Sample records for actinomucor elegans var

  1. Fatal Actinomucor elegans var. kuwaitiensis Infection following Combat Trauma?

    PubMed Central

    Tully, Charla C.; Romanelli, Anna M.; Sutton, Deanna A.; Wickes, Brian L.; Hospenthal, Duane R.

    2009-01-01

    We report the first case of invasive mucormycosis secondary to Actinomucor elegans infection. A severely injured soldier with a fatal A. elegans var. kuwaitiensis infection is described. The identification of this fungus was performed by classical and molecular methods, and this report documents the pathogenicity of the recently described variety Actinomucor elegans var. kuwaitiensis. PMID:19675213

  2. Novel aminopeptidase specific for glycine from Actinomucor elegans.

    PubMed

    Ito, Kiyoshi; Ma, Xiaohang; Azmi, Nik; Huang, Hua-Shan; Fujii, Mikio; Yoshimoto, Tadashi

    2003-01-01

    Glycyl aminopeptidase was purified 600-fold from a cell extract of Actinomucor elegans by ammonium sulfate fractionation and sequential chromatography on DEAE-Toyopearl, Toyopearl HW65C, and FPLC-Superdex 200 HR, with recovery of 3.3% of the activity. The enzyme highly specifically hydrolyzed Gly-X (amino acid, peptide, or arylamide) bonds. The enzyme hydrolyzed other amino acid residues but at a rate of less than one fifth that with Gly. The order was Gly > Ala > Met > Arg > Ser > Leu. The Km value for glycyl-2-naphthylamide was 0.24 mM. The enzyme was most active at pH 8.0 with glycyl-2-naphthylamide as the substrate and its optimal temperature was 40 degrees C. The enzyme was inhibited by iodoacetic acid, and p-chloromercuribenzoate but not done by diisopropylfluorophosphate, o-phenanthroline, or EDTA. Magnesium and calcium had no effect on enzymic activity, but the activity was suppressed by cadmium, zinc, and copper ions. The molecular mass was estimated to be 320 kDa by gel filtration on FPLC-Superdex 200 HR and 56.5 kDa by SDS-PAGE, so the enzyme probably was a hexamer. PMID:12619677

  3. Abutilon theophrasti's defense against the allelochemical benzoxazolin-2(3H)-one: support by Actinomucor elegans.

    PubMed

    Kia, Sevda Haghi; Schulz, Margot; Ayah, Emmanuel; Schouten, Alexander; M黮lenborn, Carmen; Paetz, Christian; Schneider, Bernd; Hofmann, Diana; Disko, Ulrich; Tabaglio, Vincenzo; Marocco, Adriano

    2014-12-01

    Abutilon theophrasti Medik., previously found to be rather insensitive to benzoxazinoid containing rye mulch and the allelochemical benzoxazolin-2(3H)-one (BOA), can be associated with the zygomycete Actinomucor elegans, whereby the fungus colonizes the root relatively superficially and mainly in the maturation zone. The fungus mitigates necrosis of the cotyledons when seedlings are incubated with 2 mM BOA, in contrast to those that lack the fungus. In liquid cultures of the fungus, tryptophan was identified. The accumulation of tryptophan is increased in presence of BOA. This amino acid seems to be important in protecting Abutilon against BOA and its derivatives since it suppressed the accumulation of BOA derived, highly toxic 2-aminophen-oxazin-3-one (APO) in the medium and on the root surface during BOA incubations of Abutilon seedlings. Although A. elegans is insensitive to BOA and APO, the fungus is not able to protect the plant against harmful effects of APO, when seedlings are treated with the compound. Abutilon can detoxify BOA via BOA-6-OH glucosylation probably by a cell wall associated glucosyltransferase, but only low amounts of the product accumulate. Low tryptophan concentrations can contribute to a degradation of the toxic intermediate BOA-6-OH by Fenton reactions, whereby the amino acid is oxidized. One of the oxidation products was identified as 4(1H)-quinolinone, which is the core substructure of the quorum sensing molecule 2-heptyl-3-hydroxy-4-quinolone. The mutualistic association of Abutilon theophrasti with Actinomucor elegans is considered as opportunistic and facultative. Such plant-fungus associations depend rather likely on environmental conditions, such as the mode of fertilization. PMID:25432667

  4. Necrosis in C. elegans

    PubMed Central

    Crook, Matt; Upadhyay, Avni; Hanna-Rose, Wendy

    2015-01-01

    To use Caenorhabditis elegans to study the mechanisms for initiation and execution of necrosis, the experimentalist should be familiar with the established models of necrosis in C. elegans and the genetic and molecular tools available. We present a summary of two contrasting models for studying necrosis in C. elegans and outline the methods for scoring necrosis in each. These methods are useful for the study of necrosis under other conditions in C. elegans and for comparative studies both between established and new necrosis models. We also present a list of the genetic and drug tools available for perturbing pathways known to be important for initiation or execution of necrosis and describe their use in C. elegans. Specifically, we outline methods to inhibit autophagy, to perturb calcium homeostasis, and to disrupt lysosomal function in the C. elegans system. PMID:23733577

  5. [C. elegans defence mechanisms].

    PubMed

    Ziegler, Katja; Pujol, Nathalie

    2009-05-01

    The nematode Caenorhabditis elegans has evolved as a powerful invertebrate model to study innate immunity to pathogens. C. elegans possesses inducible defence mechanisms to protect itself from pathogenic attack, mainly by the production of antimicrobial effector molecules. Its innate immune system is under the control of a surprisingly complex network of evolutionary conserved signalling pathways, which are activated depending on the pathogen, suggesting that C. elegans is able to mount a specific defence response to different pathogens. In this review we will introduce the worm's immune system and discuss the different signalling pathways that regulate its response to bacterial pathogens which mainly infect C. elegans by an oral route and by invading its intestine, before focusing our attention on the resistance of C. elegans to a natural occurring fungal -pathogen that infects the worm by invading its -epidermis. PMID:19480831

  6. C. elegans sirtuins.

    PubMed

    Viswanathan, Mohan; Tissenbaum, Heidi A

    2013-01-01

    The nematode Caenorhabditis elegans (C. elegans) has four Sir2 paralogs, sir-2.1, sir-2.2, sir-2.3, and sir-2.4. Thus far, most of the research tools to study worm sirtuins have been developed for sir-2.1, due to its homology to yeast SIR2 and human SIRT1. Here, we have compiled a listing of the currently available strains (including both loss-of-function alleles and transgenics), antibodies, and RNAi constructs relevant to studies on all C. elegans sirtuin family members. We also describe the methods used in the analysis of C. elegans sirtuin function, including life span analysis, various stress-resistance assays, and fat content analysis and provide an overview of all phenotypic data relevant to C. elegans sir-2.1. PMID:24014398

  7. C. elegans TRP Channels

    Microsoft Academic Search

    Rui Xiao; X. Z. Shawn Xu

    \\u000a Transient receptor potential (TRP) channels represent a superfamily of cation channels found in all eukaryotes. The C. elegans genome encodes seventeen TRP channels covering all of the seven TRP subfamilies. Genetic analyses in C. elegans have implicated TRP channels in a wide spectrum of behavioral and physiological processes, ranging from sensory transduction\\u000a (e.g. chemosensation, touch sensation, proprioception and osmosensation) to

  8. Laser Microsurgery in Caenorhabditis elegans

    PubMed Central

    Fang-Yen, Christopher; Gabel, Christopher V.; Samuel, Aravinthan D. T.; Bargmann, Cornelia I.; Avery, Leon

    2013-01-01

    Laser killing of cell nuclei has long been a powerful means of examining the roles of individual cells in C. elegans. Advances in genetics, laser technology, and imaging have further expanded the capabilities and usefulness of laser surgery. Here, we review the implementation and application of currently used methods for target edoptical disruption in C. elegans. PMID:22226524

  9. 11 RNAi (nematodes: Caenorhabditis elegans)

    Microsoft Academic Search

    Craig C. Mello

    2002-01-01

    RNA interference in Caenorhabditis elegans is a type of homology dependent post-transcriptional gene silencing induced by dsRNA. In this chapter we describe the history of the discovery of RNAi, its systematic nature, inheritance, and connection to other homology-dependent silencing phenomena like co-suppression and transcriptional gene silencing. We discuss RNAi-deficient mutants in C. elegans as well as characterized components of the

  10. Neuropeptide GPCRs in C. elegans

    PubMed Central

    Frooninckx, Lotte; Van Rompay, Liesbeth; Temmerman, Liesbet; Van Sinay, Elien; Beets, Isabel; Janssen, Tom; Husson, Steven J.; Schoofs, Liliane

    2012-01-01

    Like most organisms, the nematode Caenorhabditis elegans relies heavily on neuropeptidergic signaling. This tiny animal represents a suitable model system to study neuropeptidergic signaling networks with single cell resolution due to the availability of powerful molecular and genetic tools. The availability of the worm抯 complete genome sequence allows researchers to browse through it, uncovering putative neuropeptides and their cognate G protein-coupled receptors (GPCRs). Many predictions have been made about the number of C. elegans neuropeptide GPCRs. In this review, we report the state of the art of both verified as well as predicted C. elegans neuropeptide GPCRs. The predicted neuropeptide GPCRs are incorporated into the receptor classification system based on their resemblance to orthologous GPCRs in insects and vertebrates. Appointing the natural ligand(s) to each predicted neuropeptide GPCR (receptor deorphanization) is a crucial step during characterization. The development of deorphanization strategies resulted in a significant increase in the knowledge of neuropeptidergic signaling in C. elegans. Complementary localization and functional studies demonstrate that neuropeptides and their GPCRs represent a rich potential source of behavioral variability in C. elegans. Here, we review all neuropeptidergic signaling pathways that so far have been functionally characterized in C. elegans. PMID:23267347

  11. The glia of Caenorhabditis elegans

    PubMed Central

    Oikonomou, Grigorios; Shaham, Shai

    2010-01-01

    Glia have been, in many ways, the proverbial elephant in the room. Although glia are as numerous as neurons in vertebrate nervous systems, technical and other concerns had left research on these cells languishing, while research on neurons marched on. Importantly, model systems to study glia had lagged considerably behind. A concerted effort in recent years to develop the canonical invertebrate model animals, Drosophila melanogaster and Caenorhabditis elegans, as settings to understand glial roles in nervous system development and function has begun to bear fruit. In this review we summarize our current understanding of glia and their roles in the nervous system of the nematode C. elegans. The recent studies we describe highlight the similarities and differences between C. elegans and vertebrate glia, and focus on novel insights that are likely to have general relevance to all nervous systems. PMID:21732423

  12. CAENORHABDITIS ELEGANS Deficiency Mapping

    PubMed Central

    Sigurdson, D. Christine; Spanier, Gail J.; Herman, Robert K.

    1984-01-01

    Six schemes were used to identify 80 independent recessive lethal deficiencies of linkage group (LG) II following X-ray treatment of the nematode Caenorhabditis elegans. Complementation tests between the deficiencies and ethyl methanesulfonate-induced recessive visible, lethal and sterile mutations and between different deficiencies were used to characterize the extents of the deficiencies. Deficiency endpoints thus helped to order 36 sites within a region representing about half of the loci on LG II and extending over about 5 map units. New mutations occurring in this region can be assigned to particular segments of the map by complementation tests against a small number of deficiencies; this facilitates the assignment of single-site mutations to particular genes, as we illustrate. Five sperm-defective and five oocyte-defective LG II sterile mutants were identified and mapped. Certain deficiency-by-deficiency complementation tests allowed us to suggest that the phenotypes of null mutations at two loci represented by visible alleles are wild type and that null mutations at a third locus confer a visible phenotype. A segment of LG II that is about 12 map units long and largely devoid of identified loci seems to be greatly favored for crossing over. PMID:6500256

  13. The Genetics of CAENORHABDITIS ELEGANS

    PubMed Central

    Brenner, S.

    1974-01-01

    Methods are described for the isolation, complementation and mapping of mutants of Caenorhabditis elegans, a small free-living nematode worm. About 300 EMS-induced mutants affecting behavior and morphology have been characterized and about one hundred genes have been defined. Mutations in 77 of these alter the movement of the animal. Estimates of the induced mutation frequency of both the visible mutants and X chromosome lethals suggests that, just as in Drosophila, the genetic units in C. elegans are large. PMID:4366476

  14. Variable Declaration var x: T P

    E-print Network

    Hehner, Eric C.R.

    Variable Declaration var x: T路 P 1/80 #12;Variable Declaration var x: T路 P declare local state variable x with type T and scope P 2/80 #12;Variable Declaration var x: T路 P declare local state variable x with type T and scope P = x, x: T路 P 3/80 #12;Variable Declaration var x: T路 P declare local state variable

  15. Electrophysiological Methods for C. elegans Neurobiology

    PubMed Central

    Goodman, Miriam B.; Lindsay, Theodore H.; Lockery, Shawn R.; Richmond, Janet E.

    2014-01-01

    Patch-clamp electrophysiology is the technique of choice for the biophysical analysis of the function of nerve, muscle, and synapse in C. elegans nematodes. Considerable technical progress has been made in C. elegans electrophysiology in the decade since the initial publication of this technique. Today, most, if not all electrophysiological studies that can be done in larger animal preparations can also be done in C. elegans. This chapter has two main goals. The first is to present to a broad audience the many techniques available for patch-clamp analysis of neurons, muscles, and synapses in C. elegans. The second is to provide a methodological introduction to the techniques for patch-clamping C. elegans neurons and body-wall muscles in vivo, including emerging methods for optogenetic stimulation coupled with post-synaptic recording. We also present samples of the cell-intrinsic and post-synaptic ionic currents that can be measured in C. elegans nerve and muscle. PMID:22226532

  16. Meiotic recombination in Caenorhabditis elegans

    Microsoft Academic Search

    Tatiana Garcia-Muse; Simon J. Boulton

    2007-01-01

    The faithful segregation of homologous chromosomes during meiosis is dependent on the formation of physical connections (chiasma)\\u000a that form following reciprocal exchange of DNA molecules during meiotic recombination. Here we review the current knowledge\\u000a in the Caenorhabditis elegans meiotic recombination field. We discuss recent developments that have improved our understanding of the crucial steps that\\u000a must precede the initiation and

  17. Touch sensitivity in Caenorhabditis elegans

    Microsoft Academic Search

    Alexander Bounoutas; Martin Chalfie

    2007-01-01

    The nematode Caenorhabditis elegans was the first organism for which touch insensitive mutants were obtained. The study of the genes defective in these mutants\\u000a has led to the identification of components of a mechanosensory complex needed for specific cells to sense gentle touch to\\u000a the body. Multiple approaches using genetics, cell biology, biochemistry, and electrophysiology have characterized a channel\\u000a complex,

  18. Systematic functional analysis of the Caenorhabditis elegans

    E-print Network

    Ahringe, Julie

    in C. elegans by RNAi, we constructed a library of bacterial strains, each capable of expressing dsSystematic functional analysis of the Caenorhabditis elegans genome using RNAi Ravi S. Kamath to share transcriptional profiles. Our resulting data set and reusable RNAi library of 16,757 bacterial

  19. The Morphology, Fertility and Chromosomes of Mimulus glabratus Var. michiganensis and M. glabratus Var. fremontii (Schrophulariaceae)

    Microsoft Academic Search

    Margaret Bliss

    1986-01-01

    Mimulus glabratus var. michiganensis (Pennell) Fassett, an endemic of northern Michigan, is morphologically distinct from its sympatric relative, M. glabratus var. fremontii (Benth.) A. L. Grant. Pistil and style lengths are the best morphological characters to distinguish the two varieties. Mimulus glabratus var. michiganensis is primarily a vegetative apomict; its percentages of viable pollen and seed set are significantly lower

  20. Prion protein in Caenorhabditis elegans

    PubMed Central

    Park, Kyung-Won

    2011-01-01

    The infectious agent of prion diseases is believed to be nucleic acid-free particles composed of misfolded conformational isomers of a host protein known as prion protein (PrP). Although this 損rotein-only concept is generally accepted, decades of extensive research have not been able to elucidate the mechanisms by which PrP misfolding leads to neurodegeneration and infectivity. The challenges in studying prion diseases relate in part to the limitations of mammalian prion models, which include the long incubation period post-infection until symptoms develop, the high expense of maintaining mammals for extended periods, as well as safety issues. In order to develop prion models incorporating a genetically tractable simple system with a well-defined neuronal system, we generated transgenic C. elegans expressing the mouse PrP behind the pan-neuronal ric-19 promoter (Pric-19). We show here that high expression of Pric-19::PrP in C. elegans can result in altered morphology, defective mobility and shortened lifespan. Low expression of Pric-19::PrP, however, does not cause any detectable harm. Using the dopamine neuron specific promoter Pdat-1, we also show that expression of the murine BAX, a pro-apoptotic member of the Bcl-2 family, causes dopamine neuron destruction in the nematode. However, co-expression of PrP inhibits BAX-mediated dopamine neuron degeneration, demonstrating for the first time that PrP has anti-BAX activity in living animals. Thus, these distinct PrP-transgenic C. elegans lines recapitulate a number of functional and neuropathological features of mammalian prion models and provide an opportunity for facile identification of genetic and environmental contributors to prion-associated pathology. PMID:21084837

  1. Using C. elegans for aging research

    PubMed Central

    Tissenbaum, Heidi A.

    2015-01-01

    Over a century ago, the zoologist Emile Maupas first identified the nematode, Rhabditis elegans, in the soil in Algiers. Subsequent work and phylogenic studies renamed the species Caenorhabditis elegans or more commonly referred to as C. elegans; (Caeno meaning recent; rhabditis meaning rod; elegans meaning nice). However, it was not until 1963, when Sydney Brenner, already successful from his work on DNA, RNA, and the genetic code, suggested the future of biological research lay in model organisms. Brenner believed that biological research required a model system that could grow in vast quantities in the lab, were cheap to maintain and had a simple body plan, and he chose the nematode C. elegans to fulfill such a role. Since that time, C. elegans has emerged as one of the premiere model systems for aging research. This paper reviews some initial identification of mutants with altered lifespan with a focus on genetics and then discusses advantages and disadvantages for using C. elegans as a model system to understand human aging. This review focuses on molecular genetics aspects of this model organism.

  2. The Neuroethology of C. elegans Escape

    PubMed Central

    Pirri, Jennifer K.; Alkema, Mark J.

    2012-01-01

    Escape behaviors are crucial to survive predator encounters. Touch to the head of C. elegans induces an escape response where the animal rapidly backs away from the stimulus and suppresses foraging head movements. The coordination of head and body movements facilitates escape from predacious fungi that cohabitate with nematodes in organic debris. An appreciation of the natural habitat of laboratory organisms, like C. elegans, enables a comprehensive neuroethological analysis of behavior. In this review we discuss the neuronal mechanisms and the ecological significance of the C. elegans touch response. PMID:22226513

  3. Outline Var. integrability Var. smoothness DHR Sequence spaces Embeddings Proofs... Open problems Sobolev and Jawerth embeddings for spaces with

    E-print Network

    Novak, Erich

    Outline Var. integrability Var. smoothness DHR Sequence spaces Embeddings Proofs... Open problems Sobolev and Jawerth embeddings for spaces with variable smoothness and integrability January 2009 Sobolev and Jawerth embeddings for spaces with variable smoothness and integrability #12; Outline Var. integrability

  4. Gait synchronization in Caenorhabditis elegans

    PubMed Central

    Yuan, Jinzhou; Raizen, David M.; Bau, Haim H.

    2014-01-01

    Collective motion is observed in swarms of swimmers of various sizes, ranging from self-propelled nanoparticles to fish. The mechanisms that govern interactions among individuals are debated, and vary from one species to another. Although the interactions among relatively large animals, such as fish, are controlled by their nervous systems, the interactions among microorganisms, which lack nervous systems, are controlled through physical and chemical pathways. Little is known, however, regarding the mechanism of collective movements in microscopic organisms with nervous systems. To attempt to remedy this, we studied collective swimming behavior in the nematode Caenorhabditis elegans, a microorganism with a compact nervous system. We evaluated the contributions of hydrodynamic forces, contact forces, and mechanosensory input to the interactions among individuals. We devised an experiment to examine pair interactions as a function of the distance between the animals and observed that gait synchronization occurred only when the animals were in close proximity, independent of genes required for mechanosensation. Our measurements and simulations indicate that steric hindrance is the dominant factor responsible for motion synchronization in C. elegans, and that hydrodynamic interactions and genotype do not play a significant role. We infer that a similar mechanism may apply to other microscopic swimming organisms and self-propelled particles. PMID:24778261

  5. VAR Analysis and the Great Moderation

    Microsoft Academic Search

    Luca Benati; Paolo Surico

    2009-01-01

    Most analyses of the US Great Moderation are based on structural VARs, and point toward good luck as the main explanation for the recent macroeconomic stability. Based on an estimated New-Keynesian model where the only source of change is the move from passive to active monetary policy, we show that (i) the theoretical VAR innovation variances for all series decrease

  6. The 3D7 var5.2 ( var COMMON) type var gene family is commonly expressed in non-placental Plasmodium falciparum malaria

    Microsoft Academic Search

    Gerhard Winter; Qijun Chen; Kirsten Flick; Peter Kremsner; Victor Fernandez; Mats Wahlgren

    2003-01-01

    Relapse variants in chronic Plasmodium falciparum infections are antigenically distinct from the parental parasites. The variable antigen PfEMP1 expressed at the surface of the infected erythrocyte (IE) is encoded by the var gene family with ?60 copies per haploid genome. Placental isolates commonly express DBL? containing subtypes of var genes with homology to either 3D7var5.2 (varCOMMON) or FCR3varCSA. Here we

  7. Genetics of Aging in Caenorhabditis elegans

    Microsoft Academic Search

    Adam Antebi

    2007-01-01

    A dissection of longevity in Caenorhabditis elegans reveals that animal life span is influenced by genes, environment, and stochastic factors. From molecules to physiology, a remarkable degree of evolutionary conservation is seen.

  8. Large-scale transgenesis and nerve regeneration in C. elegans

    E-print Network

    Gilleland, Cody Lee

    2014-01-01

    Caenorhabditis elegans (C. elegans) is a widely studied model organism due to their fully mapped neural network of 302 neurons and amenable genetics. Their small size and short life cycle allows for rapid studies to be ...

  9. Chemically defined medium and Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Szewczyk, Nathaniel J.; Kozak, Elena; Conley, Catharine A.

    2003-01-01

    BACKGROUND: C. elegans has been established as a powerful genetic system. Use of a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of use in large-scale growth and screening of animals. RESULTS: We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats to using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change the composition of the defined medium. CONCLUSIONS: As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  10. Biotransformation of mirtazapine by Cunninghamella elegans.

    PubMed

    Moody, Joanna D; Freeman, James P; Fu, Peter P; Cerniglia, Carl E

    2002-11-01

    The fungus Cunninghamella elegans was used as a microbial model of mammalian metabolism to biotransform the tetracyclic antidepressant drug mirtazapine, which is manufactured as a racemic mixture of R(-)- and S(+)-enantiomers. In 168 h, C. elegans transformed 91% of the drug into the following seven metabolites: 8-hydroxymirtazapine, N-desmethyl-8-hydroxymirtazapine, N-desmethylmirtazapine, 13-hydroxymirtazapine, mirtazapine N-oxide, 12-hydroxymirtazapine, and N-desmethyl-13-hydroxymirtazapine. Circular dichroism spectral analysis of unused mirtazapine indicated that it was slightly enriched with the R(-)-enantiomer. When the fungus was treated with the optically pure forms of the drug, the S(+)-enantiomer produced all seven metabolites whereas the R(-)-enantiomer produced only 8-hydroxymirtazapine, N-desmethyl-8-hydroxymirtazapine, N-desmethylmirtazapine, and mirtazapine N-oxide. C. elegans produced five mammalian and two novel metabolites and is therefore a suitable microbial model for mirtazapine metabolism. PMID:12386135

  11. Metabolism of naphthalene by Cunninghamella elegans.

    PubMed Central

    Cerniglia, C E; Gibson, D T

    1977-01-01

    Cunninghamella elegans grown on Sabouraud dextrose broth in the presence of naphthalene produced six metabolites. Each product was isolated and identified by conventional chemical techniques. The major metabolites were 1-naphthol (67.9%) and 4-hydroxy-1-tetralone (16.7%). Minor products isolated were 1,4-naphthoquinone (2.8%), 1,2-naphthoquinone (0.2%), 2-naphthol (6.3%), and trans-1,2-dihydroxy-1,2-dihydronaphthalene (5.3%). C. elegans oxidized both 1-naphthol and 1,4-naphthoquinone to 4-hydroxy-1-tetralone. The results suggest that C. elegans oxidizes naphthalene by a sequence of reactions similar to those reported for the mammalian metabolism of this hydrocarbon. PMID:921262

  12. Eph receptor signaling in C. elegans

    PubMed Central

    Miller, Michael A.; Chin-Sang, Ian D.

    2014-01-01

    Eph receptor protein-tyrosine kinases are among the oldest known animal receptors and have greatly expanded in number during vertebrate evolution. Their complex transduction mechanisms are capable of bidirectional and bimodal (multi-response) signaling. Eph receptors are expressed in almost every cell type in the human body, yet their roles in development, physiology, and disease are incompletely understood. Studies in C. elegans have helped identify biological functions of these receptors, as well as transduction mechanisms. Here we review advances in our understanding of Eph receptor signaling made using the C. elegans model system. PMID:23197476

  13. Induction of germline apoptosis in Caenorhabditis elegans.

    PubMed

    Lant, Benjamin; Derry, W Brent

    2014-03-01

    RNA interference (RNAi) is an incredibly powerful tool for rapid and efficient knockdown of gene expression. This technology can be used to induce apoptosis in the germline of Caenorhabditis elegans. Genotoxic stressors such as ionizing radiation (IR), ultraviolet light, chemical mutagens (e.g., N-ethyl-N-nitrosourea [ENU]), and DNA cross-linking reagents can also be used to stimulate apoptosis. These approaches, described here, combined with the powers of in vivo imaging methods, should keep C. elegans apoptosis researchers busy for several years, sorting out how various signaling pathways influence life and death decisions in this organism. PMID:24591690

  14. Caenorhabditis elegans neuronal regeneration is influenced by life stage, ephrin signaling,

    E-print Network

    Yanik, Mehmet Fatih

    Caenorhabditis elegans neuronal regeneration is influenced by life stage, ephrin signaling functional regeneration of Caenorhabditis elegans motor neurons after femtosecond laser axotomy. We report in C. elegans neurons. axotomy laser femtosecond laser microsurgery Regeneration of neuronal processes

  15. A protocol to infect Caenorhabditis elegans with Salmonella typhimurium.

    PubMed

    Zhang, Jiuli; Jia, Kailiang

    2014-01-01

    In the last decade, C. elegans has emerged as an invertebrate organism to study interactions between hosts and pathogens, including the host defense against gram-negative bacterium Salmonella typhimurium. Salmonella establishes persistent infection in the intestine of C. elegans and results in early death of infected animals. A number of immunity mechanisms have been identified in C. elegans to defend against Salmonella infections. Autophagy, an evolutionarily conserved lysosomal degradation pathway, has been shown to limit the Salmonella replication in C. elegans and in mammals. Here, a protocol is described to infect C. elegans with Salmonella typhimurium, in which the worms are exposed to Salmonella for a limited time, similar to Salmonella infection in humans. Salmonella infection significantly shortens the lifespan of C. elegans. Using the essential autophagy gene bec-1 as an example, we combined this infection method with C. elegans RNAi feeding approach and showed this protocol can be used to examine the function of C. elegans host genes in defense against Salmonella infection. Since C. elegans whole genome RNAi libraries are available, this protocol makes it possible to comprehensively screen for C. elegans genes that protect against Salmonella and other intestinal pathogens using genome-wide RNAi libraries. PMID:24998902

  16. Guidelines for monitoring autophagy in Caenorhabditis elegans.

    PubMed

    Zhang, Hong; Chang, Jessica T; Guo, Bin; Hansen, Malene; Jia, Kailiang; Kov醕s, Attila L; Kumsta, Caroline; Lapierre, Louis R; Legouis, Renaud; Lin, Long; Lu, Qun; Mel閚dez, Alicia; O'Rourke, Eyleen J; Sato, Ken; Sato, Miyuki; Wang, Xiaochen; Wu, Fan

    2015-01-01

    The cellular recycling process of autophagy has been extensively characterized with standard assays in yeast and mammalian cell lines. In multicellular organisms, numerous external and internal factors differentially affect autophagy activity in specific cell types throughout the stages of organismal ontogeny, adding complexity to the analysis of autophagy in these metazoans. Here we summarize currently available assays for monitoring the autophagic process in the nematode C. elegans. A combination of measuring levels of the lipidated Atg8 ortholog LGG-1, degradation of well-characterized autophagic substrates such as germline P granule components and the SQSTM1/p62 ortholog SQST-1, expression of autophagic genes and electron microscopy analysis of autophagic structures are presently the most informative, yet steady-state, approaches available to assess autophagy levels in C. elegans. We also review how altered autophagy activity affects a variety of biological processes in C. elegans such as L1 survival under starvation conditions, dauer formation, aging, and cell death, as well as neuronal cell specification. Taken together, C. elegans is emerging as a powerful model organism to monitor autophagy while evaluating important physiological roles for autophagy in key developmental events as well as during adulthood. PMID:25569839

  17. Movie of normal C. elegans development

    NSDL National Science Digital Library

    PhD Bob Goldstein (UNC Chapel Hill Biology Dept,)

    2006-07-19

    C. elegans develops from a single cell, the fertilized egg, to a 558-celled worm in about 14 hours. The worm that crawls out of its eggshell has a functioning feeding apparatus, gut, nervous system and muscles. This movie shows that in time lapse.

  18. Programmed Cell Death in C. elegans

    Microsoft Academic Search

    Andrew G. Fraser

    1999-01-01

    Genetic screens in the hermaphrodite nematode worm Caenorhabditis elegans resulted in the identification of the basal conserved machinery of apoptosis, arguably the single most important finding for our understanding of cell death. The last two years have seen enormous progress in the elucidation of the molecular interactions that lie at the heart of this conserved machinery, along with major insights

  19. The microRNAs of Caenorhabditis elegans

    E-print Network

    Bartel, David

    in the nematode Caenorhabditis elegans. The total number of validated miRNA genes stands at 88, with no more than of their roles in mediating RNA interference (RNAi) in ani- mals and posttranscriptional gene silencing in plants. 2001a; Klahre et al. 2002). During RNAi, long double- stranded RNA (either a bimolecular duplex

  20. Staphylococcal Biofilm Exopolysaccharide Protects against Caenorhabditis elegans

    E-print Network

    Ausubel, Frederick M.

    Staphylococcal Biofilm Exopolysaccharide Protects against Caenorhabditis elegans Immune Defenses of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere that the icaADBC locus, which synthesizes the biofilm-associated polysaccharide intercellular adhesin (PIA

  1. RNAi mechanisms in Caenorhabditis elegans Alla Grishok*

    E-print Network

    Grishok, Alla

    Minireview RNAi mechanisms in Caenorhabditis elegans Alla Grishok* Center for Cancer Research, MIT (RNAi) is a form of gene silencing induced by double stranded RNA (dsRNA) that is processed into short interfering RNAs (siRNAs). RNAi can induce both post-transcriptional and transcriptional gene silencing

  2. Transgenesis in C. elegans Vida Praitisy

    E-print Network

    Maduro, Morris F.

    of Gene Function G. Marking Extrachromosomal Arrays to Probe Gene Regulation III. Construction., 1994). The discovery of RNA-mediated interfer- ence (RNAi) (Fire et al., 1998) expanded further of all three approaches: genetics, transgenes, and RNAi. Early approaches for transgenesis in C. elegans

  3. Characterization of the C. elegans erlin homologue

    PubMed Central

    2012-01-01

    Background Erlins are highly conserved proteins associated with lipid rafts within the endoplasmic reticulum (ER). Biochemical studies in mammalian cell lines have shown that erlins are required for ER associated protein degradation (ERAD) of activated inositol-1,4,5-trisphosphate receptors (IP3Rs), implying that erlin proteins might negatively regulate IP3R signalling. In humans, loss of erlin function appears to cause progressive intellectual disability, motor dysfunction and joint contractures. However, it is unknown if defects in IP3R ERAD are the underlying cause of this disease phenotype, whether ERAD of activated IP3Rs is the only function of erlin proteins, and what role ERAD plays in regulating IP3R-dependent processes in the context of an intact animal or embryo. In this study, we characterize the erlin homologue of the nematode Caenorhabditis elegans and examine erlin function in vivo. We specifically set out to test whether C. elegans erlin modulates IP3R-dependent processes, such as egg laying, embryonic development and defecation rates. We also explore the possibility that erlin might play a more general role in the ERAD pathway of C. elegans. Results We first show that the C. elegans erlin homologue, ERL-1, is highly similar to mammalian erlins with respect to amino acid sequence, domain structure, biochemical properties and subcellular location. ERL-1 is present throughout the C. elegans embryo; in adult worms, ERL-1 appears restricted to the germline. The expression pattern of ERL-1 thus only partially overlaps with that of ITR-1, eliminating the possibility of ERL-1 being a ubiquitous and necessary regulator of ITR-1. We show that loss of ERL-1 does not affect overall phenotype, or alter brood size, embryonic development or defecation cycle length in either wild type or sensitized itr-1 mutant animals. Moreover we show that ERL-1 deficient worms respond normally to ER stress conditions, suggesting that ERL-1 is not an essential component of the general ERAD pathway. Conclusions Although loss of erlin function apparently causes a strong phenotype in humans, no such effect is seen in C. elegans. C. elegans erlin does not appear to be a ubiquitous major modulator of IP3 receptor activity nor does erlin appear to play a major role in ERAD. PMID:22269071

  4. Capacitor-Less VAR Compensator Based on a Matrix Converter

    E-print Network

    Balakrishnan, Divya Rathna

    2012-02-14

    (chokes) instead of capacitors to supply reactive power to support the load. Chokes are regarded as robust and rugged elements; but, they operate with lagging power factor and thus consume VARs instead of generating VARs like capacitors. A matrix converter...

  5. A Polymorphism in npr-1 Is a Behavioral Determinant of Pathogen Susceptibility in C. elegans

    E-print Network

    Reddy, Kirthi C.

    The nematode Caenorhabditis elegans responds to pathogenic bacteria with conserved innate immune responses and pathogen avoidance behaviors. We investigated natural variation in C. elegans resistance to pathogen infection. ...

  6. Basic Caenorhabditis elegans Methods: Synchronization and Observation

    PubMed Central

    Porta-de-la-Riva, Montserrat; Fontrodona, Laura; Villanueva, Alberto; Cer髇, Juli醤

    2012-01-01

    Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3. C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them. PMID:22710399

  7. Basic Caenorhabditis elegans methods: synchronization and observation.

    PubMed

    Porta-de-la-Riva, Montserrat; Fontrodona, Laura; Villanueva, Alberto; Cer髇, Juli醤

    2012-01-01

    Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved. C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology, aging, stem cell biology and germ line biology. An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them. PMID:22710399

  8. Hormetic effect of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J., E-mail: Kirsten.J.Helmcke@gmail.com; Aschner, Michael, E-mail: Michael.Aschner@vanderbilt.ed

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis.

  9. Efficient strategies for deriving the subset VAR models

    Microsoft Academic Search

    Cristian Gatu; Erricos John Kontoghiorghes

    2005-01-01

    Algorithms for computing the subset Vector Autoregressive (VAR) models are proposed. These algorithms can be used to choose a subset of the most statistically-significant variables of a VAR model. In such cases, the selection criteria are based on the residual sum of squares or the estimated residual covariance matrix. The VAR model with zero coefficient restrictions is formulated as a

  10. C. Elegans Chemotaxis and Reproduction Following Environmental Exposure

    Microsoft Academic Search

    Mulumebet Worku; Carresse Gerald

    \\u000a The free-living nematode Caenorhabditis elegans (C. elegans) is a well established biological model. Chemotaxis is an important behavior in enabling it to locate food sources\\u000a such as E.coli. This study evaluates the chemotaxis of C.elegans to food following exposure to Moxidectin (Cydectin), Black Seed Oil, non-fat milk, or colostrum. A ring of bacteria (food)\\u000a on nematode growth agar medium served

  11. Receptor-mediated Endocytosis in the Caenorhabditis elegans Oocyte

    Microsoft Academic Search

    Barth Grant; David Hirsh

    1999-01-01

    The Caenorhabditis elegans oocyte is a highly amenable system for forward and reverse genetic analysis of receptor-mediated endocytosis. We describe the use of transgenic strains expressing a vitellogenin::green fluorescent protein (YP170::GFP) fusion to monitor yolk endocytosis by the C. elegans oocyte in vivo. This YP170::GFP reporter was used to assay the functions of C. elegans predicted proteins homologous to vertebrate

  12. Bacteria and the Aging and Longevity of Caenorhabditis elegans

    E-print Network

    Kim, Dennis H.

    The molecular genetic analysis of longevity of Caenorhabditis elegans has yielded fundamental insights into evolutionarily conserved pathways and processes governing the physiology of aging. Recent studies suggest that ...

  13. Lipid constituents of Trifolium resupinatum var. microcephalum

    Microsoft Academic Search

    Temine Sabudak; Emel Isik; Sevil Oksuz

    2007-01-01

    The two new compounds (3-methyl-1-nonene-3-ol and 2?,3?-dihydroxy propyl pentadecanoate) and four known compounds were isolated from Trifolium resupinatum L. var. microcephalum Zoh. (Leguminosae). All the compounds were reported for the first time from this plant. The stuructures of the isolates were determined by 1D, 2D NMR techniques and MS spectroscopy.

  14. Lipid constituents of Trifolium resupinatum var. microcephalum.

    PubMed

    Sabudak, Temine; Isik, Emel; Oksuz, Sevil

    2007-07-20

    The two new compounds (3-methyl-1-nonene-3-ol and 2',3'-dihydroxy propyl pentadecanoate) and four known compounds were isolated from Trifolium resupinatum L. var. microcephalum Zoh. (Leguminosae). All the compounds were reported for the first time from this plant. The stuructures of the isolates were determined by 1D, 2D NMR techniques and MS spectroscopy. PMID:17654289

  15. Hexagram converter for static VAR compensation

    Microsoft Academic Search

    Jun Wen; K. M. Smedley

    2008-01-01

    A new multilevel converter - Hexagram converter is proposed for static VAR compensation in high-voltage high- power applications. The new converter is composed of six three- phase two-level standard voltage source converter (VSC) modules interconnected through inductors. It has the advantages of modular structure leading to easy construction and maintenance, no voltage unbalance, low voltage stress, low dc energy storage,

  16. PROPUESTA DE ACTIVIDAD TIC-VAR-005

    E-print Network

    Autonoma de Madrid, Universidad

    PROPUESTA DE ACTIVIDAD ACAD蒑ICA TIC-VAR-005 TIPO DE ACTIVIDAD1 : PFC, PPG, TM 罵EA2 : TIC T蚑ULO Mozambique PERSONA QUE PROPONE M Fernanda Dulcey, Coordinadora de TICs Tel閒ono o correo-e de contacto espec韋ico, sin que tenga necesariamente un fin acad閙ico. 2 TIC, Agua, Energ韆, Desarrollo Agropecuario y

  17. Estimation of VAR Models Computational Aspects

    Microsoft Academic Search

    Paolo Foschi; Erricos J. Kontoghiorghes

    2003-01-01

    The Vector Autoregressive (VAR) model with zero coefficient restrictions canbe formulated as a Seemingly Unrelated Regression Equation (SURE) model. Boththe response vectors and the coefficient matrix of the regression equationscomprise columns from a Toeplitz matrix. Efficient numerical and computationalmethods which exploit the Toeplitz and Kronecker product structure of thematrices are proposed. The methods are also adapted to provide numericallystable algorithms

  18. Metal-induced neurodegeneration in C. elegans

    PubMed Central

    Chen, Pan; Martinez-Finley, Ebany J.; Bornhorst, Julia; Chakraborty, Sudipta; Aschner, Michael

    2013-01-01

    The model species, Caenorhabditis elegans, has been used as a tool to probe for mechanisms underlying numerous neurodegenerative diseases. This use has been exploited to study neurodegeneration induced by metals. The allure of the nematode comes from the ease of genetic manipulation, the ability to fluorescently label neuronal subtypes, and the relative simplicity of the nervous system. Notably, C. elegans have approximately 6080% of human genes and contain genes involved in metal homeostasis and transport, allowing for the study of metal-induced degeneration in the nematode. This review discusses methods to assess degeneration as well as outlines techniques for genetic manipulation and presents a comprehensive survey of the existing literature on metal-induced degeneration studies in the worm. PMID:23730287

  19. Caenorhabditis elegans Pheromones Regulate Multiple Complex Behaviors

    PubMed Central

    Edison, Arthur S.

    2009-01-01

    Summary of recent advances A family of small molecules called ascarosides act as pheromones to control multiple behaviors in the nematode Caenorhabditis elegans. At picomolar concentrations, a synergistic mixture of at least three ascarosides produced by hermaphrodites causes male-specific attraction. At higher concentrations, the same ascarosides, perhaps in a different mixture, induce the developmentally arrested stage known as dauer. The production of ascarosides is strongly dependent on environmental conditions, although relatively little is known about the major variables and mechanisms of their regulation. Thus, male mating and dauer formation are linked through a common set of small molecules whose expression is sensitive to a given microenvironment, suggesting a model by which ascarosides regulate the overall life cycle of C. elegans. PMID:19665885

  20. In Vivo Imaging of Caenorhabditis elegans Glycans

    PubMed Central

    2009-01-01

    The nematode Caenorhabditis elegans is an excellent model organism for studies of glycan dynamics, a goal that requires tools for imaging glycans in vivo. Here we applied the bioorthogonal chemical reporter technique for the molecular imaging of mucin-type O-glycans in live C. elegans. We treated worms with azidosugar variants of N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GalNAc), and N-acetylmannosamine (ManNAc), resulting in the metabolic labeling of their cell-surface glycans with azides. Subsequently, the worms were reacted via copper-free click reaction with fluorophore-conjugated difluorinated cyclooctyne (DIFO) reagents. We identified prominent localization of mucins in the pharynx of all four larval stages, in the adult hermaphrodite pharynx, vulva and anus, and in the tail of the adult male. Using a multicolor, time-resolved imaging strategy, we found that the distribution and dynamics of the glycans varied anatomically and with respect to developmental stage. PMID:19954190

  1. Mechanisms of iron metabolism in Caenorhabditis elegans

    PubMed Central

    Anderson, Cole P.; Leibold, Elizabeth A.

    2014-01-01

    Iron is involved in many biological processes essential for sustaining life. In excess, iron is toxic due to its ability to catalyze the formation of free radicals that damage macromolecules. Organisms have developed specialized mechanisms to tightly regulate iron uptake, storage and efflux. Over the past decades, vertebrate model organisms have led to the identification of key genes and pathways that regulate systemic and cellular iron metabolism. This review provides an overview of iron metabolism in the roundworm Caenorhabditis elegans and highlights recent studies on the role of hypoxia and insulin signaling in the regulation of iron metabolism. Given that iron, hypoxia and insulin signaling pathways are evolutionarily conserved, C. elegans provides a genetic model organism that promises to provide new insights into mechanisms regulating mammalian iron metabolism. PMID:24904417

  2. C. elegans Gene Index (CeGI)

    NSDL National Science Digital Library

    The Institute for Genomic Research (TIGR) has released the C. elegans Gene Index (CeGI), including over 22,900 unique sequences (TCs, ETs, and ESTs). CeGI includes data files (FASTA) "containing the complete, minimally redundant C. elegans Index (TCs and singletons),... the complete set of TC sequences in the Index (with previous TC identities in the definition line), ... [and] a file containing the TC id's and the ESTs that comprise them." The Index is searchable by Nucleotide or Protein Sequence, Identifier (TC, ET, EST, GB), or Tissue, cDNA Library Name, or cDNA Library Identifier(cat#). Note that all data in CeGI are "freely available to researchers at nonprofit institutions using them for non-commercial purposes."

  3. Extracellular Proteins Needed for C. elegans Mechanosensation

    Microsoft Academic Search

    Hongping Du; Guoqiang Gu; Chris M William; Martin Chalfie

    1996-01-01

    The mec-5 and mec-9 genes encode putative extracellular proteins that allow a set of six touch receptor neurons in C. elegans to respond to gentle touch. MEC-5 is a collagen made by the epidermal cells that surround the touch cells. Mutations causing touch insensitivity affect the Gly-X-Y repeats of this collagen. mec-9 produces two transcripts, the larger of which is

  4. New phenolic compounds from Liatris elegans

    Microsoft Academic Search

    Zhizhen Zhang; Stacy Ownby; Ping Wang; Wei Yuan; Wanli Zhang; Shiyou Li

    2010-01-01

    Chemical investigation on the whole plants of Liatris elegans resulted in the isolation and identification of the new ferulic acid ester (1) and arylnaphthalene lignan (2), together with 13 known compounds. The structures of the new compounds were established as p-hydroxyphenylferulate (1) and 5,3?-dihydroxy-4,4?-dimethoxy-2,7?-cycloligna-7,7?-diene-9,9?-lactone (2) by extensive NMR and HRESIMS spectroscopic analyses.

  5. Claudin family proteins in Caenorhabditis elegans.

    PubMed

    Simske, Jeffrey S; Hardin, Jeff

    2011-01-01

    In the last decade, the claudin family of integral membrane proteins has been identified as the major protein component of the tight junctions in all vertebrates. The claudin superfamily proteins also function to regulate channel activity, intercellular signaling, and cell morphology. Subsequently, claudin homologues have been identified in invertebrates, including Drosophila and Caenorhabditis elegans. Recent studies demonstrate that the C. elegans claudins, clc-1 to clc-5, and similar proteins in the greater PMP22/EMP/claudin/calcium channel ? subunit family, including nsy-1-nsy-4 and vab-9, while highly divergent at a sequence level from each other and from the vertebrate claudins, in some cases play roles similar to those traditionally assigned to their vertebrate homologues. These include regulating cell adhesion and passage of small molecules through the paracellular space. The claudin superfamily proteins also function to regulate channel activity, intercellular signaling, and cell morphology. Study of claudin superfamily proteins in C. elegans should continue to provide clues as to how core claudin protein function can be modified to serve various specific roles at regions of cell-cell contact in metazoans. PMID:21717355

  6. Toxicological Effects of Fullerenes on Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Schomaker, Justin; Snook, Renee; Howell, Carina

    2014-03-01

    The nematode species Caenorhabditis elegans is a useful genetic model organism due to its simplicity and the substantial molecular, genetic, and developmental knowledge about the species. In this study, this species was used to test the toxicological effects of C60 fullerene nanoparticles. In previous studies using rats, a solution of C60 fullerenes in olive oil proved to extend the life of the subjects. The purpose of this experiment was to subject C. elegans to varying concentrations of C60 fullerenes and observe their toxicological effects. Initial findings indicate a link between fullerene exposure and enlargement of the vulva as well as the formation of a small nodule at the base of the tail in some individuals. While the fullerenes are not lethally toxic in C. elegans, results will be presented that pertain to changes in life span and progeny of the nematodes exposed to varying concentrations of fullerenes as well as the mechanisms of toxicity. High magnification imaging via SEM and/or AFM will be used to characterize the fullerene nanoparticles. Testing the toxicity of fullerenes in a wide variety of organisms will lead to a more complete understanding of the effects of fullerenes on living organisms to ultimately understand their effects in humans. This work was supported by National Science Foundation grants DUE-1058829, DMR-0923047, DUE-0806660 and Lock Haven FPDC grants.

  7. Glianeuron interactions in the nervous system of Caenorhabditis elegans

    E-print Network

    Shaham, Shai

    Author's personal copy Glia颅neuron interactions in the nervous system of Caenorhabditis elegans their intricate and important roles in nervous system development and function. Recent studies in the nematode, functional and molecular features of the nervous systems between C. elegans and vertebrates, these recent

  8. A novel mode of ecdysozoan growth in Caenorhabditis elegans

    Microsoft Academic Search

    Christopher G. Knight; Mavji N. Patel; Ricardo B. R. Azevedo; Armand M. Leroi

    2002-01-01

    SUMMARY Whereas growth in many ecdysozoa is associ- ated with only molting, larval growth in nematodes, specifical- ly Caenorhabditis elegans , is thought to be continuous and exponential. However, this has never been closely investigat- ed. Here we report several detailed studies of growth in wild- type and dwarf C. elegans strains. We find that apparent ex- ponential growth between

  9. Chromosome dosage as a life span determinant in Caenorhabiditis elegans

    Microsoft Academic Search

    Phil S. Hartman; Naoaki Ishii

    2007-01-01

    Caenorhabiditis elegans males live longer than hermaphrodites when cultured individually. Since hermaphrodites contain a pair of X chromosomes (XX) and males are XO (there is no Y chromosome in C. elegans), we questioned whether chromosomal differences per se might impact life span. The use of mutations in the sex-determination genes tra-1 and her-1 allowed us to uncouple sexual phenotype from

  10. A Relationship Between Thermotolerance and Longevity in Caenorhabditis elegans

    Microsoft Academic Search

    Glenda A Walker; David W Walker; Gordon J Lithgow

    1998-01-01

    Studies of aging in the nematode Caenorhabditis elegans have revealed a relationship between stress resistance and the rate of aging: Mutations which extend mean and maximum life-span also confer resistance to thermal stress. We review the molecular genetics of aging in C. elegans and introduce methods for obtaining novel mutants which display altered aging rates. We present the use of

  11. Polymorphic segmental duplication in the nematode Caenorhabditis elegans

    Microsoft Academic Search

    Ismael A Vergara; Allan K Mah; Jim C Huang; Maja Tarailo-Graovac; Robert C Johnsen; David L Baillie; Nansheng Chen

    2009-01-01

    BACKGROUND: The nematode Caenorhabditis elegans was the first multicellular organism to have its genome fully sequenced. Over the last 10 years since the original publication in 1998, the C. elegans genome has been scrutinized and the last gaps were filled in November 2002, which present a unique opportunity for examining genome-wide segmental duplications. RESULTS: Here, we performed analysis of the

  12. Biomechanical analysis of gait adaptation in the nematode Caenorhabditis elegans

    E-print Network

    Biomechanical analysis of gait adaptation in the nematode Caenorhabditis elegans Christopher Fang to adapt its locomotory gait to its physical surroundings. The nema- tode Caenorhabditis elegans, between swimming in water and crawling on surfaces, adapts its locomotory gait to surroundings that impose

  13. Quantitative Classification and Natural Clustering of C. elegans Behavioral Phenotypes

    E-print Network

    Cosman, Pamela C.

    Learning; Phenotypic analysis #12;2 ABSTRACT Genetic analysis of nervous system function relies the behavioral patterns of C. elegans nervous system mutants. We have used an automated tracking and image. elegans has a simple nervous system consisting of 302 neurons of known position, cell lineage

  14. Molecular Correlates of Genes Exhibiting RNAi Phenotypes in Caenorhabditis elegans

    E-print Network

    Good, Jeffrey M.

    Molecular Correlates of Genes Exhibiting RNAi Phenotypes in Caenorhabditis elegans Asher D. Cutter particular RNAi phenotypes in Caenorhabditis elegans and sequence characteristics of the corresponding proteins and DNA. We find that genes showing RNAi phenotypes are long and highly expressed with little

  15. Variable Pathogenicity Determines Individual Lifespan in Caenorhabditis elegans

    Microsoft Academic Search

    Adolfo S醤chez-Blanco; Stuart K. Kim

    2011-01-01

    A common property of aging in all animals is that chronologically and genetically identical individuals age at different rates. To unveil mechanisms that influence aging variability, we identified markers of remaining lifespan for Caenorhabditis elegans. In transgenic lines, we expressed fluorescent reporter constructs from promoters of C. elegans genes whose expression change with age. The expression levels of aging markers

  16. Laser Microsurgery in Caenorhabditis elegans Christopher Fang-Yen*

    E-print Network

    Fang-Yen, Christopher

    CHAPTER 6 Laser Microsurgery in Caenorhabditis elegans Christopher Fang-Yen* , Christopher V. Identifying Cells in C. elegans III. Laser Ablation Theory and Apparatus A. Tissue Damage by Nanosecond and Femtosecond Lasers B. The Laser Apparatus IV. Laser Killing of Cells A. Procedures B. Experimental Design

  17. Evaluation of the pathogenicity of Listeria spp. in Caenorhabditis elegans.

    PubMed

    Forrester, Stacyann; Milillo, Sara Rose; Hoose, Wendy A; Wiedmann, Martin; Schwab, Ute

    2007-01-01

    Caenorhabditis has proven to be a useful model for studying host-pathogen interactions as well as the ability of nematodes to serve as vectors for the dispersal of foodborne pathogens. In this study, we evaluated whether C. elegans can serve as a host for Listeria spp. While there was an effect of growth media on C. elegans killing, C. elegans exposed to L. monocytogenes and L. innocua pregrown in Luria-Bertani medium showed reduced survival when compared to nonpathogenic E. coli OP50, while L. seeligeri showed survival similar to E. coli OP50. In a preference assay, C. elegans preferred E. coli over L. monocytogenes and L. innocua, but showed no preference between L. monocytogenes and L. innocua. A gentamicin assay indicated that L. monocytogenes did not persist within the C. elegans intestinal tract. Our findings that L. monocytogenes and L. innocua strains tested have equally deleterious effects on C. elegans and that L. monocytogenes did not establish intestinal infection conflict with other recently published results, which found intestinal infection and killing of C. elegans by L. monocytogenes. Further studies are thus needed to clarify the interactions between L. monocytogenes and C. elegans, including effects of environmental conditions and strain differences on killing and intestinal infection. PMID:17378710

  18. Nerve Regeneration in Caenorhabditis elegans After Femtosecond Laser Axotomy

    Microsoft Academic Search

    Mehmet Fatih Yanik; Hulusi Cinar; Hediye Nese Cinar; Aaron Gibby; Andrew D. Chisholm; Yishi Jin; Adela Ben-Yakar

    2006-01-01

    We perform submicrometer-scale surgery with femtosecond lasers to study nerve regeneration in the tiny nematode Caenorhabditis elegans, an invertebrate model organism with only 302 neurons. By cutting nanoscale nerve connections inside the nematode C. elegans , the feedback loops that control backward motion of the worm can be disconnected. This operation stops the whole worm from moving backward while leaving

  19. Bioactive constituents of Cirsium japonicum var. australe.

    PubMed

    Lai, Wan-Chun; Wu, Yang-Chang; Dank, Bal醶s; Cheng, Yuan-Bin; Hsieh, Tusty-Jiuan; Hsieh, Chi-Ting; Tsai, Yu-Chi; El-Shazly, Mohamed; Martins, Ana; Hohmann, Judit; Hunyadi, Attila; Chang, Fang-Rong

    2014-07-25

    Cirsium japonicum var. australe, used as a folk medicine in Taiwan, has been employed traditionally in the treatment of diabetes and inflammatory symptoms. Bioactivity-guided fractionation of its ethanolic extract, utilizing centrifugal partition chromatography monitored by DPPH-TLC analysis, led to the isolation of three new acetylenic phenylacrylic acid esters (1-3) and two new polyacetylenes (4 and 5), together with seven known compounds (6-12). The structures of 1-5 were elucidated by spectroscopic methods including 1D and 2D NMR techniques. The absolute configurations of 4 and 7 were determined utilizing Mosher's method and ECD/CD experiments. The DPPH scavenging activity of the constituents isolated from the C. japonicum var. australe ethanolic extract was evaluated. The potential antidiabetic activity of some of the isolates was evaluated using in vitro cellular glucose uptake and oil red staining assays. PMID:25025240

  20. Receptor-mediated Endocytosis in the Caenorhabditis elegans Oocyte

    PubMed Central

    Grant, Barth; Hirsh, David

    1999-01-01

    The Caenorhabditis elegans oocyte is a highly amenable system for forward and reverse genetic analysis of receptor-mediated endocytosis. We describe the use of transgenic strains expressing a vitellogenin::green fluorescent protein (YP170::GFP) fusion to monitor yolk endocytosis by the C. elegans oocyte in vivo. This YP170::GFP reporter was used to assay the functions of C. elegans predicted proteins homologous to vertebrate endocytosis factors using RNA-mediated interference. We show that the basic components and pathways of endocytic trafficking are conserved between C. elegans and vertebrates, and that this system can be used to test the endocytic functions of any new gene. We also used the YP170::GFP assay to identify rme (receptor-mediated endocytosis) mutants. We describe a new member of the low-density lipoprotein receptor superfamily, RME-2, identified in our screens for endocytosis defective mutants. We show that RME-2 is the C. elegans yolk receptor. PMID:10588660

  1. MAP kinase cascades regulating axon regeneration in C. elegans

    PubMed Central

    PASTUHOV, Strahil Iv.; HISAMOTO, Naoki; MATSUMOTO, Kunihiro

    2015-01-01

    Mitogen-activated protein kinase (MAPK) signaling cascades are activated by diverse stimuli such as growth factors, cytokines, neurotransmitters and various types of cellular stress. Our evolving understanding of these signal cascades has been facilitated by genetic analyses and physiological characterization in model organisms such as the nematode Caenorhabditis elegans. Genetic and biochemical studies in C. elegans have shed light on the physiological roles of MAPK cascades in the control of cell fate decision, neuronal function and immunity. Recently it was demonstrated that MAPK signaling is also important for axon regeneration in C. elegans, and the use of C. elegans as a model system has significantly advanced our understanding of the largely conserved molecular mechanisms underlying axon regeneration. This review summarizes our current understanding of the role and regulation of MAPK signaling in C. elegans axon regeneration. PMID:25792136

  2. Withanolides from Jaborosa caulescens var. bipinnatifida

    PubMed Central

    Zhang, Huaping; Cao, Cong-Mei; Gallagher, Robert J.; Day, Victor W.; Montenegro, Gloria; Timmermann, Barbara N.

