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     

Formation of L-(+)-Tartaric Acid in Leaves of the Bean, Phaseolus vulgaris L.: Radioisotopic Studies with Putative Precursors

The biosynthetic pathway from D-glucose to L-(+)-tartaric acid(TA) in detached leaves of the bean, Phaseolus vulgaris L.,was studied in three cultivars, two of which were known to containTA and one of which lacked TA, with the aid of several putativeradiolabeled intermediates, namely D-[l-¹⁴C]glucose, D-[6-¹⁴C]glucose,D-[U-¹⁴C]glucose, D-[U-¹⁴C]gluconate, L-[U-¹⁴C]-ascorbic acid,L-[l-^l4C]idonate, D-xylo-5-[U-¹⁴C]hexulosonate, D-xylo-5-[l-¹⁴C]hexulosonate,D-xylo-5-[6-^l4C]hexulosonate and L-[U-^l4C]threonate. D-[U-¹⁴C]Glucoseand D-[U-^l4C]gluconate were converted to TA with low isotopicyield but this yield was further reduced when leaf tissues weresupplied with unlabeled D-gluconate or D-xylo-5-hexulosonate.D-xylo-5-[U-¹⁴C]Hexulosonate and D-xylo-5-[l-¹⁴C]hexulosonatewere good precursors of TA. D-xylo-5-[6-¹⁴C]Hexulosonate didnot furnish ¹⁴C to TA. Addition of a metabolic product of D-xylo-5-hexulosonate(which was labeled by D-xylo-5-[l-¹⁴C]hexulosonate but not byD-xylo-5-[6-¹⁴C]hexulosonate) to leaves labeled with D-xylo-5-[l-¹⁴C]hexulosonatedoubled the incorporation of ¹⁴C into TA. L-[U-¹⁴C]Ascorbicacid, L-[l-¹⁴C]idonate and L-[U-¹⁴C]threonate failed to producelabeled TA. A metabolic scheme to accommodate these observationsis presented. (Received October 21, 1988; Accepted March 29, 1989)     

In situ oxygen microelectrode measurements of bottom-ice algal production in McMurdo Sound, Antarctica

In-situ estimates of fast-ice algal productivity at Cape Evans, McMurdo Sound, in 1999 were lower than at the same site in previous years. Under-ice irradiance was between 0 and 8 µmol photons m^-2 s^-1; the ice was between 1.9 and 2.0 m thick and the algal biomass averaged 150 mg chl a m^-2, although values as high as 378 mg chl a m^-2 were recorded. Production on 11 and 12 November was between 0.053 and 1.474 mg C m^-2 h^-1. When the data from 11 November were fitted to a hyperbolic tangent function, a multilinear regression gave estimates for P_max of 0.571 nmol O₂ cm^-2 s^-1, an ! of 0.167 nmol O₂ cm^-2 s^-1 µmol^-1 photons m^-2 s^-1 and an E_k of 3.419 µmol photons m^-2 s^-1. A P_max of 2.674 nmol O₂ cm^-2 s^-1, an ! of 0.275 nmol O₂ cm^-2 s^-1 µmol^-1 photons m^-2 s^-1, r of 0.305 nmol O₂ cm^-2 s^-1 and an E_k of 9.724 µmol^-1 photons m^-2 s^-1 were estimated from the 12 November data. The sea-ice algal community was principally comprised of Nitzschia stellata, Entomoneis kjellmanii and Berkeleya adeliensis. Other taxa present included N. lecointei, Fragilariopsis spp., Navicula glaciei, Pleurosigma spp. and Amphora spp. Variations in the method for estimating the thickness of the diffusive boundary layer were not found to significantly affect the measurements of oxygen flux. However, the inability to accurately measure fine-scale variations in biomass is thought to contribute to the scatter of the P versus E data.     

