Meeting Announcements

3^rd International Meeting on the Congenital Disorders of Glycosylation ASIEM - 6 rue Albert de Lapparent - 75007 PARIS, France October18--19, 2007 The     

Meeting Announcements

3^rd International Meeting on the Congenital Disorders of Glycosylation ASIEM - 6 rue Albert de Lapparent - 75007 PARIS, France October18–19, 2007     

Electrophysiological characterization of the node in Chara corallina: functional differentiation for wounding response

Electrical characteristics of the node were analyzed in comparisonwith those of the flank of the internodal cell in Chara corallina.The dependence of the membrane potential of the node on pH andK⁺ concentration was almost the same as that of the flank. Inthe flank, the increase in the Ca²⁺ concentration stopped thedepolarization in the presence of 100 mM KCl. In the node, however,Ca²⁺ could not stop the depolarization induced by 100 mM KCl.It has been reported that the node has a function to tranducethe signal of osmotic shock into a transient depolarization.In combination with osmotic shock, 10 mM K⁺ could induce a long-lastingdepolarization of the node. These electrical characteristicsof the node were suggested to be responsible for the electricalresponse to wounding in Characeae.     

UMBONIUM VESTIARIUM (L.) (GASTROPODA, TROCHACEA) AS THE FOOD SOURCE FOR NATICID GASTROPODS AND A STARFISH ON A MALAYSIAN SANDY SHORE

Umbonium vestiarium (L.) forms virtually the entire diet of3 (possibly 4) species of naticid snails and the starfish Astropectenvappa Mueller annd Troschel on some north Penang sandy shores.Umbonium comprises about 99% of numbers and tissue of macrofauna.Predation totalled some 1.75 Umbonium (ca. 33 mg dry tissue).m^-2.day^-1 across much of the downshore sand flats rising to 2.3Umbonium (ca. 45 mg). m^-2. day^-1 near MLWS. Natica maculosaLamarck comprised > 80% of the predators and took 77–94%of the Umbonium eaten. Natica antonii Phillippi alone addedto this toll on the upper reaches of the zone while Polinicesspp and Astropecten appear to have taken 12–14% of thetotal toll of Umbonium near MLWS. Total predation is indicatedat 237–327 kJ.m^-2. year^-1 across the shore and this representsalmost the total flow of energy from primary consumers to intertidalbenthic predators on such shores and accounts for some 15.6%(lower shore)—20.5% (upper shore) of total Umbonium production. (Received 10 September 1982;     

Rhythmic and Light-Inducible Appearance of Clock-Associated Pseudo-Response Regulator Protein PRR9 through Programmed Degradation in the Dark in Arabidopsis thaliana

The above article was published in Plant and Cell Physiology48(11): 1644–1651. Figure 1 was shown incorrectly online. The figure legend inFigure 1C was missing. The correct figure is given below. View larger version (26K):   Fig. 1 Construction     

The signaling role of extracellular ATP and its dependence on Ca2+ flux in elicitation of Salvia miltiorrhiza hairy root cultures

The application of a polysaccharide elicitor from yeast extract,YE, to Salvia miltiorrhiza hairy root cultures induced transientrelease of ATP from the roots to the medium, leading to a dose-dependentincrease in the extracellular ATP (eATP) level. The eATP levelrose to a peak (about 6.5 nM with 100 mg l^–1 YE) at about10 h after YE treatment, but dropped to the control level 6h later. The elicitor-induced ATP release was dependent on membraneCa²⁺ influx, and abolished by the Ca²⁺ chelator EGTA or thechannel blocker La³⁺. The YE-induced H₂O₂ production was stronglyinhibited by reactive blue (RB), a specific inhibitor of membranepurinoceptors. On the other hand, the application of exogenousATP at 10–100 µM to the cultures also induced rapidand dose-dependent increases in H₂O₂ production and medium pH,both of which were effectively blocked by RB and EGTA. The non-hydrolyzableATP analog ATPS was as effective as ATP, but the hydrolyzedderivatives ADP or AMP were not so effective in inducing thepH and H₂O₂ increases. Our results suggest that ATP releaseis an early event and that eATP plays a signaling role in theelicitation of plant cell responses; Ca²⁺ is required for activationof the elicitor-induced ATP release and the eATP signal transduction.This is the first report on ATP release induced by a fungalelicitor and its involvement in the elicitor-induced responsesin plant cells.     