    2013-01-01

    Two new withanolides 2,3-dihydrotrechonolide A (1) and 2,3-dihydro-21-hydroxytrechonolide A (2) were isolated along with two known withanolides trechonolide A (3) and jaborosalactone 39 (4) from Jaborosa caulescens var. bipinnatifida (Solanaceae). The structures of 1-2 were elucidated through 2D NMR and other spectroscopic techniques. In addition, the structure of withanolide 1 was confirmed by X-ray crystallographic analysis. PMID:24314746

  3. Steroidal saponins from Hemerocallis fulva var. kwanso.

    PubMed

    Konishi, T; Fujiwara, Y; Konoshima, T; Kiyosawa, S; Nishi, M; Miyahara, K

    2001-03-01

    Two steroidal saponins, hemeroside A and B, were isolated from the aerial part of Hemerocallis fulva var. kwanso for the first time. The structures of these compounds were established as 24S-hydroxy-neotokorogenin 1-O-alpha-L-arabinopyranosyl 24-O-beta-D-glucopyranoside (1) and isorhodeasapogenin 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside (2) through NMR experiments. PMID:11253923

  4. Pharmacognostical Studiies on Aglaia Roxburghiana Miq. Var. Beddomei

    PubMed Central

    Sasikala, E.; Janaki, S.; Rao, Bhima; Vijayasekaran, V.

    1999-01-01

    Morphological, anatomical, quantitative microscopy powder microscopy, physical constant preliminary phytochemical analysis and fluorescence analysis of the leaves of Aglaia roxburghiana Var. Beddome were carried out. PMID:22556922

  5. Longevity and stress in Caenorhabditis elegans

    PubMed Central

    Zhou, Katherine I.; Pincus, Zachary; Slack, Frank J.

    2011-01-01

    It has long been understood that many of the same manipulations that increase longevity in Caenorhabditis elegans also increase resistance to various acute stressors, and vice-versa; moreover these findings hold in more complex organisms as well. Nevertheless, the mechanistic relationship between these phenotypes remains unclear, and in many cases the overlap between stress resistance and longevity is inexact. Here we review the known connections between stress resistance and longevity, discuss instances in which these connections are absent, and summarize the theoretical explanations that have been posited for these phenomena. PMID:21937765

  6. Nuclear receptor signal transduction in C. elegans.

    PubMed

    Antebi, Adam

    2015-01-01

    Nuclear receptors are transcription factors that often respond to small molecule metabolites and fat-soluble compounds to regulate gene expression. They broadly govern development, reproduction, metabolism, and homeostasis in diverse metazoan species and their dysregulation is associated with numerous diseases. Work in C. elegans has shed light on the seminal role of nuclear receptors in life history regulation, stem cell progression, developmental timing, cell fate specification, nutrient sensing, metabolism, and longevity. Here we highlight recent advances on the best-studied nuclear receptors in the worm, and how they illuminate metazoan biology. PMID:26069085

  7. Caenorhabditis elegans as a model system for identifying effectors of a-synuclein misfolding and dopaminergic cell death associated

    E-print Network

    Caldwell, Guy

    -syn misfolding and toxicity in the nematode roundworm, Caenorhabditis elegans. Transgenic nematodes engineered interference (RNAi) and transgenic gene expression to functionally elucidate potential therapeutic gene targets models available to study PD, the nematode Caenorhabditis elegans (C. elegans) has proven

  8. PCH-2 regulates Caenorhabditis elegans lifespan

    PubMed Central

    Qian, Hong; Xu, Xiangru; Niklason, Laura E

    2015-01-01

    Components or downstream targets of many signaling pathways such as Insulin/IGF-1 and TOR, as well as genes involved in cellular metabolism and bioenergetics can extend worm lifespan 20% or more. The C. elegans gene pch-2 and its homologs, including TRIP13 in humans, have been studied for their functions in cell mitosis and meiosis, but have never been implicated in lifespan regulation. Here we show that over-expression of TRIP13 in human fibroblasts confers resistance to environmental stressors such as UV radiation and oxidative stress. Furthermore, pch-2 overexpression in C. elegans extends worm lifespan, and enhances worm survival in response to various stressors. Conversely, reducing pch-2 expression with RNAi shortens worm lifespan. Additional genetic epistasis analysis indicates that the molecular mechanism of pch-2 in worm longevity is tied to functions of the sirtuin family, implying that pch-2 is another chromatin regulator for worm longevity. These findings suggest a novel function of the pch-2 gene involved in lifespan determination. PMID:25635513

  9. Mutations affecting nerve attachment of Caenorhabditis elegans.

    PubMed Central

    Shioi, G; Shoji, M; Nakamura, M; Ishihara, T; Katsura, I; Fujisawa, H; Takagi, S

    2001-01-01

    Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans. PMID:11290717

  10. Food transport in the C. elegans pharynx

    PubMed Central

    Avery, Leon; Shtonda, Boris B.

    2014-01-01

    Summary Pumping of the C. elegans pharynx transports food particles (bacteria) posteriorly. We examined muscle motions to determine how this posterior transport is effected. We find that the motions of the middle section of the pharynx, the anterior isthmus, are delayed relative to the anterior section, the corpus. Simulations in which particles are assumed to move at mean fluid velocity when not captured by the walls of the pharyngeal lumen show that delayed isthmus motions do indeed cause net particle transport; however, the amount is much less than in the real pharynx. We propose that the geometry of the pharyngeal lumen forces particles to the center, where they move faster than mean fluid velocity. When this acceleration is incorporated into the simulation, particles are transported efficiently. The transport mechanism we propose explains past observations that the timing of muscle relaxation is important for effective transport. Our model also makes a prediction, which we confirm, that smaller bacteria are better food sources for C. elegans than large ones. PMID:12796460

  11. Nucleologenesis in the Caenorhabditis elegans Embryo

    PubMed Central

    Kor?ekov, Darina; Gombitov, Adri醤a; Ra歬a, Ivan; Cmarko, Du歛n; Lanct魌, Christian

    2012-01-01

    In the Caenorhabditis elegans nematode, the oocyte nucleolus disappears prior to fertilization. We have now investigated the re-formation of the nucleolus in the early embryo of this model organism by immunostaining for fibrillarin and DAO-5, a putative NOLC1/Nopp140 homolog involved in ribosome assembly. We find that labeled nucleoli first appear in somatic cells at around the 8-cell stage, at a time when transcription of the embryonic genome begins. Quantitative analysis of radial positioning showed the nucleolus to be localized at the nuclear periphery in a majority of early embryonic nuclei. At the ultrastructural level, the embryonic nucleolus appears to be composed of a relatively homogenous core surrounded by a crescent-shaped granular structure. Prior to embryonic genome activation, fibrillarin and DAO-5 staining is seen in numerous small nucleoplasmic foci. This staining pattern persists in the germline up to the ?100-cell stage, until the P4 germ cell divides to give rise to the Z2/Z3 primordial germ cells and embryonic transcription is activated in this lineage. In the ncl-1 mutant, which is characterized by increased transcription of rDNA, DAO-5-labeled nucleoli are already present at the 2-cell stage. Our results suggest a link between the activation of transcription and the initial formation of nucleoli in the C. elegans embryo. PMID:22768349

  12. Original article Residues in wax and honey after Apilife VAR

    E-print Network

    Paris-Sud XI, Universit de

    Original article Residues in wax and honey after Apilife VAR treatment Stefan Bogdanov Anton Apilife VAR treatment in autumn of 1992, the residues in honey and comb were examined the following spring. Only thymol residues were found in honey, whereas in comb the residues consisted of 99 % thymol

  13. % Read and echo names; count them. var count : int := 0

    E-print Network

    Toronto, University of

    % Read and echo names; count them. var count : int := 0 % How many names so far? put "Please type a series of names." put "Tell me 'quit' at the end" loop put "Next name? " .. var person : string get, " people." 1 #12; Let's use the name颅entering program. turingx example1.t Please type a series of names

  14. Malaria var gene expression: Keeping up with the neighbors

    PubMed Central

    Kim, Kami

    2014-01-01

    Plasmodium falciparum PfEMP1 is a malaria virulence protein whose expression is epigenetically regulated. The parasite抯 ability to express exclusively only one of the sixty var genes that encode PfEMP1 is essential for disease pathogenesis. Two recent papers identify key molecular players in determining whether a var gene is active or silenced. PMID:22264506

  15. Exploring functional structure through system organization: Caenorhabditis elegans neuronal network

    E-print Network

    Park, Namkyoo

    Exploring functional structure through system organization: Caenorhabditis elegans neuronal network, systemic organization, modular structure, functional circuit #12; Hyeok Jung Kang1 , Myung-Kyu Choi2, Junho Lee2 , Namkyoo Park*1 *nkpark@snu.ac.kr 1 Photonic Systems

  16. Caenorhabditis elegans: An Emerging Model in Biomedical and Environmental Toxicology

    PubMed Central

    Leung, Maxwell C. K.; Williams, Phillip L.; Benedetto, Alexandre; Au, Catherine; Helmcke, Kirsten J.; Aschner, Michael; Meyer, Joel N.

    2008-01-01

    The nematode Caenorhabditis elegans has emerged as an important animal model in various fields including neurobiology, developmental biology, and genetics. Characteristics of this animal model that have contributed to its success include its genetic manipulability, invariant and fully described developmental program, well-characterized genome, ease of maintenance, short and prolific life cycle, and small body size. These same features have led to an increasing use of C. elegans in toxicology, both for mechanistic studies and high-throughput screening approaches. We describe some of the research that has been carried out in the areas of neurotoxicology, genetic toxicology, and environmental toxicology, as well as high-throughput experiments with C. elegans including genome-wide screening for molecular targets of toxicity and rapid toxicity assessment for new chemicals. We argue for an increased role for C. elegans in complementing other model systems in toxicological research. PMID:18566021

  17. Genetic screens in Caenorhabditis elegans models for neurodegenerative diseases.

    PubMed

    Sin, Olga; Michels, Helen; Nollen, Ellen A A

    2014-10-01

    Caenorhabditis elegans comprises unique features that make it an attractive model organism in diverse fields of biology. Genetic screens are powerful to identify genes and C. elegans can be customized to forward or reverse genetic screens and to establish gene function. These genetic screens can be applied to "humanized" models of C. elegans for neurodegenerative diseases, enabling for example the identification of genes involved in protein aggregation, one of the hallmarks of these diseases. In this review, we will describe the genetic screens employed in C. elegans and how these can be used to understand molecular processes involved in neurodegenerative and other human diseases. This article is part of a Special Issue entitled: From Genome to Function. PMID:24525026

  18. Tomosyn Inhibits Synaptic Vesicle Priming in Caenorhabditis elegans

    E-print Network

    Gracheva, Elena O.; Burdina, Anna O.; Holgado, Andrea M.; Berthelot-Grosjean, Martine; Ackley, Brian D.; Hadwiger, Gayla; Nonet, Michael L.; Weimer, Robby M.; Richmond, Janet E.

    2006-07-25

    Caenorhabditis elegans TOM-1 is orthologous to vertebrate tomosyn, a cytosolic syntaxin-binding protein implicated in the modulation of both constitutive and regulated exocytosis. To investigate how TOM-1 regulates exocytosis of synaptic vesicles...

  19. Caenorhabditis elegans, a Model Organism for Investigating Immunity

    PubMed Central

    Marsh, Elizabeth K.

    2012-01-01

    The nematode Caenorhabditis elegans has been a powerful experimental organism for almost half a century. Over the past 10 years, researchers have begun to exploit the power of C. elegans to investigate the biology of a number of human pathogens. This work has uncovered mechanisms of host immunity and pathogen virulence that are analogous to those involved during pathogenesis in humans or other animal hosts, as well as novel immunity mechanisms which appear to be unique to the worm. More recently, these investigations have uncovered details of the natural pathogens of C. elegans, including the description of a novel intracellular microsporidian parasite as well as new nodaviruses, the first identification of viral infections of this nematode. In this review, we consider the application of C. elegans to human infectious disease research, as well as consider the nematode response to these natural pathogens. PMID:22286994

  20. Tertiary siRNAs mediate paramutation in C. elegans

    E-print Network

    Sapetschnig, Alexandra; Sarkies, Peter; Lehrbach, Nicolas J.; Miska, Eric A.

    2015-03-26

    for epigenetic inheritance of acquired traits in animals. This resurrection of Larmarckism is poised to rewrite the textbook on heredity [2], but a clearer understanding of the molecular mechanisms involved is needed. In the nematode Caenorhabditis elegans...

  1. C. Elegans and Microbeam Models in Bystander Effect Research

    E-print Network

    Feng, Shaoyong

    2013-08-01

    been utilized in bystander effects research. In the Loma Linda/TAMU experiment, a L1 larva C. elegans model was devloped to study the radiation bystander effects by irradiating single intestine cell nuclei with a microbeam of protons. Due...

  2. Proteins interacting withCaenorhabditis elegans G? subunits

    Microsoft Academic Search

    Edwin Cuppen; Alexander M. van der Linden; Gert Jansen; Ronald H. A. Plasterk

    2003-01-01

    To identify novel components in heterotrimeric G-protein signalling, we performed an extensive screen for proteins interacting with Caenorhabditis elegans G? subunits. The genome of C. elegans contains homologues of each of the four mammalian classes of G? subunits (Gs, Gi\\/o, Gq and G12), and 17 other G? subunits. We tested 19 of the G? subunits and four constitutively activated G?

  3. BACTERIAL ATTRACTION AND QUORUM SENSING INHIBITION IN CAENORHABDITIS ELEGANS EXUDATES

    PubMed Central

    KAPLAN, FATMA; BADRI, DAYAKAR V.; ZACHARIAH, CHERIAN; AJREDINI, RAMADAN; SANDOVAL, FRANCISCO J; ROJE, SANJA; LEVINE, LANFANG H.; ZHANG, FENGLI; ROBINETTE, STEVEN L.; ALBORN, HANS T.; ZHAO, WEI; STADLER, MICHAEL; NIMALENDRAN, RATHIKA; DOSSEY, AARON T.; BR躍CHWEILER, RAFAEL; VIVANCO, JORGE M.; EDISON, ARTHUR S.

    2014-01-01

    Caenorhabditis elegans, a bacterivorous nematode, lives in complex rotting fruit, soil, and compost environments, and chemical interactions are required for mating, monitoring population density, recognition of food, avoidance of pathogenic microbes, and other essential ecological functions. Despite being one of the best-studied model organisms in biology, relatively little is known about the signals that C. elegans uses to chemically interact with its environment or as defense. C. elegans exudates were analyzed using several analytical methods and found to contain 36 common metabolites including organic acids, amino acids and sugars, all in relatively high abundance. Furthermore, the concentrations of amino acids in the exudates were dependent on developmental stage. The C. elegans exudates were tested for bacterial chemotaxis using Pseudomonas putida (KT2440), a plant growth promoting rhizobacterium, Pseudomonas aeruginosa (PAO1), a soil bacterium pathogenic to C. elegans, and E. coli (OP50), a non-motile bacterium tested as a control. The C. elegans exudates attracted the two Psuedomonas species, but had no detectable antibacterial activity against P. aeruginosa. To our surprise, the exudates of young adult and adult life stages of C. elegans exudates inhibited quorum sensing in the reporter system based on the LuxR bacterial quorum sensing (QS) system, which regulates bacterial virulence and other factors in Vibrio fischeri. We were able to fractionate the QS inhibition and bacterial chemotaxis activities, demonstrating that these activities are chemically distinct. Our results demonstrate that C. elegans can attract its bacterial food and has the potential of partially regulating the virulence of bacterial pathogens by inhibiting specific QS systems. PMID:19649780

  4. Genomic response of the nematode Caenorhabditis elegans to spaceflight

    NASA Astrophysics Data System (ADS)

    Selch, Florian; Higashibata, Akira; Imamizo-Sato, Mari; Higashitani, Atsushi; Ishioka, Noriaki; Szewczyk, Nathaniel J.; Conley, Catharine A.

    On Earth, it is common to employ laboratory animals such as the nematode Caenorhabditis elegans to help understand human health concerns. Similar studies in Earth orbit should help understand and address the concerns associated with spaceflight. The 揑nternational Caenorhabditis elegans Experiment FIRST (ICE FIRST), was carried out onboard the Dutch Taxiflight in April of 2004 by an international collaboration of laboratories in France, Canada, Japan and the United States. With the exception of a slight movement defect upon return to Earth, the result of altered muscle development, no significant abnormalities were detected in spaceflown C. elegans. Work from Japan revealed apoptosis proceeds normally and work from Canada revealed no significant increase in the rate of mutation. These results suggest that C. elegans can be used to study non-lethal responses to spaceflight and can possibly be developed as a biological sensor. To further our understanding of C. elegans response to spaceflight, we examined the gene transcription response to the 10 days in space using a near full genome microarray analysis. The transcriptional response is consistent with the observed normal developmental timing, apoptosis, DNA repair, and altered muscle development. The genes identified as altered in response to spaceflight are enriched for genes known to be regulated, in C. elegans, in response to altered environmental conditions (Insulin and TGF-? regulated). These results demonstrate C. elegans can be used to study the effects of altered gravity and suggest that C. elegans responds to spaceflight by altering the expression of at least some of the same metabolic genes that are altered in response to differing terrestrial environments.

  5. A systematic RNAi screen for longevity genes in C. elegans

    Microsoft Academic Search

    Benjamin Hamilton; Yuqing Dong; Mami Shindo; Wenyu Liu; Ian Odell; Gary Ruvkun; Siu Sylvia Lee

    2005-01-01

    We report here the first genome-wide functional genomic screen for longevity genes. We systematically surveyed Caenorhabditis elegans genes using large-scale RNA interference (RNAi), and found that RNAi inactivation of 89 genes extend C. elegans lifespan. Components of the daf-2\\/insulin-like signaling pathway are recovered, as well as genes that regulate metabolism, signal transduction, protein turnover, and gene expression. Many of these

  6. The geometry of locomotive behavioral states in C. elegans.

    PubMed

    Gallagher, Thomas; Bjorness, Theresa; Greene, Robert; You, Young-Jai; Avery, Leon

    2013-01-01

    We develop a new hidden Markov model-based method to analyze C elegans locomotive behavior and use this method to quantitatively characterize behavioral states. In agreement with previous work, we find states corresponding to roaming, dwelling, and quiescence. However, we also find evidence for a continuum of intermediate states. We suggest that roaming, dwelling, and quiescence may best be thought of as extremes which, mixed in any proportion, define the locomotive repertoire of C elegans foraging and feeding behavior. PMID:23555813

  7. Production of volatile metabolites in potatoes infected by Erwinia carotovora var. carotovora and E. carotovora var. atroseptica

    Microsoft Academic Search

    D. R. Waterer; M. K. Pritchard

    1985-01-01

    Gas chromatography of headspace atmospheres was used to evaluate the production of metabolic volatiles by small lots of stored potato tubers (Solanum tuberosum) infected with either Erwinia carotovora var. carotovora or Erwinia carotovora var. atroseptica bacteria. The total concentration of volatiles in the headspace of the plastic bags in which the potatoes were maintained increased exponentially as infection by both

  8. Japanese studies on neural circuits and behavior of Caenorhabditis elegans

    PubMed Central

    Sasakura, Hiroyuki; Tsukada, Yuki; Takagi, Shin; Mori, Ikue

    2013-01-01

    The nematode Caenorhabditis elegans is an ideal organism for studying neural plasticity and animal behaviors. A total of 302 neurons of a C. elegans hermaphrodite have been classified into 118 neuronal groups. This simple neural circuit provides a solid basis for understanding the mechanisms of the brains of higher animals, including humans. Recent studies that employ modern imaging and manipulation techniques enable researchers to study the dynamic properties of nervous systems with great precision. Behavioral and molecular genetic analyses of this tiny animal have contributed greatly to the advancement of neural circuit research. Here, we will review the recent studies on the neural circuits of C. elegans that have been conducted in Japan. Several laboratories have established unique and clever methods to study the underlying neuronal substrates of behavioral regulation in C. elegans. The technological advances applied to studies of C. elegans have allowed new approaches for the studies of complex neural systems. Through reviewing the studies on the neuronal circuits of C. elegans in Japan, we will analyze and discuss the directions of neural circuit studies. PMID:24348340

  9. A Transparent window into biology: A primer on Caenorhabditis elegans.

    PubMed

    Corsi, Ann K; Wightman, Bruce; Chalfie, Martin

    2015-01-01

    A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues. PMID:26087236

  10. Key players in chromosome segregation in Caenorhabditis elegans

    PubMed Central

    Kitagawa, Risa

    2009-01-01

    In contrast to many eukaryotic organisms in which kinetochores are assembled on localized centromeres of monocentric chromosomes, Caenorhabditis elegans has diffuse kinetochores, termed holo-kinetochores, which are assembled along the entire length of the mitotic chromosome. Despite this cytologically distinct chromosomal architecture, holo-kinetochores of C. elegans and kinetochores of other eukaryotes share structurally and functionally conserved properties. The amphitelic attachment of sister kinetochores to microtubules can be achieved by proper chromosomal organization, which relies on spatiotemporally orchestrated functions of conserved protein complexes such as the cohesin, condensin, and chromosomal passenger complexes during mitosis and meiosis in C. elegans. Moreover, the structure of spindle assembly checkpoint components and their safeguard function are also well conserved in C. elegans. Extensive efforts in the last few years to elucidate the molecular mechanisms of the C. elegans spindle assembly checkpoint have revealed its unique features. In this review, I will focus on the conservation and diversity of proteins that are required to maintain chromosome transmission fidelity during mitosis and meiosis in C. elegans. PMID:19273145

  11. The nematode Caenorhabditis elegans as a model to study viruses.

    PubMed

    Diogo, Jesica; Bratanich, Ana

    2014-11-01

    Caenorhabditis elegans is a worm that has been extensively studied, and it is today an accepted model in many different biological fields. C. elegans is cheap to maintain, it is transparent, allowing easy localization studies, and it develops from egg to adult in around 4 days. Many mutants, available to the scientific community, have been developed. This has facilitated the study of the role of particular genes in many cellular pathways, which are highly conserved when compared with higher eukaryotes. This review describes the advantages of C. elegans as a laboratory model and the known mechanisms utilized by this worm to fight pathogens. In particular, we describe the strong C. elegans RNAi machinery, which plays an important role in the antiviral response. This has been shown in vitro (C. elegans cell cultures) as well as in vivo (RNAi-deficient strains) utilizing recently described viruses that have the worm as a host. Infections with mammalian viruses have also been achieved using chemical treatment. The role of viral genes involved in pathogenesis has been addressed by evaluating the phenotypes of transgenic strains of C. elegans expressing those genes. Very simple approaches such as feeding the worm with bacteria transformed with viral genes have also been utilized. The advantages and limitations of different approaches are discussed. PMID:25000902

  12. A Transparent Window into Biology: A Primer on Caenorhabditis elegans.

    PubMed

    Corsi, Ann K; Wightman, Bruce; Chalfie, Martin

    2015-06-01

    A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues. PMID:26088431

  13. Genetic maps for Pinus elliottii var. elliottii and P. caribaea var. hondurensis using AFLP and microsatellite markers.

    PubMed

    Shepherd, M; Cross, M; Dieters, M J; Henry, R

    2003-05-01

    Genetic maps for individual Pinus elliottii var. elliottii and P. caribaea var. hondurensis trees were generated using a pseudo-testcross mapping strategy. A total of 329 amplified fragment length polymorphic (AFLP) and 12 microsatellite markers were found to segregate in a sample of 93 interspecfic F(1) progeny. The male P. caribaea var. hondurensis parent was more heterozygous than the female P. elliottii var. elliottii parent with 19% more markers segregating on the male side. Framework maps were constructed using a LOD 5 threshold for grouping and interval support threshold of LOD 2. The framework map length for the P. elliottii var. elliottii megagametophyte parent (1,170 cM Kosambi; 23 linkage groups) was notably smaller than the P. caribaea var. hondurensis pollen parent (1,658 cM Kosambi; 27 linkage groups). The difference in map lengths was assumed to be due to sex-related recombination variation, which has been previously reported for pines, as the difference in map lengths not be accounted for by the larger number of markers mapping to the P. caribaea var. hondurensis parent - 109 compared with 78 in P. elliottii var. elliottii parent. Based on estimated genome sizes for these species, the framework maps for P. elliottii var. elliottii and P. caribaea var. hondurensis covered 82% and 88% of their respective genomes. The pseudo-testcross strategy was extended to include AFLP and microsatellite markers in an intercross configuration. These comprehensive maps provided further genome coverage, 1,548 and 1,828 cM Kosambi for P. elliottii var. elliottii and P. caribaea var. hondurensis, respectively, and enabled homologous linkage groups to be identified in the two parental maps. Homologous linkage groups were identified for 11 out of 24 P. elliottii var. elliottii and 10 out of 25 P. caribaea var. hondurensis groups. A higher than expected level of segregation distortion was found for both AFLP and microsatellite markers. An explanation for this segregation distortion was not clear, but it may be at least in part due to genetic mechanisms for species isolation in this wide cross. PMID:12750783

  14. Caenorhabditis elegans NPR-1杕ediated behaviors are suppressed in the presence of mucoid bacteria

    E-print Network

    Reddy, Kirthi C.

    Caenorhabditis elegans exhibits a diverse range of behaviors in response to bacteria. The presence of bacterial food influences C. elegans aerotaxis, aggregation, locomotion, and pathogen avoidance behaviors through the ...

  15. Spread and transmission of bacterial pathogens in experimental nematode populations of Caenorhabditis elegans.

    E-print Network

    Diaz, S. Anaid; Restif, Olivier

    2014-06-22

    . Evolution of host innate 498 defence: insights from Caenorhabditis elegans and primitive invertebrates. 499 Nat. Rev. Immunol. 10:4758. 500 3. Ewbank JJ. 2002. Tackling both sides of the host-pathogen equation with 501 Caenorhabditis elegans. Microbes...

  16. Title : Liquid C. elegans culture for the study of Burkholderia pathogenesis Authors : Vaughn Cooper1

    E-print Network

    Title : Liquid C. elegans culture for the study of Burkholderia pathogenesis Authors : Vaughn and allows the study of Burkholderia infection in pure liquid C. elegans cultures, in which each competitor

  17. Dynamic patterning of maternal mRNAs in the Early C. elegans embryo

    E-print Network

    Li, Jialing, Ph. D. Massachusetts Institute of Technology

    2012-01-01

    Asymmetric segregation of maternally-encoded proteins is essential to cell fate determination during early cell divisions of the Caenorhabditis elegans (C. elegans) embryo, but little is known about the patterning of ...

  18. Ultrafast endocytosis at Caenorhabditis elegans neuromuscular junctions

    PubMed Central

    Watanabe, Shigeki; Liu, Qiang; Davis, M Wayne; Hollopeter, Gunther; Thomas, Nikita; Jorgensen, Nels B; Jorgensen, Erik M

    2013-01-01

    Synaptic vesicles can be released at extremely high rates, which places an extraordinary demand on the recycling machinery. Previous ultrastructural studies of vesicle recycling were conducted in dissected preparations using an intense stimulation to maximize the probability of release. Here, a single light stimulus was applied to motor neurons in intact Caenorhabditis elegans nematodes expressing channelrhodopsin, and the animals rapidly frozen. We found that docked vesicles fuse along a broad active zone in response to a single stimulus, and are replenished with a time constant of about 2 s. Endocytosis occurs within 50 ms adjacent to the dense projection and after 1 s adjacent to adherens junctions. These studies suggest that synaptic vesicle endocytosis may occur on a millisecond time scale following a single physiological stimulus in the intact nervous system and is unlikely to conform to current models of endocytosis. DOI: http://dx.doi.org/10.7554/eLife.00723.001 PMID:24015355

  19. Chemotaxis of crawling and swimming Caenorhabditis Elegans

    NASA Astrophysics Data System (ADS)

    Patel, Amar; Bilbao, Alejandro; Padmanabhan, Venkat; Khan, Zeina; Armstrong, Andrew; Rumbaugh, Kendra; Vanapalli, Siva; Blawzdziewicz, Jerzy

    2012-11-01

    A soil-dwelling nematode Caenorhabditis Elegans efficiently navigates through complex environments, responding to chemical signals to find food or avoid danger. According to previous studies, the nematode uses both gradual-turn and run-and-tumble strategies to move in the direction of the increasing concentration of chemical attractants. We show that both these chemotaxis strategies can be described using our kinematic model [PLoS ONE, 7: e40121 (2012)] in which harmonic-curvature modes represent elementary nematode movements. In our chemotaxis model, the statistics of mode changes is governed by the time history of the chemoattractant concentration at the position of the nematode head. We present results for both nematodes crawling without transverse slip and for swimming nematodes. This work was supported by NSF grant No. CBET 1059745.

  20. Rapid RNA analysis of individual Caenorhabditis elegans?

    PubMed Central

    Ly, Kien; Reid, Suzanne J.; Snell, Russell G.

    2015-01-01

    Traditional RNA extraction methods rely on the use of hazardous chemicals such as phenol, chloroform, guanidinium thiocyanate to disrupt cells and inactivate RNAse simultaneously. RNA isolation from Caenorhabditis elegans presents another challenge due to its tough cuticle, therefore several repeated freeze杢haw cycles may be needed to disrupt the cuticle before the cell contents are released. In addition, a large number of animals are required for successful RNA isolation. To overcome these issues, we have developed a simple and efficient method using proteinase K and a brief heat treatment to release RNA of quality suitable for quantitative PCR analysis.The benefits of the method are: Faster and safer compared to conventional RNA extraction methods Released RNA can be used directly for cDNA synthesis without purification As little as a single worm is sufficient

  1. Prostaglandin Extraction and Analysis in Caenorhabditis elegans

    PubMed Central

    Prasain, Jeevan K.; Hoang, Hieu D.; Edmonds, Johnathan W.; Miller, Michael A.

    2013-01-01

    Caenorhabditis elegans is emerging as a powerful animal model to study the biology of lipids1-9. Prostaglandins are an important class of eicosanoids, which are lipid signals derived from polyunsaturated fatty acids (PUFAs)10-14. These signalling molecules are difficult to study because of their low abundance and reactive nature. The characteristic feature of prostaglandins is a cyclopentane ring structure located within the fatty acid backbone. In mammals, prostaglandins can be formed through cyclooxygenase enzyme-dependent and -independent pathways10,15. C. elegans synthesizes a wide array of prostaglandins independent of cyclooxygenases6,16,17. A large class of F-series prostaglandins has been identified, but the study of eicosanoids is at an early stage with ample room for new discoveries. Here we describe a procedure for extracting and analyzing prostaglandins and other eicosanoids. Charged lipids are extracted from mass worm cultures using a liquid-liquid extraction technique and analyzed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The inclusion of deuterated analogs of prostaglandins, such as PGF2 ?-d4 as an internal standard is recommended for quantitative analysis. Multiple reaction monitoring or MRM can be used to quantify and compare specific prostaglandin types between wild-type and mutant animals. Collision-induced decomposition or MS/MS can be used to obtain information on important structural features. Liquid chromatography mass spectrometry (LC-MS) survey scans of a selected mass range, such as m/z 315-360 can be used to evaluate global changes in prostaglandin levels. We provide examples of all three analyses. These methods will provide researchers with a toolset for discovering novel eicosanoids and delineating their metabolic pathways. PMID:23851568

  2. [Chemical constituents of Camellia sinensis var. assamica].

    PubMed

    Zhu, Hong-Bo; Li, Bao-Min; Liu, Chao; Chen, Ruo-Yun

    2013-05-01

    To study the chemical constituents of Camellia sinensis var. assamica. The compounds were isolated by NKA Macroporous resin silica gel, Sephadex LH-20, RP-C18 column chromatographies and semi-preparative HPLC,and their structures were elucidated by physicochemical properties and spectral analysis. Thirteen compounds were isolated and identified as caffeine (1), theobromine (2), gallic acid (3), (+)-catechin (4), ampelopsin (5), (-)-epicatechin (6), (-)-epiafzelechin (7), (-)-epicatechin-3-O-gallate (8), (-)-epiafzelechin-3-O-gallate (9) , (+)-catechin-3-O-gallate (10) , (+)-afzelechin-3-O-gallate (11), quemefin-3-O-alpha-L-arabinopyranosid (12), and (-)-epicatechin-3-O-p-hydroxybenzoate (13). Compounds 2, 5, 10-13 were isolated from this plant for the first time, and compound 11 is a new natural product. PMID:23944074

  3. C. elegans as a Resource for Studies on Plant Parasitic Nematodes

    Microsoft Academic Search

    Laura M. Jones; Carla De Giorgi; Peter E. Urwin

    \\u000a \\u000a C. elegans provides a suitable model to study basic and conserved nematode biology. The short life-cycle, adult size, easy maintenance\\u000a in large numbers and the tractability of C. elegans facilitate its use in translational biology. The C. elegans genome project has greatly assisted the mapping, sequencing and annotation of parasitic nematode genomes. Furthermore, the\\u000a development of RNAi in C. elegans

  4. Phytologia (December 2009) 91(3) 361 JUNIPERUS RECURVA VAR. UNCINATA, THE HOOKED

    E-print Network

    Adams, Robert P.

    Phytologia (December 2009) 91(3) 361 JUNIPERUS RECURVA VAR. UNCINATA, THE HOOKED BRANCHLET JUNIPER of sequence data from nrDNA and cpDNA (petN-psbM) of Juniperus indica, J. i. var. caespitosa, J. i. var hybridization. Phytologia 91(3): 361-382 (December, 2009). KEY WORDS: Juniperus indica, J. i. var. caespitosa, J

  5. Killing of Caenorhabditis elegans by Cryptococcus neoformans as a model of yeast pathogenesis

    E-print Network

    Ausubel, Frederick M.

    Killing of Caenorhabditis elegans by Cryptococcus neoformans as a model of yeast pathogenesis.However,thehumanpathogenicyeastCryptococcusneoformans killed C. elegans, and the C. neoformans polysaccharide capsule as well as several C. neoformans genes previously shown to be involved in mammalian virulence were also shown to play a role in C. elegans killing

  6. Pseudomonas aeruginosa killing of Caenorhabditis elegans used to identify P. aeruginosa virulence factors

    Microsoft Academic Search

    MAN-WAH TAN; L AURENCE G. RAHME; A. STERNBERG; R ONALD G. TOMPKINS; FREDERICK M. AUSUBEL

    1999-01-01

    We reported recently that the human oppor- tunistic pathogen Pseudomonas aeruginosa strain PA14 kills Caenorhabditis elegans and that many P. aeruginosa virulence factors (genes) required for maximum virulence in mouse patho- genicity are also required for maximum killing of C. elegans. Here we report that among eight P. aeruginosa PA14 TnphoA mutants isolated that exhibited reduced killing of C. elegans,

  7. Attenuation of Pseudomonas aeruginosa virulence by medicinal plants in a Caenorhabditis elegans

    E-print Network

    Ausubel, Frederick M.

    factors and innate antibiotic resistance enables the opportunistic human pathogen Pseudomonas aeruginosa examined for their effects on P. aeruginosa killing of the nematode Caenorhabditis elegans. The results killing of the nematode Caenorhabditis elegans. Caenorhabditis elegans is well established as a pertinent

  8. Cytochrome b Phylogeny Does Not Match Subspecific Classification in the Western Terrestrial Garter Snake, Thamnophis elegans

    Microsoft Academic Search

    Anne M. Bronikowski; Stevan J. Arnold; J. D. McEachran

    2001-01-01

    We sequenced a 307-bp fragment of the mitochondrial cytochrome b gene from 42 individuals representing 14 populations of the western terrestrial garter snake, Thamnophis elegans. Current taxonomy recognizes either five or six subspecies of T. elegans based on color and scale morphology, but all agree on three major geograph- ic races (T. e. elegans, terrestris, and vagrans). Although the cytochrome

  9. SPK-1, an SR protein kinase, inhibits programmed cell death in Caenorhabditis elegans

    E-print Network

    Horvitz, H. Robert

    within dying cells to control nearly all somatic programmed cell deaths in C. elegans (10, 12, 13); lossSPK-1, an SR protein kinase, inhibits programmed cell death in Caenorhabditis elegans Brendan D programmed cell death in Caenorhabditis elegans, we performed a genetic screen to isolate mutations

  10. Puccinia jaceae var.solstitialis teliospore priming on yellow starthistle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Following the introduction of Puccinia jaceae var. solstitialis to California for biological control of yellow starthistle (Centaurea solstitialis, Asteraceae), teliospores, pycnia, and multiple urediniospore generations have been observed in the field. Because urediniospores have a relatively short...

  11. New phenylpropanoid glycosides from Juniperus communis var. depressa.

    PubMed

    Iida, Naoki; Inatomi, Yuka; Murata, Hiroko; Murata, Jin; Lang, Frank A; Tanaka, Toshiyuki; Nakanishi, Tsutomu; Inada, Akira

    2010-05-01

    Two new phenylpropanoid glycosides were isolated from the leaves and stems of Juniperus communis var. depressa (Cupressaceae) along with 14 known compounds. Their structures were determined by spectral analyses, in particular by 2D-NMR spectral evidence. PMID:20460808

  12. Chemically Defined Medium and Caenorhabditis elegans: A Powerful Approach

    NASA Technical Reports Server (NTRS)

    Szewczyk, N. J.; Kozak, E.; Conley, C. A.

    2003-01-01

    C. elegans has been established as a powerful genetic system. Growth in a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of me in large-scale growth and screening of animals. Here we present our initial results from developing culture systems with CeMM. We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats of using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change defined medium composition. As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  13. LRRK2 modulates vulnerability to mitochondrial dysfunction in C. elegans

    PubMed Central

    Saha, Shamol; Guillily, Maria; Ferree, Andrew; Lanceta, Joel; Chan, Diane; Ghosh, Joy; Hsu, Cindy H.; Segal, Lilach; Raghavan, Kesav; Matsumoto, Kunihiro; Hisamoto, Naoki; Kuwahara, Tomoki; Iwatsubo, Takeshi; Moore, Landon; Goldstein, Lee; Cookson, Mark; Wolozin, Benjamin

    2009-01-01

    Summary Mutations in leucine rich repeat kinase 2 (LRRK2) cause autosomal dominant familial Parkinson抯 disease. We generated lines of C. elegans expressing neuronally directed human LRRK2. Expressing human LRRK2 expression increased nematode survival in response to rotenone or paraquat, which are agents that cause mitochondrial dysfunction. Protection by G2019S, R1441C or kinase dead LRRK2 was less than protection by wild type LRRK2. Knockdown of lrk-1, the endogenous orthologue of LRRK2 in C. elegans, reduced survival associated with mitochondrial dysfunction. C. elegans expressing LRRK2 showed rapid loss of dopaminergic markers (DAT?GFP fluorescence and dopamine levels) beginning in early adulthood. Loss of dopaminergic markers was greater for the G2019S LRRK2 line than for the WT line. Rotenone treatment induced a larger loss of dopamine markers in C. elegans expressing G2019S LRRK2 than in C. elegans expressing WT LRRK2; however loss of dopaminergic markers in the G2019S LRRK2 nematode lines was not statistically different than that in the control line. These data suggest that LRRK2 plays an important role in modulating the response to mitochondrial inhibition, and raises the possibility that mutations in LRRK2 selectively enhance the vulnerability of dopaminergic neurons to a stressor associated with Parkinson抯 disease. PMID:19625511

  14. var genes, PfEMP1 and the human host

    Microsoft Academic Search

    Kirsten Flick; Qijun Chen

    2004-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is an important virulence factor encoded by a family of roughly 60 var genes and is used by the parasite to interact with the human host. The parasite regularly exchanges the expressed var gene generating antigenic variation of the infected RBCs (pRBC) surface which is crucial for successful proliferation and transmission. PfEMP1 is

  15. Chromosome Karyotypes of Echinacea angustifolia var. angustifolia and

    Microsoft Academic Search

    Xiping Wang; Eatherley Hood; Meihua Wang; Richard Scalzo

    Chromosome karyotypes of the most commonly cultivated and medicinally used Echinacea taxa, E. angustifolia DC. var. angustifolia and E. purpurea (L.) Moench., were analyzed. The chromosomes of both taxa are medium in length, ranging from 4.12 to 5.83 祄 in E. angustifolia var. angustifolia and 3.99 to 6.08 祄 in E. purpurea. No abrupt length changes in the chromosomes were

  16. Tissue Culture and Alkaloid Production of Erthroxylum coca var. coca

    Microsoft Academic Search

    John Lydon; Richard H. Zimmerman; Ingrid M. Fordham; William R. Lusby

    1993-01-01

    A tissue culture method was developed to study the biosynthesis of alkaloids in Erythroxylum coca var. coca. Shoot cultures were established from excised embryos of seed from Erythyroxylum coca var. coca and grown on a semi-solid medium. Alkaloids extracted from leaves of shoot cultures and the parent plant were identified by gas chromatography-mass spectrometric (GC\\/MS) analysis and quanitifed by gas

  17. Malaria var gene expression: keeping up with the neighbors.

    PubMed

    Kim, Kami

    2012-01-19

    Plasmodium falciparum PfEMP1 is a malaria virulence protein whose expression is epigenetically regulated. The parasite's ability to express exclusively only one of the sixty var genes that encode PfEMP1 is essential for disease pathogenesis. Two recent papers identify key molecular players in determining whether a var gene is active or silenced (Volz et燼l., 2012; Zhang et燼l., 2011). PMID:22264506

  18. Mapping and analysis of Caenorhabditis elegans transcription factor sequence specificities.

    PubMed

    Narasimhan, Kamesh; Lambert, Samuel A; Yang, Ally Wh; Riddell, Jeremy; Mnaimneh, Sanie; Zheng, Hong; Albu, Mihai; Najafabadi, Hamed S; Reece-Hoyes, John S; Fuxman Bass, Juan I; Walhout, Albertha Jm; Weirauch, Matthew T; Hughes, Timothy R

    2015-01-01

    Caenorhabditis elegans is a powerful model for studying gene regulation, as it has a compact genome and a wealth of genomic tools. However, identification of regulatory elements has been limited, as DNA-binding motifs are known for only 71 of the estimated 763 sequence-specific transcription factors (TFs). To address this problem, we performed protein binding microarray experiments on representatives of canonical TF families in C. elegans, obtaining motifs for 129 TFs. Additionally, we predict motifs for many TFs that have DNA-binding domains similar to those already characterized, increasing coverage of binding specificities to 292 C. elegans TFs (?40%). These data highlight the diversification of binding motifs for the nuclear hormone receptor and C2H2 zinc finger families and reveal unexpected diversity of motifs for T-box and DM families. Motif enrichment in promoters of functionally related genes is consistent with known biology and also identifies putative regulatory roles for unstudied TFs. PMID:25905672

  19. Caenorhabditis elegans as a model organism to study APP function

    PubMed Central

    Ewald, Collin Y.; Li, Chris

    2013-01-01

    The brains of Alzheimer's disease patients show an increased number of senile plaques compared with normal patients. The major component of the plaques is the ?-amyloid peptide, a cleavage product of the amyloid precursor protein (APP). Although the processing of APP has been well-described, the physiological functions of APP and its cleavage products remain unclear. This article reviews the multifunctional roles of an APP orthologue, the C. elegans APL-1. Understanding the function of APL-1 may provide insights into the functions and signaling pathways of human APP. In addition, the physiological effects of introducing human ?-amyloid peptide into C. elegans are also reviewed. The C. elegans system provides a powerful genetic model to identify genes regulating the molecular mechanisms underlying intracellular ?-amyloid peptide accumulation. PMID:22038715

  20. Measuring Food Intake and Nutrient Absorption in Caenorhabditis elegans.

    PubMed

    Gomez-Amaro, Rafael L; Valentine, Elizabeth R; Carretero, Maria; LeBoeuf, Sarah E; Rangaraju, Sunitha; Broaddus, Caroline D; Solis, Gregory M; Williamson, James R; Petrascheck, Michael

    2015-06-01

    Caenorhabditis elegans has emerged as a powerful model to study the genetics of feeding, food-related behaviors, and metabolism. Despite the many advantages of C. elegans as a model organism, direct measurement of its bacterial food intake remains challenging. Here, we describe two complementary methods that measure the food intake of C. elegans. The first method is a microtiter plate-based bacterial clearing assay that measures food intake by quantifying the change in the optical density of bacteria over time. The second method, termed pulse feeding, measures the absorption of food by tracking de novo protein synthesis using a novel metabolic pulse-labeling strategy. Using the bacterial clearance assay, we compare the bacterial food intake of various C. elegans strains and show that long-lived eat mutants eat substantially more than previous estimates. To demonstrate the applicability of the pulse-feeding assay, we compare the assimilation of food for two C. elegans strains in response to serotonin. We show that serotonin-increased feeding leads to increased protein synthesis in a SER-7-dependent manner, including proteins known to promote aging. Protein content in the food has recently emerged as critical factor in determining how food composition affects aging and health. The pulse-feeding assay, by measuring de novo protein synthesis, represents an ideal method to unequivocally establish how the composition of food dictates protein synthesis. In combination, these two assays provide new and powerful tools for C. elegans research to investigate feeding and how food intake affects the proteome and thus the physiology and health of an organism. PMID:25903497

  1. Anterior-posterior patterning within the Caenorhabditis elegans endoderm.

    PubMed

    Schroeder, D F; McGhee, J D

    1998-12-01

    The endoderm of higher organisms is extensively patterned along the anterior/posterior axis. Although the endoderm (gut or E lineage) of the nematode Caenorhabditis elegans appears to be a simple uniform tube, cells in the anterior gut show several molecular and anatomical differences from cells in the posterior gut. In particular, the gut esterase ges-1 gene, which is normally expressed in all cells of the endoderm, is expressed only in the anterior-most gut cells when certain sequences in the ges-1 promoter are deleted. Using such a deleted ges-1 transgene as a biochemical marker of differentiation, we have investigated the basis of anterior-posterior gut patterning in C. elegans. Although homeotic genes are involved in endoderm patterning in other organisms, we show that anterior gut markers are expressed normally in C. elegans embryos lacking genes of the homeotic cluster. Although signalling from the mesoderm is involved in endoderm patterning in other organisms, we show that ablation of all non-gut blastomeres from the C. elegans embryo does not affect anterior gut marker expression; furthermore, ectopic guts produced by genetic transformation express anterior gut markers generally in the expected location and in the expected number of cells. We conclude that anterior gut fate requires no specific cell-cell contact but rather is produced autonomously within the E lineage. Cytochalasin D blocking experiments fully support this conclusion. Finally, the HMG protein POP-1, a downstream component of the Wnt signalling pathway, has recently been shown to be important in many anterior/posterior fate decisions during C. elegans embryogenesis (Lin, R., Hill, R. J. and Priess, J. R. (1998) Cell 92, 229-239). When RNA-mediated interference is used to eliminate pop-1 function from the embryo, gut is still produced but anterior gut marker expression is abolished. We suggest that the C. elegans endoderm is patterned by elements of the Wnt/pop-1 signalling pathway acting autonomously within the E lineage. PMID:9811572

  2. Developmental genetics of the Caenorhabditis elegans pharynx

    PubMed Central

    Pilon, Marc

    2014-01-01

    The Caenorhabditis elegans pharynx is a rhythmically pumping organ composed initially of 80 cells that, through fusions, amount to 62 cells in the adult worm. During the first 100 min of development, most future pharyngeal cells are born and gather into a double-plate primordium surrounded by a basal lamina. All pharyngeal cells express the transcription factor PHA-4, of which the concentration increases throughout development, triggering a sequential activation of genes with promoters responding differentially to PHA-4 protein levels. The oblong-shaped pharyngeal primordium becomes polarized, many cells taking on wedge shapes with their narrow ends toward the center, hence forming an epithelial cyst. The primordium then elongates, and reorientations of the cells at the anterior and posterior ends form the mouth and pharyngeal-intestinal openings, respectively. The 20 pharyngeal neurons establish complex but reproducible trajectories using 慺ishing line and growth cone-driven mechanisms, and the gland cells also similarly develop their processes. The genetics behind many fate decisions and morphogenetic processes are being elucidated, and reveal the pharynx to be a fruitful model for developmental biologists. PMID:25262818

  3. Functional Genomic Analysis of C. elegans Molting

    PubMed Central

    Frand, Alison R; Russel, Sascha

    2005-01-01

    Although the molting cycle is a hallmark of insects and nematodes, neither the endocrine control of molting via size, stage, and nutritional inputs nor the enzymatic mechanism for synthesis and release of the exoskeleton is well understood. Here, we identify endocrine and enzymatic regulators of molting in C. elegans through a genome-wide RNA-interference screen. Products of the 159 genes discovered include annotated transcription factors, secreted peptides, transmembrane proteins, and extracellular matrix enzymes essential for molting. Fusions between several genes and green fluorescent protein show a pulse of expression before each molt in epithelial cells that synthesize the exoskeleton, indicating that the corresponding proteins are made in the correct time and place to regulate molting. We show further that inactivation of particular genes abrogates expression of the green fluorescent protein reporter genes, revealing regulatory networks that might couple the expression of genes essential for molting to endocrine cues. Many molting genes are conserved in parasitic nematodes responsible for human disease, and thus represent attractive targets for pesticide and pharmaceutical development. PMID:16122351

  4. ASI regulates satiety quiescence in C. elegans

    PubMed Central

    Gallagher, Thomas; Kim, Jeongho; Oldenbroek, Marieke; Kerr, Rex; You, Young-Jai

    2013-01-01

    In C. elegans, satiety quiescence mimics behavioral aspects of satiety and post-prandial sleep in mammals. On the basis of calcium-imaging, genetics and behavioral studies, here we report that a pair of amphid neurons ASI is activated by nutrition and regulates worms behavioral states specifically promoting satiety quiescence; ASI inhibits the switch from quiescence to dwelling (a browsing state) and accelerates the switch from dwelling to quiescence. The canonical TGF? pathway, whose ligand is released from ASI, regulates satiety quiescence. The mutants of a ligand, a receptor and SMADs in the TGF? pathway all eat more and show less quiescence than wild type. The TGF? receptor in downstream neurons RIM and RIC is sufficient for worms to exhibit satiety quiescence, suggesting neuronal connection from ASI to RIM and RIC is essential for feeding regulation through the TGF? pathway. ASI also regulates satiety quiescence partly through cGMP signaling; restoring cGMP signaling in ASI rescues the satiety quiescence defect of cGMP signaling mutants. From these results, we propose that TGF? and cGMP pathways in ASI connect nutritional status to promotion of satiety quiescence, a sleep-like behavioral state. PMID:23739968

  5. Identification of an estrogenic hormone receptor in Caenorhabditis elegans

    SciTech Connect

    Mimoto, Ai; Fujii, Madoka [Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan); Usami, Makoto [Division of Pharmacology, National Institute of Health Sciences, Tokyo (Japan); Shimamura, Maki; Hirabayashi, Naoko [Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan); Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Tokyo (Japan); Kaneko, Takako [Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Tokyo (Japan); Sasagawa, Noboru [Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan); Ishiura, Shoichi [Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan)], E-mail: cishiura@mail.ecc.u-tokyo.ac.jp

    2007-12-28

    Changes in both behavior and gene expression occur in Caenorhabditis elegans following exposure to sex hormones such as estrogen and progesterone, and to bisphenol A (BPA), an estrogenic endocrine-disrupting compound. However, only one steroid hormone receptor has been identified. Of the 284 known nuclear hormone receptors (NHRs) in C. elegans, we selected nhr-14, nhr-69, and nhr-121 for analysis as potential estrogenic hormone receptors, because they share sequence similarity with the human estrogen receptor. First, the genes were cloned and expressed in Escherichia coli, and then the affinity of each protein for estrogen was determined using a surface plasmon resonance (SPR) biosensor. All three NHRs bound estrogen in a dose-dependent fashion. To evaluate the specificity of the binding, we performed a solution competition assay using an SPR biosensor. According to our results, only NHR-14 was able to interact with estrogen. Therefore, we next examined whether nhr-14 regulates estrogen signaling in vivo. To investigate whether these interactions actually control the response of C. elegans to hormones, we investigated the expression of vitellogenin, an estrogen responsive gene, in an nhr-14 mutant. Semi-quantitative RT-PCR showed that vitellogenin expression was significantly reduced in the mutant. This suggests that NHR-14 is a C. elegans estrogenic hormone receptor and that it controls gene expression in response to estrogen.