广州市红树林和滩涂湿地生态系统与大气二氧化碳交换

在生物量调查和土壤温室气体排放量测定基础上,对广州市红树林和滩涂湿地生态系统与大气CO₂交换进行研究,分析湿地植被净生产力吸收CO₂的能力和不同积水状态下(常年积水、间歇积水、无积水)湿地碳汇功能.结果表明:红树林湿地植被净生产力吸收CO₂ 33.74 t·hm^-2·a^-1,土壤排放CO₂(包括CH₄折算成CO₂的温室效应量)12.26 t·hm^-2·a^-1,湿地每年净吸收大气CO₂ 21.48 t·hm^-2,说明红树林湿地是一个强的碳汇;滩涂湿地植被净生产力吸收CO₂ 8.54 t·hm^-2·a^-1,土壤排放CO₂ 5.88 t·hm^-2·a^-1,排放CH₄ 0.19 t·hm^-2·a^-1,若按碳素折算,湿地每年吸收大气中碳素2.33 t·hm^-2,土壤排放碳素1.74 t·hm^-2包括（CH₄中的碳),系统净固定碳0.59 t·hm^-2,说明滩涂湿地是一个弱的碳汇,若将CH₄的温室效应折算成CO₂量,则土壤排放CO₂ 9.78 t·hm^-2·a^-1,排放比吸收多1.24 t·hm^-2·a^-1,对大气温室效应而言,滩涂湿地是一个弱碳源;常年积水下排放的温室气体主要是CH₄,无积水下排放的温室气体主要是CO₂;常年积水湿地碳汇功能最大,无积水湿地碳汇功能最小.     

湖南藤本植物胸径与其支柱木胸径的相关性

采用野外样株调查方法和11种数学方程与计算机软件SPSS13.0相结合的统计分析方法,对湖南藤本植物胸径大小与其支柱木的胸径大小之间的相关性进行了研究,其结果是:(1)全部藤本植物胸径大小与其支柱木胸径大小的比率是1:6.36,而缠绕、卷曲、搭靠和吸固各攀援方式的胸径大小与其支柱木的胸径大小的比率分别为1:5.61、1:4.92、1:5.89、1:15.46;其中吸固类藤本的支柱木胸径的平均值是最大的。(2)全部藤本植物胸径大小(y)与其支柱木胸径大小(x)的相关曲线是:y=-4.75×10-1 3.44×10-1x-1.13×10-2x2 1.61×10-4x3;缠绕类藤本植物胸径大小与其支柱木胸径大小的相关曲线是:y=2.68×10-1x0.829;卷曲类藤本植物胸径大小与其支柱木胸径大小的相关曲线有两条,分别是:y1=1.88×10-1x01.981,y2=e(1.93-12.222/x2);搭靠类藤本植物胸径大小与其支柱木胸径大小的相关曲线是:y=6.92-8.74×10-1x 4.95×10-2x2-7.45×10-4x3;吸固类藤本植物胸径大小与其支柱木胸径大小的相关曲线是:y=-1.16 3.64×10-1x-1.72×10-2x2 2.56×10-4x3。     

Microplankton and primary production in the Sea of Okhotsk in summer 1994

Phytoplankton composition, density, vertical distribution andprimary production were investigated in the Sea of Okhotsk andin the adjacent northern north Pacific in July–August1994, together with measurements of density and distributionof planktonic microheterotrophs: bacteria, nanoheterotrophsand ciliates. Different phases of phytoplankton seasonal successionwere encountered during the period of investigation in variousregions of this sea. Primary production measured at 144 stationswas found to be greatest (1.5–4 g C m^-2day^-1) in areasof spring-phase succession along the Sakhalin shelf and theKashevarov bank. Periodic relapses of the spring blooms of ‘heavy’diatoms during the whole growth season were recorded over thisbank. The summer phase of the phytoplankton minimum prevailedin the central and eastern parts of the sea, manifested by thedominance of nanoflagellates in terms of phytoplankton biomass.Primary production was 0.5–1 g C m^-2 day^-1. The earlyautumn phase of succession was typical of the Kurile straitarea and the adjacent north Pacific. Primary production therevaried from 0.7 to 2 g C m^-2 day^-1. The integrated phytoplanktonbiomass in the water column varied from 9–12 g m^-2 inzones supporting the summer minimum assemblage to 15–20g m^-2 in zones of early autumn recovery of phytoplankton growth,and up to 40–70 g m^-2 in areas of remnant or relapseddiatom blooms. The numerical density of bacterioplankton wasbetween 1 x 10⁶ and 3 x 10⁶ cells ml^-1 and its wet biomass wasbetween 100 and 370 mg m^-3. In deep waters it was 8–15mg m^-3. The integrated bacterioplankton biomass in the upperwater column varied from 6 to 29 g m^-2. The numerical densityof zooflagellates varied in the upper layer between 0.8 x 10⁶and 4 x 10⁶ l^-1 and their biomass was between 20 and 50 mg m^-3.In deep waters they were still present at a density of 0.05x 10⁶ to 0.2 x 10⁶ cells l^-1. The biomass of planktonic ciliatesvaried between stations from 20 to 100 mg m^-3. The joint biomassof planktonic protozoa in the water column was between 3 and12 g m^-3 at most of the stations.     