Auxin Stimulates Cl-Uptake by Oat Coleoptiles

The effects of auxin on net ion fluxes near parenchyma of oatcoleoptiles were studied using the non-invasive MIFE systemto measure specific ion fluxes using ion selective microelectrodes.Application of 10 µM1-naphthaleneacetic acid (NAA) for3 h caused doubling of coleoptile segment growth, without changingthe pH of the unbuffered bathing solution from pH 5.4 duringthat time. Short term experiments revealed that auxin led toan immediate three-fold increase of chloride influx to 1200nmol m^-2s^-1, maintained for at least 1 h. In the first minutesafter auxin application, proton fluxes were small (-25 nmolm^-2s^-1, an efflux) and tended to decrease, whereas potassiumand calcium fluxes changed little, fluctuating from -100 to0 nmol m^-2s^-1and from -15 to 0 nmol m^-2s^-1, respectively. Itis suggested that one target of auxin action in plant cellsis the plasma membrane chloride transport system mediating increasedchloride uptake.Copyright 1998 Annals of Botany Company Auxin, chloride transport, ion flux,Avena sativaL., oat.     

Effect of proline on wound vessel member formation

Pretreatment of Coleus blumei (BENTH.) stem explants for 24hr with L-proline (P) (1.0 mM) by the successive cup techniqueresulted in the redifferentiation of extremely high numbersof wound vessel members (WVM) from pith and cortical parenchymatissues following the addition of a xylogenic concentrationof 5 ppm indoleacetic acid (IAA). The addition of P with auxinor after auxin had been introduced into the segments was ineffectivein altering the numbers of WVM formed as compared to controls.P-treated segments showed both normal and aberrant WVM withthe addition of colchicine (0.01 %) and IAA; colchicine-treatedsegments invariably produced aberrant WVM when P and IAA weregiven. These results suggest that a P-rich substance may interactwith auxin in initiating wound vessel member differentiation. ¹Fulbright Professor of Botany, 1967-68. Permanent address:Department of Biological Sciences, University of Idaho, Moscow,Idaho, 83843, U. S. A.     

Effects of Nutrient Supply on Pre-emergence Growth and Nutrient Absorption in Wheat (Triticum aestivumL.) and Sugarbeet (Beta vulgarisL.)

Nutrient absorption in wheat and sugarbeet was studied duringpre-emergence growth by adding 0, 7, 10.5 or 14 mol m^-3nitrogen(N) to the growth medium. Seedling growth and carbon, N and¹⁵Ncontents of the seedling parts were measured. Differences betweenthe natural abundance of¹⁵N in seeds and in nutrient solutionwere used to determine the proportion of N in the organs originatingfrom seed reserves and from absorption. Absorption began laterfor wheat than for sugarbeet and had less effect on seedlinggrowth. The absorbed N was found mainly in roots. Compared towheat, sugarbeet seedling N content was greatly altered andthe hypocotyl showed increased elongation when nutrients wereadded. Most of the absorbed N was found in the radicle and hypocotylwith less in the cotyledons. Sugarbeet seedling emergence andearly growth could be decreased by adverse conditions occurringafter sowing by affecting mineral availability in the soil orthrough altered root absorption.Copyright 1998 Annals of BotanyCompany Triticum aestivumL., wheat,Beta vulgarisL., emergence, natural isotopic composition, seedling, seed reserves     

Xylem Hydraulic Characteristics, Water Relations and Wood Anatomy of the Resurrection PlantMyrothamnus flabellifoliusWelw.

Myrothamnus flabellifoliusWelw. is a desiccation-tolerant (‘resurrection’)plant with a woody stem. Xylem vessels are narrow (14 µmmean diameter) and perforation plates are reticulate. This leadsto specific and leaf specific hydraulic conductivities thatare amongst the lowest recorded for angiosperms (k_s0.87 kg m^-1MPa^-1s^-1;k_l3.28x10^-5kg m^-1MPa^-1s^-1, stem diameter 3 mm). Hydraulic conductivitiesdecrease with increasing pressure gradient. Transpiration ratesin well watered plants were moderate to low, generating xylemwater potentials of -1 to -2 MPa. Acoustic emissions indicatedextensive cavitation events that were initiated at xylem waterpotentials of -2 to -3 MPa. The desiccation-tolerant natureof the tissue permits this species to survive this interruptionof the water supply. On rewatering the roots pressures thatwere developed were low (2.4 kPa). However capillary forceswere demonstrated to be adequate to account for the refillingof xylem vessels and re-establishment of hydraulic continuityeven when water was under a tension of -8 kPa. During dehydrationand rehydration cycles stems showed considerable shrinking andswelling. Unusual knob-like structures of unknown chemical compositionwere observed on the outer surface of xylem vessels. These maybe related to the ability of the stem to withstand the mechanicalstresses associated with this shrinkage and swelling.Copyright1998 Annals of Botany Company cavitation, desiccation, hydraulic conductivity, refilling, resurrection plant, root pressure, xylem anatomy,Myrothamnus flabellifolius     

Lactate inhibits Ca2+-activated Ca2+-channel activity from skeletal muscle sarcoplasmic reticulum