  6. Genome-wide RNAi analysis of Caenorhabditis elegans

    E-print Network

    Ahringe, Julie

    that had been covalently labelled with the fluorescent dye BODIPY, and was similar to the pattern of fat of Caenorhabditis elegans fat regulatory genes Kaveh Ashrafi*, Francesca Y. Chang*, Jennifer L. Watts, Andrew G ............................................................................................................................................................................. Regulation of body fat storage involves signalling between centres that regulate feeding in the brain

  7. Caenorhabditis elegans glia modulate neuronal activity and behavior

    PubMed Central

    Stout Jr., Randy F.; Verkhratsky, Alexei; Parpura, Vladimir

    2014-01-01

    Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general. PMID:24672428

  8. A Test for Epistasis Among Induced Mutations in Caenorhabditis elegans

    Microsoft Academic Search

    Andrew D. Peters; Peter D. Keightley

    2000-01-01

    Synergistic epistasis, in which deleterious mutations tend to magnify each other's effects, is a necessary component of the mutational deterministic hypothesis for the maintenance of sexual production. We tested for epistasis for life-history traits in the soil nematode Caenorhabditis elegans by inducing mutations in two genetic backgrounds: a wild-type strain and a set of genetically loaded lines that contain large

  9. Caenorhabditis elegans development requires mitochondrial function in the nervous system

    Microsoft Academic Search

    Sarah Ndegwa; Bernard D. Lemire

    2004-01-01

    The mitochondrial respiratory chain (MRC) supplies the majority of the energy requirements of most eucaryotic cells. A null mutation in the Caenorhabditis elegans nuo-1 gene encoding a subunit of complex I (NADH杣biquinone oxidoreductase) is lethal, leading to a developmental arrest at the third larval stage. To identify the tissues that regulate development in response to mitochondrial dysfunction, we restored nuo-1

  10. Diverse roles of actin in C. elegans early embryogenesis

    Microsoft Academic Search

    Nathalie Velarde; Kristin C Gunsalus; Fabio Piano

    2007-01-01

    BACKGROUND: The actin cytoskeleton plays critical roles in early development in Caenorhabditis elegans. To further understand the complex roles of actin in early embryogenesis we use RNAi and in vivo imaging of filamentous actin (F-actin) dynamics. RESULTS: Using RNAi, we found processes that are differentially sensitive to levels of actin during early embryogenesis. Mild actin depletion shows defects in cortical

  11. Sequence Signatures of Nucleosome Positioning in Caenorhabditis elegans

    Microsoft Academic Search

    Kaifu Chen; Lei Wang; Meng Yang; Jiucheng Liu; Chengqi Xin; Songnian Hu; Jun Yu

    2010-01-01

    Our recent investigation in the protist Trichomonas vaginalis suggested a DNA sequence periodicity with a unit length of 120.9 nt, which represents a sequence signature for nucleosome positioning. We now extended our observation in higher eukaryotes and identified a similar periodicity of 175 nt in length in Caenorhabditis elegans. In the process of defining the sequence compositional characteristics, we found

  12. Histidine Protects Against Zinc and Nickel Toxicity in Caenorhabditis elegans

    Microsoft Academic Search

    John T. Murphy; Janelle J. Bruinsma; Daniel L. Schneider; Sara Collier; James Guthrie; Asif Chinwalla; J. David Robertson; Elaine R. Mardis; Kerry Kornfeld

    2011-01-01

    Zinc is an essential trace element involved in a wide range of biological processes and human diseases. Zinc excess is deleterious, and animals require mechanisms to protect against zinc toxicity. To identify genes that modulate zinc tolerance, we performed a forward genetic screen for Caenorhabditis elegans mutants that were resistant to zinc toxicity. Here we demonstrate that mutations of the

  13. RESEARCH ARTICLE Open Access Pathogen-induced Caenorhabditis elegans

    E-print Network

    Paris-Sud XI, Universit de

    RESEARCH ARTICLE Open Access Pathogen-induced Caenorhabditis elegans developmental plasticity has and lifespan of adult nematodes. Bacterial strains used in this study were either pathogenic or innocuous to nematodes. Exposure to the pathogen during development did not affect larval survival. However

  14. The art and design of genetic screens: Caenorhabditis elegans

    Microsoft Academic Search

    Erik M. Jorgensen; Susan E. Mango

    2002-01-01

    The nematode Caenorhabditis elegans was chosen as a model genetic organism because its attributes, chiefly its hermaphroditic lifestyle and rapid generation time, make it suitable for the isolation and characterization of genetic mutants. The most important challenge for the geneticist is to design a genetic screen that will identify mutations that specifically disrupt the biological process of interest. Since 1974,

  15. Characterization of the astacin family of metalloproteases in C. elegans

    Microsoft Academic Search

    Ja-On Park; Jie Pan; Frank M鰄rlen; Marcus-Oliver Schupp; Robert Johnsen; David L Baillie; Richard Zapf; Donald G Moerman; Harald Hutter

    2010-01-01

    BACKGROUND: Astacins are a large family of zinc metalloproteases found in bacteria and animals. They have diverse roles ranging from digestion of food to processing of extracellular matrix components. The C. elegans genome contains an unusually large number of astacins, of which the majority have not been functionally characterized yet. RESULTS: We analyzed the expression pattern of previously uncharacterized members

  16. Identification of genes expressed in C. elegans touch receptor neurons

    Microsoft Academic Search

    Yun Zhang; Charles Ma; Thomas Delohery; Brian Nasipak; Barrett C. Foat; Alexander Bounoutas; Harmen J. Bussemaker; Stuart K. Kim; Martin Chalfie

    2002-01-01

    The extent of gene regulation in cell differentiation is poorly understood. We previously used saturation mutagenesis to identify 18 genes that are needed for the development and function of a single type of sensory neuron-the touch receptor neuron for gentle touch in Caenorhabditis elegans. One of these genes, mec-3, encodes a transcription factor that controls touch receptor differentiation. By culturing

  17. Achieving immortality in the C. elegans germline Chris Smelickb

    E-print Network

    Mayfield, John

    Viewpoints Achieving immortality in the C. elegans germline Chris Smelickb , Shawn Ahmeda August 2004; accepted 21 September 2004 Abstract Germline immortality is a topic that has intrigued of mechanisms that foster eternal youth in germ cells is lacking. The mysteries of germline immortality

  18. Cell lineage and cell death: Caenorhabditis elegans and cancer research

    Microsoft Academic Search

    Malia B. Potts; Scott Cameron

    2010-01-01

    Cancer is a complex disease in which cells have circumvented normal restraints on tissue growth and have acquired complex abnormalities in their genomes, posing a considerable challenge to identifying the pathways and mechanisms that drive fundamental aspects of the malignant phenotype. Genetic analyses of the normal development of the nematode Caenorhabditis elegans have revealed evolutionarily conserved mechanisms through which individual

  19. Real-time Embryogenesis in Live Caenorhabditis elegans Worms

    NSDL National Science Digital Library

    Dr. Anita G Fernandez (Fairfield University Biology)

    2011-11-21

    This is a lab exercise geared toward first-year undergraduate biology majors, where they get to view early embryogenesis in a live animal. In this exercise students will prepare slides if live C. elegans embryos, find one- or two-cell stage embryos, and observe cleavage stage of embryogenesis over the course of 30 minutes.

  20. Developmental Cell A Role for C. elegans Eph RTK

    E-print Network

    Chin-Sang, Ian

    and vascular system development. We show that in C. elegans, the VAB-1 Eph kinase domain physically interacts with and phosphorylates PTEN (DAF-18), diminishing its protein levels and function. vab-1 mutants show increased longevity-like signaling. Moreover, daf-18 mutations suppress vab-1 oocyte maturation phenotypes inde- pendent of PI3K

  1. Caenorhabditis elegans pathways that surveil and defend mitochondria.

    PubMed

    Liu, Ying; Samuel, Buck S; Breen, Peter C; Ruvkun, Gary

    2014-04-17

    Mitochondrial function is challenged by toxic by-products of metabolism as well as by pathogen attack. Caenorhabditis elegans normally responds to mitochondrial dysfunction with activation of mitochondrial-repair, drug-detoxification and pathogen-response pathways. Here, from a genome-wide RNA interference (RNAi) screen, we identified 45 C. elegans genes that are required to upregulate detoxification, pathogen-response and mitochondrial-repair pathways after inhibition of mitochondrial function by drug-induced or genetic disruption. Animals defective in ceramide biosynthesis are deficient in mitochondrial surveillance, and addition of particular ceramides can rescue the surveillance defects. Ceramide can also rescue the mitochondrial surveillance defects of other gene inactivations, mapping these gene activities upstream of ceramide. Inhibition of the mevalonate pathway, either by RNAi or statin drugs, also disrupts mitochondrial surveillance. Growth of C. elegans with a significant fraction of bacterial species from their natural habitat causes mitochondrial dysfunction. Other bacterial species inhibit C. elegans defence responses to a mitochondrial toxin, revealing bacterial countermeasures to animal defence. PMID:24695221

  2. Cell Lineages of the Embryo of the Nematode Caenorhabditis elegans

    Microsoft Academic Search

    Uwe Deppe; Einhard Schierenberg; Thomas Cole; Christian Krieg; David Schmitt; Bonita Yoder; Gunter von Ehrenstein

    1978-01-01

    Embryogenesis of the free-living soil nematode Caenorhabditis elegans produces a juvenile having about 550 cells at hatching. We have determined the lineages of 182 cells by tracing the divisions of individual cells in living embryos. An invariant pattern of cleavage divisions of the egg generates a set of stem cells. These stem cells are the founders of six stem cell

  3. INTRODUCTION The worm Caenorhabditis elegans generally employs three types

    E-print Network

    Mahadevan, L.

    1554 INTRODUCTION The worm Caenorhabditis elegans generally employs three types of crawling modes reorientations. However, in the presence of attractants, worms are able to track gradients using a biased random in the absence of food, worms also exhibit a large number of small angle turns by forming higher or lower

  4. Pseudomonas aeruginosa PAO1 Kills Caenorhabditis elegans by Cyanide Poisoning

    Microsoft Academic Search

    LARRY A. GALLAGHER; COLIN MANOIL

    2001-01-01

    In this report we describe experiments to investigate a simple virulence model in which Pseudomonas aerugi- nosa PAO1 rapidly paralyzes and kills the nematode Caenorhabditis elegans. Our results imply that hydrogen cyanide is the sole or primary toxic factor produced by P. aeruginosa that is responsible for killing of the nematode. Four lines of evidence support this conclusion. First, a

  5. Control of Larval Development by Chemosensory Neurons in Caenorhabditis elegans

    Microsoft Academic Search

    Cornelia I. Bargmann; H. Robert Horvitz

    1991-01-01

    Larval development of the nematode Caenorhabditis elegans is controlled by the activities of four classes of chemosensory neurons. The choice between normal development and development into a specialized larval form called a dauer larva is regulated by competing environmental stimuli: food and a dauer pheromone. When the neuron classes ADF, ASG, ASI, and ASJ are killed, animals develop as dauer

  6. Disruption of Iron Homeostasis Increases Phosphine Toxicity in Caenorhabditis elegans

    Microsoft Academic Search

    Ubon Cha; Nicholas Valmas; Patrick J. Collins; Paul E. B. Reilly; Bruce D. Hammock; Paul R. Ebert

    2007-01-01

    The aim of this study is to identify the biochemical mechanism of phosphine toxicity and resistance, using Caenorhabditis elegans as a model organism. To date, the precise mode of phosphine action is unclear. In this report, we demonstrate the following dose-dependent actions of phosphine, in vitro: (1) reduction of ferric iron (Fe3+) to ferrous iron (Fe2+), (2) release of iron

  7. Behavioral Degradation Under Mutation Accumulation in Caenorhabditis elegans

    Microsoft Academic Search

    Beverly C. Ajie; Suzanne Estes; Michael Lynch; Patrick C. Phillips

    2005-01-01

    Spontaneous mutations play a fundamental role in the maintenance of genetic variation in natural populations, the nature of inbreeding depression, the evolution of sexual reproduction, and the conserva- tion of endangered species. Using long-term mutation-accumulation lines of the nematode Caenorhabditis elegans, we estimate the rate and magnitude of mutational effects for a suite of behaviors characterizing individual chemosensory responses to

  8. Concentration dependent differential activity of signalling molecules in Caenorhabditis elegans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caenorhabditis elegans employs specific glycosides of the dideoxysugar ascarylose (the 慳scarosides) for monitoring population density/ dauer formation and finding mates. A synergistic blend of three ascarosides, called ascr#2, ascr#3 and ascr#4 acts as a dauer pheromone at a high concentration na...

  9. Cell Host & Microbe Antifungal Innate Immunity in C. elegans

    E-print Network

    Ewbank, Jonathan

    Signaling and a Conserved p38 MAPK Cascade Katja Ziegler,1,2,3,4 C. Le opold Kurz,1,2,3,4 Sophie Cypowyj,1.03.006 SUMMARY Like other multicellular organisms, the model nema- tode C. elegans responds to infection by inducing the expression of defense genes. Among the genes upregulated in response to a natural fungal

  10. RESEARCH COMMUNICATION The C. elegans p38 MAPK

    E-print Network

    Blackwell, Keith

    kinase (MAPK) cascade is an integral part of the response to a variety of environmental stresses. Here we, a major mechanism of oxidative stress defense is orchestrated by the two NF-E2-related factors Nrf1 pathway in the C. elegans oxidative stress response, as a model sys- tem for stress-induced signal

  11. Fine structure of the coelomic epithelium of Sagitta elegans (Chaetognatha)

    Microsoft Academic Search

    Ulrich Welsch; Volker Storch

    1982-01-01

    The coelomic space in the trunk of the arrow worm Sagitta elegans is lined by a thin epithelium, which may be termed coelomic epithelium. The visceral part of this epithelium is composed of flat cells characterized by thin and thick myofilaments, which constitute the circular musculature of the gut. In addition mitochondria, rough ER, and smooth walled cisterns, as well

  12. Enhanced Caenorhabditis elegans Locomotion in a Structured Microfluidic Environment

    PubMed Central

    Park, Sungsu; Hwang, Hyejin; Nam, Seong-Won; Martinez, Fernando; Austin, Robert H.; Ryu, William S.

    2008-01-01

    Background Behavioral studies of Caenorhabditis elegans traditionally are done on the smooth surface of agar plates, but the natural habitat of C. elegans and other nematodes is the soil, a complex and structured environment. In order to investigate how worms move in such environments, we have developed a technique to study C. elegans locomotion in microstructures fabricated from agar. Methodology/Principal Findings When placed in open, liquid-filled, microfluidic chambers containing a square array of posts, we discovered that worms are capable of a novel mode of locomotion, which combines the fast gait of swimming with the more efficient movements of crawling. When the wavelength of the worms matched the periodicity of the post array, the microstructure directed the swimming and increased the speed of C. elegans ten-fold. We found that mutants defective in mechanosensation (mec-4, mec-10) or mutants with abnormal waveforms (unc-29) did not perform this enhanced locomotion and moved much more slowly than wild-type worms in the microstructure. Conclusion/Significance These results show that the microstructure can be used as a behavioral screen for mechanosensory and uncoordinated mutants. It is likely that worms use mechanosensation in the movement and navigation through heterogeneous environments. PMID:18575618

  13. A Method for Evaluating Volt-VAR Optimization Field Demonstrations

    SciTech Connect

    Schneider, Kevin P.; Weaver, T. F.

    2014-08-31

    In a regulated business environment a utility must be able to validate that deployed technologies provide quantifiable benefits to the end-use customers. For traditional technologies there are well established procedures for determining what benefits will be derived from the deployment. But for many emerging technologies procedures for determining benefits are less clear and completely absent in some cases. Volt-VAR Optimization is a technology that is being deployed across the nation, but there are still numerous discussions about potential benefits and how they are achieved. This paper will present a method for the evaluation, and quantification of benefits, for field deployments of Volt-VAR Optimization technologies. In addition to the basic methodology, the paper will present a summary of results, and observations, from two separate Volt-VAR Optimization field evaluations using the proposed method.

  14. Characterization of the arginine kinase isoforms in Caenorhabditis elegans.

    PubMed

    Fraga, Dean; Aryal, Manish; Hall, Joseph E; Rae, Evan; Snider, Mark

    2015-09-01

    Phosphagen kinases (PKs) are well-studied enzymes involved in energy homeostasis in a wide range of animal, protozoan, and even some bacterial species. Recent genome efforts have allowed comparative work on the PKs to extend beyond the biochemistry of individual proteins to the comparative cellular physiology and examining of the role of all PK family members in an organism. The sequencing of the Caenorhabditis elegans genome and availability of sophisticated genetic tools within that system affords the opportunity to conduct a detailed physiological analysis of the PKs from a well known invertebrate for comparison with the extensive work conducted on vertebrate systems. As a first step in this effort we have carried out a detailed molecular genetic and biochemical characterization of the PKs in C. elegans. Our results reveal that C. elegans has five PK genes encoding arginine kinases that range in catalytic efficiency (kcat/KM(Arg)) from (3.10.6)10(4) to (94)10(5)M(-1)s(-1). This range is generally within the range seen for arginine kinases from a variety of species. Our molecular genetic and phylogenetic analysis reveals that the gene family has undergone extensive intron loss and gain within the suborder Rhabditina. In addition, within C. elegans we find evidence of gene duplication and loss. The analysis described here for the C. elegans AKs represents one of the most complete biochemical and molecular genetic analysis of a PK family within a genetically tractable invertebrate system and opens up the possibility of conducting detailed physiological comparisons with vertebrate systems using the sophisticated tools available with this model invertebrate system. PMID:25981702

  15. A gene expression fingerprint of C. elegans embryonic motor neurons

    PubMed Central

    Fox, Rebecca M; Von Stetina, Stephen E; Barlow, Susan J; Shaffer, Christian; Olszewski, Kellen L; Moore, Jason H; Dupuy, Denis; Vidal, Marc; Miller, David M

    2005-01-01

    Background Differential gene expression specifies the highly diverse cell types that constitute the nervous system. With its sequenced genome and simple, well-defined neuroanatomy, the nematode C. elegans is a useful model system in which to correlate gene expression with neuron identity. The UNC-4 transcription factor is expressed in thirteen embryonic motor neurons where it specifies axonal morphology and synaptic function. These cells can be marked with an unc-4::GFP reporter transgene. Here we describe a powerful strategy, Micro-Array Profiling of C. elegans cells (MAPCeL), and confirm that this approach provides a comprehensive gene expression profile of unc-4::GFP motor neurons in vivo. Results Fluorescence Activated Cell Sorting (FACS) was used to isolate unc-4::GFP neurons from primary cultures of C. elegans embryonic cells. Microarray experiments detected 6,217 unique transcripts of which ~1,000 are enriched in unc-4::GFP neurons relative to the average nematode embryonic cell. The reliability of these data was validated by the detection of known cell-specific transcripts and by expression in UNC-4 motor neurons of GFP reporters derived from the enriched data set. In addition to genes involved in neurotransmitter packaging and release, the microarray data include transcripts for receptors to a remarkably wide variety of signaling molecules. The added presence of a robust array of G-protein pathway components is indicative of complex and highly integrated mechanisms for modulating motor neuron activity. Over half of the enriched genes (537) have human homologs, a finding that could reflect substantial overlap with the gene expression repertoire of mammalian motor neurons. Conclusion We have described a microarray-based method, MAPCeL, for profiling gene expression in specific C. elegans motor neurons and provide evidence that this approach can reveal candidate genes for key roles in the differentiation and function of these cells. These methods can now be applied to generate a gene expression map of the C. elegans nervous system. PMID:15780142

  16. Propagating C. Elegans The easiest way to prolong Caenorhabditis elegans cultures is by a method known as

    E-print Network

    Rose, Michael R.

    of agar + bacterial lawn + C. elegans and place the chunk onto a fresh bacterial lawn agar plate. Thus within the worm plate by poking the tweezers through the agar. a. Make sure all sides have been cut 5. Use the tweezers to pick up the chunk of agar from the side of the piece of agar a. Do not let your

  17. BZ UMa and Var Her 04: Orphan TOADS

    NASA Astrophysics Data System (ADS)

    Price, A.; Howell, S.

    2005-05-01

    Both BZ UMa and Var Her 04 are cataclysmic variable stars without a home. Neither fit easily into current classification systems so may extend the population distribution of two unique CV types: UGWZ dwarf novae and intermediate polars. New outburst photometry and archival X-Ray data shed some new light on BZ UMa's high energy state and new spectral and IR observations from Spitzer of dust around the newly discovered cataclysmic variable Var Her 04 may help find it a home as well.

  18. Characterization of the Caenorhabditis elegans G protein-coupled serotonin receptors

    Microsoft Academic Search

    Ma飔 Carre-Pierrat; David Baillie; Robert Johnsen; Rhonda Hyde; Anne Hart; Laure Granger; Laurent S間alat

    2006-01-01

    Serotonin (5-HT) regulates a wide range of behaviors in Caenorhabditis elegans, including egg laying, male mating, locomotion and pharyngeal pumping. So far, four serotonin receptors have been described in the nematode C. elegans, three of which are G protein-coupled receptors (GPCR), (SER-1, SER-4 and SER-7), and one is an ion channel (MOD-1). By searching the C. elegans genome for additional

  19. The C. elegans heterochronic gene lin-4 encodes small RNAs with antisense complementarity to lin-14

    Microsoft Academic Search

    Rosalind C. Lee; Rhonda L. Feinbaum; Victor Ambros

    1993-01-01

    Summary h-4 is essential for the normal temporal control of diverse postembryonic developmental events in C. elegans. \\/in-4 acts by negatively regulating the level of LIN-14 protein, creating a temporal decrease in LIN-14 protein starting in the first larval stage (Ll). We have cloned the C. elegans lin-4 locus by chromosomal walking and transformation rescue. We used the C. elegans

  20. Overexpression of SUMO perturbs the growth and development of Caenorhabditis elegans

    Microsoft Academic Search

    Miia M. Rytinki; Merja Lakso; Petri Pehkonen; Vuokko Aarnio; Kaja Reisner; Mikael Per鋕yl; Garry Wong; Jorma J. Palvimo

    Small ubiquitin-related modifiers (SUMOs) are important regulator proteins. Caenorhabditis elegans contains a single SUMO ortholog, SMO-1, necessary for the reproduction of C. elegans. In this study, we constructed transgenic C. elegans strains expressing human SUMO-1 under the control of pan-neuronal (aex-3) or pan-muscular (myo-4) promoter and SUMO-2 under the control of myo-4 promoter. Interestingly, muscular overexpression of SUMO-1 or -2

  1. Population Genomics of the Immune Evasion (var) Genes of Plasmodium falciparum

    Microsoft Academic Search

    Alyssa E Barry; Aleksandra Leliwa-Sytek; Livingston Tavul; Heather Imrie; Florence Migot-Nabias; Stuart M Brown; Gilean A. V McVean; Karen P Day

    2007-01-01

    Var genes encode the major surface antigen (PfEMP1) of the blood stages of the human malaria parasite Plasmodium falciparum. Differential expression of up to 60 diverse var genes in each parasite genome underlies immune evasion. We compared the diversity of the DBL? domain of var genes sampled from 30 parasite isolates from a malaria endemic area of Papua New Guinea

  2. Isolation of Cryptococcus neoformans var. gattii from Eucalyptus camaldulensis in India

    Microsoft Academic Search

    ARUNALOKE CHAKRABARTI; M. JATANA; P. KUMAR; L. CHATHA; A. KAUSHAL; ARVIND A. PADHYE

    1997-01-01

    Cryptococcus neoformans var. gattii has an ecological association with five Eucalyptus species: E. blakelyi, E. camaldulensis, E. gomphocephala, E. rudis, and E. tereticornis. After human infections due to C. neoformans var. gattii were diagnosed in the states of Punjab, Himachal Pradesh, and Karnataka, India, a study was un- dertaken to investigate the association of C. neoformans var. gattii with Indian

  3. A Hierarchical Approach to Reactive Volt Ampere (VAR) Optimization in System Planning

    Microsoft Academic Search

    W. M. Lebow; R. Rouhani; R. Nadira; P. B. Usoro; R. K. Mehra; D. W. Sobieski; M. K. Pal; M. P. Bhavaraju

    1985-01-01

    A two-level hierarchical approach for optimum allocation of reactive volt ampere (VAR) sources in large scale power system planning is presented in this paper. The approach takes advantage of the natural distinction between var dispatch in system operation (Level 1) and var allocation in system planning (Level 2). The two levels are related together using the Generalized Benders Decomposition. The

  4. CoOrdination of Static Var Compensators With Long Distance Radial Transmission System for Damping Improvement

    Microsoft Academic Search

    B. T. Ooi; M. H. Banakar

    1984-01-01

    The capability of static var compensators to use supplementary signals for damping improvement has been studied. Damping is shown to be a function of the transmission system loading and a function of the static var compensator The study offers insights as to how static var compensators should be coordinated with respect to the transmission system. The technology under study is

  5. Wnt and EGF pathways act together to induce C. elegans male hook development

    E-print Network

    Sternberg, Paul W.

    Comparative studies of vulva development between Caenorhabditis elegans and other nematode species have provided some insight into the evolution of patterning networks. However, molecular genetic details are available ...

  6. The effects of maternal corticosterone levels on offspring behavior in fast-and slow-growth garter snakes (Thamnophis elegans)

    E-print Network

    Bronikowski, Anne

    snakes (Thamnophis elegans) Kylie A. Robert 1 , Carol Vleck, Anne M. Bronikowski Department of Ecology of the resulting offspring. We treated pregnant female garter snakes (Thamnophis elegans) with low levels

  7. Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans

    E-print Network

    Bronikowski, Anne

    Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free

  8. Artificial Stimulation of Cephalic Cholinergic Sensory Neurons Induces Mating-Like Motor Responses in Male Caenorhabditis elegans

    E-print Network

    Midkiff, James

    2012-12-06

    . These large neural circuits modulate complex behaviors. The nematode roundworm Caenorhabditis elegans uses a small but highly-interconnected nervous system to carry out complex behaviors. The nervous system of C. elegans is a tractable model to determine...

  9. The Essential Oil from Elsholtzia eriostachya var. pusilla

    Microsoft Academic Search

    Anil K. Pant; Vasu Dev; Rashmi Parihar; Chandra S. Mathela; Josef Rauscher; Otto Vostrowsky; H. J. Bestmann

    1992-01-01

    GC, CG\\/MS, FTIR, H-NMR and C-NMR analyses revealed that the essential oil of Elsholtzia eriostachya var. pusilla growing in Kumaun region (India) contained 53% geranial and 39% neral together with 19 other, mainly terpenoid constituents.

  10. A STUDY OF RAPESEED (BRASSICA NAPUS L. VAR. OLEIFERA METZGER)

    E-print Network

    Paris-Sud XI, Universit de

    A STUDY OF RAPESEED (BRASSICA NAPUS L. VAR. OLEIFERA METZGER) FLOWER NECTAR SECRETIONS Jacques compared to establish a reliable basis for analysis and comparison of nectar production of rapeseed lines pollinators. Various studies of rapeseed pollinating agents have indicated that the plant benefits from insect

  11. Antifungal activity of Brassica oleracea var. botrytis fresh aqueous juice.

    PubMed

    Sisti, M; Amagliani, G; Brandi, G

    2003-07-01

    The antifungal activity of fresh, aqueous Brassica oleracea var. botrytis juice against Candida albicans and other pathogenic fungi was investigated. The juice was found to be effective both in inhibiting the growth of blastoconidia and reducing the appearance of C. albicans germ tubes. Furthermore, the juice inhibited the growth of some pathogenic, filamentous fungi. PMID:12837360

  12. A New Static Var Compensator for an Arc Furnace

    Microsoft Academic Search

    M. D. Cox; A. Mirbod

    1986-01-01

    This paper presents the design of an electronic compensator that can compensate the reactive current drawn by an arc furnace. Consisting of three independent single-phase pulse-width modulated (PWM) inverters, the proposed compensator responds quickly to any sudden load changes and compensates both the fundamental displacement current and the harmonic distortion current drawn by the load. Unlike conventional static var compensators,

  13. neo-Clerodane Diterpenoids from Ajuga macrosperma var. breviflora.

    PubMed

    Castro, Amaya; Coll, Josep; Pant, Anil K; Pakrash, Om

    2015-06-01

    Six new naturally occurring ajugarin-like neo-clerodane diterpenoids, ajugaflorins A-F, along with six known compounds [the parent ajugarin I, ajugalides B and C, ajugamarin F4, ajugamacrin E, and ajugatakasin B] were isolated from A. macrosperma var. breviflora. The structures were elucidated by extensive NMR spectroscopic and MS analyses and comparison with data previously reported. PMID:26197499

  14. Neolignan and flavonoid glycosides in Juniperus communis var. depressa

    Microsoft Academic Search

    Tsutomu Nakanishi; Naoki Iida; Yuka Inatomi; Hiroko Murata; Akira Inada; Jin Murata; Frank A. Lang; Munekazu Iinuma; Toshiyuki Tanaka

    2004-01-01

    Two neolignan glycosides (junipercomnosides A and B) were isolated from aerial parts of Juniperus communis var. depressa along with two known neolignan glycosides and seven flavonoid glycosides. The structures of the isolated compounds were determined by spectral analysis, in particular by 2D-NMR analysis. The significance of distribution of flavonoids in the chemotaxonomy of genus Juniperus was also discussed.

  15. Voltage versus VAr\\/power factor regulation on synchronous generators

    Microsoft Academic Search

    Thomas W. Eberly; Richard C. Schaefer

    2002-01-01

    When paralleled to the utility bus, synchronous generators can be controlled using either terminal voltage or VAr\\/power factor control. Selection is dependent upon the size of the generator and the stiffness of the connecting utility bus. For large generators where the kVA is significant, these machines are usually terminal voltage regulated and dictate the system's bus voltage. When smaller terminal

  16. Chemopreventive and Anticancer Activities of Allium victorialis var. platyphyllum Extracts

    PubMed Central

    Kim, Hyun-Jeong; Park, Min Jeong; Park, Hee-Juhn; Chung, Won-Yoon; Kim, Ki-Rim; Park, Kwang-Kyun

    2014-01-01

    Background: Allium victorialis var. platyphyllum is an edible perennial herb and has been used as a vegetable or as a Korean traditional medicine. Allium species have received much attention owing to their diverse pharmacological properties, including antioxidative, anti-inflammatory, and anticancer activities. However, A. victorialis var. platyphyllum needs more study. Methods: The chemopreventive potential of A. victorialis var. platyphyllum methanol extracts was examined by measuring 12-O-tetra-decanoylphorbol 13-acetate (TPA)-induced superoxide anion production in the differentiated HL-60 cells, TPA-induced mouse ear edema, and Ames/Salmonella mutagenicity. The apoptosis-inducing capabilities of the extracts were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, 4,6-diamidino-2-phenylindole staining, and the DNA fragmentation assay in human colon cancer HT-29 cells. Antimetastatic activities of the extracts were also investigated in an experimental mouse lung metastasis model. Results: The methanol extracts of A. victorialis var. platyphyllum rhizome (AVP-R) and A. victorialis var. platyphyllum stem (AVP-S) dose-dependently inhibited the TPA-induced generation of superoxide anion in HL-60 cells and TPA-induced ear edema in mice, as well as 7,12-dimethylbenz[a]anthracene (DMBA) and tert-butyl hydroperoxide (t-BOOH) -induced bacterial mutagenesis. AVP-R and AVP-S reduced cell viability in a dose-related manner and induced apoptotic morphological changes and internucleosomal DNA fragmentation in HT-29 cells. In the experimental mouse lung metastasis model, the formation of tumor nodules in lung tissue was significantly inhibited by the treatment of the extracts. Conclusions: AVP-R and AVP-S possess antioxidative, anti-inflammatory, antimutagenic, proapoptotic, and antimetastatic activities. Therefore, these extracts can serve as a beneficial supplement for the prevention and treatment of cancer. PMID:25337587

  17. Determination of Re(. var epsilon. prime /. var epsilon. ) by the simultaneous detection of the four K sub L , S r arrow. pi. pi. decay modes

    SciTech Connect

    Patterson, J.R.; Barker, A.; Briere, R.A.; Gibbons, L.K.; Makoff, G.; Papadimitriou, V.; Somalwar, S.; Wah, Y.W.; Winstein, B.; Winston, R.; Woods, M.; Yamamoto, H. (The Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA) The Department of Physics, The University of Chicago, Chicago, Illinois 60637 (USA)); Swallow, E. (Department of Physics, Elmhurst College, Elmhurst, Illinois 60126 (USA) Department of Physics, The University of Chicago, Chicago, Illinois 60637 (USA)); Bock, G.J.; Coleman, R.; Enagonio, J.; Hsiung, Y.B.; Stanfield, K.; Stefanski, R.; Yamanaka, T. (Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (USA)); Blair, G.; Gollin, G.D.; Karlsson, M.; Okamitsu, J.K.; Tschirhart, R. (Department of Physics, Princeton University, Princeton, New Jersey 08544 (USA)); Brisson, J.C.; Debu, P.; Peyaud, B.; Turlay, R.; Vallage, B. (Department de Physique des Particules Elementaires, Centre d'Etudes Nucleaires de Saclay, F-91191 Gif-sur-Yvette CEDEX,

    1990-03-26

    The E731 experiment at Fermilab has searched for direct {ital CP} violation in {ital K}{sup 0}{r arrow}{pi}{pi}, which is parametrized by {var epsilon}{prime}/{var epsilon}. For the first time all four of the {ital K}{sub {ital L},}{ital S}{r arrow}{pi}{pi} modes were collected simultaneously, which greatly facilitated studies of systematic uncertainty. We find Re({var epsilon}{prime}/{var epsilon})={minus}0.0004{plus minus}0.0014(stat){plus minus}0.0006(syst). The result provides no evidence for direct {ital CP} violation.

  18. Determination of Re(. var epsilon. prime \\/. var epsilon. ) by the simultaneous detection of the four K sub L , S r arrow. pi. pi. decay modes

    Microsoft Academic Search

    J. R. Patterson; A. Barker; R. A. Briere; L. K. Gibbons; G. Makoff; V. Papadimitriou; S. Somalwar; Y. W. Wah; B. Winstein; R. Winston; M. Woods; H. Yamamoto; E. Swallow; G. J. Bock; R. Coleman; J. Enagonio; Y. B. Hsiung; K. Stanfield; R. Stefanski; T. Yamanaka; G. Blair; G. D. Gollin; M. Karlsson; J. K. Okamitsu; R. Tschirhart; J. C. Brisson; P. Debu; B. Peyaud; R. Turlay; B. Vallage

    1990-01-01

    The E731 experiment at Fermilab has searched for direct {ital CP} violation in {ital K}掳{r arrow}舷, which is parametrized by {var epsilon}獠\\/{var epsilon}. For the first time all four of the {ital K}{sub {ital L},}{ital S}{r arrow}舷 modes were collected simultaneously, which greatly facilitated studies of systematic uncertainty. We find Re({var epsilon}獠\\/{var epsilon})=-0.0004{plus minus}0.0014(stat){plus minus}0.0006(syst). The result provides no evidence

  19. Running Worms: C. elegans Self-Sorting by Electrotaxis

    PubMed Central

    Mani鑢e, Xavier; Lebois, F閘ix; Matic, Ivan; Ladoux, Benoit; Di Meglio, Jean-Marc; Hersen, Pascal

    2011-01-01

    The nematode C. elegans displays complex dynamical behaviors that are commonly used to identify relevant phenotypes. Although its maintenance is straightforward, sorting large populations of worms when looking for a behavioral phenotype is difficult, time consuming and hardly quantitative when done manually. Interestingly, when submitted to a moderate electric field, worms move steadily along straight trajectories. Here, we report an inexpensive method to measure worms crawling velocities and sort them within a few minutes by taking advantage of their electrotactic skills. This method allows to quantitatively measure the effect of mutations and aging on worm's crawling velocity. We also show that worms with different locomotory phenotypes can be spatially sorted, fast worms traveling away from slow ones. Group of nematodes with comparable locomotory fitness could then be isolated for further analysis. C. elegans is a growing model for neurodegenerative diseases and using electrotaxis for self-sorting can improve the high-throughput search of therapeutic bio-molecules. PMID:21326598

  20. Lysosomal Signaling Molecules Regulate Longevity in Caenorhabditis elegans

    PubMed Central

    Folick, Andrew; Oakley, Holly Doebbler; Yu, Yong; Armstrong, Eric H.; Kumari, Manju; Sanor, Lucas; Moore, David D.; Ortlund, Eric A.; Zechner, Rudolf; Wang, Meng C.

    2015-01-01

    Lysosomes are crucial cellular organelles for human health that function in digestion and recycling of extracellular and intracellular macromolecules. We describe a signaling role for lysosomes that affects aging. In the worm, Caenorhabditis elegans, the lysosomal acid lipase LIPL-4 triggered nuclear translocalization of a lysosomal lipid chaperone LBP-8, consequently promoting longevity by activating the nuclear hormone receptors NHR-49 and NHR-80. We used high-throughput metabolomic analysis to identify several lipids whose abundance was increased in worms constitutively over-expressing LIPL-4. Among them, oleoylethanolamide directly bound to LBP-8 and NHR-80 proteins, activated transcription of target genes of NHR-49 and NHR-80, and promoted longevity in C. elegans. These findings reveal a lysosome-to-nucleus signaling pathway that promotes longevity and suggest a function of lysosomes as signaling organelles in metazoans. PMID:25554789

  1. Aging. Lysosomal signaling molecules regulate longevity in Caenorhabditis elegans.

    PubMed

    Folick, Andrew; Oakley, Holly D; Yu, Yong; Armstrong, Eric H; Kumari, Manju; Sanor, Lucas; Moore, David D; Ortlund, Eric A; Zechner, Rudolf; Wang, Meng C

    2015-01-01

    Lysosomes are crucial cellular organelles for human health that function in digestion and recycling of extracellular and intracellular macromolecules. We describe a signaling role for lysosomes that affects aging. In the worm Caenorhabditis elegans, the lysosomal acid lipase LIPL-4 triggered nuclear translocalization of a lysosomal lipid chaperone LBP-8, which promoted longevity by activating the nuclear hormone receptors NHR-49 and NHR-80. We used high-throughput metabolomic analysis to identify several lipids in which abundance was increased in worms constitutively overexpressing LIPL-4. Among them, oleoylethanolamide directly bound to LBP-8 and NHR-80 proteins, activated transcription of target genes of NHR-49 and NHR-80, and promoted longevity in C. elegans. These findings reveal a lysosome-to-nucleus signaling pathway that promotes longevity and suggest a function of lysosomes as signaling organelles in metazoans. PMID:25554789

  2. Behavioral avoidance of pathogenic bacteria by Caenorhabditis elegans.

    PubMed

    Meisel, Joshua D; Kim, Dennis H

    2014-10-01

    The simple animal host Caenorhabditis elegans utilizes its nervous system to respond to diverse microbial cues, and can engage in a protective behavioral avoidance response to environmental pathogens. This behavior bears hallmarks of an immune response, with sensors and recognition systems that trigger a protective response following a learning experience. Neuronal circuits required for aversive learning have been defined, revealing conserved signaling modules with dual roles in immunity and neuronal responses to pathogenic bacteria. Identification of natural polymorphisms that modulate avoidance behavior has enabled an improved understanding of host-microbe interactions at the molecular level. We review here these findings and discuss how the microbial cues and host responses defined in C. elegans may provide insight into evolutionarily diverse host-microbe interactions. PMID:25240986

  3. Noncanonical cell death in the nematode Caenorhabditis elegans

    PubMed Central

    Kinet, Maxime J.; Shaham, Shai

    2014-01-01

    The nematode Caenorhabditis. elegans has served as a fruitful setting for cell death research for over three decades. A conserved pathway of four genes, egl-1/BH3-only, ced-9/Bcl-2, ced-4/Apaf-1, and ced-3/caspase, coordinates most developmental cell deaths in C. elegans. However, other cell death forms, programmed and pathological, have also been described in this animal. Some of these share morphological and/or molecular similarities with the canonical apoptotic pathway, while others do not. Indeed, recent studies suggest the existence of an entirely novel mode of programmed developmental cell destruction that may also be conserved beyond nematodes. Here we review evidence for these noncanonical pathways. We propose that different cell death modalities can function as backup mechanisms for apoptosis, or as tailor-made programs that allow specific dying cells to be efficiently cleared from the animal. PMID:25065890

  4. A microfluidic device for efficient chemical testing using Caenorhabditis elegans.

    PubMed

    Song, Pengfei; Zhang, Weize; Sobolevski, Alexandre; Bernard, Kristine; Hekimi, Siegfried; Liu, Xinyu

    2015-04-01

    The nematode worm Caenorhabditis elegans has been employed as a popular model organism in many fields of biological research. In this paper, we present a microfluidic device for facilitating chemical testing using C. elegans. For testing chemicals on chip, the device houses single nematodes in microfluidic chambers and precisely adjusts the chamber's chemical environment during experiments. Eight nematodes can be readily loaded into the chambers through separate loading channels in a quick and gentle manner. In addition, a custom-made software with a graphic user interface is also created for quantitative analysis of locomotion parameters (swimming frequency and bend amplitude) of the nematodes in response to chemical stimuli, thus greatly enhancing the efficiency of data collection. We perform proof-of-concept experiments using two chemicals, zinc ion (Zn(2+)) and glucose, to demonstrate the effectiveness of the microfluidic device. PMID:25744157

  5. C.V. Riley抯 lost aphids: Siphonophora fragariae var. immaculata and Aphis rapae var. laevigata (Hemiptera: Aphididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The syntypes of Siphonophora fragariae var. immaculata Riley were rediscovered in the Aphidoidea collection of the United States of America National Museum of Natural History. Previously, S. fragariae immaculata was largely lost and forgotten. Through examination of the specimens, we hereby establ...

  6. Caenorhabditis elegans Innate Immune Response Triggered by Salmonella enterica Requires Intact LPS and Is Mediated by a MAPK Signaling Pathway

    Microsoft Academic Search

    Alejandro Aballay; Eliana Drenkard; Layla R. Hilbun; Frederick M. Ausubel

    2003-01-01

    Compared to mammals, insects, and plants, relatively little is known about innate immune responses in the nematode Caenorhabditis elegans. Previous work showed that Salmonella enterica serovars cause a persistent infection in the C. elegans intestine [1, 2] that triggers gonadal programmed cell death (PCD) and that C. elegans cell death (ced) mutants are more susceptible to Salmonella-mediated killing [3]. To

  7. Adaptive divergence within and between ecotypes of the terrestrial garter snake, Thamnophis elegans, assessed with FST-QST

    E-print Network

    Palumbi, Stephen

    Adaptive divergence within and between ecotypes of the terrestrial garter snake, Thamnophis elegans study system, populations of the terrestrial garter snake (Thamnophis elegans) in the Eagle Lake basin-statistics; scalation. Abstract Populations of the terrestrial garter snake (Thamnophis elegans) around Eagle Lake

  8. Evidence for Selection on Thermoregulation: Effects of Temperature on Embryo Mortality in the Garter Snake Thamnophis elegans

    E-print Network

    Arnold, Stevan J.

    in the Garter Snake Thamnophis elegans RYAN P. O'DONNELL AND STEVAN J. ARNOLD Despite widespread belief-four female Thamnophis elegans were maintained at one of nine constant temperatures during pregnancy (2133 C snake Thamnophis elegans. Two studies found evidence for the effects of thermoregulation on fitness

  9. Phylogeographic Inferences Concerning Evolution of Brazilian Passiflora actinia and P. elegans (Passifloraceae) Based on ITS (nrDNA) Variation

    E-print Network

    Eizirik, Eduardo

    Phylogeographic Inferences Concerning Evolution of Brazilian Passiflora actinia and P. elegans electronically: 14 February 2005 Background and Aims Passiflora actinia and P. elegans, two markedly parapatric sometimes paternal. Key words: Passiflora actinia, Passiflora elegans, Passifloraceae, ITS, trnL-trnF, psb

  10. A transcribed polyketide synthase gene from Xanthoria elegans

    Microsoft Academic Search

    Georg Brunauer; Lucia Muggia; Elfie Stocker-W鰎g鰐ter; Martin Grube

    2009-01-01

    We characterize the transcript of a polyketide synthase gene (PKS) from the cultured mycobiont of Xanthoria elegans (XePKS1) using SMART-rapid amplification of cDNA ends (RACE) cDNA synthesis. Sequence analysis of the cloned cDNA reveals an open reading frame of 2144 amino acid residues. It contains features of a non-reducing fungal type I燩KS with an N-terminal starter unit: acyl carrier protein

  11. Tyrosylprotein sulfotransferase regulates collagen secretion in Caenorhabditis elegans

    Microsoft Academic Search

    Tai Hoon Kim; Do Hyun Kim; Hyung Wook Nam; Sang Yoon Park; Jaegal Shim; Jin Won Cho

    2010-01-01

    The sulfation of tyrosine residues is an important post-translational modification involved in the regulation of protein function.\\u000a We examined the activity of worm tyrosylprotein sulfotransferase (TPST-1) on a typical cuticle collagen, ROL-6, in C. elegans. We verified that TPST-1 sulfates three tyrosine residues of ROL-6 in vitro. We found that these tyrosine residues are important for the secretion of ROL-6::GFP.

  12. Caenorhabditis Elegans Mutants Resistant to Inhibitors of Acetylcholinesterase

    PubMed Central

    Nguyen, M.; Alfonso, A.; Johnson, C. D.; Rand, J. B.

    1995-01-01

    We characterized 18 genes from Caenorhabditis elegans that, when mutated, confer recessive resistance to inhibitors of acetylcholinesterase. These include previously described genes as well as newly identified genes; they encode essential as well as nonessential functions. In the absence of acetylcholinesterase inhibitors, the different mutants display a wide range of behavioral deficits, from mild uncoordination to almost complete paralysis. Measurements of acetylcholine levels in these mutants suggest that some of the genes are involved in presynaptic functions. PMID:7498734

  13. Molecular Analysis of X Chromosome Dosage Compensation in Caenorhabditis elegans

    Microsoft Academic Search

    Laurel M. Donahue; Barbara A. Quarantillo; William B. Wood

    1987-01-01

    We used a convenient quantitative dot blot assay to measure transcript levels for two X chromosome-linked genes, myo-2 and act-4, in the nematode Caenorhabditis elegans. We show that there is dosage compensation of transcript levels for these two genes between XX hermaphrodites and XO males and that a mutation in the dpy-21 gene, postulated from genetic analysis to be involved

  14. Electrocardiography in anaesthetised red-eared sliders ( Trachemys scripta elegans)

    Microsoft Academic Search

    R. M Holz; P Holz

    1995-01-01

    Electrocardiographic (ECG) values were measured in nine red-eared sliders (Trachemys scripta elegans), anaesthetised with either ketamine, ketamine\\/xylazine or ketamine\\/midazolam, for the purpose of cardiocentesis. Lead II traces were then recorded through three cutaneous electrodes. The ECG complexes consisted of small upright P waves, larger R waves and no Q or S wave deflections, very long QT intervals, small upright T

  15. The emergence of stereotyped behaviors in C. elegans

    Microsoft Academic Search

    Greg Stephens; William Ryu; William Bialek

    2010-01-01

    Many organisms, including humans, engage in stereotyped behaviors and these are often attributed to a deterministic command process within the nervous system. Here we use the locomotor dynamics of the nematode C. elegans to suggest an alternative explanation in which stereotyped behavior emerges due to noise within a non-linear dynamical system. In previous work (PLoS Comp Bio 4, e1000028 (2008))

  16. Lettuce black root rot a disease caused by Chalara elegans

    Microsoft Academic Search

    R G. O払rien

    1994-01-01

    Lettuce plants in several fields in south-eastern Queensland were affected by a black root rot resulting in slow growth, small\\u000a head size and harvest reductions. Isolation and pathogenicity tests showed Chalara elegans was the causal fungus. The host range included bean and cucurbits but not capsicum, celery, cotton, eggplant, parsley,\\u000a radish or tomato. The weed Sonchus oleraceus was a natural

  17. Rte-1, a retrotransposon-like element in Caenorhabditis elegans

    Microsoft Academic Search

    Sandra Youngman; Ronald H. A. Plasterk

    1996-01-01

    We have characterized a retrotransposon-like element (Rte-1) in C. elegans. It was identified while we were sequencing the pim related kinase-1 (prk-1) gene. The element is 3,298 bp long and flanked by a 200 bp direct repeat. 95 bp of the direct repeat are present in the coding region of prk-1. Rte-1 contains an open reading frame, in the opposite

  18. Gene interactions affecting mechanosensory transduction in Caenorhabditis elegans

    Microsoft Academic Search

    Mingxia Huang; Martin Chalfie

    1994-01-01

    GENETIC screening has identified a group ofmec (mechanosensory) genes that are required for the function of a set of six touch-receptor neurons in the nematode Caenorhabditis elegans 1,2. Such genes potentially encode components of the mechanosensory apparatus. We have cloned one of these genes, mec-10, which is a member of the degenerin gene family (genes such as mec-4 and deg-1

  19. Copulation in C. elegans males requires a nuclear hormone receptor

    Microsoft Academic Search

    Ge Shan; W. W. Walthall

    2008-01-01

    In Caenorhabditis elegans, uncoordinated (unc)-55 encodes a nuclear hormone receptor that is necessary for coordinated movement and male mating. An unc-55 reporter gene revealed a sexually dimorphic pattern: early in post-embryonic motor neurons in both sexes; and later in a subset of male-specific cells that included an interneuron and eight muscle cells. A behavioral analysis coupled with RNA interference (RNAi)

  20. Mutator Phenotype of Caenorhabditis elegans DNA Damage Checkpoint Mutants

    Microsoft Academic Search

    Jasper Harris; Mia Lowden; Iuval Clejan; Monika Tzoneva; James H. Thomas; Jonathan Hodgkin; Shawn Ahmed

    2006-01-01

    DNA damage response proteins identify sites of DNA damage and signal to downstream effectors that orchestrate either apoptosis or arrest of the cell cycle and DNA repair. The C. elegans DNA damage response mutants mrt-2, hus-1 ,a ndclk-2(mn159) displayed 8- to 15-fold increases in the frequency of spontaneous mutation in their germlines. Many of these mutations were small- to medium-sized

  1. Genome-wide RNAi screening in Caenorhabditis elegans

    Microsoft Academic Search

    Ravi S. Kamath; Julie Ahringer

    2003-01-01

    In Caenorhabditis elegans, introduction of double-stranded RNA (dsRNA) results in the specific inactivation of an endogenous gene with corresponding sequence; this technique is known as RNA interference (RNAi). It has previously been shown that RNAi can be performed by direct microinjection of dsRNA into adult hermaphrodite worms, by soaking worms in a solution of dsRNA, or by feeding worms Escherichia

  2. Genetic Requirements for Inheritance of RNAi in C. elegans

    Microsoft Academic Search

    Alla Grishok; Hiroaki Tabara; Craig C. Mello

    2000-01-01

    In Caenorhabditis elegans, the introduction of double-stranded RNA triggers sequence-specific genetic interference (RNAi) that is transmitted to offspring. The inheritance properties associated with this phenomenon were examined. Transmission of the interference effect occurred through a dominant extragenic agent. The wild-type activities of the RNAi pathway genes rde-1 and rde-4 were required for the formation of this interfering agent but were

  3. Hormonal regulation of the basic peroxidase isoenzyme from Zinnia elegans

    Microsoft Academic Search

    Jorge Guti閞rez; Mar韆 Josefa L髉ez Nez-Flores; Laura V. G髆ez-Ros; Esther Novo Uzal; Alberto Esteban Carrasco; Jos D韆z; Mariana Sottomayor; Juan Cuello; Alfonso Ros Barcel

    2009-01-01

    Xylem differentiation in plants is under strict hormonal regulation. Auxins and cytokinins, together with brassinosteroids\\u000a (BRs), appear to be the main hormones controlling vascular differentiation. In this report, we study the effect of these hormones\\u000a on the basic peroxidase isoenzyme from Zinnia elegans (ZePrx), an enzyme involved in lignin biosynthesis. Results showed that auxins and cytokinins induce ZePrx, similarly to

  4. Genomic analysis of stress response against arsenic in Caenorhabditis elegans.

    PubMed

    Sahu, Surasri N; Lewis, Jada; Patel, Isha; Bozdag, Serdar; Lee, Jeong H; Sprando, Robert; Cinar, Hediye Nese

    2013-01-01

    Arsenic, a known human carcinogen, is widely distributed around the world and found in particularly high concentrations in certain regions including Southwestern US, Eastern Europe, India, China, Taiwan and Mexico. Chronic arsenic poisoning affects millions of people worldwide and is associated with increased risk of many diseases including arthrosclerosis, diabetes and cancer. In this study, we explored genome level global responses to high and low levels of arsenic exposure in Caenorhabditis elegans using Affymetrix expression microarrays. This experimental design allows us to do microarray analysis of dose-response relationships of global gene expression patterns. High dose (0.03%) exposure caused stronger global gene expression changes in comparison with low dose (0.003%) exposure, suggesting a positive dose-response correlation. Biological processes such as oxidative stress, and iron metabolism, which were previously reported to be involved in arsenic toxicity studies using cultured cells, experimental animals, and humans, were found to be affected in C. elegans. We performed genome-wide gene expression comparisons between our microarray data and publicly available C. elegans microarray datasets of cadmium, and sediment exposure samples of German rivers Rhine and Elbe. Bioinformatics analysis of arsenic-responsive regulatory networks were done using FastMEDUSA program. FastMEDUSA analysis identified cancer-related genes, particularly genes associated with leukemia, such as dnj-11, which encodes a protein orthologous to the mammalian ZRF1/MIDA1/MPP11/DNAJC2 family of ribosome-associated molecular chaperones. We analyzed the protective functions of several of the identified genes using RNAi. Our study indicates that C. elegans could be a substitute model to study the mechanism of metal toxicity using high-throughput expression data and bioinformatics tools such as FastMEDUSA. PMID:23894281

  5. Aging Uncouples Heritability and Expression-QTL in Caenorhabditis elegans

    Microsoft Academic Search

    A. Vi駏ela Rodriguez; L. B. Snoek; J. A. G. Riksen; J. E. Kammenga

    2012-01-01

    The number and distribution of gene expression QTL (eQTL) represent the genetic architecture of many complex traits, including common human diseases. We previously reported that the heritable eQTL patterns are highly dynamic with age in an N2 CB4856 recombinant inbred population of the nematode Caenorhabditis elegans. In particular, we showed that the number of eQTL decreased with age. Here,

  6. Caenorhabditis elegans Neuromuscular Junction: GABA Receptors and Ivermectin Action

    PubMed Central

    Hernando, Guillermina; Bouzat, Cecilia

    2014-01-01

    The prevalence of human and animal helminth infections remains staggeringly high, thus urging the need for concerted efforts towards this area of research. GABA receptors, encoded by the unc-49 gene, mediate body muscle inhibition in Caenorhabditis elegans and parasitic nematodes and are targets of anthelmintic drugs. Thus, the characterization of nematode GABA receptors provides a foundation for rational anti-parasitic drug design. We therefore explored UNC-49 channels from C. elegans muscle cultured cells of the first larval stage at the electrophysiological and behavioral levels. Whole-cell recordings reveal that GABA, muscimol and the anthelmintic piperazine elicit macroscopic currents from UNC-49 receptors that decay in their sustained presence, indicating full desensitization. Single-channel recordings show that all drugs elicit openings of ?2.5 pA (+100 mV), which appear either as brief isolated events or in short bursts. The comparison of the lowest concentration required for detectable channel opening, the frequency of openings and the amplitude of macroscopic currents suggest that piperazine is the least efficacious of the three drugs. Macroscopic and single-channel GABA-activated currents are profoundly and apparently irreversibly inhibited by ivermectin. To gain further insight into ivermectin action at C. elegans muscle, we analyzed its effect on single-channel activity of the levamisol-sensitive nicotinic receptor (L-AChR), the excitatory receptor involved in neuromuscular transmission. Ivermectin produces a profound inhibition of the frequency of channel opening without significant changes in channel properties. By revealing that ivermectin inhibits C. elegans muscle GABA and L-AChR receptors, our study adds two receptors to the already known ivermectin targets, thus contributing to the elucidation of its pleiotropic effects. Behavioral assays in worms show that ivermectin potentiates piperazine-induced paralysis, thus suggesting that their combination is a good strategy to overcome the increasing resistance of parasites, an issue of global concern for human and animal health. PMID:24743647

  7. Analyzing cell physiology in C. elegans with fluorescent ratiometric reporters.

    PubMed

    Wang, Hongning; Karadge, Uma; Humphries, William H; Fisher, Alfred L

    2014-08-01

    Ratiometric fluorescent reporters have recently emerged a new technique to non-invasively measure aspects of cell physiology such as redox status, calcium levels, energy production, and NADH levels. These reporters consist of either a single or pair of fluorophores along with specific modifications, such as the addition of a protein domain which binds to a metabolite of interest, thereby producing gradual alterations in fluorescence in response to changes in the measured parameter. Measurement of the changes in fluorescence produces a quantitative read-out of the cellular environment. While these reporters were initially developed to easily visualize and track changes in cultured cells, several groups have adapted these reporters to use in Caenorhabditis elegans which opens a new avenue through which to explore cell physiology during development or aging, in response to changes in external environment, or in response to genetic manipulation. These reporters have the advantage of being easily targeted to any part of the worm, and because C. elegans is transparent both the reporters and changes in their fluorescence can be clearly observed in vivo. Here we discuss the application of ratiometric reporters to C. elegans, and outline a method to quantitatively measure changes in intracellular peroxide levels using the HyPer ratiometric reporter. However, these principles can be applied to alternate ratiometric reporters which are designed to measure either other chemical species or other cellular parameters. PMID:24915644

  8. Aluminium exposure disrupts elemental homeostasis in Caenorhabditis elegans

    PubMed Central

    Page, Kathryn E.; White, Keith N.; McCrohan, Catherine R.