Effect of dilution rate on competitive interactions between the cyanobacterium Microcystis novacekii and the green alga Scenedesmus quadricauda in mixed chemostat cultures

We examined the competition between the cyanobacterium Microcystisnovacekii (Kom.) Comp. and the green alga Scenedesmus quadricauda(Turpin) Brébisson using unialgal and mixed chemostatcultures with various supply rates of culture medium where limited algal growth. In unialgal cultures, bothspecies grew at all of the dilution rates examined (0.1, 0.3and 0.8 day^-1): steady-state cell densities were 1 x 10⁴ to8 x 10⁴ cells mL^-1 for M. novacekii and 0.5 x 10⁵ to 2.1 x 10⁵cells mL^-1 for S. quadricauda. Microcystis novacekii was dominantin mixed cultures at a dilution rate of 0.1 day^-1, where thesteady-state cell density was 1 x 10⁴ to 7 x 10⁴ cells mL^-1for M. novacekii and 1 x 10² to 5 x 10² cells mL^-1 for S. quadricauda.Scenedesmus quadricauda was dominant in mixed cultures at thehigher dilution rates (0.3 and 0.8 day^-1), where the final celldensity was 0.5 x 10² to 6.4 x 10² cells mL^-1 for M. novacekiiand 0.2 x 10⁵ to 7 x 10⁵ cells mL^-1 for S. quadricauda. Thisresult indicates that the dilution rate affects the competitiveinteraction. We conclude that it is necessary to consider waterexchange in the study of mechanisms of cyanobacterial blooms.     

濒危植物珙桐的组织培养与植株再生

以珙桐冬芽为材料进行组织培养和植株再生研究,结果表明：珙桐冬芽直接诱导丛生芽的最适培养基为WPM+NAA 0.2 mg·L^-1+6-BA 3.0 mg·L^-1+AC 2.0 g·L^-1;珙桐带芽茎段增殖的适宜培养基为WPM+NAA 0.05 mg·L^-1+6-BA 1.0 mg·L^-1+GA₃ 2.0 mg·L^-1+AC 2.0 g·L^-1;生根最佳培养基为White+IBA3.0 mg·L^-1+6-BA 1.0 mg·L^-1+AC 2.0 g·L^-1,在此条件下,根发育良好,植株健壮;组培苗炼苗后移栽,成活率可达80%。     

野葛叶片和茎段高频再生体系的建立

探讨几种因子对野葛叶片和茎段高频再生体系建立的影响。采用植物组织培养、正交实验和单因子实验的方法。野葛叶片和茎段的最佳消毒方式为70%酒精处理30 s后再用0.1%HgCl₂处理15 min;野葛叶片愈伤组织诱导的最佳培养基为MS+NAA 1.0 mg·L^-1+2,4-D 2 mg·L^-1,野葛茎段愈伤组织诱导的最佳培养基为MS+NAA 0.5 mg·L^-1+6-BA 1.0 mg·L^-1+2,4-D 2 mg·L^-1;暗培养更有利于野葛愈伤组织的诱导;野葛叶片和茎段愈伤组织诱导的最佳蔗糖浓度均为30 g·L^-1;野葛叶片愈伤组织的最佳出芽培养基为MS+NAA 1.0 mg·L^-1+6-BA 3.0 mg·L^-1,而野葛茎段愈伤组织的最佳出芽培养基为MS+ NAA 0.5 mg·L^-1+KT 2 mg·L^-1;光照培养更有利于野葛叶片和茎段愈伤组织芽的再分化;野葛叶片愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 0.5 mg·L^-1,而野葛茎段愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 3.0 mg·L^-1;野葛叶片和茎段愈伤组织再生芽生根的最佳蔗糖浓度均为30 g·L^-1;叶片再生苗移栽的最佳PP₃₃₃浓度为1.0 mg·L^-1,茎段再生苗移栽的最佳PP₃₃₃浓度为3.0 mg·L^-1;叶片和茎段再生苗的最佳移栽基质均为蛭石:珍珠岩（2:1）。     