Favero, Terence G., Anthony C. Zable, David Colter, andJonathan J. Abramson. Lactate inhibits Ca²⁺-activatedCa²⁺-channel activity from skeletal muscle sarcoplasmicreticulum. J. Appl. Physiol. 82(2): 447-452, 1997.Sarcoplasmic reticulum (SR) Ca²⁺-release channelfunction is modified by ligands that are generated during about ofexercise. We have examined the effects of lactate on Ca²⁺-and caffeine-stimulated Ca²⁺ release,[³H]ryanodine binding, and singleCa²⁺-release channel activity of SR isolated from rabbitwhite skeletal muscle. Lactate, at concentrations from 10 to 30 mM,inhibited Ca²⁺- and caffeine-stimulated[³H]ryanodine binding to and inhibited Ca²⁺-and caffeine-stimulated Ca²⁺ release from SR vesicles.Lactate also inhibited caffeine activation of single-channel activityin bilayer reconstitution experiments. These findings suggest thatintense muscle activity, which generates high concentrations oflactate, will disrupt excitation-contraction coupling. This may lead todecreases in Ca²⁺ transients promoting a decline in tensiondevelopment and contribute to muscle fatigue.

     

Effect of Nasal Dilators on Perceived Odor Intensity

Subjects wearing nasal dilators rated olfactory stimuli as beingmore intense compared with ratings done without nasal expansion.The results support a perceptual constancy model in olfaction.Chem. Senses 22: 177–180, 1997. ¹Present address: Biology Department, St Lawrence UniversityCanton, NY 13617, USA ²Present address: PO Box 802, Drew University, Madison, NJ 07940,USA     

Bimodal (Taste/Tactile) Fibers Innervate the Maxillary Barbel in the Channel Catfish

Analysis of single fibers isolated from a branch of the facial/trigeminalcomplex innervating the maxillary barbel of the channel catfish,Ictalurus punctatus, indicated the existence of bimodal (taste/tactile)fibers. Of the 60 single fibers recorded, 14 (23%) respondedto both taste (amino acid) and tactile stimulation, 43 (72%)were responsive to only tactile stimulation and three (5%) respondedonly to taste stimulation. Quinine hydrochloride at a concentrationof 1.0 mM suppressed the mechanosensory activity of the bimodalfibers, but had no effect on the tactile-only fibers. Chem.Senses 22: 477–482, 1997. ¹Current address: Department of Otolaryngology, Kagoshima UniversityMedical School, 8-35-1 Sakuragaoka, Kagoshima 890, Japan ²Current address: Department of Oral Physiology, Ohu UniversitySchool of Detistry, 31-1 Misumido, Tomita, Koriyama, Fukushima963, Japan     

Gut evacuation rates and ingestion rates of Eudiaptomus graciloides measured by means of the gut fluorescence method

Journal of Plankton Research, 8, 973–983, 1986 FIg. 2. Time-dependent changes in the gut content (percentageof initial ng pigment) of E. gro.ciloides at different temperaturesunder simultaneous feeding. Fig. 4. The relationship between instantaneous evacuation rateand temperature of E. graciloides. The regresston equation forfeeding animals: y = 0.0044 e(0.141 ) (r² = 0.90). For comparisonthe results of non-feeding animals are indicated with open circles.     

Effects of Blue Light Pretreatments on Internode Extension Growth in Mustard Seedlings after the Transition to Darkness: Analysis of the Interaction with Phytochrome

The effects of blue light (B) pretreatments on internode extensiongrowth and their possible interaction with phytochrome mediatedresponses were examined in Sinapis alba seedlings grown for11 d under 280 µmol m^–2 s^–1 of continuousblue-deficient light from low pressure sodium lamps (SOX). SupplementaryB (16 µmol m^–2 s^–1) caused no detectable inhibitionof the first internode growth rate under continuous SOX, butgrowth rate was inhibited after transfer to darkness. This effect,and the growth promotion caused by far-red bend-of-day' lightpulses were additive. The addition of B at 16 µmol m^–2s^–1 during 11 d, or only during the first 9 or 10 d orthe latest 0.75, 1 or 2 d of the SOX pretreatment caused approximatelythe same extent of inhibition after the transition to darkness.A single hour of supplementary B before darkness caused morethan 50% of the maximum inhibition. However, 24 h of lower fluencerates of B (4 or 7 µmol m^–2 s^–1) were ineffective.Covering the internode during the supplementary B period didnot prevent the response to B after the transition to darkness.Far-red light given simultaneously with B (instead of the SOXbackground) reduced the inhibitory effect of B. Above a given threshold fluence rate, B perceived mainly inthe leaves inhibits extension growth in subsequent darkness,provided that high phytochrome photo-equilibria are presentduring the irradiation with B. Once triggered, this effect doesnot interact significantly with the ‘end-of-day’phytochrome effect. Key words: Blue light, extension growth, phytochrome     