    2013-01-01

    Aluminium (Al) is highly abundant in the environment and can elicit a variety of toxic responses in biological systems. Here we characterize the effects of Al on Caenorhabditis elegans by identifying phenotypic abnormalities and disruption in whole-body metal homeostasis (metallostasis) following Al exposure in food. Widespread changes to the elemental content of adult nematodes were observed when chronically exposed to Al from the first larval stage (L1). Specifically, we saw increased barium, chromium, copper and iron content, and a reduction in calcium levels. Lifespan was decreased in worms exposed to low levels of Al, but unexpectedly increased when the Al concentration reached higher levels (4.8 mM). This bi-phasic phenotype was only observed when Al exposure occurred during development, as lifespan was unaffected by Al exposure during adulthood. Lower levels of Al slowed C. elegans developmental progression, and reduced hermaphrodite self-fertility and adult body size. Significant developmental delay was observed even when Al exposure was restricted to embryogenesis. Similar changes in Al have been noted in association with Al toxicity in humans and other mammals, suggesting that C. elegans may be of use as a model for understanding the mechanisms of Al toxicity in mammalian systems. PMID:22534883

  9. hecd-1 Modulates Notch Activity in Caenorhabditis elegans

    PubMed Central

    Chen, Yunting; Greenwald, Iva

    2014-01-01

    Notch is a receptor that mediates cell朿ell interactions that specify binary cell fate decisions in development and tissue homeostasis. Inappropriate Notch signaling is associated with cancer, and mutations in Notch pathway components have been associated with developmental diseases and syndromes. In Caenorhabditis elegans, suppressors of phenotypes associated with constitutively active LIN-12/Notch have identified many conserved core components and direct or indirect modulators. Here, we molecularly identify sel(ar584), originally isolated as a suppressor of a constitutively active allele of lin-12. We show that sel(ar584) is an allele of hecd-1, the ortholog of human HECDT1, a ubiquitin ligase that has been implicated in several different mammalian developmental events. We studied interactions of hecd-1 with lin-12 in the somatic gonad and with the other C. elegans Notch gene, glp-1, in the germ line. We found that hecd-1 acts as a positive modulator of lin-12/Notch activity in a somatic gonad context梩he original basis for its isolation梑ut acts autonomously as a negative modulator of glp-1/Notch activity in the germ line. As the yeast ortholog of HECD-1, Ufd4p, has been shown to function in quality control, and C. elegans HECD-1 has been shown to affect mitochondrial maintenance, we propose that the different genetic interactions between hecd-1 and Notch genes we observed in different cell contexts may reflect differences in quality control regulatory mechanisms or in cellular metabolism. PMID:25552605

  10. Caenorhabditis elegans is a useful model for anthelmintic discovery

    PubMed Central

    Burns, Andrew R.; Luciani, Genna M.; Musso, Gabriel; Bagg, Rachel; Yeo, May; Zhang, Yuqian; Rajendran, Luckshika; Glavin, John; Hunter, Robert; Redman, Elizabeth; Stasiuk, Susan; Schertzberg, Michael; Angus McQuibban, G.; Caffrey, Conor R.; Cutler, Sean R.; Tyers, Mike; Giaever, Guri; Nislow, Corey; Fraser, Andy G.; MacRae, Calum A.; Gilleard, John; Roy, Peter J.

    2015-01-01

    Parasitic nematodes infect one quarter of the world's population and impact all humans through widespread infection of crops and livestock. Resistance to current anthelmintics has prompted the search for new drugs. Traditional screens that rely on parasitic worms are costly and labour intensive and target-based approaches have failed to yield novel anthelmintics. Here, we present our screen of 67,012 compounds to identify those that kill the non-parasitic nematode Caenorhabditis elegans. We then rescreen our hits in two parasitic nematode species and two vertebrate models (HEK293 cells and zebrafish), and identify 30 structurally distinct anthelmintic lead molecules. Genetic screens of 19 million C. elegans mutants reveal those nematicides for which the generation of resistance is and is not likely. We identify the target of one lead with nematode specificity and nanomolar potency as complex II of the electron transport chain. This work establishes C. elegans as an effective and cost-efficient model system for anthelmintic discovery. PMID:26108372

  11. Specioside ameliorates oxidative stress and promotes longevity in Caenorhabditis elegans.

    PubMed

    Asthana, Jyotsna; Yadav, A K; Pant, Aakanksha; Pandey, Swapnil; Gupta, M M; Pandey, Rakesh

    2015-03-01

    Specioside (6-O-coumaroylcatalpol) is an iridoid glucoside which possesses multifunctional activities viz. analgesic, antidyspeptic, astringent, liver stimulating and wound healing properties. The present study for the first time delineates stress alleviating and lifespan prolonging action of specioside (SPC), isolated from Stereospermum suaveolens in the free living, multicellular nematode model Caenorhabditis elegans. A strong correlation between lifespan extension and stress modulation in adult worms was established in a dose dependent manner. The dietary intake of this phytomolecule elevated juglone induced oxidative and heat induced thermal stress tolerance in C. elegans. On evaluation, it was found that 25 ?M dose of SPC significantly extended lifespan by 15.47% (P?0.0001) with reduction in stress level. Furthermore, SPC enhanced mean survival in mev-1 mutant suggesting its oxidative stress reducing potential. Furthermore, SPC augmented stress modulatory enzymes superoxide dismutase (SOD) and catalase (CAT) level in C. elegans. Altogether, these findings broaden current perspectives concerning stress alleviating potentials of SPC and have implications in development of therapeutics for curing age related disorders. PMID:25619942

  12. Isotopic Ratio Outlier Analysis Global Metabolomics of Caenorhabditis elegans

    PubMed Central

    Szewc, Mark A.; Garrett, Timothy; Menger, Robert F.; Yost, Richard A.; Beecher, Chris; Edison, Arthur S.

    2014-01-01

    We demonstrate the global metabolic analysis of Caenorhabditis elegans stress responses using a mass spectrometry-based technique called Isotopic Ratio Outlier Analysis (IROA). In an IROA protocol, control and experimental samples are isotopically labeled with 95% and 5% 13C, and the two sample populations are mixed together for uniform extraction, sample preparation, and LC-MS analysis. This labeling strategy provides several advantages over conventional approaches: 1) compounds arising from biosynthesis are easily distinguished from artifacts, 2) errors from sample extraction and preparation are minimized because the control and experiment are combined into a single sample, 3) measurement of both the molecular weight and the exact number of carbon atoms in each molecule provides extremely accurate molecular formulae, and 4) relative concentrations of all metabolites are easily determined. A heat shock perturbation was conducted on C. elegans to demonstrate this approach. We identified many compounds that significantly changed upon heat shock, including several from the purine metabolism pathway, which we use to demonstrate the approach. The metabolomic response information by IROA may be interpreted in the context of a wealth of genetic and proteomic information available for C. elegans. Furthermore, the IROA protocol can be applied to any organism that can be isotopically labeled, making it a powerful new tool in a global metabolomics pipeline. PMID:24274725

  13. Affinity Purification of Protein Complexes in C. elegans

    PubMed Central

    Zanin, Esther; Dumont, Julien; Gassmann, Reto; Cheeseman, Iain; Maddox, Paul; Bahmanyar, Shirin; Carvalho, Ana; Niessen, Sherry; Yates, John R.; Oegema, Karen; Desai, Arshad

    2012-01-01

    C. elegans is a powerful metazoan model system to address fundamental questions in cell and developmental biology. Research in C. elegans has traditionally focused on genetic, physiological, and cell biological approaches. However, C. elegans is also a facile system for biochemistry: worms are easy to grow in large quantities, the functionality of tagged fusion proteins can be assessed using mutants or RNAi, and the relevance of putative interaction partners can be rapidly tested in vivo. Combining biochemistry with function-based genetic and RNA interference screens can rapidly accelerate the delineation of protein networks and pathways in diverse contexts. In this chapter, we focus on two strategies to identify protein杙rotein interactions: single-step immunoprecipitation and tandem affinity purification. We describe methods for growth of worms in large-scale liquid culture, preparation of worm and embryo extracts, immunoprecipitation, and tandem affinity purification. In addition, we describe methods to test specificity of antibodies, strategies for optimizing starting material, and approaches to distinguish specific from non-specific interactions. PMID:22118282

  14. Caenorhabditis elegans is a useful model for anthelmintic discovery.

    PubMed

    Burns, Andrew R; Luciani, Genna M; Musso, Gabriel; Bagg, Rachel; Yeo, May; Zhang, Yuqian; Rajendran, Luckshika; Glavin, John; Hunter, Robert; Redman, Elizabeth; Stasiuk, Susan; Schertzberg, Michael; Angus McQuibban, G; Caffrey, Conor R; Cutler, Sean R; Tyers, Mike; Giaever, Guri; Nislow, Corey; Fraser, Andy G; MacRae, Calum A; Gilleard, John; Roy, Peter J

    2015-01-01

    Parasitic nematodes infect one quarter of the world's population and impact all humans through widespread infection of crops and livestock. Resistance to current anthelmintics has prompted the search for new drugs. Traditional screens that rely on parasitic worms are costly and labour intensive and target-based approaches have failed to yield novel anthelmintics. Here, we present our screen of 67,012 compounds to identify those that kill the non-parasitic nematode Caenorhabditis elegans. We then rescreen our hits in two parasitic nematode species and two vertebrate models (HEK293 cells and zebrafish), and identify 30 structurally distinct anthelmintic lead molecules. Genetic screens of 19 million C. elegans mutants reveal those nematicides for which the generation of resistance is and is not likely. We identify the target of one lead with nematode specificity and nanomolar potency as complex II of the electron transport chain. This work establishes C. elegans as an effective and cost-efficient model system for anthelmintic discovery. PMID:26108372

  15. Differential expression pattern of UBX family genes in Caenorhabditis elegans

    SciTech Connect

    Yamauchi, Seiji [Division of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Sasagawa, Yohei [Division of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Ogura, Teru [Division of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan)]. E-mail: ogura@gpo.kumamoto-u.ac.jp; Yamanaka, Kunitoshi [Division of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan)]. E-mail: yamanaka@gpo.kumamoto-u.ac.jp

    2007-06-29

    UBX (ubiquitin regulatory X)-containing proteins belong to an evolutionary conserved protein family and determine the specificity of p97/VCP/Cdc48p function by binding as its adaptors. Caenorhabditis elegans was found to possess six UBX-containing proteins, named UBXN-1 to -6. However, no general or specific function of them has been revealed. During the course of understanding not only their function but also specified function of p97, we investigated spatial and temporal expression patterns of six ubxn genes in this study. Transcript analyses showed that the expression pattern of each ubxn gene was different throughout worm's development and may show potential developmental dynamics in their function, especially ubxn-5 was expressed specifically in the spermatogenic germline, suggesting a crucial role in spermatogenesis. In addition, as ubxn-4 expression was induced by ER stress, it would function as an ERAD factor in C. elegans. In vivo expression analysis by using GFP translational fusion constructs revealed that six ubxn genes show distinct expression patterns. These results altogether demonstrate that the expression of all six ubxn genes of C. elegans is differently regulated.

  16. Optical reversal of halothane-induced immobility in C. elegans.

    PubMed

    Singaram, Vinod K; Somerlot, Benjamin H; Falk, Scott A; Falk, Marni J; Sedensky, Margaret M; Morgan, Philip G

    2011-12-20

    Volatile anesthetics (VAs) cause profound neurological effects, including reversible loss of consciousness and immobility. Despite their widespread use, the mechanism of action of VAs remains one of the unsolved puzzles of neuroscience [1, 2]. Genetic studies in Caenorhabditis elegans [3, 4], Drosophila [3, 5], and mice [6-9] indicate that ion channels controlling the neuronal resting membrane potential (RMP) also control anesthetic sensitivity. Leak channels selective for K(+) [10-13] or permeable to Na(+) [14] are critical for establishing RMP. We hypothesized that halothane, a VA, caused immobility by altering the neuronal RMP. In C. elegans, halothane-induced immobility is acutely and completely reversed by channelrhodopsin-2 based depolarization of the RMP when expressed specifically in cholinergic neurons. Furthermore, hyperpolarizing cholinergic neurons via halorhodopsin activation increases sensitivity to halothane. The sensitivity of C. elegans to halothane can be altered by 25-fold by either manipulation of membrane conductance with optogenetic methods or generation of mutations in leak channels that set the RMP. Immobility induced by another VA, isoflurane, is not affected by these treatments, thereby excluding the possibility of nonspecific hyperactivity. The sum of our data indicates that leak channels and the RMP are important determinants of halothane-induced general anesthesia. PMID:22137475

  17. In vivo Neuronal Calcium Imaging in C. elegans

    PubMed Central

    Gabel, Christopher V.

    2013-01-01

    The nematode worm C. elegans is an ideal model organism for relatively simple, low cost neuronal imaging in vivo. Its small transparent body and simple, well-characterized nervous system allows identification and fluorescence imaging of any neuron within the intact animal. Simple immobilization techniques with minimal impact on the animal's physiology allow extended time-lapse imaging. The development of genetically-encoded calcium sensitive fluorophores such as cameleon 1 and GCaMP 2 allow in vivo imaging of neuronal calcium relating both cell physiology and neuronal activity. Numerous transgenic strains expressing these fluorophores in specific neurons are readily available or can be constructed using well-established techniques. Here, we describe detailed procedures for measuring calcium dynamics within a single neuron in vivo using both GCaMP and cameleon. We discuss advantages and disadvantages of both as well as various methods of sample preparation (animal immobilization) and image analysis. Finally, we present results from two experiments: 1) Using GCaMP to measure the sensory response of a specific neuron to an external electrical field and 2) Using cameleon to measure the physiological calcium response of a neuron to traumatic laser damage. Calcium imaging techniques such as these are used extensively in C. elegans and have been extended to measurements in freely moving animals, multiple neurons simultaneously and comparison across genetic backgrounds. C. elegans presents a robust and flexible system for in vivo neuronal imaging with advantages over other model systems in technical simplicity and cost. PMID:23603812

  18. Courtship herding in the fiddler crab Uca elegans.

    PubMed

    How, Martin J; Hemmi, Jan M

    2008-12-01

    Male and female animals are not always complicit during reproduction, giving rise to coercion. One example of a system that is assumed to involve sexual coercion is the mate herding behaviour of fiddler crabs: males push females towards the home burrow with the goal of forcing copulation at the burrow entrance. We recorded and analysed in detail the courtship behaviour of a North Australian species of fiddler crab Uca elegans. Courtship was composed of four main phases: broadcast waving, outward run, herding and at burrow display. During interactions males produced claw-waving displays which were directed posteriorly towards the female and which varied in timing and structure depending on the courtship phase. We suggest that courtship herding in U. elegans is driven primarily by mate choice for the following reasons, (1) females can evade herding, (2) no other reproductive strategies were observed, (3) males broadcast their presence and accompany courtship with conspicuous claw waves, and (4) the behaviour ends with the female leading the male into the home burrow. As an alternative function for herding in U. elegans we suggest that the behaviour represents a form of courtship guiding, in which males direct complicit females to the correct home burrow. PMID:18846353

  19. Mating Damages the Cuticle of C. elegans Hermaphrodites

    PubMed Central

    Woodruff, Gavin C.; Knauss, Christine M.; Maugel, Timothy K.; Haag, Eric S.

    2014-01-01

    Lifespan costs to reproduction are common across multiple species, and such costs could potentially arise through a number of mechanisms. In the nematode Caenorhabditis elegans, it has been suggested that part of the lifespan cost to hermaphrodites from mating results from physical damage owing to the act of copulation itself. Here, we examine whether mating damages the surface of the hermaphrodite cuticle via scanning electron microscopy. It is found that mated hermaphrodites suffered delamination of cuticle layers surrounding the vulva, and that the incidence of such damage depends on genetic background. Unmated hermaphrodites demonstrated almost no such damage, even when cultured in soil with potentially abrasive particles. Thus, a consequence of mating for C. elegans hermaphrodites is physical cuticle damage. These experiments did not assess the consequences of cuticle damage for lifespan, and the biological significance of this damage remains unclear. We further discuss our results within the context of recent studies linking the lifespan cost to mating in C. elegans hermaphrodites to male secretions. PMID:25105881

  20. Structure and Evolution of the C. elegans Embryonic Endomesoderm Network

    PubMed Central

    Maduro, Morris F.

    2009-01-01

    Summary The specification of the C. elegans endomesoderm has been the subject of study for more than 15 years. Specification of the 4-cell stage endomesoderm precursor, EMS, occurs as a result of the activation of a transcription factor cascade that starts with SKN-1, coupled with input from the Wnt/?-catenin asymmetry pathway through the nuclear effector POP-1. As development proceeds, transient cell fate factors are succeeded by stable, tissue/organ-specific regulators. The pathway is complex and uses motifs found in all transcriptional networks. Here, the regulators that function in the C. elegans endomesoderm network are described. An examination of the motifs in the network suggests how they may have evolved from simpler gene interactions. Flexibility in the network is evident from the multitude of parallel functions that can been identified, and from an apparent change in parts of the corresponding network in C. briggsae. Overall, the complexities of C. elegans endomesoderm specification build a picture of a network that is robust, complex, and still evolving. PMID:18778800

  1. Tat-mediated protein delivery in living Caenorhabditis elegans

    SciTech Connect

    Delom, Frederic [Department of Surgery, McGill University, Montreal, Que. (Canada); Fessart, Delphine [Department of Medicine, McGill University, Montreal, Que. (Canada); Caruso, Marie-Elaine [Department of Surgery, McGill University, Montreal, Que. (Canada); Chevet, Eric [Department of Surgery, McGill University, Montreal, Que. (Canada) and Department of Medicine, McGill University, Montreal, Que. (Canada) and Department of Anatomy and Cell Biology, McGill University, Montreal, Que. (Canada) and INSERM, E362, Universite Bordeaux 2, Bordeaux (France)]. E-mail: eric.chevet@mcgill.ca

    2007-01-19

    The Tat protein from HIV-1 fused with heterologous proteins traverses biological membranes in a transcellular process called: protein transduction. This has already been successfully exploited in various biological models, but never in the nematode worm Caenorhabditis elegans. TAT-eGFP or GST-eGFP proteins were fed to C. elegans worms, which resulted in the specific localization of Tat-eGFP to epithelial intestinal cells. This system represents an efficient tool for transcellular transduction in C. elegans intestinal cells. Indeed, this approach avoids the use of tedious purification steps to purify the TAT fusion proteins and allows for rapid analyses of the transduced proteins. In addition, it may represent an efficient tool to functionally analyze the mechanisms of protein transduction as well as to complement RNAi/KO in the epithelial intestinal system. To sum up, the advantage of this technology is to combine the potential of bacterial expression system and the Tat-mediated transduction technique in living worm.

  2. Caenorhabditis elegans Mutants Resistant to Attachment of Yersinia Biofilms

    PubMed Central

    Darby, Creg; Chakraborti, Amrita; Politz, Samuel M.; Daniels, Calvin C.; Tan, Li; Drace, Kevin

    2007-01-01

    The detailed composition and structure of the Caenorhabditis elegans surface are unknown. Previous genetic studies used antibody or lectin binding to identify srf genes that play roles in surface determination. Infection by Microbacterium nematophilum identified bus (bacterially unswollen) genes that also affect surface characteristics. We report that biofilms produced by Yersinia pestis and Y. pseudotuberculosis, which bind the C. elegans surface predominantly on the head, can be used to identify additional surface-determining genes. A screen for C. elegans mutants with a biofilm absent on the head (Bah) phenotype identified three novel genes: bah-1, bah-2, and bah-3. The bah-1 and bah-2 mutants have slightly fragile cuticles but are neither Srf nor Bus, suggesting that they are specific for surface components involved in biofilm attachment. A bah-3 mutant has normal cuticle integrity, but shows a stage-specific Srf phenotype. The screen produced alleles of five known surface genes: srf-2, srf-3, bus-4, bus-12, and bus-17. For the X-linked bus-17, a paternal effect was observed in biofilm assays. PMID:17339204

  3. Global genetic diversity and evolution of var genes associated with placental and severe childhood malaria.

    PubMed

    Trimnell, Adama R; Kraemer, Susan M; Mukherjee, Sandeep; Phippard, David J; Janes, Joel H; Flamoe, Eric; Su, Xin-zhuan; Awadalla, Philip; Smith, Joseph D

    2006-08-01

    In Plasmodium falciparum, var genes encode adhesive proteins that are transported to the surface of infected erythrocytes and act as major virulence determinants for infected erythrocyte binding and immune evasion. Var genes are highly diverse and can be classified into five major groups (UpsA, B, C, D, and E). Previous serological studies have suggested that the UpsA var group may contain common antigenic types that have important roles in severe childhood malaria. Here, our analysis found that UpsA vars are highly diverse between 22 world-wide parasite isolates, although they could be grouped into two broad clusters that may be separately recombining. By comparison, orthologs of the UpsA-linked Type 3 var and UpsE-linked var2csa were detected in nearly all parasite isolates, and a var2csa ortholog was also present in a chimpanzee malaria P. reichenowi that diverged from P. falciparum approximately 5-7 million years ago. Although the specific function of Type 3 var genes is unknown, var2csa is a leading candidate for a pregnancy associated malaria vaccine. Compared to typical var genes, var2csa is unusually conserved but still had only 54-94% amino acid identity in extracellular binding regions. However, var2csa alleles have extensive gene mosaicism within polymorphic blocks that are shared between world-wide parasite isolates and recognizable in P. rechenowi suggesting a high rate of self-self recombination and an ancient and globally-related pool of var2csa polymorphism. These studies aid our understanding of the evolutionary mechanisms that shape var diversity and will be important to the development of vaccines against pregnancy associated malaria and severe malaria. PMID:16697476

  4. Identification of chicken and C. elegans fibulin-1 homologs and characterization of the C. elegans fibulin-1 gene

    Microsoft Academic Search

    Jeremy L. Barth; Kelley M. Argraves; Eileen F. Roark; Charles D. Little; W. Scott Argraves

    1998-01-01

    Fibulin-1, a member of the emerging family of fibulin proteins, is a component of elastic extracellular matrix fibers, basement membranes and blood. Homologs of fibulin-1 have been described in man, mouse and zebrafish. In this study, we describe the isolation and sequencing of chicken fibulin-1C and D cDNA variants. We also describe identification of a C. elegans cDNA encoding fibulin-1D

  5. Functional organization of Caenorhabditis elegans neural network with neurobiological information weighted connectome

    E-print Network

    Park, Namkyoo

    Functional organization of Caenorhabditis elegans neural network with neurobiological information of neurobiological information to C.elegans' connectome is critical in the accurate identification of finer modular structures, by analyzing in detail the impact of each neurobiological element to the modular organization

  6. Mapping a Mutation in "Caenorhabditis elegans" Using a Polymerase Chain Reaction-Based Approach

    ERIC Educational Resources Information Center

    Myers, Edith M.

    2014-01-01

    Many single nucleotide polymorphisms (SNPs) have been identified within the "Caenorhabditis elegans" genome. SNPs present in the genomes of two isogenic "C. elegans" strains have been routinely used as a tool in forward genetics to map a mutation to a particular chromosome. This article describes a laboratory exercise in which

  7. Ancestral roles of glia suggested by the nervous system of Caenorhabditis elegans

    E-print Network

    Shaham, Shai

    Ancestral roles of glia suggested by the nervous system of Caenorhabditis elegans maxwell g. heiman and shai shaham The nematode Caenorhabditis elegans has a simple nervous system with glia restricted some glial activities may be fundamentally required for nervous system function. A priori, one might

  8. Genetic and molecular analysis of a Caenorhabditis elegans beta-tubulin that conveys benzimidazole sensitivity

    Microsoft Academic Search

    M. Driscoll; Ellen Dean; Evelyn Reilly; Elke Bergholz; Martin Chalfie

    1989-01-01

    Benzimidazole anti-microtubule drugs, such as benomyl, induce paralysis and slow the growth of the nematode Caenorhabditis elegans. We have identified 28 mutations in C elegans that confer resis- tance to benzimidazoles. All resistant mutations map to a single locus, bend. Virtually all these mutations are genetically dominant. Molecular cloning and DNA sequence analysis established that bend encodes a \\/3-tubulin. Some

  9. Interpreting a Sequenced Genome: Toward a Cosmid Transgenic Library of Caenorhabditis elegans

    Microsoft Academic Search

    Diana L. Janke; Jacqueline E. Schein; Norman W. Franz; Nigel J. O'Neil; Greg P. Vatcher; Helen I. Stewart; Lynnette M. Kuervers; David L. Baillie; Ann M. Rose

    2007-01-01

    We have generated a library of transgenic Caenorhabditis elegans strains that carry sequenced cosmids from the genome of the nematode. Each strain carries an extrachromosomal array containing a single cosmid, sequenced by the C. elegans Genome Sequencing Consortium, and a dominate Rol-6 marker. More than 500 transgenic strains representing 250 cosmids have been constructed. Collectively, these strains contain approximately 8

  10. The complete family of genes encoding G proteins of Caenorhabditis elegans

    Microsoft Academic Search

    Gert Jansen; Karen L Thijssen; Pia Werner; Marieke van derHorst; Esther Hazendonk; Ronald H A Plasterk

    1999-01-01

    Caenorhabditis elegans is the first animal whose genomic sequence has been determined. One of the new possibilities in post-sequence genetics is the analysis of complete gene families at once. We studied the family of heterotrimeric G proteins. C. elegans has 20 G?, 2 G? and 2 G? genes. There is 1 homologue of each of the 4 mammalian classes of

  11. Modeling the Establishment of PAR Protein Polarity in the One-Cell C. elegans Embryo

    E-print Network

    Howard, Martin

    Modeling the Establishment of PAR Protein Polarity in the One-Cell C. elegans Embryo Filipe ABSTRACT At the one-cell stage, the C. elegans embryo becomes polarized along the anterior-posterior axis by cytoskeletal rearrangement. Initially, the PAR proteins are uniformly distributed throughout the embryo. After

  12. Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

    Microsoft Academic Search

    Tina L. Gumienny; Eric Lambie; Erika Hartwieg; H. Robert Horvitz; Michael O. Hengartner

    1999-01-01

    Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same

  13. Mutations in the Caenorhabditis elegans Serotonin Reuptake Transporter MOD-5 Reveal Serotonin-Dependent and -Independent

    E-print Network

    Horvitz, H. Robert

    Mutations in the Caenorhabditis elegans Serotonin Reuptake Transporter MOD-5 Reveal Serotonin the only sero- tonin reuptake transporter (SERT) in C. elegans. The selective serotonin reuptake inhibitor; fluoxetine; serotonin; reuptake; modulation of behavior; SSRI The activity of serotonin (5-HT), a key

  14. A C. elegans mutant screen based on antibody or histochemical staining

    Microsoft Academic Search

    Guofeng Xie; Yiwen Jia; Eric Aamodt

    1995-01-01

    A method has been developed for isolating mutations in Caenorhabditis elegans that alter antibody or histochemical staining patterns. The basis for this method is a new procedure for making C. elegans permeable that does not kill the eggs contained within the uterus of gravid adult hermaphrodites. A mutagenized population of gravid hermaphrodites is made permeable and then stained with either

  15. Isolation of C. elegans gene knockouts by PCR screening of chemically mutagenized libraries.

    E-print Network

    Lesa, Giovanni

    . elegans: transposon insertion followed by imprecise excision1,2 and chemical mutagenesis. The protocol://www.ucl.ac.uk/lmcb/research-groups/lesa.htm #12;2 ABSTRACT Here I describe how to generate C. elegans deletion mutants by chemical mutagenesis presented here uses chemical mutagenesis. Treatment with ethyl methane sulfonate (EMS) and trimethyl

  16. Nature Macmillan Publishers Ltd 1998 gate C. elegans genes. Comparison with pre-

    E-print Network

    Koehl, Mimi

    the course of the Human Genome Project, pushing it from a mapping mode to a sequencing mode. Second, the C. elegans project has been a model for how an efficient genome effort can be run. As far as I know rather than a researcher-orientated strategy. Third, the C. elegans Genome Project has stimulated

  17. Dissection of K currents in Caenorhabditis elegans muscle cells by genetics and RNA interference

    E-print Network

    Nonet, Michael L.

    Dissection of K currents in Caenorhabditis elegans muscle cells by genetics and RNA interference C subunits are expressed in Caeno- rhabditis elegans muscle. By using genetic, RNA interference, and physiological techniques we revealed the molecular identity of the major components of the outward K currents

  18. Author's personal copy The C. elegans adult male germline: Stem cells and sexual dimorphism

    E-print Network

    Kimble, Judith

    Author's personal copy The C. elegans adult male germline: Stem cells and sexual dimorphism Dyan E on an analysis of the adult C. elegans male germline, focusing on its predicted stem cell region at the distal by regeneration of a functional germline from the adult stem cell pool after starvation (Angelo and Van Gilst

  19. Behavioral effects of clozapine: Involvement of trace amine pathways in C. elegans and M. musculus

    Microsoft Academic Search

    Rakesh Karmacharya; Spencer K. Lynn; Sarah Demarco; Angelica Ortiz; Xin Wang; Miriam Y. Lundy; Zhihua Xie; Bruce M. Cohen; Gregory M. Miller; Edgar A. Buttner

    2011-01-01

    Clozapine is an antipsychotic medication with superior efficacy in treatment refractory schizophrenia. The molecular basis of clozapine's therapeutic profile is not well understood. We studied behavioral effects of clozapine in Caenorhabditis elegans to identify novel pathways that modulate clozapine's biological effects. Clozapine stimulated egg laying in C. elegans in a dose-dependent manner. This effect was clozapine-specific, as it was not

  20. Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"

    ERIC Educational Resources Information Center

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH

  1. C. elegans rrf-1 Mutations Maintain RNAi Efficiency in the Soma in Addition to the Germline

    Microsoft Academic Search

    Caroline Kumsta; Malene Hansen

    2012-01-01

    Gene inactivation through RNA interference (RNAi) has proven to be a valuable tool for studying gene function in C. elegans. When combined with tissue-specific gene inactivation methods, RNAi has the potential to shed light on the function of a gene in distinct tissues. In this study we characterized C. elegans rrf-1 mutants to determine their ability to process RNAi in

  2. A Chemosensory Adaptation Module for the Physiology Laboratory from Student-Directed "C. elegans" Research

    ERIC Educational Resources Information Center

    Lindblom, Tim

    2006-01-01

    The model organism, "Caenorhabditis elegans," in addition to being well suited to genetics and cell biology teaching applications, can also be useful in the physiology laboratory. In this article, the author describes how students in a junior level college Comparative Physiology course have made use of "C. elegans" in semester-long,

  3. FMRFamide neuropeptides and acetylcholine synergistically inhibit egg-laying by C. elegans

    E-print Network

    Horvitz, H. Robert

    FMRFamide neuropeptides and acetylcholine synergistically inhibit egg-laying by C. elegans Niels Ringstad & H Robert Horvitz Egg-laying behavior of the Caenorhabditis elegans hermaphrodite is regulated by G protein signaling pathways. Here we show that the egg laying璬efective mutant egl-6(n592) carries

  4. A potent dauer pheromone component in Caenorhabditis elegans that acts synergistically with other components

    Microsoft Academic Search

    Rebecca A. Butcher; Justin R. Ragains; Edward Kim; Jon Clardy

    2008-01-01

    In the model organism Caenorhabditis elegans, the dauer pheromone is the primary cue for entry into the developmentally arrested, dauer larval stage. The dauer is specialized for survival under harsh environmental conditions and is considered ``nonaging'' because larvae that exit dauer have a normal life span. C. elegans constitutively secretes the dauer pheromone into its environment, enabling it to sense

  5. Successful reproduction of the introduced slider turtle(Trachemys scripta elegans) in the South of France

    Microsoft Academic Search

    Antoine Cadi; Virginie Delmas; Anne-Caroline Pr関ot-Julliard; Pierre Joly; Claude Pieau; Marc Girondot

    2004-01-01

    Massive importation of slider turtles (Trachemys scripta elegans) as a pet in France over the past few decades has been followed by the release of many of these turtles into natural environments. T. scripta elegans is now widely distributed in France. 2. This paper reports on the successful reproduction of this species in France, with confirmed production of both sexes

  6. Selenite Enhances Immune Response against Pseudomonas aeruginosa PA14 via SKN-1 in Caenorhabditis elegans

    PubMed Central

    Huang, Chi-Wei; Wei, Chia-Cheng; Liao, Vivian Hsiu-Chuan

    2014-01-01

    Background Selenium (Se) is an important nutrient that carries out many biological processes including maintaining optimal immune function. Here, inorganic selenite (Se(IV)) was evaluated for its pathogen resistance and potential-associated factors in Caenorhabditis elegans. The immune effects of Se(IV) were investigated by examining the responses of C. elegans to Pseudomonas aerugonisa PA14 strain. Principal Findings Se(IV)-treated C. elegans showed increased survival under PA14 infection compared with untreated controls. The significant pathogen resistance of Se(IV) on C. elegans might not be attributed to the effects of Se(IV) on PA14 as Se(IV) showed no effect on bacterial quorum-sensing and virulence factors of PA14. This study showed that Se(IV) enhanced the expression of a gene pivotal for the innate immunity in C. elegans. The study found that the pathogen-resistant phenotypes contributed by Se(IV) was absent from the skn-1 mutant worms. Moreover, Se(IV) influenced the subcellular distribution of SKN-1/Nrf in C. elegans upon PA14 infection. Furthermore, Se(IV) increased mRNA levels of SKN-1 target genes (gst-4 and gcs-1). Conclusions This study found evidence of Se(IV) protecting C. elegans against P. aeruginosa PA14 infection by exerting effects on the innate immunity of C. elegans that is likely mediated via regulation of a SKN-1-dependent signaling pathway. PMID:25147937

  7. Dietary restriction in C. elegans: From rate-of-living effects to nutrient sensing pathways

    E-print Network

    Gems, David

    Review Dietary restriction in C. elegans: From rate-of-living effects to nutrient sensing pathways subjected to dietary restriction (DR) by a number of means, with varying results in terms of fecundity study. # 2005 Published by Elsevier Ireland Ltd. Keywords: Caenorhabditis elegans; Dietary restriction

  8. New genes with roles in the C. elegans embryo revealed using RNAi of ovary-enriched

    E-print Network

    New genes with roles in the C. elegans embryo revealed using RNAi of ovary-enriched ORFeome clones (RNAi)-based functional genomic projects have been performed in Caenorhabditis elegans to identify genes essential for the first cell divisions. However, comparing RNAi results suggests that many genes involved

  9. Asako Sugimoto High-throughput RNAi in Caenorhabditis elegans : genome-wide screens

    E-print Network

    Skop, Ahna

    REVIEW Asako Sugimoto High-throughput RNAi in Caenorhabditis elegans : genome-wide screens-mediated interfer- ence (RNAi) was first discovered in the nematode Caenorhabditis elegans, in which introduction advances in RNAi methodology and the availability of the complete genome sequence have enabled the high

  10. Insight into transcription factor gene duplication from Caenorhabditis elegans Promoterome-driven expression patterns

    Microsoft Academic Search

    John S Reece-Hoyes; Jane Shingles; Denis Dupuy; Christian A Grove; Albertha JM Walhout; Marc Vidal; Ian A Hope

    2007-01-01

    BACKGROUND: The C. elegans Promoterome is a powerful resource for revealing the regulatory mechanisms by which transcription is controlled pan-genomically. Transcription factors will form the core of any systems biology model of genome control and therefore the promoter activity of Promoterome inserts for C. elegans transcription factor genes was examined, in vivo, with a reporter gene approach. RESULTS: Transgenic C.

  11. A compendium of Caenorhabditis elegans regulatory transcription factors: a resource for mapping transcription regulatory networks

    Microsoft Academic Search

    John S Reece-Hoyes; Bart Deplancke; Jane Shingles; Christian A Grove; Ian A Hope; Albertha JM Walhout

    2005-01-01

    BACKGROUND: Transcription regulatory networks are composed of interactions between transcription factors and their target genes. Whereas unicellular networks have been studied extensively, metazoan transcription regulatory networks remain largely unexplored. Caenorhabditis elegans provides a powerful model to study such metazoan networks because its genome is completely sequenced and many functional genomic tools are available. While C. elegans gene predictions have undergone

  12. Balanced Trade-Offs between Alternative Strategies Shape the Response of C. elegans Reproduction to

    E-print Network

    Ruvinsky, Ilya

    laying, and thus protecting the reproductive system, is negated by the cost associated with implementing-offs as a dynamic response of the C. elegans reproductive system to stress and an adaptation to life in variableBalanced Trade-Offs between Alternative Strategies Shape the Response of C. elegans Reproduction

  13. Deletion of smn-1, the Caenorhabditis elegans ortholog of the spinal muscular atrophy

    E-print Network

    Paris-Sud XI, Universit de

    Deletion of smn-1, the Caenorhabditis elegans ortholog of the spinal muscular atrophy gene, results Received August 15, 2008; Revised and Accepted September 29, 2008 Spinal muscular atrophy is the most elegans smn-1 is expressed in various tissues including the nervous system and body wall muscle

  14. Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates

    Microsoft Academic Search

    Javier E. Irazoqui; Jonathan M. Urbach; Frederick M. Ausubel

    2010-01-01

    The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in identifying the host response pathways that are involved in its defence against infection. Strikingly, C. elegans seems to detect, and respond to, infection without the involvement of its homologue of Toll-like receptors, in

  15. Distinct Pathogenesis and Host Responses during Infection of C. elegans by P. aeruginosa and S. aureus

    Microsoft Academic Search

    Javier E. Irazoqui; Emily R. Troemel; Rhonda L. Feinbaum; Lyly G. Luhachack; Brent O. Cezairliyan; Frederick M. Ausubel

    2010-01-01

    The genetically tractable model host Caenorhabditis elegans provides a valuable tool to dissect host-microbe interactions in vivo. Pseudomonas aeruginosa and Staphylococcus aureus utilize virulence factors involved in human disease to infect and kill C. elegans. Despite much progress, virtually nothing is known regarding the cytopathology of infection and the proximate causes of nematode death. Using light and electron microscopy, we

  16. Using Caenorhabditis elegans to probe toxicity of 1-alkyl-3-methylimidazolium chloride based ionic liquids

    E-print Network

    Caldwell, Guy

    , Caenorhabditis elegans. C. elegans is a well-studied free-living soil roundworm with a transparent anatomy as a model organism in order to probe toxicity and accumulation of pesticides6 as well as various metal ions synthesized using previously described methods.8 Before toxicity studies were carried out, the ionic liquids

  17. Automated Quantification of Synaptic Fluorescence in C. elegans

    PubMed Central

    Sturt, Brianne L.; Bamber, Bruce A.

    2012-01-01

    Synapse strength refers to the amplitude of postsynaptic responses to presynaptic neurotransmitter release events, and has a major impact on overall neural circuit function. Synapse strength critically depends on the abundance of neurotransmitter receptors clustered at synaptic sites on the postsynaptic membrane. Receptor levels are established developmentally, and can be altered by receptor trafficking between surface-localized, subsynaptic, and intracellular pools, representing important mechanisms of synaptic plasticity and neuromodulation. Rigorous methods to quantify synaptically-localized neurotransmitter receptor abundance are essential to study synaptic development and plasticity. Fluorescence microscopy is an optimal approach because it preserves spatial information, distinguishing synaptic from non-synaptic pools, and discriminating among receptor populations localized to different types of synapses. The genetic model organism Caenorhabditis elegans is particularly well suited for these studies due to the small size and relative simplicity of its nervous system, its transparency, and the availability of powerful genetic techniques, allowing examination of native synapses in intact animals. Here we present a method for quantifying fluorescently-labeled synaptic neurotransmitter receptors in C. elegans. Its key feature is the automated identification and analysis of individual synapses in three dimensions in multi-plane confocal microscope output files, tabulating position, volume, fluorescence intensity, and total fluorescence for each synapse. This approach has two principal advantages over manual analysis of z-plane projections of confocal data. First, because every plane of the confocal data set is included, no data are lost through z-plane projection, typically based on pixel intensity averages or maxima. Second, identification of synapses is automated, but can be inspected by the experimenter as the data analysis proceeds, allowing fast and accurate extraction of data from large numbers of synapses. Hundreds to thousands of synapses per sample can easily be obtained, producing large data sets to maximize statistical power. Considerations for preparing C. elegans for analysis, and performing confocal imaging to minimize variability between animals within treatment groups are also discussed. Although developed to analyze C. elegans postsynaptic receptors, this method is generally useful for any type of synaptically-localized protein, or indeed, any fluorescence signal that is localized to discrete clusters, puncta, or organelles. The procedure is performed in three steps: 1) preparation of samples, 2) confocal imaging, and 3) image analysis. Steps 1 and 2 are specific to C. elegans, while step 3 is generally applicable to any punctate fluorescence signal in confocal micrographs. PMID:22907390

  18. NCBI Handout Series | DbVar | Last Update January 8, 2014 Contact: info@ncbi.nlm.nih.gov The dbVar Database

    E-print Network

    Levin, Judith G.

    NCBI Handout Series | DbVar | Last Update January 8, 2014 Contact: info@ncbi.nlm.nih.gov The dbVar Database A collection of genomic structural variations for different organisms http://www.ncbi.nlm.nih.gov lengths of 50 nucleotides or longer. The database is accessible through its homepage (A, www.ncbi.nlm.nih.gov

  19. Peptido polysaccharide antigens from Trichophyton mentagrophytes var. granulosum.

    PubMed Central

    Arnold, M T; Grappel, S F; Lerro, A V; Blank, F

    1976-01-01

    Two highly purified peptido polysaccharide antigens have been isolated from surface-grown cultures of Trichophyton mentagrophytes var. granulosum. Trichloroacetic acid extraction and ethanol precipitation yielded a mixture containing high-molecular-weight components which were first separated on Sephadex G-200. Subsequent fractionation by ion-exchange chromatography on DE-52-cellulose (borate form) yielded the two peptido polysaccharides. Both of the peptido polysaccharides reacted with rabbit antiserum to T. mentagrophytes var. granulosum. The two peptido polysaccharides contain 73.2% hexoses (mannose-galactose-glucose, 7.5:0.7:1), 8.6% amino acids and 1.8% amino sugars and 77.4% hexoses (mannose-galactose-glucose, 9:0.3:1), 6.2% amino acids, and 0.4% amino sugars, respectively. Each contains 16 different amino acids, threonine, proline, and serine predominating. Images PMID:971953

  20. Two new compounds from Trifolium resupinatum var. microcephalum

    Microsoft Academic Search

    Temine Sabudak; Emel Isik; Sevil Oksuz

    2008-01-01

    An investigation of CH2Cl2 and EtOH extracts of Trifolium resupinatum L. var. microcephalum Zoh. has led to the isolation of two new compounds characterized as 4,15-dimethyl-2-(1,2-dihydroxyethyl)-hexadecene (1) and 1-undecene-1-O-?-2?,3?,4?,6?-tetraacetyl glucopyranoside (2a). Their structures were established by 1D and 2D NMR techniques, and mass spectroscopy.

  1. Two new compounds from Trifolium resupinatum var. microcephalum.

    PubMed

    Sabudak, Temine; Isik, Emel; Oksuz, Sevil

    2008-01-01

    An investigation of CH(2)Cl(2) and EtOH extracts of Trifolium resupinatum L. var. microcephalum Zoh. has led to the isolation of two new compounds characterized as 4,15-dimethyl-2-(1,2-dihydroxyethyl)-hexadecene (1) and 1-undecene-1-O-beta-2',3',4',6'-tetraacetyl glucopyranoside (2a). Their structures were established by 1D and 2D NMR techniques, and mass spectroscopy. PMID:19031240

  2. Aegilops cylindrica var. kastorianum ( Poaceae ): A new variety from Greece

    Microsoft Academic Search

    S. S. Karataglis

    1989-01-01

    A native population ofAegilops cylindrica was encountered for the first time in Greece in 1980 (near Kastoria, NW. Greece), completely isolated and at a great distance from its main distribution area. There are morphological and chromosomal, but no protein and esterase pattern differences from otherAe. cylindrica populations. This justifies the recognition of a new variety: var.kastorianum. Our comparative and karyotypic

  3. Developmental selection of var gene expression in Plasmodium falciparum

    Microsoft Academic Search

    Qijun Chen; Victor Fernandez; Annika Sundstr鰉; Martha Schlichtherle; Santanu Datta; Per Hagblom; Mats Wahlgren

    1998-01-01

    The protozoan Plasmodium falciparum causes lethal malaria. Adhesion of erythrocytes infected with P. falciparum to vascular endothelium and to uninfected red blood cells (rosetting) may be involved in the pathogenesis of severe malaria. The binding is mediated by the antigenically variant erythrocyte-membrane-protein-1 (PfEMP-1), which is encoded by members of the P. falciparum var gene family,. The control of expression and

  4. Identification of Phytophthora fragariae var. rubi by PCR.

    PubMed

    Schlenzig, Alexandra

    2009-01-01

    The following chapter describes a PCR method for the identification of the raspberry root rot pathogen Phytophthora fragariae var. rubi. Furthermore, a nested PCR suitable for the detection of the pathogen in infected raspberry roots and validated against the "Duncan bait test" (EPPO Bull 35:87-91, 2005) is explained. Protocols for different DNA extraction methods are given which can be transferred to other fungal pathogens. PMID:19301754

  5. Plant regeneration from callus culture of Cymbidium ensifolium var. misericors

    Microsoft Academic Search

    C. Chang; W. C. Chang

    1998-01-01

    Totipotent calli of Cymbidium ensifolium var. misericors, a locally grown orchid of high commercial value, were induced from sections of pseudobulbs, rhizomes and\\u000a roots of seed-derived plantlets on 1\\/2-strength Murashige and Skoog medium plus 10 mg\\/l 2,4-dichlorophenoxyacetic acid and\\u000a 0.1 mg\\/l thiadiazuron. The calli could be maintained by subculturing in the same medium. The calli could be induced to develop

  6. Micropropagation of the Rare Lakeside Daisy (Hymenoxys acaulis var. glabra)

    Microsoft Academic Search

    James R. Ault

    Shoot tip and stem segment explants collected from greenhouse-maintained plants of Hymenoxys acaulis var. glabra were cultured in vitro for shoot initiation on a Murashige and Skoog (MS) medium supplemented with 30 g稬 -1 sucrose, 2.5 礛 BA, and 7 g稬 -1 agar at a pH of 5.7. Unbranched shoot explants were subcultured to MS medium with 0.0, 0.5, 1,

  7. Oil composition and some morphological characters of Crambe orientalis var. orientalis and Crambe tataria var. tataria from Turkey.

    PubMed

    Comlekcioglu, N; Karaman, S; Ilcim, A

    2008-04-15

    Native Crambe orientalis var. orientalis and Crambe tataria var. tataria collected from Kahramanmaras flora were morphologically examined and seed oil composition was determined. Volatile acid and fatty acid composition of seeds were examined with GC and GC/MS and the ratio of volatile acids to total oil was 3.49% in C. orientalis and 17.49% in C. tataria. The ratio of fatty acids to total oil was 92.03 and 67.28% in C. orientalis, and C. Tataria, respectively. The amount of erucic acid was 39.29% in C. orientalis and 29.87% in C. tataria. High linolenic acid (21.21%) and linoleic acid (12.42%) was found in C. orientalis oil, and high linolenic acid (15.01%) and linoleic acid (9.00%) was also found in C. tataria oil. PMID:18415861

  8. Sumoylation of Drosophila SU(VAR)3-7 is required for its heterochromatic function

    PubMed Central

    Reo, Emanuela; Seum, Carole; Spierer, Pierre; Bontron, S関erine

    2010-01-01

    In Drosophila, SU(VAR)3-7 is an essential heterochromatin component. It is required for proper chromatin condensation, and changing its dose modifies position-effect variegation. Sumoylation is a post-translational modification shown to play a role in diverse biological processes. Here, we demonstrate that sumoylation is essential for proper heterochromatin function in Drosophila through modification of SU(VAR)3-7. Indeed, SU(VAR)3-7 is sumoylated at lysine K839; this modification is required for localization of SU(VAR)3-7 at pericentric heterochromatin, chromosome 4, and telomeres. In addition, sumoylation of SU(VAR)3-7 is a prerequisite for its ability to enhance position-effect variegation. Thus, these results show that the heterochromatic function of SU(VAR)3-7 depends on its own sumoylation, and unveil a role for sumoylation in Drosophila heterochromatin. PMID:20299342

  9. Sumoylation of Drosophila SU(VAR)3-7 is required for its heterochromatic function.

    PubMed

    Reo, Emanuela; Seum, Carole; Spierer, Pierre; Bontron, S関erine

    2010-07-01

    In Drosophila, SU(VAR)3-7 is an essential heterochromatin component. It is required for proper chromatin condensation, and changing its dose modifies position-effect variegation. Sumoylation is a post-translational modification shown to play a role in diverse biological processes. Here, we demonstrate that sumoylation is essential for proper heterochromatin function in Drosophila through modification of SU(VAR)3-7. Indeed, SU(VAR)3-7 is sumoylated at lysine K839; this modification is required for localization of SU(VAR)3-7 at pericentric heterochromatin, chromosome 4, and telomeres. In addition, sumoylation of SU(VAR)3-7 is a prerequisite for its ability to enhance position-effect variegation. Thus, these results show that the heterochromatic function of SU(VAR)3-7 depends on its own sumoylation, and unveil a role for sumoylation in Drosophila heterochromatin. PMID:20299342

  10. Forecasting of Value at Risk (VAR) by Cluster Method in Chinese Stock Market

    Microsoft Academic Search

    Chin-Shan Hsieh; Jian-Hsin Chou

    The Conventional methods of VAR (Value at Risk) estimation includes Historical Simulation, Variance-Covariance and Monte Carlo Simulation method. These methods all use percentile of statistics method to determinate the VAR. This study proposes a Cluster method to compare the Conventional method for estimating VAR in Chinese stock markets (ShangHai A, B share and ShenZhen A, B share). Empirical results demonstrated

  11. Caenorhabditis elegans: a model to monitor bacterial air quality

    PubMed Central

    2011-01-01

    Background Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards to chemicals and particles contrary to micro-organisms. Indeed, pertinent and reliable tests to evaluate this biohazard are scarce. In this work, our purpose was to evaluate the Caenorhaditis elegans killing test, a model considered as an equivalent to the mouse acute toxicity test in pharmaceutical industry, in order to monitor air bacterial quality. Findings The present study investigates the bacterial population in dust clouds generated during crop ship loading in harbor installations (Rouen harbor, Normandy, France). With a biocollector, airborne bacteria were impacted onto the surface of agar medium. After incubation, a replicate of the colonies on a fresh agar medium was done using a velvet. All the replicated colonies were pooled creating the "Total Air Sample". Meanwhile, all the colonies on the original plate were isolated. Among which, five representative bacterial strains were chosen. The virulence of these representatives was compared to that of the "Total Air Sample" using the Caenorhaditis elegans killing test. The survival kinetic of nematodes fed with the "Total Air Sample" is consistent with the kinetics obtained using the five different representatives strains. Conclusions Bacterial air quality can now be monitored in a one shot test using the Caenorhaditis elegans killing test. PMID:22099854

  12. Characterizing temporal patterns in the swimming activity of Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Choi, Yeontaek; Jeon, Wonju; Kang, Seung-Ho; Lee, Sang-Hee; Chon, Tae-Soo

    2012-06-01

    The locomotion behavior of Caenorhabditis elegans has been studied extensively to understand the respective roles of neural control and biomechanics as well as the interaction between them. In the present study, we suggest a new approach to characterize the temporal patterns in the swimming behavior of the organism. The approach is based on the branching length similarity (BLS) entropy defined on a simple branching network consisting of a single node and branches. The organism's swimming activity is recorded using a charge-coupled device (CCD) camera for 3 h at a rate of 4 frames per second. In each frame, we place 13 points as nodes, those points being distributed at equal intervals along the organism's length. Thus, the organism is represented by 13 nodes and 12 edges between nodes. By using the nodes and edges, we construct two simple networks. One is formed by connecting the center point to all other points, and the other is generated from the angles between edges. The BLS entropy values are calculated as S L for the former network and S ? for the latter. We investigate the distributions of the S L and the S ? values in the phase space of S L S ? and compare those with the values obtained from a simulated C. elegans generated by using randomly-moving chained particles along a certain angle. The comparison revealed distinctive features of the movement patterns of C. elegans during swimming activity. In addition, we briefly discuss the application of our method to bio-monitoring systems to capture behavioral changes of test organisms before and after chemical treatment at low concentrations.