Longitudinal Water Movement in the Primary Root of Zea mays

The rates of transfer of tritiated water (THO) along lengthsof excised primary roots of Zea mays have been measured undera variety of conditions. The following values of ‘apparentdiffusion coefficients’ for THO in the root tissue havebeen evaluated: 1.5±0.1x10^-5 cm² sec^-1 in roots boiledfor 3 min before use,0.5±0.03x10^-5 cm² sec^-1 in rootspoisoned with 10^-2 M NaF,0.9±0.07x10^-5 cm² sec^-1 in rootspoisoned with 10^-2 M NaN₃,and 2.1±0.2x10^-5 cm² sec^-1in normal roots. The bathing medium in all cases was 1.0 mMKCl/0.1 mM CaCl₂ with the addition of the inhibitors where appropriate.Thefourfold increase in the rate of THO transfer in normal rootscompared with poisoned ones is attributed to the existence ofa long-distance convective flow in the first case, which isterminated by the addition of inhibitors. Since experimentsshow that this convective flow must occur both acropetally andbasipetally with equal velocity, it is thought to occur in thephloem.By assuming the ‘streaming transcellular strands’model for phloem transport, the rate of movement required togive the observed transfer has been computed as approximately4.5x10^-2 cm sec^-1 (160 cm h^-1).The earlier report of the existenceof a highly impermeable barrier surrounding the xylem vesselshas been further substantiated by the experiments reported here.     

The effects of eutrophication-related alterations to coral reef communities on agents and rates of bioerosion (Reunion Island,Indian Ocean)

This study investigated the variation of bioerosional processes in relation to disturbances of reefal communities due to eutrophication. La Saline fringing reef (Reunion Island) is subjected to nutrient inputs from the adjacent land. Bioerosion by grazers, microborers, and macroborers was measured using experimental substrata exposed for 1 year in three sites characterized by different levels of nutrient input and benthic community response. The relationship between bioerosion and epilithic algal cover of hard substrata and the interactions between the various agents of bioerosion were analyzed with parametric statistics. Significant variations in bioerosion were found among sites, ranging from 1.63 to 3.52 kg CaCO₃ m^-2 year^-1 for grazing rates, from 6.73 to 32.25 g m^-2 year^-1 for macroboring rates, and from 43.78 to 67.56 g m^-2 year^-1 for microboring rates. One of the major factors controlling these variations appeared to be changes in the epilithic algal cover on substrata in response to changes in reefal water chemistry. In low nutrient areas, where dead corals were colonized mainly by algal turfs, erosion by microorganisms was low (43.78 g m^-2 year^-1) due to intense grazing (3.52 kg m^-2 year^-1). In reef zones receiving high nutrient inputs, the development of encrusting calcareous algae and macroalgae was associated with the lowest grazing (1.63 kg m^-2 year^-1) and macroboring (6.73 g m^-2 year^-1) rates recorded among sites. In contrast, high microboring rates (57.54 and 67.56 g m^-2 year^-1) were found in enriched areas in association with high macroalgal cover.     

淡水驯化对桐花树光合生理特性的影响

以实验地全光照条件下淡水和人工海水培养种植的桐花树（Aegiceras corniculatum）幼苗为材料,采用Li 6400光合测定仪对不同月份桐花树幼苗的光合生理生态特性日动态进行测定,研究了桐花树的光合生理生态特性。结果表明：在7、10月份桐花树的净光合速率日变化呈双峰型,均出现“光合午休”现象。在7月份人工海水组和淡水组的最大净光合速率（P_max）分别为9.97和11.95 μmol·m^-2·s^-1;而10月份的P_max分别为12.2和12.9 μmol·m^-2·s^-1。而且淡水驯化下,桐花树的净光合速率较人工海水组高。由光响应曲线可知,桐花树人工海水组的最大净光合速率（P_max）、光饱和点（LSP）、光补偿点（LCP）和表观量子效率（AQY）分别为7 μmol·m^-2·s^-1,1 477 μmol·m^-2·s^-1,30 μmol·m^-2·s^-1,0.031 3;而淡水组为8.69 μmol·m^-2·s^-1,980 μmol·m^-2·s^-1,40 μmol·m^-2·s^-1,0.011。在所测的生理生态因子中,光合有效辐射和气孔导度是影响桐花树光合作用最为强烈的因子,与桐花树的净光合速率和蒸腾速率均有极显著的相关关系（p<0.01）。试验说明淡水驯化的桐花树对光强的利用范围变窄,但有较高的净光合速率,表明桐花树对淡水环境具有较强的适应性。     

佛手山药组织培养的研究

以佛手山药块茎、叶片、茎段为外植体, 探讨了其组织培养技术。结果表明：块茎培养以暗培养MS+6-BA1.0 mg·L^-1+NAA0 1 mg·L^-1效果较好;叶片诱导的适宜培养基为MS+ 6-BA0.5～1.0 mg·L^-1+NAA2.0 mg·L^-1, 暗培养;茎段培养都是光培养,无节茎段以MS+6-BA1.0 mg·L^-1+NAA0.5 mg·L^-1较好;带节茎段的初代培养则以MS+6-BA0.5～1.0 mg·L^-1+NAA0.1 mg·L^-1效果较好,继代增殖培养基为MS+6-BA0.5 mg·L^-1+NAA0.1 mg·L^-1,生根培养基为1/2MS +NAA0.5 mg·L^-1。     