Can sugars be produced from fatty acids? A test case for pathway analysis tools

Motivation: In recent years, several methods have been proposedfor determining metabolic pathways in an automated way basedon network topology. The aim of this work is to analyse thesemethods by tackling a concrete example relevant in biochemistry.It concerns the question whether even-chain fatty acids, beingthe most important constituents of lipids, can be convertedinto sugars at steady state. It was proved five decades agothat this conversion using the Krebs cycle is impossible unlessthe enzymes of the glyoxylate shunt (or alternative bypasses)are present in the system. Using this example, we can comparethe various methods in pathway analysis. Results: Elementary modes analysis (EMA) of a set of enzymescorresponding to the Krebs cycle, glycolysis and gluconeogenesissupports the scientific evidence showing that there is no pathwaycapable of converting acetyl-CoA to glucose at steady state.This conversion is possible after the addition of isocitratelyase and malate synthase (forming the glyoxylate shunt) tothe system. Dealing with the same example, we compare EMA withtwo tools based on graph theory available online, PathFindingand Pathway Hunter Tool. These automated network generatingtools do not succeed in predicting the conversions known fromexperiment. They sometimes generate unbalanced paths and revealproblems identifying side metabolites that are not responsiblefor the carbon net flux. This shows that, for metabolic pathwayanalysis, it is important to consider the topology (includingbimolecular reactions) and stoichiometry of metabolic systems,as is done in EMA. Contact: ldpf{at}minet.uni-jena.de; schuster{at}minet.uni-jena.de Supplementary information: Supplementary data are availableat Bioinformatics online. FOOTNOTES Associate Editor: Alfonso Valencia Received on July 24, 2008; revised on September 18, 2008; accepted on September 18, 2008     

GlycoBase and autoGU: tools for HPLC-based glycan analysis

Summary: The development of robust high-performance liquid chromatography(HPLC) technologies continues to improve the detailed analysisand sequencing of glycan structures released from glycoproteins.Here, we present a database (GlycoBase) and analytical tool(autoGU) to assist the interpretation and assignment of HPLC-glycanprofiles. GlycoBase is a relational database which containsthe HPLC elution positions for over 350 2-AB labelled N-glycanstructures together with predicted products of exoglycosidasedigestions. AutoGU assigns provisional structures to each integratedHPLC peak and, when used in combination with exoglycosidasedigestions, progressively assigns each structure automaticallybased on the footprint data. These tools are potentially verypromising and facilitate basic research as well as the quantitativehigh-throughput analysis of low concentrations of glycans releasedfrom glycoproteins. Availability: http://glycobase.ucd.ie Contact: matthew.campbell{at}nibrt.ie Associate Editor: Limsoon Wong Present address: Dublin-Oxford Glycobiology Laboratory, NationalInstitute for Bioprocessing Research and Training, Conway Institute,University College Dublin, Dublin, Ireland. Present address: Ludger Ltd, Culham Science Centre, Abingdon,Oxfordshire OX14 3EB., UK.     

Intercellular Transport and Cytoplasmic Streaming in Chara hispida

The correlation between the velocities of cytoplasmic streamingand of translocation of ¹⁴C-photosynthate and ³²P-phosphateassociated radioactivity has been investigated in whole plantsof the green freshwater alga Chara hispida L. Tracer was suppliedto the plant's rhizoid system in a split-chamber. The velocityof cytoplasmic streaming of 52±3.3 µm s^–1compares with 57±10 µm s^–1 found for ¹⁴C-transportand 32±20 µm s^–1 found for ³²P-transport.There was no indication of intercellular translocation at avelocity faster than visible streaming. Cytochalasin B inhibitedthe translocation of ³²P and cytoplasmic streaming. CytochalasinB becomes fully effective in inhibiting streaming and transportafter an incubation time of at least 5 h. Key words: Chara hispida, Cytoplasmic streaming, Intercellular transport     

BicOverlapper: a tool for bicluster visualization

Summary: BicOverlapper is a tool to visualize biclusters fromgene-expression matrices in a way that helps to compare biclusteringmethods, to unravel trends and to highlight relevant genes andconditions. A visual approach can complement biological andstatistical analysis and reduce the time spent by specialistsinterpreting the results of biclustering algorithms. The techniqueis based on a force-directed graph where biclusters are representedas flexible overlapped groups of genes and conditions. Availability: The BicOverlapper software and supplementary materialare available at http://vis.usal.es/bicoverlapper Contact: rodri{at}usal.es Associate Editor: John Quackenbush The first two authors should be reported as joint first authors.