  13. Polyamine-independent Expression of Caenorhabditis elegans Antizyme.

    PubMed

    Stegehake, Dirk; Kurosinski, Marc-Andr; Sch黵mann, Sabine; Daniel, Jens; L黣rsen, Kai; Liebau, Eva

    2015-07-17

    Degradation of ornithine decarboxylase, the rate-limiting enzyme of polyamine biosynthesis, is promoted by the protein antizyme. Expression of antizyme is positively regulated by rising polyamine concentrations that induce a +1 translational frameshift required for production of the full-length protein. Antizyme itself is negatively regulated by the antizyme inhibitor. In our study, the regulation of Caenorhabditis elegans antizyme was investigated, and the antizyme inhibitor was identified. By applying a novel GFP-based method to monitor antizyme frameshifting in vivo, we show that the induction of translational frameshifting also occurs under stressful conditions. Interestingly, during starvation, the initiation of frameshifting was independent of polyamine concentrations. Because frameshifting was also prevalent in a polyamine auxotroph double mutant, a polyamine-independent regulation of antizyme frameshifting is suggested. Polyamine-independent induction of antizyme expression was found to be negatively regulated by the peptide transporter PEPT-1, as well as the target of rapamycin, but not by the daf-2 insulin signaling pathway. Stress-dependent expression of C. elegans antizyme occurred morely slowly than expression in response to increased polyamine levels, pointing to a more general reaction to unfavorable conditions and a diversion away from proliferation and reproduction toward conservation of energy. Interestingly, antizyme expression was found to drastically increase in aging individuals in a postreproductive manner. Although knockdown of antizyme did not affect the lifespan of C. elegans, knockdown of the antizyme inhibitor led to a significant reduction in lifespan. This is most likely caused by an increase in antizyme-mediated degradation of ornithine decarboxylase-1 and a resulting reduction in cellular polyamine levels. PMID:26032421

  14. Google matrix analysis of C.elegans neural network

    NASA Astrophysics Data System (ADS)

    Kandiah, V.; Shepelyansky, D. L.

    2014-05-01

    We study the structural properties of the neural network of the C.elegans (worm) from a directed graph point of view. The Google matrix analysis is used to characterize the neuron connectivity structure and node classifications are discussed and compared with physiological properties of the cells. Our results are obtained by a proper definition of neural directed network and subsequent eigenvector analysis which recovers some results of previous studies. Our analysis highlights particular sets of important neurons constituting the core of the neural system. The applications of PageRank, CheiRank and ImpactRank to characterization of interdependency of neurons are discussed.

  15. Diurnal ventilatory patterns in the garter snake, Thamnophis elegans

    Microsoft Academic Search

    James W. Hicks; Marvin L. Riedesel

    1983-01-01

    Garter snakes,Thamnophis elegans, were entrained to a 14L (06.3020.30 h) 10D (20.3006.30 h) cycle for five weeks at 25 癈. Following entrainment, simultaneous measurements of ventilation and oxygen uptake were made. Pulmonary oxygen uptake (\\u000a$$\\\\dot V_{O_2 } $$\\u000a) exhibited a diurnal rhythm with minimum values of\\u000a$$\\\\dot V_{O_2 } $$\\u000a occurring during 10D. The diurnal rhythm persisted during

  16. Google matrix analysis of C.elegans neural network

    E-print Network

    Kandiah, Vivek

    2013-01-01

    We study the structural properties of the neural network of the C.elegans (worm) from a directed graph point of view. The Google matrix analysis is used to characterize the neuron connectivity structure and node classifications are discussed and compared with physiological properties of the cells. Our results are obtained by a proper definition of neural directed network and subsequent eigenvector analysis which recovers some results of previous studies. Our analysis highlights particular sets of important neurons constituting the core of the neural system. The applications of PageRank, CheiRank and ImpactRank to characterization of interdependency of neurons are discussed.

  17. Mating behavior, male sensory cilia, and polycystins in Caenorhabditis elegans.

    PubMed

    O'Hagan, Robert; Wang, Juan; Barr, Maureen M

    2014-09-01

    The investigation of Caenorhabditis elegans males and the male-specific sensory neurons required for mating behaviors has provided insight into the molecular function of polycystins and mechanisms that are needed for polycystin ciliary localization. In humans, polycystin 1 and polycystin 2 are needed for kidney function; loss of polycystin function leads to autosomal dominant polycystic kidney disease (ADPKD). Polycystins localize to cilia in C. elegans and mammals, a finding that has guided research into ADPKD. The discovery that the polycystins form ciliary receptors in male-specific neurons needed for mating behaviors has also helped to unlock insights into two additional exciting new areas: the secretion of extracellular vesicles; and mechanisms of ciliary specialization. First, we will summarize the studies done in C. elegans regarding the expression, localization, and function of the polycystin 1 and 2 homologs, LOV-1 and PKD-2, and discuss insights gained from this basic research. Molecules that are co-expressed with the polycystins in the male-specific neurons may identify evolutionarily conserved molecular mechanisms for polycystin function and localization. We will discuss the finding that polycystins are secreted in extracellular vesicles that evoke behavioral change in males, suggesting that such vesicles provide a novel form of communication to conspecifics in the environment. In humans, polycystin-containing extracellular vesicles are secreted in urine and can be taken up by cilia, and quickly internalized. Therefore, communication by polycystin-containing extracellular vesicles may also use mechanisms that are evolutionarily conserved from nematode to human. Lastly, different cilia display structural and functional differences that specialize them for particular tasks, despite the fact that virtually all cilia are built by a conserved intraflagellar transport (IFT) mechanism and share some basic structural features. Comparative analysis of the male-specific cilia with the well-studied cilia of the amphid and phasmid neurons has allowed identification of molecules that specialize the male cilia. We will discuss the molecules that shape the male-specific cilia. The cell biology of cilia in male-specific neurons demonstrates that C. elegans can provide an excellent model of ciliary specialization. PMID:24977333

  18. Redox regulation of germline and vulval development in Caenorhabditis elegans.

    PubMed

    Shibata, Yukimasa; Branicky, Robyn; Landaverde, Irene Oviedo; Hekimi, Siegfried

    2003-12-01

    In vitro studies have indicated that reactive oxygen species (ROS) and the oxidation of signaling molecules are important mediators of signal transduction. We have identified two pathways by which the altered redox chemistry of the clk-1 mutants of Caenorhabditis elegans acts in vivo on germline development. One pathway depends on the oxidation of an analog of vertebrate low density lipoprotein (LDL) and acts on the germline through the Ack-related tyrosine kinase (ARK-1) kinase and inositol trisphosphate (IP3) signaling. The other pathway is the oncogenic ras signaling pathway, whose action on germline as well as vulval development appears to be modulated by cytoplasmic ROS. PMID:14657502

  19. Immune defense mechanisms in the Caenorhabditis elegans intestinal epithelium

    PubMed Central

    Pukkila-Worley, Read; Ausubel, Frederick M

    2013-01-01

    Intestinal epithelial cells provide an essential line of defense for Caenorhabditis elegans against ingested pathogens. Because nematodes consume microorganisms as their food source, there has presumably been selection pressure to evolve and maintain immune defense mechanisms within the intestinal epithelium. Here we review recent advances that further define the immune signaling network within these cells and suggest mechanisms used by the nematode to monitor for infection. In reviewing studies of pathogenesis that use this simple model system, we hope to illustrate some of the basic principles of epithelial immunity that may also be of relevance in higher order hosts. PMID:22236697

  20. Population dynamics and habitat sharing of natural populations of Caenorhabditis elegans and C. briggsae

    PubMed Central

    2012-01-01

    Background The nematode Caenorhabditis elegans is a major model organism in laboratory biology. Very little is known, however, about its ecology, including where it proliferates. In the past, C. elegans was mainly isolated from human-made compost heaps, where it was overwhelmingly found in the non-feeding dauer diapause stage. Results C. elegans and C. briggsae were found in large, proliferating populations in rotting plant material (fruits and stems) in several locations in mainland France. Both species were found to co-occur in samples isolated from a given plant species. Population counts spanned a range from one to more than 10,000 Caenorhabditis individuals on a single fruit or stem. Some populations with an intermediate census size (10 to 1,000) contained no dauer larvae at all, whereas larger populations always included some larvae in the pre-dauer or dauer stages. We report on associated micro-organisms, including pathogens. We systematically sampled a spatio-temporally structured set of rotting apples in an apple orchard in Orsay over four years. C. elegans and C. briggsae were abundantly found every year, but their temporal distributions did not coincide. C. briggsae was found alone in summer, whereas both species co-occurred in early fall and C. elegans was found alone in late fall. Competition experiments in the laboratory at different temperatures show that C. briggsae out-competes C. elegans at high temperatures, whereas C. elegans out-competes C. briggsae at lower temperatures. Conclusions C. elegans and C. briggsae proliferate in the same rotting vegetal substrates. In contrast to previous surveys of populations in compost heaps, we found fully proliferating populations with no dauer larvae. The temporal sharing of the habitat by the two species coincides with their temperature preference in the laboratory, with C. briggsae populations growing faster than C. elegans at higher temperatures, and vice at lower temperatures. PMID:22731941

  1. Crude Extracts of Caenorhabditis elegans Suppress Airway Inflammation in a Murine Model of Allergic Asthma

    PubMed Central

    Min, Byung-Hoon; Bae, Young Mee; Hong, Sung-Tae; Choi, Min-Ho

    2012-01-01

    Epidemiological studies suggest an inverse relationship between helminth infections and allergic disease, and several helminth-derived products have been shown to suppress allergic responses in animals. This study was undertaken to evaluate the effect of a crude extract of Caenorhabditis elegans on allergic airway inflammation in a murine model of asthma. Allergic airway inflammation was induced in BALB/c mice by sensitization with ovalbumin. The effect of the C. elegans crude extract on the development of asthma and on established asthma was evaluated by analyzing airway hyperresponsiveness, serum antibody titers, lung histology and cell counts and cytokine levels in the bronchoalveolar lavage fluid. The role of IFN-? in the suppression of asthma by the C. elegans crude extract was investigated in IFN-? knockout and wild-type mice. When mice were sensitized with ovalbumin together with the crude extract of C. elegans, cellular infiltration into the lung was dramatically reduced in comparison with the ovalbumin-treated group. Treatment of mice with the C. elegans crude extract significantly decreased methacholine-induced airway hyperresponsiveness and the total cell counts and levels of IL-4, IL-5 and IL-13 in the bronchoalveolar lavage fluid but increased the levels of IFN-? and IL-12. Sensitization with the C. elegans crude extract significantly diminished the IgE and IgG1 responses but provoked elevated IgG2a levels. However, the suppressive effect of the C. elegans crude extract was abolished in IFN-? knockout mice, and the Th2 responses in these mice were as strong as those in wild-type mice sensitized with ovalbumin. The crude extract of C. elegans also suppressed the airway inflammation associated with established asthma. This study provides new insights into immune modulation by the C. elegans crude extract, which suppressed airway inflammation in mice not only during the development of asthma but also after its establishment by skewing allergen-induced Th2 responses to Th1 responses. PMID:22558152

  2. The Genetics of Levamisole Resistance in the Nematode CAENORHABDITIS ELEGANS

    PubMed Central

    Lewis, James A.; Wu, C.-H.; Berg, Howard; Levine, Joseph H.

    1980-01-01

    We have characterized a small group of genes (13 loci) in the nematode Caenorhabditis elegans that, when mutated, confer resistance to the potent anthelmintic levamisole. Mutants at the 7 loci conferring the most extreme resistance generally possess almost identical visible and pharmacological phenotypes: uncoordinated motor behavior, most severe in early larval life, extreme resistance to cholinergic agonists and sensitivity to hypo-osmotic shock. Mutants with exceptional phenotypes suggest possible functions for several of the resistance loci. The most extreme mutants can readily be selected by their drug resistance (211 mutants, as many as 74 alleles of one gene). The more common resistance loci are likely to be unessential genes, while loci identified by only a few alleles may be essential genes or genes conferring resistance only when mutated in a special way. We propose that these mutants represent a favorable system for understanding how a small group of related genes function in a simple animal. The extreme drug resistance of these mutants makes them useful tools for the genetic manipulation of C. elegans. And, as the most resistant class of mutants might lack pharmacologically functional acetylcholine receptors (Lewis et al. 1980), these mutants may also be of some neurobiological significance. PMID:7203008

  3. Starvation-induced collective behavior in C. elegans

    PubMed Central

    Artyukhin, Alexander B.; Yim, Joshua J.; Cheong Cheong, Mi; Avery, Leon

    2015-01-01

    We describe a new type of collective behavior in C. elegans nematodes, aggregation of starved L1 larvae. Shortly after hatching in the absence of food, L1 larvae arrest their development and disperse in search for food. In contrast, after two or more days without food, the worms change their behavior梩hey start to aggregate. The aggregation requires a small amount of ethanol or acetate in the environment. In the case of ethanol, it has to be metabolized, which requires functional alcohol dehydrogenase sodh-1. The resulting acetate is used in de novo fatty acid synthesis, and some of the newly made fatty acids are then derivatized to glycerophosphoethanolamides and released into the surrounding medium. We examined several other Caenorhabditis species and found an apparent correlation between propensity of starved L1s to aggregate and density dependence of their survival in starvation. Aggregation locally concentrates worms and may help the larvae to survive long starvation. This work demonstrates how presence of ethanol or acetate, relatively abundant small molecules in the environment, induces collective behavior in C. elegans associated with different survival strategies. PMID:26013573

  4. Mutator Phenotype of Caenorhabditis elegans DNA Damage Checkpoint Mutants

    PubMed Central

    Harris, Jasper; Lowden, Mia; Clejan, Iuval; Tzoneva, Monika; Thomas, James H.; Hodgkin, Jonathan; Ahmed, Shawn

    2006-01-01

    DNA damage response proteins identify sites of DNA damage and signal to downstream effectors that orchestrate either apoptosis or arrest of the cell cycle and DNA repair. The C. elegans DNA damage response mutants mrt-2, hus-1, and clk-2(mn159) displayed 8- to 15-fold increases in the frequency of spontaneous mutation in their germlines. Many of these mutations were small- to medium-sized deletions, some of which had unusual sequences at their breakpoints such as purine-rich tracts or direct or inverted repeats. Although DNA-damage-induced apoptosis is abrogated in the mrt-2, hus-1, and clk-2 mutant backgrounds, lack of the apoptotic branch of the DNA damage response pathway in cep-1/p53, ced-3, and ced-4 mutants did not result in a Mutator phenotype. Thus, DNA damage checkpoint proteins suppress the frequency of mutation by ensuring that spontaneous DNA damage is accurately repaired in C. elegans germ cells. Although DNA damage response defects that predispose humans to cancer are known to result in large-scale chromosome aberrations, our results suggest that small- to medium-sized deletions may also play roles in the development of cancer. PMID:16951081

  5. Bacopa monnieri promotes longevity in Caenorhabditis elegans under stress conditions

    PubMed Central

    Phulara, Suresh C.; Shukla, Virendra; Tiwari, Sudeep; Pandey, Rakesh

    2015-01-01

    Background: Bacopa monnieri (L.) Pennell, commonly known as Brahmi is an important medicinal plant traditionally used as memory enhancer and antiepileptic agent. Objective: The present study investigated antioxidant and stress resistance potentials of B. monnieri aqueous extract (BMW) using Caenorhabditis elegans animal model system. Materials and Methods: The antioxidant activity of the BMW was measured using in vitro (DPPH, reducing power and total polyphenol content) and in vivo (DCF-DA assay) assays. The antistress potential of BMW (0.1, 0.01, and 0.001 mg/ml) was evaluated through thermal stress (37癈) and oxidative stress (10 mM paraquat) using C. elegans. Quantification of the HSP-16.2 level was done using CL2070 transgenic worms. Results: Present study reveals that BMW possess in vitro and in vivo antioxidant activities. BMW significantly enhanced stress tolerance and increased the mean lifespan of worms during thermal and oxidative stress, although it did not extend lifespan at 20癈 and attenuated age dependent decline in physiological behaviors. Moreover, it was shown that BMW was able to up-regulate expression of stress associated gene hsp-16.2, which significantly (P < 0.001) extends the mean lifespan of worms under stress conditions. Conclusion: The study strongly suggests that BMW acts as an antistressor and potent reactive oxygen species scavenger which enhances the survival of the worms in different stress conditions. PMID:25829783

  6. Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans

    PubMed Central

    Boyd, Lynn; Hajjar, Connie; O'Connell, Kevin

    2011-01-01

    Caenorhabditis elegans has often been used as a model system in studies of early developmental processes. The transparency of the embryos, the genetic resources, and the relative ease of transformation are qualities that make C. elegans an excellent model for early embryogenesis. Laser-based confocal microscopy and fluorescently labeled tags allow researchers to follow specific cellular structures and proteins in the developing embryo. For example, one can follow specific organelles, such as lysosomes or mitochondria, using fluorescently labeled dyes. These dyes can be delivered to the early embryo by means of microinjection into the adult gonad. Also, the localization of specific proteins can be followed using fluorescent protein tags. Examples are presented here demonstrating the use of a fluorescent lysosomal dye as well as fluorescently tagged histone and ubiquitin proteins. The labeled histone is used to visualize the DNA and thus identify the stage of the cell cycle. GFP-tagged ubiquitin reveals the dynamics of ubiquitinated vesicles in the early embryo. Observations of labeled lysosomes and GFP:: ubiquitin can be used to determine if there is colocalization between ubiquitinated vesicles and lysosomes. A technique for the microinjection of the lysosomal dye is presented. Techniques for generating transgenenic strains are presented elsewhere (1, 2). For imaging, embryos are cut out of adult hermaphrodite nematodes and mounted onto 2% agarose pads followed by time-lapse microscopy on a standard laser scanning confocal microscope or a spinning disk confocal microscope. This methodology provides for the high resolution visualization of early embryogenesis. PMID:21897352

  7. Phenazine derivatives cause proteotoxicity and stress in C. elegans.

    PubMed

    Ray, Arpita; Rentas, Courtney; Caldwell, Guy A; Caldwell, Kim A

    2015-01-01

    It is widely recognized that bacterial metabolites have toxic effects in animal systems. Phenazines are a common bacterial metabolite within the redox-active exotoxin class. These compounds have been shown to be toxic to the soil invertebrate Caenorhabditis elegans with the capability of causing oxidative stress and lethality. Here we report that chronic, low-level exposure to three separate phenazine molecules (phenazine-1-carboxylic acid, pyocyanin and 1-hydroxyphenazine) upregulated ER stress response and enhanced expression of a superoxide dismutase reporter in vivo. Exposure to these molecules also increased protein misfolding of polyglutamine and ?-synuclein in the bodywall muscle cells of C. elegans. Exposure of worms to these phenazines caused additional sensitivity in dopamine neurons expressing wild-type ?-synuclein, indicating a possible defect in protein homeostasis. The addition of an anti-oxidant failed to rescue the neurotoxic and protein aggregation phenotypes caused by these compounds. Thus, increased production of superoxide radicals that occurs in whole animals in response to these phenazines appears independent from the toxicity phenotype observed. Collectively, these data provide cause for further consideration of the neurodegenerative impact of phenazines. PMID:25304539

  8. Do proximate, C. elegans swimmers synchronize their gait?

    NASA Astrophysics Data System (ADS)

    Yuan, Jinzhou; Raizen, David; Bau, Haim

    2012-11-01

    We imaged two C. elegans swimming, one after the other, in a tapered conduit. The conduit was subjected to a DC electric field, with the negative pole at the narrow end and applied flow directed from the narrow end. As a result of their attraction to the negative pole (electrotaxis), both animals swam upstream. As the conduit narrowed, the average adverse flow velocity increased and the swimming speed of the leading animal decreased faster than that of the trailing animal, allowing the latter to catch up with the former. We quantified synchronization by measuring the phase lag between the gait of one animal and the extended wave pattern of the other as a function of the distance between the two animals. Only when the distance between the two animals' body centers was nearly equal to or smaller than one body length were the animals' motions synchronized. When the nematodes were parallel to one another, synchronization was essential to prevent the animals from colliding. Direct numerical simulations indicate that when the trailing animal's head is immediately downstream of the leading animal's tail, the animals derive just a slight hydrodynamic advantage from their proximity compared to a single swimmer. We thank Kun He Lee from the University of Pennsylvania for preparing C. elegans.

  9. Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans

    PubMed Central

    Sun, C-L; Kim, E; Crowder, C M

    2014-01-01

    After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 23% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death. PMID:24317200

  10. Selenium induces cholinergic motor neuron degeneration in Caenorhabditis elegans

    PubMed Central

    Estevez, Annette O.; Mueller, Catherine L.; Morgan, Kathleen L.; Szewczyk, Nathaniel J.; Teece, Luke; Miranda-Vizuete, Antonio; Estevez, Miguel

    2012-01-01

    Selenium is an essential micronutrient required for cellular antioxidant systems, yet at higher doses it induces oxidative stress. Additionally, in vertebrates environmental exposures to toxic levels of selenium can cause paralysis and death. Here we show that selenium-induced oxidative stress leads to decreased cholinergic signaling and degeneration of cholinergic neurons required for movement and egg-laying in Caenorhabditis elegans. Exposure to high levels of selenium leads to proteolysis of a soluble muscle protein through mechanisms suppressible by two pharmacological agents, levamisole and aldicarb which enhance cholinergic signaling in muscle. In addition, animals with reduction-of-function mutations in genes encoding post-synaptic levamisole-sensitive acetylcholine receptor subunits or the vesicular acetylcholine transporter developed impaired forward movement faster during selenium-exposure than normal animals, again confirming that selenium reduces cholinergic signaling. Finally, the antioxidant reduced glutathione, inhibits selenium-induced reductions in egg-laying through a cellular protective mechanism dependent on the C. elegans glutaredoxin, GLRX-21. These studies provide evidence that the environmental toxicant selenium induces neurodegeneration of cholinergic neurons through depletion of glutathione, a mechanism linked to the neuropathology of Alzheimer抯 disease, amyotrophic lateral sclerosis, and Parkinson抯 disease. PMID:22560997

  11. Fluorescent visualization of germline apoptosis in living Caenorhabditis elegans.

    PubMed

    Lant, Benjamin; Derry, W Brent

    2014-04-01

    Visualization of apoptosis using fluorescent tools is quite straightforward in living Caenorhabditis elegans. Several transgenic lines are available that mark dying cells with fluorescent proteins, making it possible to quantify kinetics at various stages of the apoptotic process. Proteins required for the engulfment of cell corpses are particularly useful for detecting early apoptotic stages using this approach. For example, expression of the engulfment protein CED-1 fused to green fluorescent protein (CED-1::GFP) creates a halo around cells during early apoptosis, before their refractile morphology can be detected by differential interference contrast (DIC) optics. In addition, vital dyes such as acridine orange (AO) and SYTO-12 are selectively retained in apoptotic cells and can be used to visualize apoptosis in the germlines of living animals. It is also possible to use vital dyes in combination with transgenic strains expressing fluorescent markers of cell corpses to examine, in detail, multiple stages of apoptosis in vivo. Because of the high optical contrast of fluorescent reagents, apoptosis can be visualized even at low magnification, facilitating the use of screening platforms to identify apoptosis regulators. This protocol describes multiple uses of fluorescent reagents for visualization of germline apoptosis in living C. elegans, including AO staining, time-course studies using fluorescent proteins, and low-throughput screening of cell death genes using RNA interference (RNAi). PMID:24692492

  12. Copulation in C. elegans males requires a nuclear hormone receptor.

    PubMed

    Shan, Ge; Walthall, W W

    2008-10-01

    In Caenorhabditis elegans, uncoordinated (unc)-55 encodes a nuclear hormone receptor that is necessary for coordinated movement and male mating. An unc-55 reporter gene revealed a sexually dimorphic pattern: early in post-embryonic motor neurons in both sexes; and later in a subset of male-specific cells that included an interneuron and eight muscle cells. A behavioral analysis coupled with RNA interference (RNAi) revealed that males require UNC-55 to execute copulatory motor programs. Two mRNA isoforms (unc-55a and unc-55b) were detected throughout post-embryonic development in males, whereas only one, unc-55a, was detected in hermaphrodites. In unc-55 mutant males isoform a rescued the locomotion and mating defect, whereas isoform b rescued the mating defect only. Isoform b represents the first report of male-specific splicing in C. elegans. In addition, isoform b extended the number of days that transgenic unc-55 mutant males mated when compared to males rescued with isoform a, suggesting an anabolic role for the nuclear hormone receptor. The male-specific expression and splicing is part of a regulatory hierarchy that includes two key genes, male abnormal (mab)-5 and mab-9, required for the generation and differentiation of male-specific cells. We suggest that UNC-55 acts as an interface between genes involved in male tail pattern formation and those responsible for function. PMID:18652814

  13. Hierarchical sparse coding in the sensory system of Caenorhabditis elegans

    PubMed Central

    Zaslaver, Alon; Liani, Idan; Shtangel, Oshrat; Ginzburg, Shira; Yee, Lisa; Sternberg, Paul W.

    2015-01-01

    Animals with compact sensory systems face an encoding problem where a small number of sensory neurons are required to encode information about its surrounding complex environment. Using Caenorhabditis elegans worms as a model, we ask how chemical stimuli are encoded by a small and highly connected sensory system. We first generated a comprehensive library of transgenic worms where each animal expresses a genetically encoded calcium indicator in individual sensory neurons. This library includes the vast majority of the sensory system in C. elegans. Imaging from individual sensory neurons while subjecting the worms to various stimuli allowed us to compile a comprehensive functional map of the sensory system at single neuron resolution. The functional map reveals that despite the dense wiring, chemosensory neurons represent the environment using sparse codes. Moreover, although anatomically closely connected, chemo- and mechano-sensory neurons are functionally segregated. In addition, the code is hierarchical, where few neurons participate in encoding multiple cues, whereas other sensory neurons are stimulus specific. This encoding strategy may have evolved to mitigate the constraints of a compact sensory system. PMID:25583501

  14. Left-right patterning in the C. elegans embryo

    PubMed Central

    2011-01-01

    The development of bilateral symmetry during the evolution of species probably 600 million years ago brought about several important innovations: It fostered efficient locomotion, streamlining and favored the development of a central nervous system through cephalization. However, to increase their functional capacities, many organisms exhibit chirality by breaking their superficial left-right (l-r) symmetry, which manifests in the lateralization of the nervous system or the l-r asymmetry of internal organs. In most bilateria, the mechanisms that maintain consistent l-r asymmetry throughout development are poorly understood. This review highlights insights into mechanisms that couple early embryonic l-r symmetry breaking to subsequent l-r patterning in the roundworm Caenorhabditis elegans. A recently identified strategy for l-r patterning in the early C. elegans embryo is discussed, the spatial separation of midline and anteroposterior axis, which relies on a rotational cellular rearrangement and non-canonical Wnt signaling. Evidence for a general relevance of rotational/torsional rearrangements during organismal l-r patterning and for non-canonical Wnt signaling/planar cell polarity as a common signaling mechanism to maintain l-r asymmetry is presented. PMID:21509174

  15. Characterization of mitochondrial thioredoxin reductase from C. elegans

    SciTech Connect

    Lacey, Brian M. [Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405 (United States); Hondal, Robert J. [Department of Biochemistry, 89 Beaumont Ave, Given Laboratory, Room B413, Burlington, VT 05405 (United States)]. E-mail: Robert.Hondal@uvm.edu

    2006-08-04

    Thioredoxin reductase catalyzes the NADPH-dependent reduction of the catalytic disulfide bond of thioredoxin. In mammals and other higher eukaryotes, thioredoxin reductases contain the rare amino acid selenocysteine at the active site. The mitochondrial enzyme from Caenorhabditis elegans, however, contains a cysteine residue in place of selenocysteine. The mitochondrial C. elegans thioredoxin reductase was cloned from an expressed sequence tag and then produced in Escherichia coli as an intein-fusion protein. The purified recombinant enzyme has a k {sub cat} of 610 min{sup -1} and a K {sub m} of 610 {mu}M using E. coli thioredoxin as substrate. The reported k {sub cat} is 25% of the k {sub cat} of the mammalian enzyme and is 43-fold higher than a cysteine mutant of mammalian thioredoxin reductase. The enzyme would reduce selenocysteine, but not hydrogen peroxide or insulin. The flanking glycine residues of the GCCG motif were mutated to serine. The mutants improved substrate binding, but decreased the catalytic rate.

  16. Genistein from Vigna angularis Extends Lifespan in Caenorhabditis elegans

    PubMed Central

    Lee, Eun Byeol; Ahn, Dalrae; Kim, Ban Ji; Lee, So Yeon; Seo, Hyun Won; Cha, Youn-Soo; Jeon, Hoon; Eun, Jae Soon; Cha, Dong Seok; Kim, Dae Keun

    2015-01-01

    The seed of Vigna angularis has long been cultivated as a food or a folk medicine in East Asia. Genistein (4?,5,7-trihydroxyisoflavone), a dietary phytoestrogen present in this plant, has been known to possess various biological properties. In this study, we investigated the possible lifespan-extending effects of genistein using Caenorhabditis elegans model system. We found that the lifespan of nematode was significantly prolonged in the presence of genistein under normal culture condition. In addition, genistein elevated the survival rate of nematode against stressful environment including heat and oxidative conditions. Further studies demonstrated that genistein-mediated increased stress tolerance of nematode could be attributed to enhanced expressions of stress resistance proteins such as superoxide dismutase (SOD-3) and heat shock protein (HSP-16.2). Moreover, we failed to find genistein-induced significant change in aging-related factors including reproduction, food intake, and growth, indicating genistein exerts longevity activity independent of affecting these factors. Genistein treatment also led to an up-regulation of locomotory ability of aged nematode, suggesting genistein affects healthspan as well as lifespan of nematode. Our results represent that genistein has beneficial effects on the lifespan of C. elegans under both of normal and stress condition via elevating expressions of stress resistance proteins. PMID:25593647

  17. Autophagy protects C. elegans against necrosis during Pseudomonas aeruginosa infection

    PubMed Central

    Zou, Cheng-Gang; Ma, Yi-Cheng; Dai, Li-Li; Zhang, Ke-Qin

    2014-01-01

    Autophagy, a conserved pathway that delivers intracellular materials into lysosomes for degradation, is involved in development, aging, and a variety of diseases. Accumulating evidence demonstrates that autophagy plays a protective role against infectious diseases by diminishing intracellular pathogens, including bacteria, viruses, and parasites. However, the mechanism by which autophagy regulates innate immunity remains largely unknown. Here, we show that autophagy is involved in host defense against a pathogenic bacterium Pseudomonas aeruginosa in the metazoan Caenorhabditis elegans. P. aeruginosa infection induces autophagy via a conserved extracellular signal-regulated kinase (ERK). Intriguingly, impairment of autophagy does not influence the intestinal accumulation of P. aeruginosa, but instead induces intestinal necrosis. Inhibition of necrosis results in the survival of autophagy-deficient worms after P. aeruginosa infection. These findings reveal a previously unidentified role for autophagy in protection against necrosis triggered by pathogenic bacteria in C. elegans and implicate that such a function of autophagy may be conserved through the inflammatory response in diverse organisms. PMID:25114220

  18. Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans.

    PubMed

    Sun, C-L; Kim, E; Crowder, C M

    2014-04-01

    After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 2-3% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death. PMID:24317200

  19. Northernmost occurrences of the protistan pathogen, Coelomomyces stegomyiae var. stegomyiae.

    PubMed

    Laird, M; Mogi, M; Sota, T

    1992-12-01

    Now reported as parasitizing the ovaries of female Aedes albopictus on Kabeshima (33.33N x 129.53E), Coelomomyces stegomyiae var. stegomyiae had been found earlier in larvae of this mosquito on Mikura-jima (33.53N x 139.35E). These findings from 2 widely separated little Japanese islands constitute the parasite's most northerly records to date. Few previous reports of Coelomomyces spp., none concerning C. stegomyiae, have involved adult mosquitoes. Possible reasons for this are advanced. PMID:1474392

  20. A 2,5-dimethoxytetrahydrofuran from Hemerocallis fulva var. kwanso

    Microsoft Academic Search

    Tenji Konishi; Tomohiro Inoue; Shiu Kiyosawa; Yasuhiro Fujiwara

    1996-01-01

    A 2,5-dimethoxytetrahydrofuran, fulvanol, has been extracted from Hemerocallis fulva var. kwanso along with fulvanines, 2,5-dihydrofuryl-?-lactams. The structure of fulvanol has been established as 3-hydroxymethyl-2,5-dimethoxy-3,4-dihydroxytetrahydrofuran by the 1H and 13C NMR spectra. The structure of fulvanol is closely related to the branched-chain tetrofuranose apiose, occurring in the form of UDP-glycoside or as other cell components. [嘑ulvanines were first named for 2,5-dihydrofuryl-?-lactam

  1. Regulation of Sugar Transport Systems in Fusarium oxysporum var. lini

    PubMed Central

    Brand鉶, Rog閘io L.; Loureiro-Dias, Maria C.

    1990-01-01

    Fusarium oxysporum var. lini (ATCC 10960) formed a facilitated diffusion system for glucose (Ks, about 10 mM) when grown under repressed conditions. Under conditions of derepression, the same system was present together with a high-affinity (Ks, about 40 ?M) active system. The maximum velocity of the latter was about 5% of that of the facilitated diffusion system. The high-affinity system was under the control of glucose repression and glucose inactivation. When lactose was the only carbon source in the medium, a facilitated diffusion system for lactose was found (Ks, about 30 mM). PMID:16348256

  2. [Chemical constituents of leaves of Panax japonicus var. major].

    PubMed

    He, Rui; Liu, Qi; Liu, Yin-Huan; Chai, Jiang; Zhao, Dong-Dong; Wang, Wei; Cui, Jiu-Cheng; Song, Xiao-Mei; Yue, Zheng-Gang

    2014-05-01

    Seven compounds were isolated from the leaves of Panax japonicus var. major by chromatographic methods including silica gel, Sephadex LH-20, ODS and semi-preparative HPLC. Their structures were elucidated by their physical and chemical properties and spectral data analysis as 5, 7-dihydroxy-8-methoxyl flavone (1), ginsenoside Rs2 (2), quinquenoside R1 (3), ginsenoside Rs1 (4), notoginsenoside Fe (5), ginsenoside Rd2 (6) and gypenosiden IX (7). Among them, compound 1 was obtained from the Panax genus for the first time, and compounds 2-7 were isolated from this plant for the first time. PMID:25095375

  3. Morphology-Guided Graph Search for Untangling Objects: C. elegans Analysis

    E-print Network

    Raviv, T. Riklin

    2010-01-01

    We present a novel approach for extracting cluttered objects based on their morphological properties. Specifically, we address the problem of untangling Caenorhabditis elegans clusters in high-throughput screening experiments. ...

  4. An image analysis toolbox for high-throughput C. elegans assays

    E-print Network

    Kamentsky, Lee

    We present a toolbox for high-throughput screening of image-based Caenorhabditis elegans phenotypes. The image analysis algorithms measure morphological phenotypes in individual worms and are effective for a variety of ...

  5. Communication between oocytes and somatic cells regulates volatile pheromone production in Caenorhabditis elegans

    PubMed Central

    Leighton, Daniel H. W.; Choe, Andrea; Wu, Shannon Y; Sternberg, Paul W.

    2014-01-01

    Males of the androdioecious species Caenorhabditis elegans are more likely to attempt to mate with and successfully inseminate C. elegans hermaphrodites that do not concurrently harbor sperm. Although a small number of genes have been implicated in this effect, the mechanism by which it arises remains unknown. In the context of the battle of the sexes, it is also unknown whether this effect is to the benefit of the male, the hermaphrodite, or both. We report that successful contact between mature sperm and oocyte in the C. elegans gonad at the start of fertilization causes the oocyte to release a signal that is transmitted to somatic cells in its mother, with the ultimate effect of reducing her attractiveness to males. Changes in hermaphrodite attractiveness are tied to the production of a volatile pheromone, the first such pheromone described in C. elegans. PMID:25453110

  6. Receptor-type guanylate cyclase is required for carbon dioxide sensation by Caenorhabditis elegans

    E-print Network

    Hallem, Elissa A.

    CO2 [CO subscript 2] is both a critical regulator of animal physiology and an important sensory cue for many animals for host detection, food location, and mate finding. The free-living soil nematode Caenorhabditis elegans ...

  7. Single molecule fluorescent in situ hybridization (smFISH) of C. elegans worms and embryos

    E-print Network

    Ji, Ni

    In C. elegans, the expression pattern of a gene provides important clues to understanding its biological function. To accurately depict endogenous transcriptional activity, a highly sensitive method is required to measure ...

  8. Biochemical and High Throughput Microscopic Assessment of Fat Mass in Caenorhabditis Elegans

    E-print Network

    Pino, Elizabeth C.

    The nematode C. elegans has emerged as an important model for the study of conserved genetic pathways regulating fat metabolism as it relates to human obesity and its associated pathologies. Several previous methodologies ...

  9. C. elegans TRP Family Protein TRP-4 Is a Pore-Forming Subunit of a Native

    E-print Network

    Schafer, William R.

    their prevalence in diverse tissues and organisms, very little is known about the genes encoding mechanotransduc in metazoans: the touch-sensitive ENaC family Na+ channel MEC-4/MEC-10 in C. elegans and the stretch

  10. Many families of Caenorhabditis elegans microRNAs are not essential for development or viability

    E-print Network

    Alvarez-Saavedra, Ezequiel

    MicroRNAs (miRNAs) are approximately 23 nt regulatory RNAs that posttranscriptionally inhibit the functions of protein-coding mRNAs. We previously found that most C. elegans miRNAs are individually not essential for ...

  11. Receptors and Other Signaling Proteins Required for Serotonin Control of Locomotion in Caenorhabditis elegans

    E-print Network

    Gustafson, Megan A.

    A better understanding of the molecular mechanisms of signaling by the neurotransmitter serotonin is required to assess the hypothesis that defects in serotonin signaling underlie depression in humans. Caenorhabditis elegans ...

  12. Alpha-Synuclein Disrupted Dopamine Homeostasis Leads to Dopaminergic Neuron Degeneration in Caenorhabditis elegans

    E-print Network

    Cao, Pengxiu; Yuan, Yiyuan; Pehek, Elizabeth A.; Moise, Alexander R.; Huang, Ying; Palczewski, Krzysztof; Feng, Zhaoyang

    2010-02-19

    Disruption of dopamine homeostasis may lead to dopaminergic neuron degeneration, a proposed explanation for the specific vulnerability of dopaminergic neurons in Parkinson's disease. While expression of human ?-synuclein in C. elegans results...

  13. Monitoring the Clearance of Apoptotic and Necrotic Cells in the Nematode Caenorhabditis elegans

    PubMed Central

    Li, Zao; Lu, Nan; He, Xiangwei; Zhou, Zheng

    2014-01-01

    The nematode Caenorhabditis elegans is an excellent model organism for studying the mechanisms controlling cell death, including apoptosis, a cell suicide event, and necrosis, pathological cell deaths caused by environmental insults or genetic alterations. C. elegans has also been established as a model for understanding how dying cells are cleared from animal bodies. In particular, the transparent nature of worm bodies and eggshells make C. elegans particularly amenable for live-cell microscopy. Here we describe methods for identifying apoptotic and necrotic cells in living C. elegans embryos, larvae, and adults and for monitoring their clearance during development. We further discuss specific methods to distinguish engulfed from unengulfed apoptotic cells, and methods to monitor cellular and molecular events occurring during phagosome maturation. These methods are based on Differential Interference Contrast (DIC) microscopy or fluorescence microscopy using GFP-based reporters. PMID:23733578

  14. Abl Kinase Inhibits the Engulfment of Apoptotic [corrected] Cells in Caenorhabditis elegans

    E-print Network

    Hurwitz, Michael Eliezer

    The engulfment of apoptotic cells is required for normal metazoan development and tissue remodeling. In Caenorhabditis elegans, two parallel and partially redundant conserved pathways act in cell-corpse engulfment. One ...

  15. Plagiorchis elegans (Trematoda) induces immune response in an incompatible snail host Biomphalaria glabrata (Pulmonata: Planorbidae).

    PubMed

    Daoust, S P; Rau, M E; McLaughlin, J D

    2012-10-01

    Plagiorchis elegans has been shown to decrease the fecundity and survivorship of the incompatible snail host Biomphalaria glabrata. Furthermore, a prior infection with P. elegans was shown to render the snails resistant to the compatible parasite Schistosoma mansoni. Here, we test the hypothesis that infection with P. elegans stimulates the immune system of B. glabrata. Our findings indicate that infection by P. elegans significantly increased the number of free hemocytes in the hemolymph of B. glabrata by an average of ~60%. Furthermore, this immuno-stimulated state lasted from the first day post-infection (PI) to some time between 7 and 21 days PI. This is one of the few reported examples of a parasite stimulating the immune response of an incompatible host. PMID:22448777

  16. Microfluidics for the analysis of behavior, nerve regeneration, and neural cell biology in C. elegans

    PubMed Central

    Ben-Yakar, Adela; Chronis, Nikos; Lu, Hang

    2010-01-01

    The nematode Caenorhabditis elegans is a widely adopted model organism for studying various neurobiological processes at the molecular and cellular level in vivo. With a small, flexible, and continuously moving body, the manipulation of C. elegans becomes a challenging task. In this review, we highlight recent advances in microfluidic technologies for the manipulation of C. elegans. These new family of microfluidic chips are capable of handling single or populations of worms in a high-throughput fashion and accurately controlling their microenvironment. So far, they have been successfully used to study neural circuits and behavior, to perform large-scale phetotyping and morphology-based screens as well as to understand axon regeneration after injury. We envision that microfluidic chips can further be used to study different aspects of the C. elegans nervous system, extending from fundamental understanding of behavioral dynamics to more complicated biological processes such as neural aging and learning and memory. PMID:19896831

  17. Ligand-Gated Chloride Channels Are Receptors for Biogenic Amines in C. elegans

    E-print Network

    Ringstad, Niels

    Biogenic amines such as serotonin and dopamine are intercellular signaling molecules that function widely as neurotransmitters and neuromodulators. We have identified in the nematode Caenorhabditis elegans three ligand-gated ...

  18. A Neuronal Acetylcholine Receptor Regulates the Balance of Muscle Excitation and Inhibition in Caenorhabditis elegans

    E-print Network

    Jospin, Maelle

    In the nematode Caenorhabditis elegans, cholinergic motor neurons stimulate muscle contraction as well as activate GABAergic motor neurons that inhibit contraction of the contralateral muscles. Here, we describe the ...

  19. C. elegans integrates food, stress, and hunger signals to coordinate motor activity

    E-print Network

    Omura, Daniel Togo

    2008-01-01

    In the presence of a bacterial food source, the small nematode C. elegans greatly reduces its rate of locomotion. While mechanical agitation greatly stimulates the locomotion of well-fed animals on bacteria, it does not ...

  20. The broad-spectrum antibiotic, zeamine, kills the nematode worm Caenorhabditis elegans

    E-print Network

    Hellberg, Josephine E. E. U.; Matilla, Miguel A.; Salmond, George P. C.

    2015-02-26

    gene cluster showed that several of them are highly virulent in C. elegans. Zeamine was described previously as a phytotoxin and broad-spectrum antibacterial compound. In addition to its nematicidal properties, we show here that zeamine can also kill...

  1. ORIGINAL RESEARCH COMMUNICATION Protective Role of DNJ-27/ERdj5 in Caenorhabditis elegans

    E-print Network

    Caldwell, Guy

    of DNJ-27/ ERdj5, an endoplasmic reticulum (ER)-resident thioredoxin protein required as a disulfide reductase for the degradation of misfolded proteins, in well-established Caenorhabditis elegans models

  2. Convex Estimation of Cointegrated VAR Models by a Nuclear Norm Penalty

    E-print Network

    Convex Estimation of Cointegrated VAR Models by a Nuclear Norm Penalty M. Signoretto and J. A. K a quadratic error function and a nuclear norm penalty used as a proxy for the cointegrating rank. We elaborate and population dynamics. In this paper we focus on VAR processes. It is well known that these processes can

  3. Amlioration des plantes Obtention chez l'chalote (Allium cepa L var

    E-print Network

    Paris-Sud XI, Universit de

    in shallot (Allium cepa L var aggregatum). Embryos of gynogenetic origin have been obtained by in vitro culture of flower buds from many shallot genotypes on basal B5 medium of Gamborg with high sucrose haploids in shallot breeding can now be proposed. Allium cepa L var aggregatum = shallot / gynogenesis

  4. FACTEURS FAVORISANT LA PRODUCTION D'ACIDE PNICILLIQUE PAR PENICILLIUM VERRUCOSUM VAR. CYCLOPIUM

    E-print Network

    Paris-Sud XI, Universit de

    , 180, chemin de Tournefeuille, 3130i0 Toulouse, France Summary ENHANCEMENT FACTORS OF PENICILLIC ACID PRODUCTION BY PENlClLLlUM VERRUCO- SUM VAR. CYCLOPlUM IN FOODSTUFFS. - Main parameters of penicillic acid (PFACTEURS FAVORISANT LA PRODUCTION D'ACIDE P蒒ICILLIQUE PAR PENICILLIUM VERRUCOSUM VAR. CYCLOPIUM

  5. Zoophilic Dermatomycosis in a Family Caused by Trichophyton mentagrophytes var. quinckeanum - A Case Report

    Microsoft Academic Search

    Z. BARANOV; M. KOZ罧; J. B蚅EK; Z. POMORSKI

    Baranov Z., M. Koz醟, J. B韑ek Z. Pomorski: Zoophilic Dermatomycosis in a Family Caused by Trichophyton mentagrophytes var. quinckeanum - A Case Report. Acta Vet Brno 2003, 72: 311-314. Trichophyton mentagrophytes var. quinckeanum is a zoophilic form of T. mentagrophytes. It induces murine favus in the form of coarse yellow scutules larger than 1 cm in diameter. In March, 2002,

  6. Forecasting VaR and Expected Shortfall using Dynamical Systems: A Risk Management Strategy

    E-print Network

    Boyer, Edmond

    in finance and economics 6, 1 (2009) 26-50" #12;Cyril Caillault, Dominique Gu間an - Forecasting VaR and Expected Shortfall using Dynamical Systems: A Risk Management Strategy Frontiers in Finance and Economics risk for different type of assets such as equities, rates or currencies. The VaR measure, which may

  7. Forecasting VARMA processes: VAR models vs. subspace-based state space models

    Microsoft Academic Search

    Segismundo Izquierdo; Cesareo Hernandez; Juan del Hoyo

    2006-01-01

    VAR modelling is a frequent technique in econometrics for assumed linear processes. VAR modelling offers some desirable features such as relatively simple procedures for model specification and the possibility of making a quick and non-iterative maximum likelihood estimation of the system parameters. However, if the process under study follows a finite-order VARMA structure, it cannot be equivalently represented by any

  8. Spiral phyllotaxis of needle fascicles on branches and scales on cones in Pinus contorta var.

    E-print Network

    Coxson, Darwyn

    Spiral phyllotaxis of needle fascicles on branches and scales on cones in Pinus contorta var-grain spiral in seedlings, young, and mature trees of Rocky Moun- tain lodgepole pine (Pinus contorta Dougl. ex, Pinus contorta var. latifolia, phyllotaxis, generative spiral, Fibonacci numbers, spiral wood grain

  9. A novel high power self-commutated static VAr compensator for load compensation

    Microsoft Academic Search

    Kishore Chatterjee; B. G. Fernandes; Gopal K. Dubey

    1997-01-01

    A novel high power self-commutated static VAr compensator for load compensation is proposed. The harmonics are eliminated by combining low frequency high power devices and high frequency low power devices. A modified control strategy is also proposed for applications involving high and faster rate of change in VAr demand. Detailed simulation studies for single phase and three phase topologies are

  10. REDUCED-RANK IDENTIFICATION OF STRUCTURAL SHOCKS IN VARS Yuriy Gorodnichenko

    E-print Network

    Sadoulet, Elisabeth

    REDUCED-RANK IDENTIFICATION OF STRUCTURAL SHOCKS IN VARS Yuriy Gorodnichenko Department facts about responses of macroeconomic variables to structural shocks such as innovations in technology only a few structural shocks such as innovations in technology, preferences, or policy. Hence, VARs can

  11. dbVar VCF SubmissionFormat Guidelines Contact:dbvar@ncbi.nlm.nih.gov

    E-print Network

    Levin, Judith G.

    dbVar VCF SubmissionFormat Guidelines Contact:dbvar@ncbi.nlm.nih.gov Lastupdated:September23 your data directlyto ClinVar (http://www.ncbi.nlm.nih.gov/clinvar/).Once yourvariants have been non-clinicalvariants. Ifyouhave questionsregardingyoursubmission, contactdbVarat dbvar@ncbi.nlm.nih.gov

  12. Essential oil constituents of different organs of fennel (Foeniculum vulgare var. vulgare)

    Microsoft Academic Search

    R. Facanali; S. P. Brazil

    Essential oil constituents of different organs of fennel (Foeniculum vulgare var. vulgare). The fennel (Foeniculum vulgare Mill.var. vulgare) is an annual herbaceous plant, whose seeds are very used in the homemade medicine and pharmaceutical industry. The fennel seeds produce yellow-clear aromatic essential oil, used in the production of several licorous drinks and of perfumery, with action carminative and stimulant. Therefore,

  13. Estimating all possible SUR models with permuted exogenous data matrices derived from a VAR process

    Microsoft Academic Search

    Cristian Gatu; Erricos J. Kontoghiorghes

    2006-01-01

    The Vector Autoregressive (VAR) process with zero coefficient constraints can be formulated as a Seemingly Unrelated Regressions (SUR) model. Within the context of subset VAR model selection a computationally efficient strategy to generate and estimate all G! SUR models when permuting the exogenous data matrices is proposed, where G is the number of the regression equations. The combinatorial algorithm is

  14. Stratospheric age of air computed with trajectories based on various 3D-Var and 4D-Var data sets

    Microsoft Academic Search

    M. P. Scheele; P. C. Siegmund; P. F. J. van Velthoven

    2005-01-01

    The age of stratospheric air is computed with a trajectory model, using ECMWF ERA-40 3D-Var and operational 4D-Var winds. Analysis as well as forecast data are used. In the latter case successive forecast segments are put together to get a time series of the wind fields. This is done for different forecast segment lengths. The sensitivity of the computed age

  15. Stratospheric age of air computed with trajectories based on various 3D-Var and 4D-Var data sets

    Microsoft Academic Search

    M. P. Scheele; P. C. Siegmund; P. F. J. van Velthoven

    2005-01-01

    The age of stratospheric air is computed with a trajectory model, using ECMWF ERA-40 3D-Var and op- erational 4D-Var winds. Analysis as well as forecast data are used. In the latter case successive forecast segments are put together to get a time series of the wind fields. This is done for different forecast segment lengths. The sensitivity of the computed

  16. Antioxidant potency of white ( Brassica oleracea L. var. capitata) and Chinese ( Brassica rapa L. var. pekinensis (Lour.)) cabbage: The influence of development stage, cultivar choice and seed selection

    Microsoft Academic Search

    Dunja 奱mec; Jasenka Piljac-巈garac; Mara Bogovi?; Ksenija Habjani?; Ji? Gr鷝

    2011-01-01

    The accumulation of total phenols (TP, Folin-Ciocalteu method) and total flavonoids (TF, colorimetric assay with AlCl3) and the evolution of antioxidant capacity (FRAP assay, DPPH and ABTS radical scavenging assays) have been monitored in juices of Croatian white cabbage (Brassica oleracea var. capitata) cultivars Vara瀌inski and Ogulinski, as well as Chinese cabbage (Brassica rapa var. pekinensis), at various developmental stages.

