dmrad54 protein displays 46 to 57% identity to its homologs from yeast and mammals. DmRAD54 RNA was detected at all stages of fly development, but an increased level was observed in early embryos and ovarian tissue. To determine the function of DmRAD54, a null mutant was isolated by random mutagenesis. DmRAD54-deficient flies develop normally, but the females …

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Quantitation And Identification Of Organic N-Chloramines Formed In Stomach Fluid On Ingestion Of Aqueous Hypochlorite, Frank E. Scully Jr., Katherine Mazina, Daniel E. Sonenshine, Frederick Kopfler Jan 1986

Quantitation And Identification Of Organic N-Chloramines Formed In Stomach Fluid On Ingestion Of Aqueous Hypochlorite, Frank E. Scully Jr., Katherine Mazina, Daniel E. Sonenshine, Frederick Kopfler

Biological Sciences Faculty Publications

The chemical reactions that hypochlorite undergoes in the body when chlorinated water is ingested have received very little attention. Because amino nitrogen compounds are important components of the average diet, the reactions of hypochlorite with amino compounds in the stomach were investigated. Stomach fluid was recovered from Sprague-Dawley rats that had been fasted for 48 hr and administered 4 mL deionized water. The chlorine demand of the stomach fluid was determined. An average volume-independent demand of 2.7 mg chlorine was measured. At doses below 40 mg/L chlorine reducing reactions appeared to account for reduction of all oxidizing species within 15 …

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