  17. Puccinia jaceae var. solstitialis teliospore priming on yellow starthistle.

    PubMed

    Fisher, A J; Aegerter, B J; Gordon, T R; Smith, L; Woods, D M

    2009-01-01

    Following the introduction of Puccinia jaceae var. solstitialis to California for biological control of yellow starthistle (Centaurea solstitialis, Asteraceae), teliospores, pycnia, and multiple urediniospore generations have been observed in the field. Because urediniospores have a relatively short life span in the field, functioning teliospores are expected to be necessary for the permanent establishment of P. jaceae var. solstitialis in California. To determine if conditions in California were conducive to this, teliospore emergence and priming were evaluated in the field. A factorial experiment in the laboratory with five incubation times and three incubation temperatures was used to determine teliospore priming requirements. Teliospore production coincided with plant senescence in August and September at two sites in 2 years; fewer teliospores were produced in 2006, suggesting inconsistent teliospore production may limit population growth and contribute to local extinctions in some areas. When teliospores were primed in the field, germination was low through the fall and abruptly peaked in January during both years. In the laboratory, teliospore germination increased as incubation time increased from 2 to 6 weeks and temperatures decreased from 12 to 4 degrees C. A degree-hour model derived from laboratory data accurately predicts when teliospores are primed for germination in the field. Based on the results obtained in this study, it is apparent that teliospore germination can occur over a range of priming conditions. However, lower temperatures and longer incubation periods are superior in breaking teliospore dormancy. PMID:19055436

  18. Physicochemical traits of Dekoko (Pisum sativum var. abyssinicum) seeds.

    PubMed

    Yemane, Asgedom; Skjelv錱, Arne O

    2003-01-01

    Dekoko (Pisum sativum var. abyssinicum) has high appreciation for its taste and obtains a premium price in local markets compared to Ater (Pisum sativum var. sativum). However, data on the physicochemical traits of Dekoko seeds were lacking. This paper reports on the physicochemical features of Dekoko and compares the results with that of Ater. Seed weight and seed volume were 36 and 30%, respectively, higher in Ater, while water absorption, percent seed swelling, and percent husk were higher in Dekoko. Cooking time was shorter for Dekoko than Ater seeds. Decortication reduced cooking time on average by 39 and 45 min in Dekoko and Ater, respectively. Cotyledon flour of Dekoko contained 251 g crude protein, 19 g fat, 31.7 g total sugars, 370 g starch, and 130 g neutral detergent fiber per kilogram DM. These traits were significantly higher in Dekoko than in Ater, except for starch, which was higher in the latter. Arginine, asparagine, and glutamine occurred in larger proportions, and collectively contributed about 39% to the total amino acids in both varieties. Lysine contributed about 7%, while sulfur containing amino acids constituted about 3.0 and 2.3% of the total amino acids in Dekoko and Ater, respectively. Ca and Mg were higher in Ater, while P was higher in Dekoko. Based on the observations it was concluded that Dekoko is a suitable supplementary protein source for a cereal-based diet. PMID:15354787

  19. A proteomic view of Caenorhabditis elegans caused by short-term hypoxic stress

    Microsoft Academic Search

    Hualing Li; Changhong Ren; Jinping Shi; Xingyi Hang; Feilong Zhang; Yan Gao; Yonghong Wu; Langlai Xu; Changsheng Chen; Chenggang Zhang

    2010-01-01

    BACKGROUND: The nematode Caenorhabditis elegans is both sensitive and tolerant to hypoxic stress, particularly when the evolutionarily conserved hypoxia response pathway HIF-1\\/EGL-9\\/VHL is involved. Hypoxia-induced changes in the expression of a number of genes have been analyzed using whole genome microarrays in C. elegans, but the changes at the protein level in response to hypoxic stress still remain unclear. RESULTS:

  20. CPEB proteins control two key steps in spermatogenesis in C. elegans

    Microsoft Academic Search

    Cameron Luitjens; Maria Gallegos; Brian Kraemer; Judith Kimble; Marvin Wickens

    2000-01-01

    Cytoplasmic polyadenylation element binding (CPEB) proteins bind to and regulate the translation of specific mRNAs. CPEBs from Xenopus, Drosophila, and Spisula participate in oogenesis. In this report, we examine the biological roles of all identifiable CPEB homologs in a single organism, Caenorhabditis elegans. We find four homologs in the C. elegans genome: cbp-1, cpb-2, cpb-3, and fog-1. Surprisingly, two homologs,

  1. Killing of Caenorhabditis elegans by Pseudomonas aeruginosa Used to Model Mammalian Bacterial Pathogenesis

    Microsoft Academic Search

    Man-Wah Tan; Shalina Mahajan-Miklos; Frederick M. Ausubel

    1999-01-01

    We show that a single clinical isolate of the human opportunistic pathogen Pseudomonas aeruginosa (strain PA14), which previously was shown to be pathogenic in mice and plants, also kills Caenorhabditis elegans. The rate of PA14-mediated killing of C. elegans depends on the composition of the agar medium on which PA14 is grown. When PA14 is grown on minimal medium, killing

  2. Hydrogen Sulfide Is an Endogenous Regulator of Aging in Caenorhabditis elegans

    PubMed Central

    Qabazard, Bedoor; Li, Ling; Gruber, Jan; Peh, Meng Teng; Ng, Li Fang; Kumar, Srinivasan Dinesh; Rose, Peter; Tan, Choon-Hong; Dymock, Brian W.; Wei, Feng; Swain, Suresh C.; Halliwell, Barry

    2014-01-01

    Abstract Aims: To investigate the role of endogenous hydrogen sulfide (H2S) in the control of aging and healthspan of Caenorhabditis elegans. Results: We show that the model organism, C. elegans, synthesizes H2S. Three H2S-synthesizing enzymes are present in C. elegans, namely cystathionine ? lyase (CSE), cystathionine ? synthetase, and 3-mercaptopyruvate transferase (MPST or 3-MST). Genetic deficiency of mpst-1 (3-MST orthologue 1), but not cth-2 (CSE orthologue), reduced the lifespan of C. elegans. This effect was reversed by a pharmacological H2S donor (GYY4137). GYY4137 also reduced detrimental age-dependent changes in a range of physiological indices, including pharyngeal contraction and defecation. Treatment of C. elegans with GYY4137 increased the expression of several age-related, stress response, and antioxidant genes, whereas MitoSOX Red fluorescence, indicative of reactive oxygen species generation, was increased in mpst-1 knockouts and decreased by GYY4137 treatment. GYY4137 additionally increased the lifespan in short-lived mev-1 mutants with elevated oxidative stress and protected wild-type C. elegans against paraquat poisoning. The lifespan-prolonging and health-promoting effects of H2S in C. elegans are likely due to the antioxidant action of this highly cell-permeable gas. Innovation: The possibility that novel pharmacological agents based on the principle of H2S donation may be able to retard the onset of age-related disease by slowing the aging process warrants further study. Conclusion: Our results show that H2S is an endogenous regulator of oxidative damage, metabolism, and aging in C. elegans and provide new insight into the mechanisms, which control aging in this model organism. Antioxid. Redox Signal. 20, 26212630. PMID:24093496

  3. Distinct mechanisms for delimiting expression of four Caenorhabditis elegans transcription factor genes encoding activators or repressors

    Microsoft Academic Search

    Sophie Bamps; Julia Wirtz; Ian A. Hope

    2011-01-01

    Regulatory transcription factors operate in networks, conferring biological robustness that makes dissection of such gene\\u000a control processes difficult. The nematode Caenorhabditis elegans is a powerful molecular genetic system that allows the close scrutiny needed to understand these processes in an animal,\\u000a in vivo. Strikingly lower levels of gene expression were observed when a gfp reporter was inserted into C.\\u000a elegans

  4. Shedding of foodborne pathogens by Caenorhabditis elegans in compost-amended and unamended soil

    Microsoft Academic Search

    Gary L. Anderson; Stephen J. Kenney; Patricia D. Millner; Larry R. Beuchat; Phillip L. Williams

    2006-01-01

    A study was done to characterize the shedding of foodborne pathogenic bacteria by Caenorhabditis elegans, evaluate the persistence of worm populations cocultured with foodborne pathogens, and determine if C. elegans disperses ingested pathogens in soil as a result of shedding. Escherichia. coli O157:H7, Salmonella enterica serotype Poona, and Listeria monocytogenes, as well as E. coli OP50, a non-pathogenic strain, were

  5. Caloric restriction, Ins\\/IGF-1 signalling and longevity in the nematode Caenorhabditis elegans

    Microsoft Academic Search

    Koen Houthoofd; Bart P. Braeckman; Annemie De Vreese; Sylvie Van Eygen; Isabelle Lenaerts; Kristel Brys; Filip Matthijssens; Jacques R. Vanfleteren

    2004-01-01

    Several mechanisms of life span extension in C. elegans have been described, including caloric restriction, reduced Ins\\/IGF-1 signalling, Clk mutation and germ line ablation. Here, we describe the effects of caloric restriction on metabolism and life span in C. elegans and examine whether Ins\\/IGF-1 signalling is involved in the life extension observed in calorically restricted worms. We show that life

  6. Homologous and unique G protein alpha subunits in the nematode Caenorhabditis elegans.

    PubMed Central

    Lochrie, M A; Mendel, J E; Sternberg, P W; Simon, M I

    1991-01-01

    A cDNA corresponding to a known G protein alpha subunit, the alpha subunit of Go (Go alpha), was isolated and sequenced. The predicted amino acid sequence of C. elegans Go alpha is 80-87% identical to other Go alpha sequences. An mRNA that hybridizes to the C. elegans Go alpha cDNA can be detected on Northern blots. A C. elegans protein that crossreacts with antibovine Go alpha antibody can be detected on immunoblots. A cosmid clone containing the C. elegans Go alpha gene (goa-1) was isolated and mapped to chromosome I. The genomic fragments of three other C. elegans G protein alpha subunit genes (gpa-1, gpa-2, and gpa-3) have been isolated using the polymerase chain reaction. The corresponding cosmid clones were isolated and mapped to disperse locations on chromosome V. The sequences of two of the genes, gpa-1 and gpa-3, were determined. The predicted amino acid sequences of gpa-1 and gpa-3 are only 48% identical to each other. Therefore, they are likely to have distinct functions. In addition they are not homologous enough to G protein alpha subunits in other organisms to be classified. Thus C. elegans has G proteins that are identifiable homologues of mammalian G proteins as well as G proteins that appear to be unique to C. elegans. Study of identifiable G proteins in C. elegans may result in a further understanding of their function in other organisms, whereas study of the novel G proteins may provide an understanding of unique aspects of nematode physiology. Images PMID:1907494

  7. Many Families of C. elegans MicroRNAs Are Not Essential for Development or Viability

    Microsoft Academic Search

    Ezequiel Alvarez-Saavedra; H. Robert Horvitz

    2010-01-01

    Summary MicroRNAs (miRNAs) are approximately 23 nt regulatory RNAs that posttranscriptionally inhibit the functions of protein-coding mRNAs. We previously found that most C. elegans miRNAs are individually not essential for devel- opment or viability and proposed that paralogous miRNAs might often function redundantly(1).To test this hypothesis, we generated mutant C. elegans strains that each lack multiple or all members of

  8. A conserved checkpoint monitors meiotic chromosome synapsis inCaenorhabditis elegans

    SciTech Connect

    Bhalla, Needhi; Dernburg, Abby F.

    2005-07-14

    We report the discovery of a checkpoint that monitorssynapsis between homologous chromosomes to ensure accurate meioticsegregation. Oocytes containing unsynapsed chromosomes selectivelyundergo apoptosis even if agermline DNA damage checkpoint is inactivated.This culling mechanism isspecifically activated by unsynapsed pairingcenters, cis-acting chromosomesites that are also required to promotesynapsis in Caenorhabditis elegans. Apoptosis due to synaptic failurealso requires the C. elegans homolog of PCH2,a budding yeast pachytenecheckpoint gene, which suggests that this surveillance mechanism iswidely conserved.

  9. A systematic RNAi screen identifies a critical role for mitochondria in C. elegans longevity

    Microsoft Academic Search

    Siu Sylvia Lee; Raymond Y. N. Lee; Andrew G. Fraser; Ravi S. Kamath; Julie Ahringer; Gary Ruvkun

    2002-01-01

    We report a systematic RNA interference (RNAi) screen of 5,690 Caenorhabditis elegans genes for gene inactivations that increase lifespan. We found that genes important for mitochondrial function stand out as a principal group of genes affecting C. elegans lifespan. A classical genetic screen identified a mutation in the mitochondrial leucyl-tRNA synthetase gene (lrs-2) that impaired mitochondrial function and was associated

  10. Leptotene\\/Zygotene Chromosome Movement Via the SUN\\/KASH Protein Bridge in Caenorhabditis elegans

    Microsoft Academic Search

    Antoine Baudrimont; Alexandra Penkner; Alexander Woglar; Thomas Machacek; Christina Wegrostek; Jiradet Gloggnitzer; Alexandra Fridkin; Franz Klein; Yosef Gruenbaum; Pawel Pasierbek; Verena Jantsch

    2010-01-01

    The Caenorhabditis elegans inner nuclear envelope protein matefin\\/SUN-1 plays a conserved, pivotal role in the process of genome haploidization. CHK-2杁ependent phosphorylation of SUN-1 regulates homologous chromosome pairing and interhomolog recombination in Caenorhabditis elegans. Using time-lapse microscopy, we characterized the movement of matefin\\/SUN-1::GFP aggregates (the equivalent of chromosomal attachment plaques) and showed that the dynamics of matefin\\/SUN-1 aggregates remained unchanged throughout

  11. Acanthopanax sessiliflorus stem confers increased resistance to environmental stresses and lifespan extension in Caenorhabditis elegans

    PubMed Central

    Park, Jin-Kook; Kim, Chul-Kyu; Gong, Sang-Ki; Yu, A-Reum; Lee, Mi-Young

    2014-01-01

    BACKGROUND/OBJECTIVES Acanthopanax sessiliflorus is a native Korean plant and used as traditional medicine or an ingredient in many Korean foods. The free radical theory of aging suggests that cellular oxidative stress caused by free radicals is the main cause of aging. Free radicals can be removed by cellular anti-oxidants. MATERIALS/METHODS Here, we examined the anti-oxidant activity of Acanthopanax sessiliflorus extract both in vitro and in vivo. Survival of nematode C. elegans under stress conditions was also compared between control and Acanthopanax sessiliflorus extract-treated groups. Then, anti-aging effect of Acanthopanax sessiliflorus extract was monitored in C. elegans. RESULTS Stem extract significantly reduced oxidative DNA damage in lymphocyte, which was not observed by leaves or root extract. Survival of C. elegans under oxidative-stress conditions was significantly enhanced by Acanthopanax sessiliflorus stem extract. In addition, Acanthopanax sessiliflorus stem increased resistance to other environmental stresses, including heat shock and ultraviolet irradiation. Treatment with Acanthopanax sessiliflorus stem extract significantly extended both mean and maximum lifespan in C. elegans. However, fertility was not affected by Acanthopanax sessiliflorus stem. CONCLUSION Different parts of Acanthopanax sessiliflorus have different bioactivities and stem extract have strong anti-oxidant activity in both rat lymphocytes and C. elegans, and conferred a longevity phenotype without reduced reproduction in C. elegans, which provides conclusive evidence to support the free radical theory of aging. PMID:25324932

  12. Locomotion and Body Shape Changes of Metabolically Different C.elegans in Fluids with Varying Viscosities

    NASA Astrophysics Data System (ADS)

    Wong, Rachel; Brenowitz, Noah; Shen, Amy

    2010-11-01

    Caenorhabditis elegans (C.elegans) are soil dwelling roundworms that have served as model organisms for studying a multitude of biological and engineering phenomena. On agar, the locomotion of the worm is sinusoidal, while in water, the swimming motion of the worm appears more episodic. The efficiency of the worm locomotion is tested by placing the worm in four fluids with varying viscosities. We quantify the locomotion pattern variations by categorizing the swimming kinematics and shapes of the C.elegans. The locomotion of two mutants C.elegans and a control C.elegans was tested: daf2, nhr49, and N2 Wildtype. The metabolic effects of the worms are evaluated by focusing on the forward swimming velocity, wavelength, amplitude and swimming frequency were compared. Using these measured values, we were able to quantify the efficiency, the speed of propagation of the wave along the body resulting in forward movement (wave velocity), and transverse velocity, defined as the amplitude times the frequency, of the worm locomotion. It was shown that C.elegans has a preferential swimming shape that adapts as the environment changes regardless of its efficiency.

  13. Identification of ciliary and ciliopathy genes in Caenorhabditis elegans through comparative genomics

    PubMed Central

    Chen, Nansheng; Mah, Allan; Blacque, Oliver E; Chu, Jeffrey; Phgora, Kiran; Bakhoum, Mathieu W; Hunt Newbury, C Rebecca; Khattra, Jaswinder; Chan, Susanna; Go, Anne; Efimenko, Evgeni; Johnsen, Robert; Phirke, Prasad; Swoboda, Peter; Marra, Marco; Moerman, Donald G; Leroux, Michel R; Baillie, David L; Stein, Lincoln D

    2006-01-01

    Background The recent availability of genome sequences of multiple related Caenorhabditis species has made it possible to identify, using comparative genomics, similarly transcribed genes in Caenorhabditis elegans and its sister species. Taking this approach, we have identified numerous novel ciliary genes in C. elegans, some of which may be orthologs of unidentified human ciliopathy genes. Results By screening for genes possessing canonical X-box sequences in promoters of three Caenorhabditis species, namely C. elegans, C. briggsae and C. remanei, we identified 93 genes (including known X-box regulated genes) that encode putative components of ciliated neurons in C. elegans and are subject to the same regulatory control. For many of these genes, restricted anatomical expression in ciliated cells was confirmed, and control of transcription by the ciliogenic DAF-19 RFX transcription factor was demonstrated by comparative transcriptional profiling of different tissue types and of daf-19(+) and daf-19(-) animals. Finally, we demonstrate that the dye-filling defect of dyf-5(mn400) animals, which is indicative of compromised exposure of cilia to the environment, is caused by a nonsense mutation in the serine/threonine protein kinase gene M04C9.5. Conclusion Our comparative genomics-based predictions may be useful for identifying genes involved in human ciliopathies, including Bardet-Biedl Syndrome (BBS), since the C. elegans orthologs of known human BBS genes contain X-box motifs and are required for normal dye filling in C. elegans ciliated neurons. PMID:17187676

  14. Stereoselective metabolism of anthracene and phenanthrene by the fungus Cunninghamella elegans.

    PubMed Central

    Cerniglia, C E; Yang, S K

    1984-01-01

    The fungus Cunninghamella elegans oxidized anthracene and phenanthrene to form predominately trans-dihydrodiols. The metabolites were isolated by reversed-phase high-pressure liquid chromatography for structural and conformational analyses. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydroanthracene to that formed by rat liver microsomes indicated that the major enantiomer of the trans-1,2-dihydroxy-1,2-dihydroanthracene formed by C. elegans had an S,S absolute stereochemistry, which is opposite to the predominately 1R,2R dihydrodiol formed by rat liver microsomes. C. elegans oxidized phenanthrene primarily in the 1,2-positions to form trans-1,2-dihydroxy-1,2-dihydrophenanthrene. In addition, a minor amount of trans-3,4-dihydroxy-3,4-dihydrophenanthrene was detected. Metabolism at the K-region (9,10-positions) of phenanthrene was not detected. Comparison of the circular dichroism spectra of the phenanthrene trans-1,2- and trans-3,4-dihydrodiols formed by C. elegans to those formed by mammalian enzymes indicated that each of the dihydrodiols formed by C. elegans had an S,S absolute configuration. The results indicate that there are differences in both the regio- and stereoselective metabolism of anthracene and phenanthrene between the fungus C. elegans and rat liver microsomes. PMID:6696409

  15. Solution structure of CEH-37 homeodomain of the nematode Caenorhabditis elegans

    SciTech Connect

    Moon, Sunjin [Structural Biochemistry and Molecular Biophysics Lab, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)] [Structural Biochemistry and Molecular Biophysics Lab, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Yong Woo; Kim, Woo Taek [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)] [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Weontae, E-mail: wlee@spin.yonsei.ac.kr [Structural Biochemistry and Molecular Biophysics Lab, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)] [Structural Biochemistry and Molecular Biophysics Lab, Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2014-01-10

    Highlights: 昗e have determined solution structures of CEH-37 homedomain. 旵EH-37 HD has a compact ?-helical structure with HTH DNA binding motif. 昐olution structure of CEH-37 HD shares its molecular topology with that of the homeodomain proteins. 昍esidues in the N-terminal region and HTH motif are important in binding to Caenorhabditis elegans telomeric DNA. 旵EH-37 could play an important role in telomere function via DNA binding. -- Abstract: The nematode Caenorhabditis elegans protein CEH-37 belongs to the paired OTD/OTX family of homeobox-containing homeodomain proteins. CEH-37 shares sequence similarity with homeodomain proteins, although it specifically binds to double-stranded C. elegans telomeric DNA, which is unusual to homeodomain proteins. Here, we report the solution structure of CEH-37 homeodomain and molecular interaction with double-stranded C. elegans telomeric DNA using nuclear magnetic resonance (NMR) spectroscopy. NMR structure shows that CEH-37 homeodomain is composed of a flexible N-terminal region and three ?-helices with a helix-turn-helix (HTH) DNA binding motif. Data from size-exclusion chromatography and fluorescence spectroscopy reveal that CEH-37 homeodomain interacts strongly with double-stranded C. elegans telomeric DNA. NMR titration experiments identified residues responsible for specific binding to nematode double-stranded telomeric DNA. These results suggest that C. elegans homeodomain protein, CEH-37 could play an important role in telomere function via DNA binding.

  16. Phytologia (August 2013) 95(3) 215 Juniperus communis var. kelleyi, a new variety from North America

    E-print Network

    Adams, Robert P.

    Phytologia (August 2013) 95(3) 215 Juniperus communis var. kelleyi, a new variety from North_Adams@baylor.edu ABSTRACT Recent molecular analysis of Juniperus communis, world-wide (Adams and Schwarzbach, 2012), has: Juniperus communis var. kelleyi R. P. Adams var. nov. in honor of a former student, Walter A. Kelley. Leaf

  17. Mesoscopic organization reveals the constraints governing C. elegans nervous system

    E-print Network

    Pan, Raj Kumar; Sinha, Sitabhra

    2009-01-01

    One of the biggest challenges in biology is to understand how activity at the cellular level of neurons, as a result of their mutual interactions, leads to the observed behavior of an organism responding to a variety of environmental stimuli. Investigating the intermediate or mesoscopic level of organization in the nervous system is a vital step towards understanding how the integration of micro-level dynamics results in macro-level functioning. In this paper, we have considered the somatic nervous system of the nematode Caenorhabditis elegans, for which the entire neuronal connectivity diagram is known. We focus on the organization of the system into modules, i.e., neuronal groups having relatively higher connection density compared to that of the overall network. We show that this mesoscopic feature cannot be explained exclusively in terms of considerations, such as optimizing for resource constraints (viz., total wiring cost) and communication efficiency (i.e., network path length). Comparison with other c...

  18. Genetic interactions affecting touch sensitivity in Caenorhabditis elegans.

    PubMed Central

    Gu, G; Caldwell, G A; Chalfie, M

    1996-01-01

    At least 13 genes (mec-1, mec-2, mec-4-10, mec-12, mec-14, mec-15, and mec-18) are needed for the response to gentle touch by 6 touch receptor neurons in the nematode Caenorhabditis elegans. Several, otherwise recessive alleles of some of these genes act as dominant enhancer mutations of temperature-sensitive alleles of mec-4, mec-5, mec-6, mec-12, and mec-15. Screens for additional dominant enhancers of mec-4 and mec-5 yielded mutations in previously known genes. In addition, some mec-7 alleles showed allele-specific, dominant suppression of the mec-15 touch-insensitive (Mec) phenotype. The dominant enhancement and suppression exhibited by these mutations suggest that the products of several touch genes interact. These results are consistent with a model, supported by the known sequences of these genes, that almost all of the touch function genes contribute to the mechanosensory apparatus. PMID:8692859

  19. Alternative meiotic chromatid segregation in the holocentric plant Luzula elegans

    PubMed Central

    Heckmann, Stefan; Jankowska, Maja; Schubert, Veit; Kumke, Katrin; Ma, Wei; Houben, Andreas

    2014-01-01

    Holocentric chromosomes occur in a number of independent eukaryotic lineages. They form holokinetic kinetochores along the entire poleward chromatid surfaces, and owing to this alternative chromosome structure, species with holocentric chromosomes cannot use the two-step loss of cohesion during meiosis typical for monocentric chromosomes. Here we show that the plant Luzula elegans maintains a holocentric chromosome architecture and behaviour throughout meiosis, and in contrast to monopolar sister centromere orientation, the unfused holokinetic sister centromeres behave as two distinct functional units during meiosis I, resulting in sister chromatid separation. Homologous non-sister chromatids remain terminally linked after metaphase I, by satellite DNA-enriched chromatin threads, until metaphase II. They then separate at anaphase II. Thus, an inverted sequence of meiotic sister chromatid segregation occurs. This alternative meiotic process is most likely one possible adaptation to handle a holocentric chromosome architecture and behaviour during meiosis. PMID:25296379

  20. Alternative meiotic chromatid segregation in the holocentric plant Luzula elegans.

    PubMed

    Heckmann, Stefan; Jankowska, Maja; Schubert, Veit; Kumke, Katrin; Ma, Wei; Houben, Andreas

    2014-01-01

    Holocentric chromosomes occur in a number of independent eukaryotic lineages. They form holokinetic kinetochores along the entire poleward chromatid surfaces, and owing to this alternative chromosome structure, species with holocentric chromosomes cannot use the two-step loss of cohesion during meiosis typical for monocentric chromosomes. Here we show that the plant Luzula elegans maintains a holocentric chromosome architecture and behaviour throughout meiosis, and in contrast to monopolar sister centromere orientation, the unfused holokinetic sister centromeres behave as two distinct functional units during meiosis I, resulting in sister chromatid separation. Homologous non-sister chromatids remain terminally linked after metaphase I, by satellite DNA-enriched chromatin threads, until metaphase II. They then separate at anaphase II. Thus, an inverted sequence of meiotic sister chromatid segregation occurs. This alternative meiotic process is most likely one possible adaptation to handle a holocentric chromosome architecture and behaviour during meiosis. PMID:25296379

  1. How Does C. elegans Respond to Altered Gravity?

    NASA Technical Reports Server (NTRS)

    Conley, Catharine A.; Udranszky, Ingrid; Hoffman, David; Kim, Stuart K.

    2001-01-01

    All organisms on Earth have evolved at unit gravity (1xG), and thus are probably adapted to function optimally at 1xG. However, with the advent of space exploration, it has been shown that organisms are capable of surviving at much less than 1xG, as well as at greater than 1xG. Organisms subjected to increased G levels exhibit alterations in physiological processes that compensate for novel environmental stresses, such as increased weight and density-driven sedimentation. These physiological adaptations illustrate the plasticity of organisms when presented with environmental conditions in which they could not possibly have evolved. Investigating the mechanism(s) behind these adaptations may uncover biological pathways that have not previously been identified. An easily-cultured and well-studied organism, such as C. elegans, would be a desirable model system for these studies. Additional information is contained in the original extended abstract.

  2. A quantifiably complete repertoire of C. elegans locomotion

    NASA Astrophysics Data System (ADS)

    Brown, Andre; Schwarz, Roland; Branicky, Robyn; Schafer, William

    2014-03-01

    Visible phenotypes have played a critical role in understanding the molecular basis of behaviour in model organisms. However, most current descriptions of behaviour are based on manually identified events or a limited set of quantitative parameters. Here we report an extension of the concept of behavioural motifs to exhaustively catalogue C. elegans locomotion and derive a repertoire that is quantifiably complete. A repertoire learned for spontaneous behaviour in wild-type worms can be used to fit data from mutants or worms in different environmental conditions and provides a sensitive measure of phenotypic similarity. Repertoire comparison can also be used to assess inter-individual variation and the compositionality of behaviour, that is, the extent to which behavioural adaptation involves the creation of novel repertoire elements or the reuse of existing elements in novel sequences. Repertoire derivation is general, so that given a representation of posture, our approach will apply to other organisms.

  3. Iron promotes protein insolubility and aging in C. elegans

    PubMed Central

    Klang, Ida M.; Schilling, Birgit; Sorensen, Dylan J.; Sahu, Alexandria K.; Kapahi, Pankaj; Andersen, Julie K.; Swoboda, Peter; Killilea, David W.; Gibson, Bradford W.; Lithgow, Gordon J.

    2014-01-01

    Many late-onset proteotoxic diseases are accompanied by a disruption in homeostasis of metals (metallostasis) including iron, copper and zinc. Although aging is the most prominent risk factor for these disorders, the impact of aging on metallostasis and its role in proteotoxic disease remain poorly understood. Moreover, it is not clear whether a loss of metallostasis influences normal aging. We have investigated the role of metallostasis in longevity of Caenorhabditis elegans. We found that calcium, copper, iron, and manganese levels increase as a function of age, while potassium and phosphorus levels tend to decrease. Increased dietary iron significantly accelerated the age-related accumulation of insoluble protein, a molecular pathology of aging. Proteomic analysis revealed widespread effects of dietary iron in multiple organelles and tissues. Pharmacological interventions to block accumulation of specific metals attenuated many models of proteotoxicity and extended normal lifespan. Collectively, these results suggest that a loss of metallostasis with aging contributes to age-related protein aggregation. PMID:25554795

  4. Electrical Activity and Behavior in the Pharynx of Caenorhabditis elegans

    PubMed Central

    Raizen, David M.; Avery, Leon

    2015-01-01

    Summary The pharynx of C. elegans, a model system for neural networks and for membrane excitability, has been chiefly studied by observing its behavior in normal worms, in mutant worms, and in worms lacking pharyngeal neurons. To complement this behavioral approach, we devised a method for recording currents produced by changes in pharyngeal muscle membrane potential. The electrical records, called electropharyngeograms, contain transients caused by pharyngeal muscle action potentials and by inhibitory synaptic transmission between pharyngeal neuron M3 and the muscle. Using the electropharyngeograms, we show that ?-aminobutyric acid is not likely to be the M3 neurotransmitter, that synaptic transmission is present but abnormal in mutants lacking synaptotagmin, and that worms mutant in the eat-4 gene are defective for M3 function or transmission. PMID:8155316

  5. Axon Regeneration Genes Identified by RNAi Screening in C. elegans

    PubMed Central

    Nix, Paola; Hammarlund, Marc; Hauth, Linda; Lachnit, Martina; Jorgensen, Erik M.

    2014-01-01

    Axons of the mammalian CNS lose the ability to regenerate soon after development due to both an inhibitory CNS environment and the loss of cell-intrinsic factors necessary for regeneration. The complex molecular events required for robust regeneration of mature neurons are not fully understood, particularly in vivo. To identify genes affecting axon regeneration in Caenorhabditis elegans, we performed both an RNAi-based screen for defective motor axon regeneration in unc-70/?-spectrin mutants and a candidate gene screen. From these screens, we identified at least 50 conserved genes with growth-promoting or growth-inhibiting functions. Through our analysis of mutants, we shed new light on certain aspects of regeneration, including the role of ?-spectrin and membrane dynamics, the antagonistic activity of MAP kinase signaling pathways, and the role of stress in promoting axon regeneration. Many gene candidates had not previously been associated with axon regeneration and implicate new pathways of interest for therapeutic intervention. PMID:24403161

  6. Comprehensive analysis of mutually exclusive alternative splicing in C. elegans

    PubMed Central

    Kuroyanagi, Hidehito; Takei, Satomi; Suzuki, Yutaka

    2014-01-01

    Mutually exclusive selection of one exon in a cluster of exons is a rare form of alternative pre-mRNA splicing, yet suggests strict regulation. However, the repertoires of regulation mechanisms for the mutually exclusive (ME) splicing in vivo are still unknown. Here, we experimentally explore putative ME exons in C. elegans to demonstrate that 29 ME exon clusters in 27 genes are actually selected in a mutually exclusive manner. Twenty-two of the clusters consist of homologous ME exons. Five clusters have too short intervening introns to be excised between the ME exons. Fidelity of ME splicing relies at least in part on nonsense-mediated mRNA decay for 14 clusters. These results thus characterize all the repertoires of ME splicing in this organism. PMID:25254147

  7. Axon regeneration genes identified by RNAi screening in C. elegans.

    PubMed

    Nix, Paola; Hammarlund, Marc; Hauth, Linda; Lachnit, Martina; Jorgensen, Erik M; Bastiani, Michael

    2014-01-01

    Axons of the mammalian CNS lose the ability to regenerate soon after development due to both an inhibitory CNS environment and the loss of cell-intrinsic factors necessary for regeneration. The complex molecular events required for robust regeneration of mature neurons are not fully understood, particularly in vivo. To identify genes affecting axon regeneration in Caenorhabditis elegans, we performed both an RNAi-based screen for defective motor axon regeneration in unc-70/?-spectrin mutants and a candidate gene screen. From these screens, we identified at least 50 conserved genes with growth-promoting or growth-inhibiting functions. Through our analysis of mutants, we shed new light on certain aspects of regeneration, including the role of ?-spectrin and membrane dynamics, the antagonistic activity of MAP kinase signaling pathways, and the role of stress in promoting axon regeneration. Many gene candidates had not previously been associated with axon regeneration and implicate new pathways of interest for therapeutic intervention. PMID:24403161

  8. Radiation-induced gene expression in the nematode Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.

    2002-01-01

    We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing radiation in a simple animal model emphasizing the unique effects of charged particle radiation. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of radiation. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of radiation. A novel statistical clustering technique identified the regulatory relationships between the radiation-modulated genes and showed that genes affected by each radiation species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to radiation exposure as a function of track structure or ionization density.

  9. Ultrastructural imaging of cell fusion in Caenorhabditis elegans.

    PubMed

    Ems, Star; Mohler, William A

    2008-01-01

    Caenorhabditis elegans is a well-established model system particularly suited for studying cell-cell fusion because of its highly predictable and rapid development and its known cell lineage. This chapter focuses on understanding the ultrastructural components of cell fusion through the use of transmission electron microscopy (TEM). Published TEM studies have described the initial demonstration of syncytial cells in the worm, the vesiculation of the bilayers between cells during widening of the normal fusion aperture, and the appearance of microfusion intermediates in the membranes of cells with fusion-defective mutations. Capturing events observed in embryos on the light microscope and preserving the integrity of cellular membranes for examination by TEM require some special considerations that differ from many ultrastructural studies of cells. The principles of different techniques for TEM and details of protocols that have been used to investigate cell fusion in the nematode are discussed in this chapter. PMID:18979248

  10. In vitro biological screening of the stem of Desmodium elegans

    PubMed Central

    Khan, Arshad; Usman, Rabia; Rauf, Abdur; Wang, Ming-Liang; Muhammad, Naveed; Aman, Akhatar; Tahir, Taha Hussein Musa

    2013-01-01

    Objective To explore the medicinal importance of the stem of Desmodium elegans, methanolic extract, and its different solvent fractions were evaluated for brine shrimp lethality, insecticidal and phytotoxicity, antifungal, and antibacterial activities. Methods The methanolic extract and its solvent fractions were tested for cytotoxic, phytotoxic, insecticidal, antifungal, and antibacterial effects using our previous published protocols. Results The methanolic, DCM, ethyl acetate and n-butanol fractions exhibited insecticidal effect against Callosobruchus analis and Rhyzopertha dominic. The methanolic extract, n-hexane, DCM ethyl acetate and n-butanol showed 75, 85, 85, 65 and 5% phytotoxicity at the tested concentration of 500 礸/mL respectively. The solvent fractions (DCM and ethyl acetate) were effective against F. solani (10% and 20% inhibition respectively). All the tested samples were devoid of cytotoxic and antibacterial effects. Conclusion It was concluded that this plant can be practiced for control of weeds and insects. PMID:23998011

  11. Genetic Analysis of Lysosomal Trafficking in Caenorhabditis elegans

    PubMed Central

    Hermann, Greg J.; Schroeder, Lena K.; Hieb, Caroline A.; Kershner, Aaron M.; Rabbitts, Beverley M.; Fonarev, Paul; Grant, Barth D.; Priess, James R.

    2005-01-01

    The intestinal cells of Caenorhabditis elegans embryos contain prominent, birefringent gut granules that we show are lysosome-related organelles. Gut granules are labeled by lysosomal markers, and their formation is disrupted in embryos depleted of AP-3 subunits, VPS-16, and VPS-41. We define a class of gut granule loss (glo) mutants that are defective in gut granule biogenesis. We show that the glo-1 gene encodes a predicted Rab GTPase that localizes to lysosome-related gut granules in the intestine and that glo-4 encodes a possible GLO-1 guanine nucleotide exchange factor. These and other glo genes are homologous to genes implicated in the biogenesis of specialized, lysosome-related organelles such as melanosomes in mammals and pigment granules in Drosophila. The glo mutants thus provide a simple model system for the analysis of lysosome-related organelle biogenesis in animal cells. PMID:15843430

  12. A transcribed polyketide synthase gene from Xanthoria elegans.

    PubMed

    Brunauer, Georg; Muggia, Lucia; Stocker-W鰎g鰐ter, Elfie; Grube, Martin

    2009-01-01

    We characterize the transcript of a polyketide synthase gene (PKS) from the cultured mycobiont of Xanthoria elegans (XePKS1) using SMART-rapid amplification of cDNA ends (RACE) cDNA synthesis. Sequence analysis of the cloned cDNA reveals an open reading frame of 2144 amino acid residues. It contains features of a non-reducing fungal type I PKS with an N-terminal starter unit: acyl carrier protein (ACP) transacetylase domain, ketosynthase, acyltransferase, two acyl carrier protein domains, and a thioesterase domain. XePKS1 was the only paralogue detected in the cDNA and the genomic DNA of the cultured X. elegans mycobiont by using a degenerate PCR approach targeted at the conserved regions of non-reducing type I PKS genes. The hypothetical protein is phylogenetically related to genes that are basal to a clade of dihydroxynaphthalene synthases (non-reducing clade II) and anthraquinone type synthases of non-lichenized fungi (non-reducing clade I). According to hplc and tlc analyses, the cultured mycobiont exclusively produced anthraquinones and its precursors. Therefore, we discuss whether the characterized paralogue is involved in anthraquinone production, which raises the possibility of a paraphyletic origin of lichen anthraquinone biosynthesis. The cDNA of XePKS1 was the first full-length coding sequence of a lichen PKS to be published. This proves SMART RACE to be a suitable tool for obtaining full-length coding sequences of genes from environmental samples and organisms, which are hardly amenable to standard molecular approaches or genomic sequencing. PMID:18822374

  13. Genome-wide analysis of condensin binding in Caenorhabditis elegans

    PubMed Central

    2013-01-01

    Background Condensins are multi-subunit protein complexes that are essential for chromosome condensation during mitosis and meiosis, and play key roles in transcription regulation during interphase. Metazoans contain two condensins, I and II, which perform different functions and localize to different chromosomal regions. Caenorhabditis elegans contains a third condensin, IDC, that is targeted to and represses transcription of the X chromosome for dosage compensation. Results To understand condensin binding and function, we performed ChIP-seq analysis of C. elegans condensins in mixed developmental stage embryos, which contain predominantly interphase nuclei. Condensins bind to a subset of active promoters, tRNA genes and putative enhancers. Expression analysis in kle-2-mutant larvae suggests that the primary effect of condensin II on transcription is repression. A DNA sequence motif, GCGC, is enriched at condensin II binding sites. A sequence extension of this core motif, AGGG, creates the condensin IDC motif. In addition to differences in recruitment that result in X-enrichment of condensin IDC and condensin II binding to all chromosomes, we provide evidence for a shared recruitment mechanism, as condensin IDC recruiter SDC-2 also recruits condensin II to the condensin IDC recruitment sites on the X. In addition, we found that condensin sites overlap extensively with the cohesin loader SCC-2, and that SDC-2 also recruits SCC-2 to the condensin IDC recruitment sites. Conclusions Our results provide the first genome-wide view of metazoan condensin II binding in interphase, define putative recruitment motifs, and illustrate shared loading mechanisms for condensin IDC and condensin II. PMID:24125077

  14. Identification of a Nuclear Carbonic Anhydrase in Caenorhabditis elegans

    PubMed Central

    Sherman, Teresa A.; Rongali, Sharath; Matthews, Tori A.; Pfeiffer, Jason; Nehrke, Keith

    2012-01-01

    Background Carbonic anhydrases (CA) catalyze the inter-conversion of CO2 with HCO3 and H+, and are involved in a wide variety of physiologic processes such as anion transport, pH regulation, and water balance. In mammals there are sixteen members of the classical ?-type CA family, while the simple genetic model organism C. elegans codes for six ?CA isoforms (cah-1 through cah-6). Methods Fluorescent reporter constructs were used to analyze gene promoter usage, splice variation, and protein localization in transgenic worms. Catalytic activity of recombinant CA proteins was assessed using Hanssons histochemistry. CA抯 ability to regulate pH as a function of CO2 and HCO3 was measured using dynamic fluorescent imaging of genetically-targeted biosensors. Results Each of the six CA genes was found to be expressed in a distinct repertoire of cell types. Surprisingly, worms also expressed a catalytically-active CA splice variant, cah-4a, in which an alternative first exon targeted the protein to the nucleus. Cah-4a expression was restricted mainly to the nervous system, where it was found in nearly all neurons, and recombinant CAH-4A protein could regulate pH in the nucleus. Conclusions In addition to establishing C. elegans as a platform for studying ?CA function, this is the first example of a nuclear-targeted ?CA in any organism to date. General Significance A classical ?CA isoform is targeted exclusively to the nucleus where its activity may impact nuclear physiologic and pathophysiologic responses. PMID:22245567

  15. Candida albicans Infection of Caenorhabditis elegans Induces Antifungal Immune Defenses

    PubMed Central

    Pukkila-Worley, Read

    2011-01-01

    Candida albicans yeast cells are found in the intestine of most humans, yet this opportunist can invade host tissues and cause life-threatening infections in susceptible individuals. To better understand the host factors that underlie susceptibility to candidiasis, we developed a new model to study antifungal innate immunity. We demonstrate that the yeast form of C. albicans establishes an intestinal infection in Caenorhabditis elegans, whereas heat-killed yeast are avirulent. Genome-wide, transcription-profiling analysis of C. elegans infected with C. albicans yeast showed that exposure to C. albicans stimulated a rapid host response involving 313 genes (124 upregulated and 189 downregulated, ?1.6% of the genome) many of which encode antimicrobial, secreted or detoxification proteins. Interestingly, the host genes affected by C. albicans exposure overlapped only to a small extent with the distinct transcriptional responses to the pathogenic bacteria Pseudomonas aeruginosa or Staphylococcus aureus, indicating that there is a high degree of immune specificity toward different bacterial species and C. albicans. Furthermore, genes induced by P. aeruginosa and S. aureus were strongly over-represented among the genes downregulated during C. albicans infection, suggesting that in response to fungal pathogens, nematodes selectively repress the transcription of antibacterial immune effectors. A similar phenomenon is well known in the plant immune response, but has not been described previously in metazoans. Finally, 56% of the genes induced by live C. albicans were also upregulated by heat-killed yeast. These data suggest that a large part of the transcriptional response to C. albicans is mediated through 損attern recognition, an ancient immune surveillance mechanism able to detect conserved microbial molecules (so-called pathogen-associated molecular patterns or PAMPs). This study provides new information on the evolution and regulation of the innate immune response to divergent pathogens and demonstrates that nematodes selectively mount specific antifungal defenses at the expense of antibacterial responses. PMID:21731485

  16. Mechanisms of plasticity in a Caenorhabditis elegans mechanosensory circuit

    PubMed Central

    Bozorgmehr, Tahereh; Ardiel, Evan L.; McEwan, Andrea H.; Rankin, Catharine H.

    2012-01-01

    Despite having a small nervous system (302 neurons) and relatively short lifespan (1421 days), the nematode Caenorhabditis elegans has a substantial ability to change its behavior in response to experience. The behavior discussed here is the tap withdrawal response, whereby the worm crawls backwards a brief distance in response to a non-localized mechanosensory stimulus from a tap to the side of the Petri plate within which it lives. The neural circuit that underlies this behavior is primarily made up of five sensory neurons and four pairs of interneurons. In this review we describe two classes of mechanosensory plasticity: adult learning and memory and experience dependent changes during development. As worms develop through young adult and adult stages there is a shift toward deeper habituation of response probability that is likely the result of changes in sensitivity to stimulus intensity. Adult worms show short- intermediate- and long-term habituation as well as context dependent habituation. Short-term habituation requires glutamate signaling and auto-phosphorylation of voltage-dependent potassium channels and is modulated by dopamine signaling in the mechanosensory neurons. Long-term memory (LTM) for habituation is mediated by down-regulation of expression of an AMPA-type glutamate receptor subunit. Intermediate memory involves an increase in release of an inhibitory neuropeptide. Depriving larval worms of mechanosensory stimulation early in development leads to fewer synaptic vesicles in the mechanosensory neurons and lower levels of an AMPA-type glutamate receptor subunit in the interneurons. Overall, the mechanosensory system of C. elegans shows a great deal of experience dependent plasticity both during development and as an adult. The simplest form of learning, habituation, is not so simple and is mediated and/or modulated by a number of different processes, some of which we are beginning to understand. PMID:23986713

  17. iVAR: a program for imputing missing data in multivariate time series using vector autoregressive models.

    PubMed

    Liu, Siwei; Molenaar, Peter C M

    2014-12-01

    This article introduces iVAR, an R program for imputing missing data in multivariate time series on the basis of vector autoregressive (VAR) models. We conducted a simulation study to compare iVAR with three methods for handling missing data: listwise deletion, imputation with sample means and variances, and multiple imputation ignoring time dependency. The results showed that iVAR produces better estimates for the cross-lagged coefficients than do the other three methods. We demonstrate the use of iVAR with an empirical example of time series electrodermal activity data and discuss the advantages and limitations of the program. PMID:24515888

  18. Anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidea and var. angustifolia on 3T3-L1 adipocytes*

    PubMed Central

    Woon, Shiau Mei; Seng, Yew Wei; Ling, Anna Pick Kiong; Chye, Soi Moi; Koh, Rhun Yian

    2014-01-01

    Objective: This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes. Methods: Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content (TFC) and total phenolic content (TPC), respectively. The study was initiated by determining the maximum non-toxic dose (MNTD) of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD (組NTD), after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density (OD) at 520 nm, respectively. Results: The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents (QE)/100 g dry weight (DW), while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents (GAE)/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were (300.028.3) and (225.021.2) ?g/ml, respectively, for var. deltoidea, while much lower MNTDs [(60.02.0) ?g/ml for methanol extracts and (8.01.0) ?g/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or 組NTD significantly inhibited the maturation of preadipocytes. Conclusions: The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects. PMID:24599694

  19. Podocarpane, isopimarane, and abietane diterpenoids from Isodon lophanthoides var. graciliflorus.

    PubMed

    Liang, Yaoguang; Xie, Haihui; Wu, Ping; Jiang, Yueming; Wei, Xiaoyi

    2013-02-15

    Four new diterpenoids including two podocarpanes, graciliflorins A (1) and B (2), an isopimarane acetal, graciliflorin C (3), and a rearranged abietane, graciliflorin D (4) were isolated from the aerial parts of Isodon lophanthoides var. graciliflorus (Lamiaceae) along with podocarpa-8,11,13-triene-3?,13-diol (5) and micranthin B (6). Their structures were elucidated based on the spectroscopic data. The in vitro cytotoxicity of compounds 1-4 and 6 against human carcinoma A549, MCF-7, and HeLa cell lines were evaluated using the MTT colourimetric assay. Micranthin B (6) showed moderate activity against all the cells with IC(50) values of 16.29, 18.20, and 22.25 ?M, while compounds 1-4 were inactive (IC(50)>50 ?g/ml). PMID:23194512

  20. Antiplasmodial sesquiterpenes from the seeds of Salacia longipes var. camerunensis.

    PubMed

    Mba'ning, Brice M; Lenta, Bruno N; Noungou, Diderot T; Antheaume, Cyril; Fongang, Yanick F; Ngouela, Silv鑢e A; Boyom, Fabrice F; Rosenthal, Philip J; Tsamo, Etienne; Sewald, Norbert; Laatsch, Hartmut

    2013-12-01

    Phytochemical investigation of the seeds of Salacia longipes var. camerunensis led to the isolation of four sesquiterpenoid derivatives, salaterpene A (1) (1?,2?,8?-triacetoxy-6?,9?-dibenzoyloxy-4?-hydroxy-dihydro-?-agarofuran), salaterpene B (2) (1?,2?,8?-triacetoxy-9?-benzoyloxy-6?-cinnamoyloxy-4?-hydroxy-dihydro-?-agarofuran), salaterpene C (3) (1?,2?-diacetoxy-6?,9?-dibenzoyloxy-4?-hydroxy-dihydro-?-agarofuran) and salaterpene D (4) (2?-acetoxy-1?,6?-dibenzoyloxy-4?-hydroxy-9?-nicotinoyloxy-dihydro-?-agarofuran) together with two known compounds (5 and 6). The structures of the compounds were established by means of NMR spectroscopy. Compounds 1-4 and 6 were tested in vitro for their antiplasmodial activity against Plasmodium falciparum chloroquine-resistant strain W2. All the tested compounds exhibited a moderate potency with IC50 below 2.7 ?M. PMID:23863332

  1. Utilization of Leek (Allium ampeloprasum var. porrum) for inulinase production.

    PubMed

    Tasar, Ozden Canli; Erdal, Serkan; Algur, Omer Faruk

    2015-08-18

    Inulinase production by Rhodotorula glutinis was carried out in this study, using leek (Allium ampeloprasum var. porrum) as an alternative carbon source due to its high inulin content and easy availability. Taguchi orthogonal array (OA) design of experiment (DOE) was used to optimize fermentation conditions. For this purpose, five influential factors (leek concentration, pH, incubation temperature, agitation speed, and fermentation time) related to inulinase production were selected at four convenient levels. The results showed that maximum inulinase activity was obtained as 30.89燯/mL, which was close to the predicted result (30.24燯/mL). To validate the obtained results, analysis of variance (ANOVA) was employed. Consequently, leek has a great potential as an effective and economical carbon source for inulinase production, and the use of Taguchi DOE enhanced enzyme activity about 2.87-fold when compared with the unoptimized condition. PMID:25036570

  2. Genetic relationships and population structure of the endangered Steamboat buckwheat, Eriogonum ovalifolium var. williamsiae (Polygonaceae).

    PubMed

    Archibald, J K; Wolf, P G; Tepedino, V J; Bair, J

    2001-04-01

    Eriogonum ovalifolium var. williamsiae (Steamboat buckwheat) is a narrow endemic subshrub, known from a single locality in Washoe County, Nevada. We examined genetic structure of the only known population by analyzing patterns of allozyme variation. Our results suggest that Steamboat buckwheat has high genetic variability, with levels of variation similar to that typical of a widespread species rather than a narrow endemic. Genotype frequencies suggest that mating is random. We detected no genetic subdivision of the population. Several clones spanning up to 67 cm were found, but we do not know if such clones are common. We used allozyme data to assess the genetic similarity of var. williamsiae to five other varieties of E. ovalifolium. All six varieties are very similar allozymically with var. williamsiae being the most similar to the widespread var. ovalifolium. Although var. williamsiae and var. ovalifolium are morphologically distinct, their genetic similarity warrants further study to determine whether or not they should be treated as separate taxa. Evidence of male sterility in var. williamsiae plus other data leads us to hypothesize that this taxon might be either a hybrid or undergoing cytoplasmic introgression. Information gathered from this study, in concert with ongoing work on the breeding system of Steamboat buckwheat, should be helpful in forming management strategies for this plant. PMID:11302845

  3. RNAi screening of human glycogene orthologs in the nematode Caenorhabditis elegans and the construction of the C. elegans glycogene database.

    PubMed

    Akiyoshi, Sayaka; Nomura, Kazuko H; Dejima, Katsufumi; Murata, Daisuke; Matsuda, Ayako; Kanaki, Nanako; Takaki, Tetsuro; Mihara, Hiroyuki; Nagaishi, Takayuki; Furukawa, Shuhei; Ando, Keiko-Gengyo; Yoshina, Sawako; Mitani, Shohei; Togayachi, Akira; Suzuki, Yoshinori; Shikanai, Toshihide; Narimatsu, Hisashi; Nomura, Kazuya

    2015-01-01

    In this study, we selected 181 nematode glycogenes that are orthologous to human glycogenes and examined their RNAi phenotypes. The results are deposited in the Caenorhabditis elegans Glycogene Database (CGGDB) at AIST, Tsukuba, Japan. The most prominent RNAi phenotypes observed are disruptions of cell cycle progression in germline mitosis/meiosis and in early embryonic cell mitosis. Along with the previously reported roles of chondroitin proteoglycans, glycosphingolipids and GPI-anchored proteins in cell cycle progression, we show for the first time that the inhibition of the functions of N-glycan synthesis genes (cytoplasmic alg genes) resulted in abnormal germline formation, ER stress and small body size phenotypes. The results provide additional information on the roles of glycoconjugates in the cell cycle progression mechanisms of germline and embryonic cells. PMID:25091817

  4. PROPERTIES OF PROTEINASE FROM STREPTOCOCCUS FAECALIS VAR. LIQUEFACIENS1

    PubMed Central

    Bleiweis, Arnold S.; Zimmerman, Leonard N.

    1964-01-01

    Bleiweis, Arnold S. (The Pennsylvania State University, University Park), and Leonard N. Zimmerman. Properties of proteinase from Streptococcus faecalis var. liquefaciens. J. Bacteriol. 88:653659. 1964.桾he extracellular group D streptococcal proteinase is inactivated by chelating agents [ethylenediamine-tetraacetate (EDTA), o-phenanthroline, and 8-quinolinol] and mercaptans (cysteine, mercaptoethanol, and thioglycolate). The optimal inhibitory concentrations of EDTA (4 10?4m) and cysteine (2.5 10?2m) promote rapid loss of activity with 50% inactivation after 4 to 5 min. Enzyme inactivated by either EDTA or cysteine is reactivated about 80% by 4 10?4m Zn++. Such reactivation of EDTA-treated enzyme is prevented completely by iodoacetate (5 10?2m) and of cysteine-treated enzyme by oxidizing conditions, which suggests that the zinc binding-site may be a thiol. High levels of zinc (10?3m) do not allow reactivation in either case, and actually inhibit native proteinase. Ca++, Mg++, Co++, Fe++, Cu++, and Ni++ do not reactivate cysteine-treated enzyme, but Mn++ (10?4 to 8 10?4m) allows 27% reversal. N2-held, cysteine-treated enzyme can be spontaneously reactivated if the substrate is flushed with O2 during the assay; leakage of air or O2 into the samples before assay leads to loss of reactivatability. Native proteinase does not lose activity after dialysis for 43 hr against 0.07 m phosphate buffer. It is concluded that the group D proteinase obtained from Streptococcus faecalis var. liquefaciens is probably a zinc metalloenzyme that is unlike the thiol-activated, group A streptococcal proteinase, but similar to the mammalian carboxypeptidase A. PMID:14208503

  5. Chemistry and biological activities of Tanacetum chiliophyllum var. oligocephalum extracts.

    PubMed

    Polato?lu, Kaan; Karako, Omer Cem; Demirci, Fatih; G鰇鏴, Ayhan; G鰎en, Nezhun

    2013-01-01

    Tanacetum chiliophyllum (Fisch. & Mey.) var. oligocephalum (D.C.) Sosn. collected in Turkey was subjected to phytochemical and biological evaluations in this study. Pure compounds were obtained from ethyl acetate extracts of the stems of the plant material. Structures of isolated compounds were determined using spectral methods. Seven known flavones, i.e., 5-hydroxy-3',4',6,7-tetramethoxyflavone, eupatilin (6-hydroxyluteolin-6,3',4'-trimethylether), cirsimaritin (scuttellarin-6,7-dimethylether), cirsilineol, 5-hydroxy-3',4',7-trimethoxy flavone, desmethoxy-centaureidin, and jaceosidin and one known triterpene, taraxasterol acetate, were identified from the ethyl acetate extracts. The first seven compounds, as well as the ethyl acetate and methanol extracts, were also investigated for their insecticidal, antimicrobial, and 1,1-diphenyl-2-picrylhydrazil radical (DPPH)-scavenging activities. The insecticidal contact toxicity of the extracts were evaluated on Sitophilus granarius. The ethyl acetate (81.8%) and methanol (88.4%) extracts of T. chiliophyllum var. oligocephalum showed high toxicity against this pest. Most promising antimicrobial activity was observed for ethyl acetate extracts of the stems against Bacillus cereus. This extract showed the same inhibition concentration (125 microL/mg) with the positive control chloramphenicol. The ethyl acetate (91.9%) and methanol (93%) extracts of the stems showed significant DPPH-scavenging activity compared with the positive controls alpha-tocopherol (94.5%) and butylated hydroxytoluene (92.9%) at 10 mg/mL concentration. Among the isolated compounds, the highest DPPH-scavenging activity was observed for jaceosidin at 1 mg/mL concentration (81.5%). PMID:24645497

  6. Aberrant meiotic behavior in Agave tequilana Weber var. azul

    PubMed Central

    Ruvalcaba-Ruiz, Domingo; Rodr韌uez-Garay, Benjamin

    2002-01-01

    Background Agave tequilana Weber var. azul, is the only one variety permitted by federal law in M閤ico to be used for tequila production which is the most popular contemporary alcoholic beverage made from agave and recognized worldwide. Despite the economic, genetic, and ornamental value of the plant, it has not been subjected to detailed cytogenetic research, which could lead to a better understanding of its reproduction for future genetic improvement. The objective of this work was to study the meiotic behavior in pollen mother cells and its implications on the pollen viability in Agave tequilana Weber var. azul. Results The analysis of Pollen Mother Cells in anaphase I (A-I) showed 82.56% of cells with a normal anaphase and, 17.44% with an irregular anaphase. In which 5.28% corresponded to cells with side arm bridges (SAB); 3.68% cells with one bridge and one fragment; 2.58% of irregular anaphase showed cells with one or two lagging chromosomes and 2.95% showed one acentric fragment; cells with two bridges and cells with two bridges and one acentric fragment were observed in frequencies of 1.60% and 1.35% respectively. In anaphase II some cells showed bridges and fragments too. Aberrant A-I cells had many shrunken or empty pollen grains (42.00%) and 58.00 % viable pollen. Conclusion The observed meiotic irregularities suggest that structural chromosome aberrations have occurred, such as heterozygous inversions, sister chromatid exchanges, deletions and duplications which in turn are reflected in a low pollen viability. PMID:12396234

  7. Vellai et al., 2006 Sex bias in learning in C. elegans Effects of sex and insulin/IGF-1 signaling on performance in

    E-print Network

    Gems, David

    Vellai et al., 2006 Sex bias in learning in C. elegans 1 Effects of sex and insulin/IGF-1 signaling with reduced insulin/IGF-1 signaling (IIS) also exhibit a greatly reduced learning ability in this learning. elegans Key words: Caenorhabditis elegans, learning, memory, behavioral plasticity, sex bias, insulin/IGF

  8. The C. elegans Zonula Occludens Ortholog ZOO-1 Cooperates with the Cadherin-Catenin Complex to Recruit Actin during

    E-print Network

    Zaidel-Bar, Ronen

    The C. elegans Zonula Occludens Ortholog ZOO-1 Cooperates with the Cadherin-Catenin Complex embryo, we have characterized the sole C. elegans ZO family member, ZOO-1. ZOO-1 localizes proteins HMR- 1/E-cadherin and VAB-9/claudin, but surprisingly, not HMP-1/-catenin or HMP-2/-catenin. zoo-1

  9. A Comparative Study of Fat Storage Quantitation in Nematode Caenorhabditis elegans Using Label and Label-Free Methods

    Microsoft Academic Search

    Kelvin Yen; Thuc T. Le; Ankita Bansal; Sri Devi Narasimhan; Ji-Xin Cheng; Heidi A. Tissenbaum; Simon Melov

    2010-01-01

    The nematode Caenorhabditis elegans has been employed as a model organism to study human obesity due to the conservation of the pathways that regulate energy metabolism. To assay for fat storage in C. elegans, a number of fat-soluble dyes have been employed including BODIPY, Nile Red, Oil Red O, and Sudan Black. However, dye-labeled assays produce results that often do

  10. Migration of Caenorhabditis elegans to manure and manure compost and potential for transport of Salmonella newport to fruits and vegetables

    Microsoft Academic Search

    Stephen J. Kenney; Gary L. Anderson; Phillip L. Williams; Patricia D. Millner; Larry R. Beuchat

    2006-01-01

    A study was done to determine if a free-living, bacterivorous nematode, Caenorhabditis elegans, migrates to bovine manure, turkey manure, composted bovine manure, composted turkey manure, and manure-amended soil inoculated with Salmonella Newport. Movement of the worm to lettuce, strawberries, and carrots was also studied. C. elegans moved most rapidly to turkey manure and strawberries, with 35% and 60% of worms,

  11. Neuron, Vol. 39, 10051017, September 11, 2003, Copyright 2003 by Cell Press In Vivo Imaging of C. elegans Mechanosensory

    E-print Network

    Schafer, William R.

    phenotype would result if this MEC-4In the nematode C. elegans, genes encoding compo- nents of a putative. elegans Mechanosensory Neurons Demonstrates a Specific Role for the MEC-4 Channel in the Process of Gentle of gentle touch. The sto- matin-related MEC-2 protein (Huang et al., 1995) and Hiroshi Suzuki,1,4 Rex Kerr,1

  12. Adaptive divergence within and between ecotypes of the terrestrial garter snake, Thamnophis elegans , assessed with F ST - Q ST comparisons

    Microsoft Academic Search

    M. K. MANIER; C. M. SEYLER; S. J. ARNOLD

    2007-01-01

    Populations of the terrestrial garter snake (Thamnophis elegans) around Eagle Lake in California exhibit dramatic ecotypic differentiation in life history, colouration and morphology across distances as small as a few kilometres. We assayed the role of selection in ecotypic differentiation in T. elegans using FST- QST analysis and identified selective agents using direct and indirect observa- tions. We extended the

  13. A test of life-history theories of immune defence in two ecotypes of the garter snake, Thamnophis elegans

    E-print Network

    Bronikowski, Anne

    immunity in replicate populations of two life- history ecotypes of the garter snake Thamnophis elegans, oneA test of life-history theories of immune defence in two ecotypes of the garter snake, Thamnophis elegans Amanda Marie Sparkman* and Maria Gabriela Palacios Department of Ecology, Evolution & Organismal

  14. First report on recording of the invasive species Trachemys scripta elegans, a potential competitor of Emys orbicularis in Latvia

    Microsoft Academic Search

    Mihails Pupins

    An exotic turtle invasive species Trachemys scripta elegans Seidel 2002 was imported to Latvia with commercial purposes for sale in pet-shops. Now illegal introduction has resulted in invasion of the species into the nature of Latvia. In the study, the author checked reports from Latvian local inhabitants about their observation of Trahemys scripta elegans in Latvia. In fi ve cases

  15. A comparative metabolomic study of NHR-49 in Caenorhabditis elegans and PPAR-a in the mouse

    E-print Network

    Miska, Eric

    The nematode worm Caenorhabditis elegans is an ideal tool for functional genomics. It has been characterised high-throughput in vivo RNA interference (RNAi) screening has been established [2]. Many of the genes of metabolomics-based functional genomics. 2. Methods 2.1. Nematode methods C. elegans was grown using standard

  16. Long-Term Nicotine Adaptation in Caenorhabditis elegans Involves PKC-Dependent Changes in Nicotinic Receptor Abundance

    E-print Network

    Schafer, William R.

    Long-Term Nicotine Adaptation in Caenorhabditis elegans Involves PKC-Dependent Changes in Nicotinic to nicotine leads to long-term changes in both the abundance and activity of nicotinic acetylcholine receptors, processes thought to contribute to nicotine addiction. We have found that in Caenorhabditis elegans

  17. C. elegans pgp-5 IS INVOLVED IN RESISTANCE TO BACTERIAL INFECTION AND HEAVY METAL AND ITS REGULATION

    E-print Network

    Baillie, David

    C. elegans pgp-5 IS INVOLVED IN RESISTANCE TO BACTERIAL INFECTION AND HEAVY METAL AND ITS of a C. elegans ABC transporter, pgp-5 is induced by both bacterial infection and heavy metal stress contributes to resistance to bacterial infection and heavy metals. Using pgp-5 transcription as a read-out, we

  18. Homologs of genes expressed in Caenorhabditis elegans GABAergic neurons are also found in the developing mouse forebrain

    Microsoft Academic Search

    Elizabeth AD Hammock; Kathie L Eagleson; Susan Barlow; Laurie R Earls; David M Miller; Pat Levitt

    2010-01-01

    BACKGROUND: In an effort to identify genes that specify the mammalian forebrain, we used a comparative approach to identify mouse homologs of transcription factors expressed in developing Caenorhabditis elegans GABAergic neurons. A cell-specific microarray profiling study revealed a set of transcription factors that are highly expressed in embryonic C. elegans GABAergic neurons. RESULTS: Bioinformatic analyses identified mouse protein homologs of

  19. Effects of Wheat Cultivar and Temperature on Suppression of Rhyzopertha dominica (Coleoptera: Bostrichidae) by the Parasitoid Theocolax elegans (Hymenoptera: Pteromalidae)

    Microsoft Academic Search

    Michael D Toews; Thomas W Phillips; Gerrit W Cuperus

    2001-01-01

    A laboratory study was conducted to examine the role of two temperatures, five divergent wheat cultivars, and the pteromalid parasitoid Theocolax elegans (Westwood) on progeny production by the lesser grain borer, Rhyzopertha dominica (F.). Adult T. elegans were introduced into half of the jars while host and parasitoid progeny were allowed to develop through the first generation. Adult R. dominica

  20. PHA-4/FoxA cooperates with TAM-1/TRIM to regulate cell fate restriction in the C. elegans foregut

    E-print Network

    Mango, Susan

    PHA-4/FoxA cooperates with TAM-1/TRIM to regulate cell fate restriction in the C. elegans foregut blastomeres in C. elegans develop into foregut (pharynx) cells in response to the selector gene PHA-4/FoxA. When pha-4 is removed from pharyngeal precursors, they exhibit two alternative responses. Before late

  1. Study about locomotory ability of dystrophin-defected C.elegans after spaceflight

    NASA Astrophysics Data System (ADS)

    Gao, Ying; Sun, Yeqing; Lei, Huang; Xu, Dan

    2012-07-01

    Space microgravity could induce a variety of biological changes such as muscular atrophy. Recent studies show that gravisensing is a key point in muscular atrophy process, but the molecular mechanism is still unknown. Dystrophin, a muscle-related protein, plays an important role in muscle development. It is reported that mutation of human dystrophin gene could cause muscular atrophy. In this study, we focus on whether dystrophin gene acts as a gravisensing factor and observe locomotory ability of dystrophin-defected Caenorhabditis elegans (C.elegans) after spaceflight. We used wild-type (WT) and dystrophin-defected (dys-1) mutant of C.elegans, which were cultured to dauer stage and sent to space by Shenzhou 8 spacecraft (from Nov 1st to 17th, 2011). These worms were divided into three groups: space group (space radiation and microgravity conditions), space control group (space radiation and chmetcnvTCSC0NumberType1NegativeFalseHasSpaceFalseSourceValue1UnitNameg1g centrifuge force conditions) and ground control group.We already observed the progeny (generation F1 and F2) of worms which were sent to space, the movement of C. elegans is restricted to a two-dimensional sinusoidal pattern, and evaluated locomotory ability by the ratio (length/width) in crawl trace wave of C. elegans. The increased value of ratio indicates the decrease in locomotory ability of C. elegans. Our results from generation F1 showed that WT worms in space group(7.71.8) demonstrated the significant decrease in locomotory ability about 15%, compared with those in space control group(6.71.2). This finding indicates that locomotory ability of C. elegans progeny could be affected by microgravity in space environment. In comparison to the obvious difference in ratio between space group and space control group for WT worms, there is no significant difference between two space groups of generation F2 .For dys-1 mutant of C.elegans (generation F1 and F2), the results show that dystrophin deficiency results in no response to microgravity, compared with WT, suggesting that dys-1 gene plays a role in locomotory ability under ground gravity. Further, we performed all genome microarray analysis and found that expression of several muscle-related genes in dys-1 mutant groups were also changed, accompanied with changes in biological processes such as oxidation, protein modification and metabolic process. Our findings suggest that dystrophin gene could act as a gravisensing and affect locomotory ability of C. elegans progeny.

  2. The evolution of plasticity of dauer larva developmental arrest in the nematode Caenorhabditis elegans

    PubMed Central

    Diaz, S Anaid; Viney, Mark

    2015-01-01

    Organisms can end up in unfavourable conditions and to survive this they have evolved various strategies. Some organisms, including nematodes, survive unfavourable conditions by undergoing developmental arrest. The model nematode Caenorhabditis elegans has a developmental choice between two larval forms, and it chooses to develop into the arrested dauer larva form in unfavourable conditions (specifically, a lack of food and high population density, indicated by the concentration of a pheromone). Wild C.elegans isolates vary extensively in their dauer larva arrest phenotypes, and this prompts the question of what selective pressures maintain such phenotypic diversity? To investigate this we grew C.elegans in four different environments, consisting of different combinations of cues that can induce dauer larva development: two combinations of food concentration (high and low) in the presence or absence of a dauer larva-inducing pheromone. Five generations of artificial selection of dauer larvae resulted in an overall increase in dauer larva formation in most selection regimes. The presence of pheromone in the environment selected for twice the number of dauer larvae, compared with environments not containing pheromone. Further, only a high food concentration environment containing pheromone increased the plasticity of dauer larva formation. These evolutionary responses also affected the timing of the worms reproduction. Overall, these results give an insight into the environments that can select for different plasticities of C.elegans dauer larva arrest phenotypes, suggesting that different combinations of environmental cues can select for the diversity of phenotypically plastic responses seen in C.elegans. PMID:25859338

  3. Understanding the molecular basis of Alzheimer抯 disease using a Caenorhabditis elegans model system

    PubMed Central

    Ewald, Collin Y.; Li, Chris

    2013-01-01

    Alzheimer抯 disease (AD) is the major cause of dementia in the United States. At the cellular level, the brains of AD patients are characterized by extracellular dense plaques and intracellular neurofibrillary tangles whose major components are the ?-amyloid peptide and tau, respectively. The ?-amyloid peptide is a cleavage product of the amyloid precursor protein (APP); mutations in APP have been correlated with a small number of cases of familial Alzheimer抯 disease. APP is the canonical member of the APP family, whose functions remain unclear. The nematode Caenorhabditis elegans, one of the premier genetic workhorses, is being used in a variety of ways to address the functions of APP and determine how the ?-amyloid peptide and tau can induce toxicity. First, the function of the C. elegans APP-related gene, apl-1, is being examined. Although different organisms may use APP and related proteins, such as APL-1, in different functional contexts, the pathways in which they function and the molecules with which they interact are usually conserved. Second, components of the ?-secretase complex and their respective functions are being revealed through genetic analyses in C. elegans. Third, to address questions of toxicity, onset of degeneration, and protective mechanisms, different human ?-amyloid peptide and tau variants are being introduced into C. elegans and the resultant transgenic lines examined. Here, we summarize how a simple system such as C. elegans can be used as a model to understand APP function and suppression of ?-amyloid peptide and tau toxicity in higher organisms. PMID:20012092

  4. A Conserved Function of C. elegans CASY-1 Calsyntenin in Associative Learning

    PubMed Central

    Hoerndli, Fr閐閞ic J.; Walser, Michael; Fr鰄li Hoier, Erika; de Quervain, Dominique; Papassotiropoulos, Andreas; Hajnal, Alex

    2009-01-01

    Background Whole-genome association studies in humans have enabled the unbiased discovery of new genes associated with human memory performance. However, such studies do not allow for a functional or causal testing of newly identified candidate genes. Since polymorphisms in Calsyntenin 2 (CLSTN2) showed a significant association with episodic memory performance in humans, we tested the C. elegans CLSTN2 ortholog CASY-1 for possible functions in the associative behavior of C. elegans. Methodology/Principal Findings Using three different associative learning paradigms and functional rescue experiments, we show that CASY-1 plays an important role during associative learning in C. elegans. Furthermore, neuronal expression of human CLSTN2 in C. elegans rescues the learning defects of casy-1 mutants. Finally, genetic interaction studies and neuron-specific expression experiments suggest that CASY-1 may regulate AMPA-like GLR-1 glutamate receptor signaling. Conclusion/Significance Our experiments demonstrate a remarkable conservation of the molecular function of Calsyntenins between nematodes and humans and point at a role of C. elegans casy-1 in regulating a glutamate receptor signaling pathway. PMID:19287492

  5. A Conserved Upstream Motif Orchestrates Autonomous, Germline-Enriched Expression of Caenorhabditis elegans piRNAs

    PubMed Central

    Day, Amanda M.; Chun, Sang Young; Khivansara, Vishal; Kim, John K.

    2013-01-01

    Piwi-interacting RNAs (piRNAs) fulfill a critical, conserved role in defending the genome against foreign genetic elements. In many organisms, piRNAs appear to be derived from processing of a long, polycistronic RNA precursor. Here, we establish that each Caenorhabditis elegans piRNA represents a tiny, autonomous transcriptional unit. Remarkably, the minimal C. elegans piRNA cassette requires only a 21 nucleotide (nt) piRNA sequence and an ?50 nt upstream motif with limited genomic context for expression. Combining computational analyses with a novel, in vivo transgenic system, we demonstrate that this upstream motif is necessary for independent expression of a germline-enriched, Piwi-dependent piRNA. We further show that a single nucleotide position within this motif directs differential germline enrichment. Accordingly, over 70% of C. elegans piRNAs are selectively expressed in male or female germline, and comparison of the genes they target suggests that these two populations have evolved independently. Together, our results indicate that C. elegans piRNA upstream motifs act as independent promoters to specify which sequences are expressed as piRNAs, how abundantly they are expressed, and in what germline. As the genome encodes well over 15,000 unique piRNA sequences, our study reveals that the number of transcriptional units encoding piRNAs rivals the number of mRNA coding genes in the C. elegans genome. PMID:23516384

  6. Solution structure of CEH-37 homeodomain of the nematode Caenorhabditis elegans.

    PubMed

    Moon, Sunjin; Lee, Yong Woo; Kim, Woo Taek; Lee, Weontae

    2014-01-10

    The nematode Caenorhabditis elegans protein CEH-37 belongs to the paired OTD/OTX family of homeobox-containing homeodomain proteins. CEH-37 shares sequence similarity with homeodomain proteins, although it specifically binds to double-stranded C. elegans telomeric DNA, which is unusual to homeodomain proteins. Here, we report the solution structure of CEH-37 homeodomain and molecular interaction with double-stranded C. elegans telomeric DNA using nuclear magnetic resonance (NMR) spectroscopy. NMR structure shows that CEH-37 homeodomain is composed of a flexible N-terminal region and three ?-helices with a helix-turn-helix (HTH) DNA binding motif. Data from size-exclusion chromatography and fluorescence spectroscopy reveal that CEH-37 homeodomain interacts strongly with double-stranded C. elegans telomeric DNA. NMR titration experiments identified residues responsible for specific binding to nematode double-stranded telomeric DNA. These results suggest that C. elegans homeodomain protein, CEH-37 could play an important role in telomere function via DNA binding. PMID:24361878

  7. Unique C. elegans telomeric overhang structures reveal the evolutionarily conserved properties of telomeric DNA

    PubMed Central

    妅ol醟ov, Petra; Foldynov-Trant韗kov, Silvie; Bedn?ov, Kl醨a; Fiala, Radovan; Vorl?kov, Michaela; Trant韗ek, Luk釟

    2015-01-01

    There are two basic mechanisms that are associated with the maintenance of the telomere length, which endows cancer cells with unlimited proliferative potential. One mechanism, referred to as alternative lengthening of telomeres (ALT), accounts for approximately 1015% of all human cancers. Tumours engaged in the ALT pathway are characterised by the presence of the single stranded 5?-C-rich telomeric overhang (C-overhang). This recently identified hallmark of ALT cancers distinguishes them from healthy tissues and renders the C-overhang as a clear target for anticancer therapy. We analysed structures of the 5?-C-rich and 3?-G-rich telomeric overhangs from human and Caenorhabditis elegans, the recently established multicellular in vivo model of ALT tumours. We show that the telomeric DNA from C. elegans and humans forms fundamentally different secondary structures. The unique structural characteristics of C. elegans telomeric DNA that are distinct not only from those of humans but also from those of other multicellular eukaryotes allowed us to identify evolutionarily conserved properties of telomeric DNA. Differences in structural organisation of the telomeric DNA between the C. elegans and human impose limitations on the use of the C. elegans as an ALT tumour model. PMID:25855805

  8. Inducible and titratable silencing of Caenorhabditis elegans neurons in vivo with histamine-gated chloride channels

    PubMed Central

    Pokala, Navin; Liu, Qiang; Gordus, Andrew; Bargmann, Cornelia I.

    2014-01-01

    Recent progress in neuroscience has been facilitated by tools for neuronal activation and inactivation that are orthogonal to endogenous signaling systems. We describe here a chemical-genetic approach for inducible silencing of Caenorhabditis elegans neurons in intact animals, using the histamine-gated chloride channel HisCl1 from Drosophila and exogenous histamine. Administering histamine to freely moving C. elegans that express HisCl1 transgenes in neurons leads to rapid and potent inhibition of neural activity within minutes, as assessed by behavior, functional calcium imaging, and electrophysiology of neurons expressing HisCl1. C. elegans does not use histamine as an endogenous neurotransmitter, and exogenous histamine has little apparent effect on wild-type C. elegans behavior. HisCl1-histamine silencing of sensory neurons, interneurons, and motor neurons leads to behavioral effects matching their known functions. In addition, the HisCl1-histamine system can be used to titrate the level of neural activity, revealing quantitative relationships between neural activity and behavioral output. We use these methods to dissect escape circuits, define interneurons that regulate locomotion speed (AVA, AIB) and escape-related omega turns (AIB), and demonstrate graded control of reversal length by AVA interneurons and DA/VA motor neurons. The histamine-HisCl1 system is effective, robust, compatible with standard behavioral assays, and easily combined with optogenetic tools, properties that should make it a useful addition to C. elegans neurotechnology. PMID:24550306

  9. Extension of Lifespan in C. elegans by Naphthoquinones That Act through Stress Hormesis Mechanisms

    PubMed Central

    Wilson, Mark A.; Yu, Quian-Sheng; Wood, William H.; Zhang, Yongqing; Becker, Kevin G.; Greig, Nigel H.; Mattson, Mark P.; Camandola, Simonetta; Wolkow, Catherine A.

    2011-01-01

    Hormesis occurs when a low level stress elicits adaptive beneficial responses that protect against subsequent exposure to severe stress. Recent findings suggest that mild oxidative and thermal stress can extend lifespan by hormetic mechanisms. Here we show that the botanical pesticide plumbagin, while toxic to C. elegans nematodes at high doses, extends lifespan at low doses. Because plumbagin is a naphthoquinone that can generate free radicals in vivo, we investigated whether it extends lifespan by activating an adaptive cellular stress response pathway. The C. elegans cap憂抍ollar (CNC) transcription factor, SKN-1, mediates protective responses to oxidative stress. Genetic analysis showed that skn-1 activity is required for lifespan extension by low-dose plumbagin in C. elegans. Further screening of a series of plumbagin analogs identified three additional naphthoquinones that could induce SKN-1 targets in C. elegans. Naphthazarin showed skn-1dependent lifespan extension, over an extended dose range compared to plumbagin, while the other naphthoquinones, oxoline and menadione, had differing effects on C. elegans survival and failed to activate ARE reporter expression in cultured mammalian cells. Our findings reveal the potential for low doses of naturally occurring naphthoquinones to extend lifespan by engaging a specific adaptive cellular stress response pathway. PMID:21765926

  10. Lipid-lowering fibrates extend C. elegans lifespan in a NHR-49/PPARalpha-dependent manner

    PubMed Central

    Zarse, Kim; Ristow, Michael

    2013-01-01

    Compounds that delay aging in model organisms may be of significant interest to anti-aging medicine, since these substances potentially provide pharmaceutical approaches to promote healthy lifespan in humans. We here aimed to test whether pharmaceutical concentrations of three fibrates, pharmacologically established serum lipid-lowering drugs and ligands of the nuclear receptor PPARalpha in mammals, are capable of extending lifespan in a nematodal model organism for aging processes, the roundworm Caenorhabditis elegans. Adult C. elegans (wild-type N2 as well as two nhr-49-deficient strains, RB1716 and VC870) were maintained on agar plates and were fed E. coli strain OP50 bacteria. Bezafibrate, clofibrate, and fenofibrate were applied to the agar, respectively, to test whether they may promote longevity by quantifying survival in the presence and absence of the respective compounds. All three fibrates extended C. elegans N2 lifespan when applied at a concentration of 10 micromolar. Bezafibrate additionally extended C. elegans N2 lifespan at concentrations of 1 micromolar and 0.1 micromolar. In strains deficient for nhr-49, a functional orthologue of the mammalian peroxisome proliferator-activated receptor alpha (PPARalpha), all three compounds were incapable of extending lifespan. Taken together, fibrates promote C. elegans longevity in an NHR-49-dependent manner possibly by promoting mitohormesis and suggesting that these compounds may promote lifespan also in mammals. PMID:23603800

  11. Cytoplasmic Expression of Mouse Prion Protein Causes Severe Toxicity in C. elegans

    PubMed Central

    Park, Kyung-Won; Li, Liming

    2008-01-01

    To test if Caenorhabditis elegans could be established as a model organism for prion study, we created transgenic C. elegans expressing the cytosolic form of the mouse prion .protein, MoPrP(23-231), which lacks the N-terminal signal sequence and the C-terminal glycosylphosphatidylinisotol (GPI) anchor site. We report here that transgenic worms expressing MoPrP(23-231)朇FP exhibited a wide range of distinct phenotypes: from normal growth and development, reduced mobility and development delay, complete paralysis and development arrest, to embryonic lethality. Similar levels of MoPrP (23-231)-CFP were produced in animals exhibiting these distinct phenotypes, suggesting that MoPrP (23-231)-CFP might have misfolded into distinct toxic species. In combining with the observation that mutations in PrP that affect prion pathogenesis also affect the toxic phenotypes in C. elegans, we conclude that the prion protein folding mechanism is similar in mammals and C. elegans. Thus, C. elegans can be a useful model organism for prion research. PMID:18519028

  12. A Highly Accurate Inclusive Cancer Screening Test Using Caenorhabditis elegans Scent Detection

    PubMed Central

    Uozumi, Takayuki; Shinden, Yoshiaki; Mimori, Koshi; Maehara, Yoshihiko; Ueda, Naoko; Hamakawa, Masayuki

    2015-01-01

    Early detection and treatment are of vital importance to the successful eradication of various cancers, and development of economical and non-invasive novel cancer screening systems is critical. Previous reports using canine scent detection demonstrated the existence of cancer-specific odours. However, it is difficult to introduce canine scent recognition into clinical practice because of the need to maintain accuracy. In this study, we developed a Nematode Scent Detection Test (NSDT) using Caenorhabditis elegans to provide a novel highly accurate cancer detection system that is economical, painless, rapid and convenient. We demonstrated wild-type C. elegans displayed attractive chemotaxis towards human cancer cell secretions, cancer tissues and urine from cancer patients but avoided control urine; in parallel, the response of the olfactory neurons of C. elegans to the urine from cancer patients was significantly stronger than to control urine. In contrast, G protein ? mutants and olfactory neurons-ablated animals were not attracted to cancer patient urine, suggesting that C. elegans senses odours in urine. We tested 242 samples to measure the performance of the NSDT, and found the sensitivity was 95.8%; this is markedly higher than that of other existing tumour markers. Furthermore, the specificity was 95.0%. Importantly, this test was able to diagnose various cancer types tested at the early stage (stage 0 or 1). To conclude, C. elegans scent-based analyses might provide a new strategy to detect and study disease-associated scents. PMID:25760772

  13. Rotundifolinol, a new 1,3-diarylpropan-2-ol from bark of Litsea rotundifolia var. oblongifolia

    Microsoft Academic Search

    Ya Zhao; Guo-Qiang Shong; Yue-Wei Guo

    2003-01-01

    A new 1,3-diarylpropan-2-ol, named rotundifolinol (1), has been isolated from the bark of Litsea rotundifolia var. oblongifolia. Its structure was elucidated on the basis of detailed spectroscopic analysis and comparison with related compounds.

  14. Patterns of Genetic Variation in Southern Appalachian Populations of Athyrium filix?femina var. asplenioides (Dryopteridaceae)

    E-print Network

    Sciarretta, Kimberly L.; Arbuckle, Erin Potter; Haufler, Christopher H.; Werth, Charles R.

    2005-09-01

    Allozyme variation (17 loci coding 11 enzymes) was investigated in 14 populations of the fern Athyrium filix?femina var. asplenioides arrayed at differing elevations and latitudes in the southern Appalachians. Allozyme fingerprints showed...

  15. Quantification of Nociceptive Escape Response in C.elegans

    NASA Astrophysics Data System (ADS)

    Leung, Kawai; Mohammadi, Aylia; Ryu, William; Nemenman, Ilya

    2013-03-01

    Animals cannot rank and communicate their pain consciously. Thus in pain studies on animal models, one must infer the pain level from high precision experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. Here we explore the feasibility of C.elegans as a model for pain transduction. The nematode has a robust neurally mediated noxious escape response, which we show to be partially decoupled from other sensory behaviors. We develop a nociceptive behavioral response assay that allows us to apply controlled levels of pain by locally heating worms with an IR laser. The worms' motions are captured by machine vision programming with high spatiotemporal resolution. The resulting behavioral quantification allows us to build a statistical model for inference of the experienced pain level from the behavioral response. Based on the measured nociceptive escape of over 400 worms, we conclude that none of the simple characteristics of the response are reliable indicators of the laser pulse strength. Nonetheless, a more reliable statistical inference of the pain stimulus level from the measured behavior is possible based on a complexity-controlled regression model that takes into account the entire worm behavioral output. Animals cannot rank and communicate their pain consciously. Thus in pain studies on animal models, one must infer the pain level from high precision experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. Here we explore the feasibility of C.elegans as a model for pain transduction. The nematode has a robust neurally mediated noxious escape response, which we show to be partially decoupled from other sensory behaviors. We develop a nociceptive behavioral response assay that allows us to apply controlled levels of pain by locally heating worms with an IR laser. The worms' motions are captured by machine vision programming with high spatiotemporal resolution. The resulting behavioral quantification allows us to build a statistical model for inference of the experienced pain level from the behavioral response. Based on the measured nociceptive escape of over 400 worms, we conclude that none of the simple characteristics of the response are reliable indicators of the laser pulse strength. Nonetheless, a more reliable statistical inference of the pain stimulus level from the measured behavior is possible based on a complexity-controlled regression model that takes into account the entire worm behavioral output. This work was partially supported by NSF grant No. IOS/1208126 and HFSP grant No. RGY0084/2011.

  16. Extent and ecological significance of physiological integration among ramets within the bunchgrass Schizachyrium scoparium var. frequens

    E-print Network

    Williams, David Greg

    1988-01-01

    EXTENT AND BXMGICAL SIGNIFICANCE OF PHYSIOLOGICAL INXKGRATION AMONG RAMEIS WITHIN THE BUN~ SCHIZACHYRIUM SCOPARIUM VAR. F3Eg3MS A Thesis by DAVID GREG WILLIAMS Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of August 1988 Major Subject: Range Science EXTENT AND ECOLOGICAL SIGNIFICANCE OF PHYSIOLOGICAL INTEGRATION AMONG ~ WITHIN THE BUNCHGRASS SCHI ZACHYRIUM SCOPARIUM VAR. FREQUENS A Thesis by DAVID GREG WILLIAMS Approved...

  17. Weinmannia marquesana var. angustifolia (Cunoniaceae), a new variety from the Marquesas Islands

    PubMed Central

    Lorence, David H.; Wagner, Warren L.

    2011-01-01

    Abstract Weinmannia marquesana F. Br. var. angustifolia Lorence & W. L. Wagner, var. nov., a new variety with narrow, simple leaves endemic to Tahuata, Marquesas Islands (French Polynesia) is described and its affinities and conservation status are discussed. It is similar to the other two varieties of this species by having simple leaves, but this new variety has much narrower leaf blades, and it resembles Weinmannia tremuloides in having narrow leaf blades but differs by having simple, not trifoliolate leaves. PMID:22171181

  18. Polysaccharides from fruit calyx of Physalis alkekengi var. francheti: Isolation, purification, structural features and antioxidant activities

    Microsoft Academic Search

    Yu Ge; Yufeng Duan; Guozhen Fang; Yan Zhang; Shuo Wang

    2009-01-01

    The conditions for extracting and purifying polysaccharides from fruit calyx of Physalis alkekengi var. francheti were investigated, including hot water extraction, ultrasonic wave-assistant extraction and enzyme extraction methods. Four polysaccharide fractions (PAVF I, II-a and III) were separated from the extracts of fruit calyx of P. alkekengi var. francheti using a DEAE anion-exchange column and Sephadex G-200 column. Their chemical

  19. Genome Sequence of Phytophthora fragariae var. fragariae, a Quarantine Plant-Pathogenic Fungus.

    PubMed

    Gao, Ruifang; Cheng, Yinghui; Wang, Ying; Wang, Ying; Guo, Liyun; Zhang, Guiming

    2015-01-01

    Phytophthora fragariae var. fragariae is a serious plant-pathogenic fungus causing red core disease in strawberries, resulting in a larger number of fruit produced, and the fungus has been regulated as a quarantine pest of many countries and regions. Here, we announce the genome sequence of P.爁ragariae var. fragariae, and this information might provide insight into the mechanism of pathogenicity and host specificity of this pathogen, as well as help us further identify targets for fungicides. PMID:25814589

  20. Forecasting VARMA processes using VAR models and subspace-based state space models

    Microsoft Academic Search

    Segismundo S. Izquierdo; Ces醨eo Hern醤dez; Juan del Hoyo

    2006-01-01

    VAR modelling is a frequent technique in econometrics for linear processes. VAR modelling offers some desirable features such as relatively simple procedures for model specification (order selection) and the possibility of obtaining quick non-iterative maximum likelihood estimates of the system parameters. However, if the process under study follows a finite-order VARMA structure, it cannot be equivalently represented by any finite-order

  1. ClinVar: public archive of relationships among sequence variation and human phenotype.

    PubMed

    Landrum, Melissa J; Lee, Jennifer M; Riley, George R; Jang, Wonhee; Rubinstein, Wendy S; Church, Deanna M; Maglott, Donna R

    2014-01-01

    ClinVar (http://www.ncbi.nlm.nih.gov/clinvar/) provides a freely available archive of reports of relationships among medically important variants and phenotypes. ClinVar accessions submissions reporting human variation, interpretations of the relationship of that variation to human health and the evidence supporting each interpretation. The database is tightly coupled with dbSNP and dbVar, which maintain information about the location of variation on human assemblies. ClinVar is also based on the phenotypic descriptions maintained in MedGen (http://www.ncbi.nlm.nih.gov/medgen). Each ClinVar record represents the submitter, the variation and the phenotype, i.e. the unit that is assigned an accession of the format SCV000000000.0. The submitter can update the submission at any time, in which case a new version is assigned. To facilitate evaluation of the medical importance of each variant, ClinVar aggregates submissions with the same variation/phenotype combination, adds value from other NCBI databases, assigns a distinct accession of the format RCV000000000.0 and reports if there are conflicting clinical interpretations. Data in ClinVar are available in multiple formats, including html, download as XML, VCF or tab-delimited subsets. Data from ClinVar are provided as annotation tracks on genomic RefSeqs and are used in tools such as Variation Reporter (http://www.ncbi.nlm.nih.gov/variation/tools/reporter), which reports what is known about variation based on user-supplied locations. PMID:24234437

  2. Sexual reproduction of the invasive green alga Caulerpa racemosa var. occidentalis in the Mediterranean Sea

    Microsoft Academic Search

    Panayotis PANAYOTIDIS; Ante 嶶LJEVI?

    2001-01-01

    Since the beginning of the 1990s, a pan-tropical species Caulerpa racemosa var. occidentalis has been recorded on the numerous new locations throughout the Mediterranean, specifically on its northwestern part where until then it had never been observed. Such extensive spreading is probably supported by successful sexual reproduction. Field observations of fertile plants and synchronous gamete release of C.爎acemosa var. occidentalis

  3. Rhus javanica var. chinensis as a new plant origin of propolis from Okayama, Japan.

    PubMed

    Murase, Masayo; Kato, Manabu; Sun, Aihua; Ono, Takayuki; Nakamura, Jun; Sato, Tsutomu; Kumazawa, Shigenori

    2008-10-01

    To directly identify the plant origin of propolis from Takebe-cho (Okayama, Japan), we observed the honeybee behavior. Honeybees scraped sap from the tree, Rhus javanica var. chinensis. We compared the constituents and radical-scavenging activity of this sap and propolis. Their chemical constituents and radical-scavenging activity were comparable. This indicates directly that the plant origin of this propolis is R. javanica var. chinensis. PMID:18838785

  4. ClinVar: public archive of relationships among sequence variation and human phenotype

    PubMed Central

    Landrum, Melissa J.; Lee, Jennifer M.; Riley, George R.; Jang, Wonhee; Rubinstein, Wendy S.; Church, Deanna M.; Maglott, Donna R.

    2014-01-01

    ClinVar (http://www.ncbi.nlm.nih.gov/clinvar/) provides a freely available archive of reports of relationships among medically important variants and phenotypes. ClinVar accessions submissions reporting human variation, interpretations of the relationship of that variation to human health and the evidence supporting each interpretation. The database is tightly coupled with dbSNP and dbVar, which maintain information about the location of variation on human assemblies. ClinVar is also based on the phenotypic descriptions maintained in MedGen (http://www.ncbi.nlm.nih.gov/medgen). Each ClinVar record represents the submitter, the variation and the phenotype, i.e. the unit that is assigned an accession of the format SCV000000000.0. The submitter can update the submission at any time, in which case a new version is assigned. To facilitate evaluation of the medical importance of each variant, ClinVar aggregates submissions with the same variation/phenotype combination, adds value from other NCBI databases, assigns a distinct accession of the format RCV000000000.0 and reports if there are conflicting clinical interpretations. Data in ClinVar are available in multiple formats, including html, download as XML, VCF or tab-delimited subsets. Data from ClinVar are provided as annotation tracks on genomic RefSeqs and are used in tools such as Variation Reporter (http://www.ncbi.nlm.nih.gov/variation/tools/reporter), which reports what is known about variation based on user-supplied locations. PMID:24234437

  5. SU(VAR)3-7 Links Heterochromatin and Dosage Compensation in Drosophila

    PubMed Central

    Spierer, Anne; Begeot, Flora; Spierer, Pierre; Delattre, Marion

    2008-01-01

    In Drosophila, dosage compensation augments X chromosome-linked transcription in males relative to females. This process is achieved by the Dosage Compensation Complex (DCC), which associates specifically with the male X chromosome. We previously found that the morphology of this chromosome is sensitive to the amounts of the heterochromatin-associated protein SU(VAR)3-7. In this study, we examine the impact of change in levels of SU(VAR)3-7 on dosage compensation. We first demonstrate that the DCC makes the X chromosome a preferential target for heterochromatic markers. In addition, reduced or increased amounts of SU(VAR)3-7 result in redistribution of the DCC proteins MSL1 and MSL2, and of Histone 4 acetylation of lysine 16, indicating that a wild-type dose of SU(VAR)3-7 is required for X-restricted DCC targeting. SU(VAR)3-7 is also involved in the dosage compensated expression of the X-linked white gene. Finally, we show that absence of maternally provided SU(VAR)3-7 renders dosage compensation toxic in males, and that global amounts of heterochromatin affect viability of ectopic MSL2-expressing females. Taken together, these results bring to light a link between heterochromatin and dosage compensation. PMID:18451980

  6. Isolation of Su(var)3-7 mutations by homologous recombination in Drosophila melanogaster.

    PubMed

    Seum, Carole; Pauli, Daniel; Delattre, Marion; Jaquet, Yannis; Spierer, Anne; Spierer, Pierre

    2002-07-01

    The Su(var)3-7 gene, a haplo-suppressor and triplo-enhancer of position-effect variegation (PEV), encodes a zinc finger heterochromatin-associated protein. To understand the role of this protein in heterochromatin and genomic silencing, mutations were generated by homologous recombination. The donor fragment contained a yellow(+) gene and 7.6 kb of the Su(var)3-7 gene inserted between two FRTs. The Su(var)3-7 sequence contained three stop codons flanking an I-SceI cut site located in the 5' half of the gene. Using two different screening approaches, we obtained an allelic series composed of three mutant alleles. The three mutations are dominant suppressors of PEV. One behaves as a null mutation and results in a maternal-effect recessive lethal phenotype that can be rescued by a zygotic paternal wild-type gene. A P transposon zygotically expressing a Su(var)3-7 full-length cDNA also rescues the mutant phenotype. One hypomorphic allele is viable and the pleiotropic phenotype showed by adult flies indicates that rapidly and late dividing cells seem the most affected by reduced amounts of Su(var)3-7 protein. All three mutants were characterized at the molecular level. Each expresses a portion of the Su(var)3-7 protein that is unable to enter the nucleus and bind chromatin. PMID:12136016

  7. Arundina graminifolia var. revoluta (Arethuseae, Orchidaceae) has fern-type rheophyte characteristics in the leaves.

    PubMed

    Yorifuji, Eri; Ishikawa, Naoko; Okada, Hiroshi; Tsukaya, Hirokazu

    2015-03-01

    Morphological and molecular variation between Arundina graminifolia var. graminifolia and the dwarf variety, A. graminifolia var. revoluta, was examined to assess the validity of their taxonomic characteristics and genetic background for identification. Morphological analysis in combination with field observations indicated that A. graminifolia var. revoluta is a rheophyte form of A. graminifolia characterized by narrow leaves, whereas the other morphological characteristics described for A. graminifolia var. revoluta, such as smaller flowers and short stems, were not always accompanied by the narrower leaf phenotype. Molecular analysis based on matK sequences indicated that only partial differentiation has occurred between A. graminifolia var. graminifolia and A. graminifolia var. revoluta. Therefore, we should consider the rheophyte form an ecotype rather than a variety. Anatomical observations of the leaves revealed that the rheophyte form of A. graminifolia possessed characteristics of the rheophytes of both ferns and angiosperms, such as narrower palisade tissue cells and thinner spongy tissue cells, as well as fewer cells in the leaf-width direction and fewer mesophyll cell layers. PMID:25502073

  8. Long-Term Imaging of Caenorhabditis elegans Using Nanoparticle-Mediated Immobilization

    PubMed Central

    Kim, Eric; Sun, Lin; Gabel, Christopher V.; Fang-Yen, Christopher

    2013-01-01

    One advantage of the nematode Caenorhabditis elegans as a model organism is its suitability for in vivo optical microscopy. Imaging C. elegans often requires animals to be immobilized to avoid movement-related artifacts. Immobilization has been performed by application of anesthetics or by introducing physical constraints using glue or specialized microfluidic devices. Here we present a method for immobilizing C. elegans using polystyrene nanoparticles and agarose pads. Our technique is technically simple, does not expose the worm to toxic substances, and allows recovery of animals. We evaluate the method and show that the polystyrene beads increase friction between the worm and agarose pad. We use our method to quantify calcium transients and long-term regrowth in single neurons following axotomy by a femtosecond laser. PMID:23301069

  9. CAF-1-Mediated Chromatin Assembly Generates a Bilateral Asymmetry in C. elegans Neuroanatomy

    PubMed Central

    Nakano, Shunji; Stillman, Bruce; Horvitz, H. Robert

    2012-01-01

    Summary Chromatin assembly is a fundamental cellular process, but its role during animal development remains largely elusive. Here we report that the CAF-1 protein complex, an evolutionarily conserved histone chaperone that deposits histone H3-H4 proteins onto replicating DNA, is required to generate a bilateral asymmetry in the C. elegans nervous system. We describe our findings that a mutation in one of 24 C. elegans histone H3 genes specifically eliminates this aspect of neuronal asymmetry. This histone H3 mutation causes a defect in the formation of a histone H3-H4 tetramer and the consequent inhibition of CAF-1-mediated nucleosome formation. Our results reveal that replication-coupled nucleosome assembly is necessary to generate a bilateral asymmetry in C. elegans neuroanatomy and suggest that left-right asymmetric epigenetic regulation can establish bilateral asymmetry in the nervous system. PMID:22177093

  10. DevStaR: high-throughput quantification of C. elegans developmental stages.

    PubMed

    White, Amelia G; Lees, Brandon; Kao, Huey-Ling; Cipriani, P Giselle; Munarriz, Eliana; Paaby, Annalise B; Erickson, Katherine; Guzman, Sherly; Rattanakorn, Kirk; Sontag, Eduardo; Geiger, Davi; Gunsalus, Kristin C; Piano, Fabio

    2013-10-01

    We present DevStaR, an automated computer vision and machine learning system that provides rapid, accurate, and quantitative measurements of C. elegans embryonic viability in high-throughput (HTP) applications. A leading genetic model organism for the study of animal development and behavior, C. elegans is particularly amenable to HTP functional genomic analysis due to its small size and ease of cultivation, but the lack of efficient and quantitative methods to score phenotypes has become a major bottleneck. DevStaR addresses this challenge using a novel hierarchical object recognition machine that rapidly segments, classifies, and counts animals at each developmental stage in images of mixed-stage populations of C. elegans. Here, we describe the algorithmic design of the DevStaR system and demonstrate its performance in scoring image data acquired in HTP screens. PMID:23722463

  11. A C. elegans Screening Platform for the Rapid Assessment of Chemical Disruption of Germline Function

    PubMed Central

    Allard, Patrick; Kleinstreuer, Nicole C.; Knudsen, Thomas B.

    2013-01-01

    Background: Despite the developmental impact of chromosome segregation errors, we lack the tools to assess environmental effects on the integrity of the germline in animals. Objectives: We developed an assay in Caenorhabditis elegans that fluorescently marks aneuploid embryos after chemical exposure. Methods: We qualified the predictive value of the assay against chemotherapeutic agents as well as environmental compounds from the ToxCast Phase I library by comparing results from the C. elegans assay with the comprehensive mammalian in vivo end point data from the ToxRef database. Results: The assay was highly predictive of mammalian reproductive toxicities, with a 69% maximum balanced accuracy. We confirmed the effect of select compounds on germline integrity by monitoring germline apoptosis and meiotic progression. Conclusions: This C. elegans assay provides a comprehensive strategy for assessing environmental effects on germline function. PMID:23603051

  12. Expression pattern and first functional characterization of riok-1 in Caenorhabditis elegans.

    PubMed

    Weinberg, Florian; Schulze, Ekkehard; Fatouros, Chronis; Schmidt, Enrico; Baumeister, Ralf; Brummer, Tilman

    2014-07-01

    Rio kinases are atypical serine/threonine kinases that emerge as potential cooperation partners in Ras-driven tumors. In the current study, we performed an RNAi screen in Caenorhabditis elegans to identify suppressors of oncogenic Ras signaling. Aberrant Ras/Raf signaling in C. elegans leads to the formation of a multi-vulva (Muv) phenotype. We found that depletion of riok-1, the C. elegans orthologue of the mammalian RioK1, suppressed the Muv phenotype. By using a promoter GFP construct, we could show that riok-1 is expressed in neuronal cells, the somatic gonad, the vulva, the uterus and the spermatheca. Furthermore, we observed developmental defects in the gonad upon riok-1 knockdown in a wildtype background. Our data suggest that riok-1 is a modulator of the Ras signaling pathway, suggesting implications for novel interventions in the context of Ras-driven tumors. PMID:24929033

  13. Modern tools to study nuclear pore complexes and nucleocytoplasmic transport in Caenorhabditis elegans.

    PubMed

    Askjaer, Peter; Galy, Vincent; Meister, Peter

    2014-01-01

    The nematode Caenorhabditis elegans is characterized by many features that make it highly attractive to study nuclear pore complexes (NPCs) and nucleocytoplasmic transport. NPC composition and structure are highly conserved in nematodes and being amenable to a variety of genetic manipulations, key aspects of nuclear envelope dynamics can be observed in great details during breakdown, reassembly, and interphase. In this chapter, we provide an overview of some of the most relevant modern techniques that allow researchers unfamiliar with C. elegans to embark on studies of nucleoporins in an intact organism through its development from zygote to aging adult. We focus on methods relevant to generate loss-of-function phenotypes and their analysis by advanced microscopy. Extensive references to available reagents, such as mutants, transgenic strains, and antibodies are equally useful to scientists with or without prior C. elegans or nucleoporin experience. PMID:24857735

  14. Pharyngeal pumping continues after laser killing of the pharyngeal nervous system of C. elegans

    SciTech Connect

    Avery, L.; Horvitz, H.R. (Massachusetts Institute of Technology, Cambridge (USA))

    1989-10-01

    Using a laser microbeam to kill specific subsets of the pharyngeal nervous system of C. elegans, we found that feeding was accomplished by two separately controlled muscle motions, isthmus peristalsis and pumping. The single neuron M4 was necessary and sufficient for isthmus peristalsis. The MC neurons were necessary for normal stimulation of pumping in response to food, but pumping continued and was functional in MC- worms. The remaining 12 neuron types were also unnecessary for functional pumping. No operation we did, including destruction of the entire pharyngeal nervous system, abolished pumping altogether. When we killed all pharyngeal neurons except M4, the worms were viable and fertile, although retarded and starved. Since feeding is one of the few known essential actions controlled by the nervous system, we suggest that most of the C. elegans nervous system is dispensable in hermaphrodites under laboratory conditions. This may explain the ease with which nervous system mutants are isolated and handled in C. elegans.

  15. Reference toxicants for toxicity testing using Caenorhabditis elegans in aquatic media

    SciTech Connect

    Cressman, C.P. III; Williams, P.L. [Univ. of Georgia, Athens, GA (United States)

    1997-09-01

    Caenorhabditis elegans aquatic toxicity assays were standardized with five common reference toxicants: CdCl{sub 2}, NaCl, KCl, sodium lauryl sulfate (SLS), and sodium pentachlorophenate (PCP). Aquatic toxicity testing was conducted in 3 media: a standard C. elegans medium; EPA moderately hard reconstituted water; and EPA moderately hard mineral water. Test duration in each medium was 24h without a food source, and 24h and 48h with Escherichia coli strain OP50 as a food source. Each test was replicated three times with each replicate having 6 wells per concentration, 10 worms per well. LC{sub 50} values were calculated using probit analysis. The average LC{sub 50}s for each set of replications were compared to assess sensitivity and reproducibility of the data, identifying expected variation between replicate tests. These reference toxicants increase the database for C. elegans and provide a benchmark for further application.

  16. Motility analysis of the nematode C. elegans on wet soft media

    NASA Astrophysics Data System (ADS)

    Sznitman, Josue; Shen, Xiaoning; Arratia, Paulo

    2011-11-01

    Undulatory locomotion is widely utilized by limbless organisms such as snakes, eels and worms. When moving on top of wet soft gels (e.g. agar), undulating organisms such as the nematode Caenorhabditis elegans display a motility gait that is characterized by crawling. Until present however, a detailed understanding of how C. elegans' crawling gait generates propulsion over soft gels is lacking. Namely, how much crawling force does C. elegans generate? Here, we propose a simple model based on lubrication theory to examine the biomechanics of crawling motion. In analogy to the well-known resistive-force theory (RFT) for low Reynolds number swimming, our model provides a mechanism for the linear relation between the sliding speeds and the drag forces, and sheds light on the role of grooves created by nematodes on agar. We further examine the kinematics of locomotion experimentally and compare muscle activity patterns between crawling and swimming gaits, emphasizing the inherent differences in nematode adaptability to different environments.

  17. Caenorhabditis elegans selects distinct crawling and swimming gaits via dopamine and serotonin.

    PubMed

    Vidal-Gadea, Andr閟; Topper, Stephen; Young, Layla; Crisp, Ashley; Kressin, Leah; Elbel, Erin; Maples, Thomas; Brauner, Martin; Erbguth, Karen; Axelrod, Abram; Gottschalk, Alexander; Siegel, Dionicio; Pierce-Shimomura, Jonathan T

    2011-10-18

    Many animals, including humans, select alternate forms of motion (gaits) to move efficiently in different environments. However, it is unclear whether primitive animals, such as nematodes, also use this strategy. We used a multifaceted approach to study how the nematode Caenorhabditis elegans freely moves into and out of water. We demonstrate that C. elegans uses biogenic amines to switch between distinct crawling and swimming gaits. Dopamine is necessary and sufficient to initiate and maintain crawling after swimming. Serotonin is necessary and sufficient to transition from crawling to swimming and to inhibit a set of crawl-specific behaviors. Further study of locomotory switching in C. elegans and its dependence on biogenic amines may provide insight into how gait transitions are performed in other animals. PMID:21969584

  18. Quantitative proteomics by amino acid labeling identifies novel NHR-49 regulated proteins in C. elegans

    PubMed Central

    Fredens, Julius; F鎟geman, Nils J.

    2012-01-01

    Stable isotope labeling by amino acids combined with mass spectrometry is a widely used methodology to quantitatively examine metabolic and signaling pathways in yeast, fruit flies, plants, cell cultures and mice. However, only metabolic labeling using 15N has been applied to examine such events in the nematode Caenorhabditis elegans. We have recently shown that C. elegans can be completely labeled with heavy-labeled lysine by feeding worms on prelabeled lysine auxotroph Escherichia coli for just one generation. We applied this methodology to examine the organismal response to functional loss or RNAi mediated knock down of the transcription factor NHR-49, and found numerous proteins involved in lipid metabolism to be downregulated, which is consistent with its previously proposed function as a transcriptional regulator of fatty acid metabolism. The combined use of quantitative proteomics and selective gene knockdown by RNAi provides a powerful tool with broad implications for C. elegans biology. PMID:24058826

  19. Functional characterisation of a cyst nematode acetylcholinesterase gene using Caenorhabditis elegans as a heterologous system.

    PubMed

    Costa, Joana C; Lilley, Catherine J; Atkinson, Howard J; Urwin, Peter E

    2009-06-01

    Migration of plant-parasitic nematode infective larval stages through soil and invasion of roots requires perception and integration of sensory cues culminating in particular responses that lead to root penetration and parasite establishment. Components of the chemoreceptive neuronal circuitry involved in these responses are targets for control measures aimed at preventing infection. Here we report, to our knowledge, the first isolation of cyst nematode ace-2 genes encoding acetylcholinesterase (AChE). The ace-2 genes from Globodera pallida (Gp-ace-2) and Heterodera glycines (Hg-ace-2) show homology to ace-2 of Caenorhabditis elegans (Ce-ace-2). Gp-ace-2 is expressed most highly in the infective J2 stage with lowest expression in the early parasitic stages. Expression and functional analysis of the Globodera gene were carried out using the free-living nematode C. elegans in order to overcome the refractory nature of the obligate parasite G. pallida to many biological studies. Caenorhabditis elegans transformed with a GFP reporter construct under the control of the Gp-ace-2 promoter exhibited specific and restricted GFP expression in neuronal cells in the head ganglia. Gp-ACE-2 protein can functionally complement its C. elegans homologue. A chimeric construct containing the Ce-ace-2 promoter region and the Gp-ace-2 coding region and 3' untranslated region was able to restore a normal phenotype to the uncoordinated C. elegans double mutant ace-1;ace-2. This study demonstrates conservation of AChE function and expression between free-living and plant-parasitic nematode species, and highlights the utility of C. elegans as a heterologous system to study neuronal aspects of plant-parasitic nematode biology. PMID:19367833

  20. Caenorhabditis elegans: A Model System for Anti-Cancer Drug Discovery and Therapeutic Target Identification

    PubMed Central

    Kobet, Robert A.; Pan, Xiaoping; Zhang, Baohong; Pak, Stephen C.; Asch, Adam S.; Lee, Myon-Hee

    2014-01-01

    The nematode Caenorhabditis elegans (C. elegans) offers a unique opportunity for biological and basic medical researches due to its genetic tractability and well-defined developmental lineage. It also provides an exceptional model for genetic, molecular, and cellular analysis of human disease-related genes. Recently, C. elegans has been used as an ideal model for the identification and functional analysis of drugs (or small-molecules) in vivo. In this review, we describe conserved oncogenic signaling pathways (Wnt, Notch, and Ras) and their potential roles in the development of cancer stem cells. During C. elegans germline development, these signaling pathways regulate multiple cellular processes such as germline stem cell niche specification, germline stem cell maintenance, and germ cell fate specification. Therefore, the aberrant regulations of these signaling pathways can cause either loss of germline stem cells or overproliferation of a specific cell type, resulting in sterility. This sterility phenotype allows us to identify drugs that can modulate the oncogenic signaling pathways directly or indirectly through a high-throughput screening. Current in vivo or in vitro screening methods are largely focused on the specific core signaling components. However, this phenotype-based screening will identify drugs that possibly target upstream or downstream of core signaling pathways as well as exclude toxic effects. Although phenotype-based drug screening is ideal, the identification of drug targets is a major challenge. We here introduce a new technique, called Drug Affinity Responsive Target Stability (DARTS). This innovative method is able to identify the target of the identified drug. Importantly, signaling pathways and their regulators in C. elegans are highly conserved in most vertebrates, including humans. Therefore, C. elegans will provide a great opportunity to identify therapeutic drugs and their targets, as well as to understand mechanisms underlying the formation of cancer. PMID:25414766

  1. A Modular Library of Small Molecule Signals Regulates Social Behaviors in Caenorhabditis elegans

    PubMed Central

    Bose, Neelanjan; Zaslaver, Alon; Mahanti, Parag; Ho, Margaret C.; O'Doherty, Oran G.; Edison, Arthur S.; Sternberg, Paul W.; Schroeder, Frank C.

    2012-01-01

    The nematode C. elegans is an important model for the study of social behaviors. Recent investigations have shown that a family of small molecule signals, the ascarosides, controls population density sensing and mating behavior. However, despite extensive studies of C. elegans aggregation behaviors, no intraspecific signals promoting attraction or aggregation of wild-type hermaphrodites have been identified. Using comparative metabolomics, we show that the known ascarosides are accompanied by a series of derivatives featuring a tryptophan-derived indole moiety. Behavioral assays demonstrate that these indole ascarosides serve as potent intraspecific attraction and aggregation signals for hermaphrodites, in contrast to ascarosides lacking the indole group, which are repulsive. Hermaphrodite attraction to indole ascarosides depends on the ASK amphid sensory neurons. Downstream of the ASK sensory neuron, the interneuron AIA is required for mediating attraction to indole ascarosides instead of the RMG interneurons, which previous studies have shown to integrate attraction and aggregation signals from ASK and other sensory neurons. The role of the RMG interneuron in mediating aggregation and attraction is thought to depend on the neuropeptide Y-like receptor NPR-1, because solitary and social C. elegans strains are distinguished by different npr-1 variants. We show that indole ascarosides promote attraction and aggregation in both solitary and social C. elegans strains. The identification of indole ascarosides as aggregation signals reveals unexpected complexity of social signaling in C. elegans, which appears to be based on a modular library of ascarosides integrating building blocks derived from lipid ?-oxidation and amino-acid metabolism. Variation of modules results in strongly altered signaling content, as addition of a tryptophan-derived indole unit to repellent ascarosides produces strongly attractive indole ascarosides. Our findings show that the library of ascarosides represents a highly developed chemical language integrating different neurophysiological pathways to mediate social communication in C. elegans. PMID:22253572

  2. Catalase activity and innate immune response of Caenorhabditis elegans against the heavy metal toxin lead.

    PubMed

    Vigneshkumar, Balasubramanian; Pandian, Shunmugiah Karutha; Balamurugan, Krishnaswamy

    2013-06-01

    The heavy metal lead-induced oxidative stress on Caenorhabditis elegans was examined at the level of catalase activity and on innate immunity. Stress-induced C. elegans was exposed to Pseudomonas aeruginosa PA14::GFP for monitoring the impact at the physiological level. Role of catalase on the innate-immune responses of C. elegans was examined. PA14::GFP did not colonize lead pretreated C. elegans intestinal cells significantly compared to untreated controls, indicating stress-mediated upregulation of host-immunity. Semiquantitative PCR analyses of lead-exposed and PA14-infected C. elegans mRNA showed significant upregulation of candidate antimicrobial enzyme gene lys-7 after 24 h of exposures. Upregulation of metallothionein(mtl-1) when compared to mtl-2 in response to the lead suggesting active detoxification of metal by mtl-1. Exogenously provided Catalase (0.4-3.2 U) induced significant upregulation of lys-7 compared to controls. lys-7 upregulation during lead exposure was reconfirmed by real-time PCR. Confocal microscopy and fluorescence spectrophotometer analyses indicated that the lead pretreated C. elegans was significantly less colonized by PA14::GFP when compared to controls. Relative expression of ctl-1 and ctl-2 mRNA was measured using real time PCR and found to be regulated during lead exposures. Over all, the upregulation of antimicrobial gene expression appears to be correlated with the level of catalase during stress emphasizing their key roles in defensive mechanism(s). These results provide a link between the stress and related immune responses which can be explored in higher systems. PMID:21656642

  3. Development of a feeding trochophore in the polychaete Hydroides elegans.

    PubMed

    Arenas-Mena, Cesar; Li, Ava

    2014-01-01

    Hydroides elegans is an indirectly developing polychaete with equal spiral cleavage, gastrulation by invagination, and a feeding trochophore. Expression of several transcription factors and differentiation genes has been characterized. Comparative analysis reveals evolutionarily conserved roles. For example, the synexpression of transcription factors FoxA and Brachyury suggests homology of primary and secondary gut openings in protostomes and deuterostomes, and the expression of Sall suggests similar regulatory controls in the posterior growth zone of bilaterians. Differences in gene expression suggest regulatory differences control gastrulation by invagination in polychaetes with a feeding trochophore and gastrulation by epiboly in polychaetes without a feeding trochophore. Association of histone variant H2A.Z with transcriptional potency and its expression suggest a developmental role during both embryogenesis and the larva-to-adult transformation. Methods are being developed for experimental exploration of the gene regulatory networks involved in trochophore development in Hydroides. It is unknown if polychaete feeding trochophores evolved from a larval stage already present in the life cycle of the last common ancestor of protostomes and deuterostomes. Previous evolutionary scenarios about larval origins overemphasize the discontinuity between larval and adult development and require the early evolution of undifferentiated and transcriptionally potent "set aside" cells. Indirect development may proceed by developmental remodeling of differentiated cells and could have evolved after gradual transformation of juveniles into larvae; undifferentiated and transcriptionally potent cells would have evolved secondarily. Comprehensive characterization of gene regulatory networks for feeding trochophore development may help resolve these major evolutionary questions. PMID:25690971

  4. Multidimensional regulation of gene expression in the C. elegans embryo

    PubMed Central

    Murray, John Isaac; Boyle, Thomas J.; Preston, Elicia; Vafeados, Dionne; Mericle, Barbara; Weisdepp, Peter; Zhao, Zhongying; Bao, Zhirong; Boeck, Max; Waterston, Robert H.

    2012-01-01

    How cells adopt different expression patterns is a fundamental question of developmental biology. We quantitatively measured reporter expression of 127 genes, primarily transcription factors, in every cell and with high temporal resolution in C. elegans embryos. Embryonic cells are highly distinct in their gene expression; expression of the 127 genes studied here can distinguish nearly all pairs of cells, even between cells of the same tissue type. We observed recurrent lineage-regulated expression patterns for many genes in diverse contexts. These patterns are regulated in part by the TCF-LEF transcription factor POP-1. Other genes' reporters exhibited patterns correlated with tissue, position, and left杛ight asymmetry. Sequential patterns both within tissues and series of sublineages suggest regulatory pathways. Expression patterns often differ between embryonic and larval stages for the same genes, emphasizing the importance of profiling expression in different stages. This work greatly expands the number of genes in each of these categories and provides the first large-scale, digitally based, cellular resolution compendium of gene expression dynamics in live animals. The resulting data sets will be a useful resource for future research. PMID:22508763

  5. Whole-genome profiling of mutagenesis in Caenorhabditis elegans.

    PubMed

    Flibotte, Stephane; Edgley, Mark L; Chaudhry, Iasha; Taylor, Jon; Neil, Sarah E; Rogula, Aleksandra; Zapf, Rick; Hirst, Martin; Butterfield, Yaron; Jones, Steven J; Marra, Marco A; Barstead, Robert J; Moerman, Donald G

    2010-06-01

    Deep sequencing offers an unprecedented view of an organism's genome. We describe the spectrum of mutations induced by three commonly used mutagens: ethyl methanesulfonate (EMS), N-ethyl-N-nitrosourea (ENU), and ultraviolet trimethylpsoralen (UV/TMP) in the nematode Caenorhabditis elegans. Our analysis confirms the strong GC to AT transition bias of EMS. We found that ENU mainly produces A to T and T to A transversions, but also all possible transitions. We found no bias for any specific transition or transversion in the spectrum of UV/TMP-induced mutations. In 10 mutagenized strains we identified 2723 variants, of which 508 are expected to alter or disrupt gene function, including 21 nonsense mutations and 10 mutations predicted to affect mRNA splicing. This translates to an average of 50 informative mutations per strain. We also present evidence of genetic drift among laboratory wild-type strains derived from the Bristol N2 strain. We make several suggestions for best practice using massively parallel short read sequencing to ensure mutation detection. PMID:20439774

  6. Whole-Genome Profiling of Mutagenesis in Caenorhabditis elegans

    PubMed Central

    Flibotte, Stephane; Edgley, Mark L.; Chaudhry, Iasha; Taylor, Jon; Neil, Sarah E.; Rogula, Aleksandra; Zapf, Rick; Hirst, Martin; Butterfield, Yaron; Jones, Steven J.; Marra, Marco A.; Barstead, Robert J.; Moerman, Donald G.

    2010-01-01

    Deep sequencing offers an unprecedented view of an organism's genome. We describe the spectrum of mutations induced by three commonly used mutagens: ethyl methanesulfonate (EMS), N-ethyl-N-nitrosourea (ENU), and ultraviolet trimethylpsoralen (UV/TMP) in the nematode Caenorhabditis elegans. Our analysis confirms the strong GC to AT transition bias of EMS. We found that ENU mainly produces A to T and T to A transversions, but also all possible transitions. We found no bias for any specific transition or transversion in the spectrum of UV/TMP-induced mutations. In 10 mutagenized strains we identified 2723 variants, of which 508 are expected to alter or disrupt gene function, including 21 nonsense mutations and 10 mutations predicted to affect mRNA splicing. This translates to an average of 50 informative mutations per strain. We also present evidence of genetic drift among laboratory wild-type strains derived from the Bristol N2 strain. We make several suggestions for best practice using massively parallel short read sequencing to ensure mutation detection. PMID:20439774

  7. Selection against males in Caenorhabditis elegans under two mutational treatments

    PubMed Central

    Manoel, Diogo; Carvalho, Sara; Phillips, Patrick C; Teot髇io, Henrique

    2006-01-01

    Within populations with mixed mating systems, selfing is expected to be favoured over outcrossing unless a countervailing process such as severe inbreeding depression is present. In this study, we consider the relationship between the expression of deleterious alleles and the maintenance of outcrossing in the nematode species, Caenorhabditis elegans. This species is characterized by an androdioecious breeding system composed of males at low frequency and self-fertilizing hermaphrodites that can only outcross via males. Here, we find that experimentally increasing the mutational load in four different isogenic wild isolates using 10 generations of Ethylmethane sulphonate (EMS) and UV irradiation mutagenesis significantly diminishes the cost of males. Males are maintained at higher frequencies in mutagenized versus non-mutagenized populations. Nevertheless, males still tend to be driven to low frequencies within isolates that are known to be prone to lose males. Further, we determine the viability effects of a single round of mutagen exposure and find that, for EMS, outcrossing overcomes the almost completely recessive and nearly lethal effects generated. We briefly interpret our results in light of current evolutionary theory of outcrossing rates. PMID:17164206

  8. xnd-1 Regulates the Global Recombination Landscape in C. elegans

    PubMed Central

    Wagner, Cynthia R.; Kuervers, Lynnette; Baillie, David; Yanowitz, Judith L.

    2010-01-01

    Meiotic crossover (CO) recombination establishes physical linkages between homologous chromosomes that are required for their proper segregation into developing gametes and promotes genetic diversity by shuffling genetic material between parental chromosomes. COs require the formation of double strand breaks (DSBs) to create the substrate for strand exchange. DSBs occur in small intervals called hotspots1-3 and significant variation in hotspot usage exists between and among individuals4. This variation is thought to reflect differences in sequence identity and chromatin structure, DNA topology and/ or chromosome domain organization1, 5-9. Chromosomes show different frequencies of nondisjunction (NDJ)10, reflecting inherent differences in meiotic crossover control, yet the underlying basis of these differences remains elusive. Here we show that a novel chromatin factor, X non-disjunction factor 1 (xnd-1), is responsible for the global distribution of COs in C. elegans. xnd-1 is also required for formation of double-strand breaks (DSBs) on the X, but surprisingly XND-1 protein is autosomally-enriched. We show that xnd-1 functions independently of genes required for X chromosome-specific gene silencing, revealing a novel pathway that distinguishes the X from autosomes in the germ line, and further show that xnd-1 exerts its effects on COs, at least in part, by modulating levels of H2A lysine 5 acetylation. PMID:20944745

  9. Male Phenotypes and Mating Efficiency in CAENORHABDITIS ELEGANS

    PubMed Central

    Hodgkin, Jonathan

    1983-01-01

    Mating behavior in adult male nematodes can be assayed by mating efficiency, i.e., the number of cross progeny sired by males under standard conditions. Mutant males from 220 strains, representing most of the known complementation groups of C. elegans, have been examined for mating efficiency and for anatomical abnormalities of the specialized male copulatory organs. These data extend the phenotypic description of these mutants and indicate what anatomical and behavioral components are necessary for the ability to mate successfully. Also, mutants with specific defects in the male were sought by establishing superficially wild-type hermaphrodite stocks after mutagenesis and testing the males segregated by these stocks for mating efficiency. Forty-nine of 1119 stocks yielded abnormal males. Seventeen were characterized in detail and found to be abnormal in sensory behavior (carrying mutations in the genes che-2 or che-3) or male genital anatomy (carrying mutations in one of the genes mab-1 to mab-10). Four of the mab (male abnormal) genes affect specific postembryonic cell lineages. PMID:17246100

  10. Genetic and Phenotypic Characterization of Roller Mutants of CAENORHABDITIS ELEGANS

    PubMed Central

    Cox, George N.; Laufer, John S.; Kusch, Meredith; Edgar, Robert S.

    1980-01-01

    Eighty-eight mutants of C. elegans that display a roller phenotype (a helically twisted body) have been isolated and characterized genetically and phenotypically. The mutations are located in 14 different genes. Most genes contain a number of alleles. Their distribution among the chromosomes appears nonrandom, with seven of the genes being located on linkage group II, some very closely linked. The phenotypes of the mutants suggest that there are five different classes of genes, each class representing a set of similar phenotypic effects: Left Roller (four genes), Right Roller (one gene), Left Squat (one gene), Right Squat (two genes) and Left Dumpy Roller (six genes). The classes of mutants differ with respect to a number of characteristics that include the developmental stages affected and the types of aberrations observed in cuticle structure. A variety of gene interactions were found, arguing that these genes are involved in a common developmental process. The presence of alterations in cuticle morphology strongly suggests that these genes are active in the formation of the nematode cuticle. PMID:17249038

  11. Analysis of Dominant Mutations Affecting Muscle Excitation in Caenorhabditis Elegans

    PubMed Central

    Reiner, D. J.; Weinshenker, D.; Thomas, J. H.

    1995-01-01

    We examined mutations that disrupt muscle activation in Caenorhabditis elegans. Fifteen of 17 of these genes were identified previously and we describe new mutations in three of them. We also describe mutations in two new genes, exp-3 and exp-4. We assessed the degree of defect in pharyngeal, body-wall, egg-laying, and enteric muscle activation in animals mutant for each gene. Mutations in all 17 genes are semidominant and, in cases that could be tested, appear to be gain-of-function. Based on their phenotypes, the genes fall into three broad categories: mutations in 11 genes cause defective muscle activation, mutations in four genes cause hyperactivated muscle, and mutations in two genes cause defective activation in some muscle types and hyperactivation in others. In all testable cases, the mutations blocked response to pharmacological activators of egg laying, but did not block muscle activation by irradiation with a laser microbeam. The data suggest that these mutations affect muscle excitation, but not the capacity of the muscle fibers to contract. For most of the genes, apparent loss-of-function mutants have a grossly wild-type phenotype. These observations suggest that there is a large group of genes that function in muscle excitation that can be identified primarily by dominant mutations. PMID:8582640

  12. Tc8, a Tourist-like transposon in Caenorhabditis elegans.

    PubMed Central

    Le, Q H; Turcotte, K; Bureau, T

    2001-01-01

    Members of the Tourist family of miniature inverted-repeat transposable elements (MITEs) are very abundant among a wide variety of plants, are frequently found associated with normal plant genes, and thus are thought to be important players in the organization and evolution of plant genomes. In Arabidopsis, the recent discovery of a Tourist member harboring a putative transposase has shed new light on the mobility and evolution of MITEs. Here, we analyze a family of Tourist transposons endogenous to the genome of the nematode Caenorhabditis elegans (Bristol N2). One member of this large family is 7568 bp in length, harbors an ORF similar to the putative Tourist transposase from Arabidopsis, and is related to the IS5 family of bacterial insertion sequences (IS). Using database searches, we found expressed sequence tags (ESTs) similar to the putative Tourist transposases in plants, insects, and vertebrates. Taken together, our data suggest that Tourist-like and IS5-like transposons form a superfamily of potentially active elements ubiquitous to prokaryotic and eukaryotic genomes. PMID:11454757

  13. A variety of dicer substrates in human and C. elegans.

    PubMed

    Rybak-Wolf, Agnieszka; Jens, Marvin; Murakawa, Yasuhiro; Herzog, Margareta; Landthaler, Markus; Rajewsky, Nikolaus

    2014-11-20

    The endoribonuclease Dicer is known for its central role in the biogenesis of eukaryotic small RNAs/microRNAs. Despite its importance, Dicer target transcripts have not been directly mapped. Here, we apply biochemical methods to human cells and C.elegans and identify thousands of Dicer-binding sites. We find known and hundreds of additional miRNAs with high sensitivity and specificity. We also report structural RNAs, promoter RNAs, and mitochondrial transcripts as Dicer targets. Interestingly, most Dicer-binding sites reside on mRNAs/lncRNAs and are not significantly processed into small RNAs. These passive sites typically harbor small, Dicer-bound hairpins within intact transcripts and generally stabilize target expression. We show that passive sites can sequester Dicer and reduce microRNA expression. mRNAs with passive sites were in human and worm significantly associated with processing-body/granule function. Together, we provide the first transcriptome-wide map of Dicer targets and suggest conserved binding modes and functions outside of the miRNA pathway. PMID:25416952

  14. Mechanisms of branchial cartilage growth in Astatotilapia elegans (Teleostei: Cichlidae).

    PubMed Central

    Huysseune, A; Verraes, W; Desender, K

    1988-01-01

    The growth of the cartilaginous infrapharyngobranchial II (part of the upper pharyngeal jaws) in the cichlid fish Astatotilapia elegans was investigated in four successive early postembryonic stages. Total cell number, individual cell volumes, total cell, total matrix and total cartilage volume were accurately measured or calculated. The share of cell and matrix volume increase in the overall growth was calculated for each of the transitions. Matrix volume increase accounted for almost 60% of the overall rudiment increase. Non-hypertrophic cells and the matrix produced by them together accounted for about three quarters of the total cartilage volume increase. Zones with particular characteristics (cell orientation, cell shape, degenerative features, etc.) were distinguished in each of the four stages separately. The sequence of increasing mean cell volume between zones was interpreted as reflecting growth directions within the cartilage. Apposition probably largely contributed to the observed cell volume increase. Mean cell volume and mean matrix volume per cell showed a highly significant positive relation. Cell density showed a highly significant negative relation to both mean cell volume and mean matrix volume. Our results indicate that the area of hypertrophy and cartilage resorption may be established quite early in the rudiment before overt manifestation of these processes. Images Fig. 2 Fig. 3 Fig. 4 PMID:3225217

  15. Undulatory locomotion of finite filaments: lessons from C. elegans

    NASA Astrophysics Data System (ADS)

    Leshansky, Alexander; Kenneth, Oded; Berman, Rotem; Sznitman, Josue

    2013-11-01

    Undulatory swimming is a widespread propulsion strategy adopted by many small-scale organisms including various single-cell eukaryotes and nematodes. In this work, we report a comprehensive study of undulatory locomotion of a finite filament using an approximate resistive force theory (RFT) and particle-based numerical computations. Using the ubiquitous model of a propagating sinusoidal waveform, we identify the limit of applicability of the RFT and determine the optimal propulsion gait in terms of (i) swimming distance covered per period of undulation and (ii) hydrodynamic propulsion efficiency. To compare the model sine swimmer to biological undulatory swimmers, we apply the particle-based approach to study locomotion of the of the model organism nematode Caenorhabditis elegans using the swimming gait extracted from experiments. The analysis reveals that the nematode overperforms the model sine swimmer in terms of both displacement and efficiency. Further comparison with common undulatory microorganisms reveals that many adopt waveforms with characteristics similar to the most efficient sine swimmer, yet real swimmers still manage to beat the latter in terms of speed. Our results emphasize the importance of the waveform optimization.

  16. Epidermal Wound Healing in the Nematode Caenorhabditis elegans

    PubMed Central

    Chisholm, Andrew D.

    2015-01-01

    Significance: Healing of epidermal wounds is a fundamentally conserved process found in essentially all multicellular organisms. Studies of anatomically simple and genetically tractable model invertebrates can illuminate the roles of key genes and mechanisms in wound healing. Recent Advances: The nematode skin is composed of a simple epithelium, the epidermis (also known as hypodermis), and an associated extracellular cuticle. Nematodes likely have a robust capacity for epidermal repair; yet until recently, relatively few studies have directly analyzed wound healing. Here we review epidermal wound responses and repair in the model nematode Caenorhabditis elegans. Critical Issues: Wounding the epidermis triggers a cutaneous innate immune response and wound closure. The innate immune response involves upregulation of a suite of antimicrobial peptides. Wound closure involves a Ca2+-triggered rearrangement of the actin cytoskeleton. These processes appear to be initiated independently, yet, their coordinated activity allows the animal to survive otherwise fatal skin wounds. Future Directions: Unanswered questions include the nature of the damage-associated molecular patterns sensed by the epidermis, the signaling pathways relaying Ca2+ to the cytoskeleton, and the mechanisms of permeability barrier repair. PMID:25945288

  17. Mortality shifts in Caenorhabditis elegans: remembrance of conditions past

    PubMed Central

    Wu, Deqing; Rea, Shane L.; Cypser, James R.; Johnson, Thomas E.

    2009-01-01

    Summary The analysis of age-specific mortality can yield insights into how anti-aging interventions operate that cannot be matched by simple assessment of longevity. Mortality, as opposed to longevity, can be used to assess the effects of an anti-aging intervention on a daily basis, rather than only after most animals have died. Various gerontogene mutations in Caenorhabditis elegans have been shown to increase longevity as much as ten-fold and to decrease mortality at some ages even more.. Environmental alterations, such as reduced food intake (dietary restriction) and lower temperature also result in reduced mortality soon after the intervention. Here we ask how soon anti-aging interventions, applied during adult life, affect age-specific mortality in nematodes. Using Maximum Likelihood Analysis, we estimated the Gompertz parameters after shifts of temperature, and of food concentration and maintenance conditions. In separate experiments, we altered expression of age-1 and daf-16, using RNAi. Using about 44,000 nematodes in total, to examine daily mortality, we find that for both types of environmental shift, mortality responded immediately in the first assessment, while RNAi-induced changes resulted in a slower response, perhaps due to delayed mechanics of RNAi action. However, under all conditions there is a permanent 搈emory of past states, such that the initial mortality component [a] of the Gompertz equation [?(x)= aebx] bears a permanent 搃mprint of that earlier state. However, 揵 (the rate of mortality increase with age) is always specified by the current conditions. PMID:19747231

  18. Gene pathways that delay Caenorhabditis elegans reproductive senescence.

    PubMed

    Wang, Meng C; Oakley, Holly D; Carr, Christopher E; Sowa, Jessica N; Ruvkun, Gary

    2014-12-01

    Reproductive senescence is a hallmark of aging. The molecular mechanisms regulating reproductive senescence and its association with the aging of somatic cells remain poorly understood. From a full genome RNA interference (RNAi) screen, we identified 32 Caenorhabditis elegans gene inactivations that delay reproductive senescence and extend reproductive lifespan. We found that many of these gene inactivations interact with insulin/IGF-1 and/or TGF-? endocrine signaling pathways to regulate reproductive senescence, except nhx-2 and sgk-1 that modulate sodium reabsorption. Of these 32 gene inactivations, we also found that 19 increase reproductive lifespan through their effects on oocyte activities, 8 of them coordinate oocyte and sperm functions to extend reproductive lifespan, and 5 of them can induce sperm humoral response to promote reproductive longevity. Furthermore, we examined the effects of these reproductive aging regulators on somatic aging. We found that 5 of these gene inactivations prolong organismal lifespan, and 20 of them increase healthy life expectancy of an organism without altering total life span. These studies provide a systemic view on the genetic regulation of reproductive senescence and its intersection with organism longevity. The majority of these newly identified genes are conserved, and may provide new insights into age-associated reproductive senescence during human aging. PMID:25474471

  19. Bioprocessing in microgravity: free flow electrophoresis of C. elegans DNA.

    PubMed

    Kobayashi, H; Ishii, N; Nagaoka, S

    1996-06-27

    Free flow electrophoresis of a nematode C. elegans DNA was carried out on the space shuttle flight STS65/Colombia. During the processes of the experiment, the house keeping data of the FFEU and the electrophoretic migration profiles were monitored at POCC (Payload Operations Control Center) of MSFC (Marshall Space Flight Center, Alabama) according to the real-time down-link system. The three dimensional electropherogram (3DEP) on the basis of the down-linked data showed some trouble with the apparatus but three sequential experiments indicated this disturbance of the apparatus is rather preferably stable. Comparing post-flight analyses of the DNA component fractionated, that is, amplification by PCR method, it revealed that the DNAs were separated approximately into two peaks: one of them contained seven-fold higher content of DNA estimated by a sod-4 gene probe than an unc-6 gene probe. These results suggested that this separation technique could be still more effective for the separation of biological macromolecules such as DNA, and the efficiency of separation of the free flow electrophoresis under microgravity environment was useful. PMID:8987575

  20. D-beta-hydroxybutyrate extends lifespan in C. elegans.

    PubMed

    Edwards, Clare; Canfield, John; Copes, Neil; Rehan, Muhammad; Lipps, David; Bradshaw, Patrick C

    2014-08-01

    The ketone body beta-hydroxybutyrate (?HB) is a histone deacetylase (HDAC) inhibitor and has been shown to be protective in many disease models, but its effects on aging are not well studied. Therefore we determined the effect of ?HB supplementation on the lifespan ofC. elegans nematodes. ?HB supplementation extended mean lifespan by approximately 20%. RNAi knockdown of HDACs hda-2 or hda-3 also increased lifespan and further prevented ?HB-mediated lifespan extension. ?HB-mediated lifespan extension required the DAF-16/FOXO and SKN-1/Nrf longevity pathways, the sirtuin SIR-2.1, and the AMP kinase subunit AAK-2. ?HB did not extend lifespan in a genetic model of dietary restriction indicating that ?HB is likely functioning through a similar mechanism. ?HB addition also upregulated ?HB dehydrogenase activity and increased oxygen consumption in the worms. RNAi knockdown of F55E10.6, a short chain dehydrogenase and SKN-1 target gene, prevented the increased lifespan and ?HB dehydrogenase activity induced by ?HB addition, suggesting that F55E10.6 functions as an inducible ?HB dehydrogenase. Furthermore, ?HB supplementation increased worm thermotolerance and partially prevented glucose toxicity. It also delayed Alzheimer's amyloid-beta toxicity and decreased Parkinson's alpha-synuclein aggregation. The results indicate that D-?HB extends lifespan through inhibiting HDACs and through the activation of conserved stress response pathways. PMID:25127866

  1. CAENORHABDITIS ELEGANS Fertilization-Defective Mutants with Abnormal Sperm

    PubMed Central

    Argon, Yair; Ward, Samuel

    1980-01-01

    Seven new fertilization-defective mutants of C. elegans have been isolated and characterized; six are temperature sensitive, one is absolute and all are autosomal recessive. One mutation is in a previously described gene, while the other six define six new fer genes that appear to code for sperm-specific functions necessary for normal fertilization. In all fer mutants, both males and hermaphrodites accumulate sperm in near normal numbers. In hermaphrodites, mutant sperm contact the oocytes, but fail to fertilize them. Instead, the sperm are swept into the uterus by the passing oocytes and are expelled when oocytes are laid. Males of two fer mutants do not transfer sperm during copulation, but the other mutant males transfer sperm that fail to move to the spermatheca. Spermatozoa from fer-1 and fer-4 mutants are motility-defective in vitro as well as in vivo, and their pseudopods have an altered morphology. The period of development during which mutant hermaphrodites are temperature sensitive for fertility overlaps the time of sperm development. Some mutants are temperature sensitive throughout the entire period, and others are temperature sensitive during or just prior to spermiogenesis. In fer-4/+ and fer-7/+ males, the fertility of the mutation-bearing sperm is diminished, reducing the transmission ratio. This implies some post-meiotic expression of these genes.桾his set of mutants provides a variety of functional and structural alterations in nematode sperm that should help identify and analyze gene products involved in sperm morphogenesis and motility. PMID:7196361

  2. Challenging muscle homeostasis uncovers novel chaperone interactions in Caenorhabditis elegans

    PubMed Central

    Frumkin, Anna; Dror, Shiran; Pokrzywa, Wojciech; Bar-Lavan, Yael; Karady, Ido; Hoppe, Thorsten; Ben-Zvi, Anat

    2014-01-01

    Proteome stability is central to cellular function and the lifespan of an organism. This is apparent in muscle cells, where incorrect folding and assembly of the sarcomere contributes to disease and aging. Apart from the myosin-assembly factor UNC-45, the complete network of chaperones involved in assembly and maintenance of muscle tissue is currently unknown. To identify additional factors required for sarcomere quality control, we performed genetic screens based on suppressed or synthetic motility defects in Caenorhabditis elegans. In addition to ethyl methyl sulfonate-based mutagenesis, we employed RNAi-mediated knockdown of candidate chaperones in unc-45 temperature-sensitive mutants and screened for impaired movement at permissive conditions. This approach confirmed the cooperation between UNC-45 and Hsp90. Moreover, the screens identified three novel co-chaperones, CeHop (STI-1), CeAha1 (C01G10.8) and Cep23 (ZC395.10), required for muscle integrity. The specific identification of Hsp90 and Hsp90 co-chaperones highlights the physiological role of Hsp90 in myosin folding. Our work thus provides a clear example of how a combination of mild perturbations to the proteostasis network can uncover specific quality control modules. PMID:25988162

  3. Mechanisms controlling sex myoblast migration in Caenorhabditis elegans hermaphrodites.

    PubMed

    Branda, C S; Stern, M J

    2000-10-01

    Sex myoblast migration in C. elegans hermaphrodites is controlled by multiple guidance mechanisms. A gonad-dependent attraction functions to guide the sex myoblasts to their precise final positions flanking the gonad. In the absence of this attraction, a gonad-dependent repulsion is revealed. In addition to gonad-dependent influences, a gonad-independent mechanism propels the sex myoblasts anteriorly to a broad range of positions near the center of the animal. Here we describe a temporal analysis of sex myoblast migration that reveals when the gonad-dependent attraction and the gonad-independent mechanisms normally function. We provide evidence that EGL-17, a fibroblast growth factor-like protein, is expressed in the gonadal cells required to attract the sex myoblasts to their precise final positions, further supporting our model that EGL-17 defines the gonad-dependent attractant. Furthermore, cell ablation experiments reveal that EGL-17 and the gonad-dependent repellent likely emanate from the same cellular sources. Analyses of candidate mutations for their effects on the gonad-dependent repulsion reveal that a set of genes known to affect multiple aspects of axonogenesis, unc-14, unc-33, unc-44, and unc-51, is essential for this repulsive mechanism. In addition, we have discovered that a SAX-3/Roundabout-dependent mechanism is used to maintain the sex myoblasts along the ventral muscle quadrants. PMID:10993679

  4. Regulation of DAF-16-mediated Innate Immunity in Caenorhabditis elegans*

    PubMed Central

    Singh, Varsha; Aballay, Alejandro

    2009-01-01

    Activation of the innate immune system results in a rapid microbicidal response against microorganisms, which needs to be fine-tuned because uncontrolled immune responses can lead to infection and cancer, as well as conditions such as Crohn disease, atherosclerosis, and Alzheimer disease. Here we report that excessive activity of the conserved FOXO transcription factor DAF-16 enhances susceptibility to bacterial infections in Caenorhabditis elegans. We found that increased temperature activates not only DAF-16 nuclear import but also a control mechanism involved in DAF-16 nuclear export. The nuclear export of DAF-16 requires heat shock transcription factor HSF-1 and Hsp70/HSP-1. Furthermore, we show that increased expression of the water channel Aquoporin-1 is responsible for the deleterious consequences of excessive DAF-16-mediated immune response. These studies reveal a stress-inducible mechanism involved in the regulation of DAF-16 and indicate that uncontrolled DAF-16 activity and water homeostasis are a cause of the deleterious effects of excessive immune responses. PMID:19858203

  5. Gene Pathways That Delay Caenorhabditis elegans Reproductive Senescence

    PubMed Central

    Wang, Meng C.; Oakley, Holly D.; Carr, Christopher E.; Sowa, Jessica N.; Ruvkun, Gary

    2014-01-01

    Reproductive senescence is a hallmark of aging. The molecular mechanisms regulating reproductive senescence and its association with the aging of somatic cells remain poorly understood. From a full genome RNA interference (RNAi) screen, we identified 32 Caenorhabditis elegans gene inactivations that delay reproductive senescence and extend reproductive lifespan. We found that many of these gene inactivations interact with insulin/IGF-1 and/or TGF-? endocrine signaling pathways to regulate reproductive senescence, except nhx-2 and sgk-1 that modulate sodium reabsorption. Of these 32 gene inactivations, we also found that 19 increase reproductive lifespan through their effects on oocyte activities, 8 of them coordinate oocyte and sperm functions to extend reproductive lifespan, and 5 of them can induce sperm humoral response to promote reproductive longevity. Furthermore, we examined the effects of these reproductive aging regulators on somatic aging. We found that 5 of these gene inactivations prolong organismal lifespan, and 20 of them increase healthy life expectancy of an organism without altering total life span. These studies provide a systemic view on the genetic regulation of reproductive senescence and its intersection with organism longevity. The majority of these newly identified genes are conserved, and may provide new insights into age-associated reproductive senescence during human aging. PMID:25474471

  6. D-beta-hydroxybutyrate extends lifespan in C. elegans

    PubMed Central

    Edwards, Clare; Canfield, John; Copes, Neil; Rehan, Muhammad; Lipps, David; Bradshaw, Patrick C.

    2014-01-01

    The ketone body beta-hydroxybutyrate (?HB) is a histone deacetylase (HDAC) inhibitor and has been shown to be protective in many disease models, but its effects on aging are not well studied. Therefore we determined the effect of ?HB supplementation on the lifespan of C. elegans nematodes. ?HB supplementation extended mean lifespan by approximately 20%. RNAi knockdown of HDACs hda-2 or hda-3 also increased lifespan and further prevented ?HB-mediated lifespan extension. ?HB-mediated lifespan extension required the DAF-16/FOXO and SKN-1/Nrf longevity pathways, the sirtuin SIR-2.1, and the AMP kinase subunit AAK-2. ?HB did not extend lifespan in a genetic model of dietary restriction indicating that ?HB is likely functioning through a similar mechanism. ?HB addition also upregulated ?HB dehydrogenase activity and increased oxygen consumption in the worms. RNAi knockdown of F55E10.6, a short chain dehydrogenase and SKN-1 target gene, prevented the increased lifespan and ?HB dehydrogenase activity induced by ?HB addition, suggesting that F55E10.6 functions as an inducible ?HB dehydrogenase. Furthermore, ?HB supplementation increased worm thermotolerance and partially prevented glucose toxicity. It also delayed Alzheimer's amyloid-beta toxicity and decreased Parkinson's alpha-synuclein aggregation. The results indicate that D-?HB extends lifespan through inhibiting HDACs and through the activation of conserved stress response pathways. PMID:25127866

  7. Abietane diterpenoids from Isodon lophanthoides var. graciliflorus and their cytotoxicity.

    PubMed

    Zhou, Wenting; Xie, Haihui; Wu, Ping; Wei, Xiaoyi

    2013-01-15

    Seven new (1-7) and three known (8-10) abietane diterpenoids were isolated from the methanolic extract of the aerial parts of Isodon lophanthoides var. graciliflorus (Lamiaceae), a folk Chinese medicine and an herb for functional beverages. They were identified as 16-acetoxylsugiol (1), graciliflorin E (2), graciliflorin F (3), 15-O-methylgraciliflorin F (4), 15-hydroxy-20-deoxocarnosol (5), 3?-hydroxysempervirol (6), 15-hydroxy-1-oxosalvibretol (7), abieta-8,11,13-triene-14,19-diol (8), 6,12,15-trihydroxy-5,8,11,13-abietatetraen-7-one (9), and 3?-hinokiol (10) based on the spectroscopic data including COSY (correlated spectroscopy), HMBC (heteronuclear multiple bond correlation), and HR-ESI-MS (high-resolution electrospray ionization mass spectrometry). All the compounds except 10 were obtained from I. lophanthoides for the first time. Compounds 1, 2, 5, 6, 8, and 9 exhibited in vitro cytotoxicity against A549 (human lung adenocarcinoma), MCF-7 (human breast adenocarcinoma), and HeLa (human cervical carcinoma) cell lines with the IC(50) values of 1.79-52.67 ?M. PMID:23122169

  8. Acylated iridoids from the roots of Valeriana officinalis var. latifolia.

    PubMed

    Han, Zhu-zhen; Yan, Zhao-hui; Liu, Qing-xin; Hu, Xian-qing; Ye, Ji; Li, Hui-liang; Zhang, Wei-dong

    2012-10-01

    Phytochemical investigation of the roots of Valeriana officinalis var. latifolia resulted in the isolation and characterization of six new acylated iridoids, (5S,7S,8S,9S)-7-hydroxy-8-isovaleroyloxy-??,构-dihyronepetalactone (1), (5S,7S,8S,9S)-7-hydroxy-10-isovaleroyloxy-??,构-dihyronepetalactone (2), (5S,8S,9S)-10-isovaleroyloxy-??,构-dihyronepetalactone (3), (5S,6S,8S,9R)-6-isovaleroyloxy-??,构-1,3-diol (4), (5S,6S,8S,9R)-1,3-isovaleroxy-?4,11-1,3-diol (5), and (5S,6S,8S,9R)-3-isovaleroxy-6-isovaleroyloxy-??,构-1,3-diol (6). Their structures were determined mainly by 1D and 2D?NMR spectroscopic techniques. We also report herein for the first time the single crystal X-ray structure of compound 1. In addition, the cytotoxic activities of compounds 1-6 were evaluated against A549 (human lung adenocarcinoma), HCT116 (human colon carcinoma), SK-BR-3 (human breast carcinoma), and HepG2 (human hepatoma) cell lines. Compound 6 showed weak cell growth inhibition of A549, HCT116, SK-BR-3, and HepG2 cells. PMID:22872588

  9. Transport of Bacillus Thuringiensis var. Kurstaki Via Fomites

    PubMed Central

    Van Cuyk, Sheila; Veal, Lee Ann B.; Simpson, Beverley

    2011-01-01

    The intentional and controlled release of an aerosolized bacterium provides an opportunity to investigate the implications of a biological attack. Since 2006, Los Alamos National Laboratory has worked with several urban areas, including Fairfax County, VA, to design experiments to evaluate biodefense concepts of operations using routine spraying of Bacillus thuringiensis var. kurstaki (Btk). Btk is dispersed in large quantities as a slurry to control the gypsy moth, Lymantria dispar. Understanding whether personnel and equipment pick up residual contamination during sampling activities and transport it to other areas is critical for the formulation of appropriate response and recovery plans. While there is a growing body of literature surrounding the transmission of viral diseases via fomites, there is limited information on the transport of Bacillus species via this route. In 2008, LANL investigated whether field sampling activities conducted near sprayed areas, post-spray, resulted in measurable cross-contamination of sampling personnel, equipment, vehicles, and hotel rooms. Viable Btk was detected in all sample types, indicating transport of the agent occurred via fomites. PMID:21882970

  10. Bauhinia variegata var. variegata lectin: isolation, characterization, and comparison.

    PubMed

    Chan, Yau Sang; Ng, Tzi Bun

    2015-01-01

    Bauhinia variegata var. variegata seeds are rich in proteins. Previously, one of the major storage proteins of the seeds was found to be a trypsin inhibitor that possessed various biological activities. By using another purification protocol, a glucoside- and galactoside-binding lectin that demonstrated some differences from the previously reported B. variegata lectin could be isolated from the seeds. It involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono Q, and also size exclusion chromatography on Superdex 75. The lectin was not retained on Affi-gel blue gel but interacted with Q-Sepharose. The lectin was a 64-kDa protein with two 32-kDa subunits. It had low thermostability (stable up to 50 癈) and moderate pH stability (stable in pH 3-10). It exhibited anti-proliferative activity on nasopharyngeal carcinoma HONE1 cells with an IC50 of 12.8 ?M after treatment for 48 h. It also slightly inhibited the growth of hepatoma HepG2 cells. The lectin may have potential in aiding cancer treatments. PMID:25240852

  11. Reduced order POD/DEIM 4-D Var data assimilation

    NASA Astrophysics Data System (ADS)

    Navon, Michael; Stefanescu, Razvan

    2014-05-01

    The computational cost of realistic ensemble and hybrid variational/ensemble data assimilation is typically dominated by the cost of ensemble forecasting. The high computational cost of ensemble forecasting limits the number of ensembles, eventually creating a severe rank reduction. Consequently, the efficiency and quality of ensemble-based data assimilation are greatly reduced. With the ever-increasing spatiotemporal resolution and complexity of numerical weather prediction (NWP) models, the room for ensemble forecasting is getting even smaller, creating a paradox: Although the NWP generally benefits from increased resolution and complexity of the models, the quality of their data assimilation is getting worse due to additional computational restrictions. We propose POD model order reduction substantially improving computational efficiency of NWP models. We present recent advances in this domain and the state-of the art of hyper reduction addressing issues of turbulence closure and nonlinearities allowing CPU speed -ups of orders of magnitude, reduced order 4-D VAR and future prospects of implementation to operational NMP models.

  12. Transport of Bacillus thuringiensis var. kurstaki via fomites.

    PubMed

    Van Cuyk, Sheila; Veal, Lee Ann B; Simpson, Beverley; Omberg, Kristin M

    2011-09-01

    The intentional and controlled release of an aerosolized bacterium provides an opportunity to investigate the implications of a biological attack. Since 2006, Los Alamos National Laboratory has worked with several urban areas, including Fairfax County, VA, to design experiments to evaluate biodefense concepts of operations using routine spraying of Bacillus thuringiensis var. kurstaki (Btk). Btk is dispersed in large quantities as a slurry to control the gypsy moth, Lymantria dispar. Understanding whether personnel and equipment pick up residual contamination during sampling activities and transport it to other areas is critical for the formulation of appropriate response and recovery plans. While there is a growing body of literature surrounding the transmission of viral diseases via fomites, there is limited information on the transport of Bacillus species via this route. In 2008, LANL investigated whether field sampling activities conducted near sprayed areas, post-spray, resulted in measurable cross-contamination of sampling personnel, equipment, vehicles, and hotel rooms. Viable Btk was detected in all sample types, indicating transport of the agent occurred via fomites. PMID:21882970

  13. High-throughput screening for novel anti-infectives using a C. elegans pathogenesis model

    PubMed Central

    Conery, Annie L.; Larkins-Ford, Jonah; Ausubel, Frederick M.; Kirienko, Natalia V.

    2014-01-01

    In recent history, the nematode Caenorhabditis elegans has provided a compelling platform for the discovery of novel antimicrobial drugs. In this protocol, we present an automated, high-throughput C. elegans pathogenesis assay, which can be used to screen for anti-infective compounds that prevent nematodes from dying due to Pseudomonas aeruginosa. New antibiotics identified from such screens would be promising candidates for treatment of human infections, and also can be used as probe compounds to identify novel targets in microbial pathogenesis or host immunity. PMID:24652621

  14. Caenorhabditis elegans in Chinese Medicinal Studies: Making the Case for Aging and Neurodegeneration

    PubMed Central

    Wang, Qiangqiang; Yang, Fan; Guo, Wei; Zhang, Ju; Xiao, Lingyun; Li, Haifeng; Jia, Weizhang

    2014-01-01

    Abstract Aging is a progressive process with degenerative changes of various tissues and organs. As a classic model organism in genetics and neurobiology, Caenorhabditis elegans is also a powerful system in aging and behavioral studies and can be used at both the molecular and organismal levels to evaluate potential therapeutics for age-related neurodegeneration, owing to its short life span, relative simplicity, and high degree of experimental tractability as well as significant conservation of disease genes and signaling pathways with humans. We attempt here to summarize the use of C. elegans models in exploring traditional Chinese medicine for potential remedies against aging and neurodegeneration. PMID:24125529

  15. Methods for the culture of C. elegans and S. cerevisiae in microgravity.

    PubMed

    Fahlen, Thomas; Sunga, June; Rask, Jon; Herrera, Anna; Lam, Kitty; Sing, Luke; Sato, Kevin; Ramos, Ross A; Kirven-Brooks, Melissa; Reiss-Bubenheim, Debra

    2005-06-01

    To support the study of the effects of microgravity on biological systems, our group is developing and testing methods that allow the cultivation of C. elegans and S. cerevisiae in microgravity. Our aim is to develop the experimental means by which investigators may conduct peer reviewed biological experiments with C. elegans or S. cerevisiae in microgravity. Our protocols are aimed at enabling investigators to grow these organisms for extended periods during which samples may be sub-cultured, collected, preserved, frozen, and/or returned to earth for analysis. Data presented include characterization of the growth phenotype of these organisms in liquid medium in OptiCells(TM) (Biocrystal, LTD). PMID:16038100

  16. Insights from Caenorhabditis elegans on the role of metals in neurodegenerative diseases

    PubMed Central

    Martinez-Finley, Ebany J.; Avila, Daiana Silva; Chakraborty, Sudipta

    2011-01-01

    Neurodegeneration is characterized by the cell death or loss of structure and/or function of neurons. Many neurodegenerative diseases including Parkinson抯 disease (PD) and Alzheimer抯 disease (AD) are the result of neurodegenerative processes. Metals are essential for many life processes, but they are also culpable for several neurodegenerative mechanisms. In this review, we discuss the role of metals in neurodegenerative diseases with emphasis on the utility of Caenorhabditis elegans (C. elegans) genetic models in deciphering mechanisms associated with the etiology of PD and AD. PMID:21210060

  17. Measurement of the longitudinal spin transfer to ? and bar{\\varLambda} hyperons in polarised muon DIS

    NASA Astrophysics Data System (ADS)

    Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Austregesilo, A.; Bade?ek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M. P.; Chapiro, A.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Colantoni, M.; Crespo, M. L.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S. S.; Denisov, O. Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A. M.; Donskov, S. V.; Doshita, N.; Duic, V.; D黱nweber, W.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; Friedrich, J. M.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Grabm黮ler, S.; Grajek, O. A.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Heinsius, F. H.; Hermann, M.; Hermann, R.; Herrmann, F.; He, C.; Hinterberger, F.; Horikawa, N.; H鰌pner, Ch.; D'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iven, B.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabu, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J. H.; Kolosov, V. N.; Komissarov, E. V.; Kondo, K.; K鰊igsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V. F.; Korzenev, A.; Kotzinian, A. M.; Kouznetsov, O.; Kowalik, K.; Kr鋗er, M.; Kral, A.; Kroumchtein, Z. V.; Kuhn, R.; Kunne, F.; Kurek, K.; Le Goff, J. M.; Lednev, A. A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G. K.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A. N.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Moinester, M. A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Olshevsky, A. G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D. V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V. A.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.-F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D. I.; Samoylenko, V. D.; Sandacz, A.; Santos, H.; Sapozhnikov, M. G.; Sarkar, S.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schmitt, L.; Schr鰀er, W.; Shevchenko, O. Yu.; Siebert, H.-W.; Silva, L.; Sinha, L.; Sissakian, A. N.; Slunecka, M.; Smirnov, G. I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L. G.; Venugopal, G.; Virius, M.; Vlassov, N. V.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wi?licki, W.; Wollny, H.; Zaremba, K.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

    2009-11-01

    The longitudinal polarisation transfer from muons to ? and bar{\\varLambda} hyperons, D_{LL}^{\\varLambda(bar{\\varLambda})} , has been studied in deep-inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to ? and bar{\\varLambda} produced in the current fragmentation region exhibit different behaviours as a function of x and x F . The measured x and x F dependences of D {/LL ? } are compatible with zero, while D_{LL}^{bar{\\varLambda}} tends to increase with x F , reaching values of 0.4-0.5. The resulting average values are D {/LL ? } = -0.0120.0470.024 and D_{LL}^{bar{\\varLambda}} = 0.2490.0560.049. These results are discussed in the frame of recent model calculations.

  18. A study of the anther size and its relation to certain other characters of the spikelets in a cross between Avena sativa L. var. Bronco and Avena sterilis L. var. Macrocarpa

    E-print Network

    Kim, Heung Bae

    1966-01-01

    A STUDY OF THE ANTHER SIZE AND ITS RELATION TO CERTAIN OTHER CHARACTERS OF THE SPIKELETS IN A CROSS BEIWEEN AVENA SATIVA L. VAR. BRONCO AND AVENA STERILIS L. VAR. MACROCARPA A Thesis By Heung Bae Kim Submitted to the Graduate College... AVENA SATIVA L. VAR. BRONCO AND AVENA STERILIS L. VAR. MACROCARPA A Thesis By Heung Bae Kim Approved as to style and content by: (Chai. rman of Committee) r (Member) ( ead of Department) (Me ber) May 1966 ACKNCMLEDGMENTS The writer is highly...

  19. A study of the anther size and its relation to certain other characters of the spikelets in a cross between Avena sativa L. var. Bronco and Avena sterilis L. var. Macrocarpa

    E-print Network

    Kim, Heung Bae

    1966-01-01

    . sativa type was dominant to wild type base. 3. Pubescence Zinnf et al. (34), in a cross between A. sativa ~atula var. Vic- tor and A. sativa nude var. Inermis, found that the pubescence at the base of the lower grain behaves as a bifactorial character...) reported that the color of grain segre- gated in F2 in the ratio of 3 black and 1 white in a cross of A. sativa var. Victor (black) with A. sativa nuda var. Inermis (white) Wakabayashi (30) studied the color of the floral glumes in the crosses of A...

  20. Genetic Linkage Map of Citrullus lanatus var. Citroides Chromosomal Segments Introgressed into the Watermelon Cultivar Crimson Sweet (Citrullus lanatus var. lanatus) Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is need to develop of introgression lines, useful for genetic studies and genetic enhancement of watermelon. In this study, we used an advanced recombinant population (BC2F2) to identify and map chromosomal segments of the wild watermelon Citrullus lanatus var. citroides that were incorporate...