Prion protein fragment 106-126 potentiates catecholamine secretion from PC-12 cells

The toxic actions of scrapie prion protein(PrP^sc) are poorly understood. We investigated the abilityof the toxic PrP^sc fragment 106-126 to interfere withevoked catecholamine secretion from PC-12 cells. Prion protein fragment106-126 (PrP106-126) caused a time- andconcentration-dependent augmentation of exocytosis due to the emergenceof a Ca²⁺ influx pathway resistant to Cd²⁺ butsensitive to other inorganic cations. In control cells, secretion wasdependent on Ca²⁺ influx through L- and N-typeCa²⁺ channels, but after exposure to PrP106-126,secretion was unaffected by N-type channel blockade. Instead, selectiveL-type channel blockade was as effective as Cd²⁺ insuppressing secretion. Patch-clamp recordings revealed no change intotal Ca²⁺ current density in PrP106-126-treated cellsor in the contribution to total current of L-type channels, but a smallCd²⁺-resistant current was found only inPrP106-126-treated cells. Thus PrP106-126 augments secretionby inducing a Cd²⁺-resistant Ca²⁺ influxpathway and alters coupling of native Ca²⁺ channels toexocytosis. These effects are likely contributory factors in the toxiccellular actions of PrP^sc.

     

Soil microbial community and bacterial functional diversity at Machu Picchu, King George Island, Antarctica

The objective of this study was to evaluate the potential contribution of the soil microbial community in the vicinity of two plant covers, Sanionia uncinata and Deschampsia antarctica, at Machu Picchu Station, King George Island, Antarctica. Soil samples were collected at the study site during the southern (pole) summer period from 0-5 cm and 5-10 cm depths, for chemical and biological analyses. Soil microbial biomass reached a maximal value of 144 µg g^-1 in soil samples taken from under the S. uncinata upper layer plant. qCO₂ ranged from 167 to 239 µg CO₂^.mgC_mic^.h^-1 at the 0-5 and 5-10 cm depths, respectively. CO₂ evolution showed values of 54.3 mg^.m^-2 h^-1 beneath plant cover and 55.9 mg^.m^-2 h^-1 in the open space. CO₂ evolved by substrate induced respiration in the soil samples taken under the plant cover in the summer period, oscillated between 0.25 and 4.78 µg CO₂ g^-1 h^-1. The data obtained from this short study may provide evidence that both activity and the composition and substrate utilization of the microbial community appear to change substantially across the moisture level and sample location.     

MHC isoform composition and Ca(2+)- or Sr(2+)-activation properties of rat skeletal muscle fibers

Chemically skinned single fibers from adult rat skeletalmuscles were used to test the hypothesis that, in mammalian muscle fibers, myosin heavy chain (MHC) isoform expression andCa²⁺- or Sr²⁺-activation characteristics areonly partly correlated. The fibers were first activated inCa²⁺- or Sr²⁺-buffered solutions undernear-physiological conditions, and then their MHC isoform compositionwas determined electrophoretically. Fibers expressing only the MHC Iisoform could be appropriately identified on the basis of either theCa²⁺- or Sr²⁺-activation characteristics or theMHC isoform composition. Fibers expressing one or a combination of fastMHC isoforms displayed no significant differences in theirCa²⁺- or Sr²⁺-activation properties; therefore,their MHC isoform composition could not be predicted from theirCa²⁺- or Sr²⁺-activation characteristics. Alarge proportion of fibers expressing both fast- and slow-twitch MHCisoforms displayed Ca²⁺- or Sr²⁺-activationproperties that were not consistent with their MHC isoform composition;thus both fiber-typing methods were needed to fully characterize suchfibers. These data show that, in rat skeletal muscles, the extent ofcorrelation between MHC isoform expression and Ca²⁺- orSr²⁺-activation characteristics is fiber-type dependent.

     

珍稀植物跳舞草的组织培养与快速繁殖

以跳舞草无菌苗为实验材料,以MS、1/2MS为基本培养基,研究不同条件对跳舞草快速繁殖的影响,初步建立了跳舞草组培快繁体系,筛选出最佳愈伤组织诱导及不定芽分化培养基为MS+6-BA2.0mg·mL-1+NAA0.1mg·mL-1+蔗糖30.0g.L-1+VC2.0mg·mL-1,最佳增殖培养基为MS+6-BA2.0mg·mL-1+NAA0.05mg·mL-1,最佳生根培养基为1/2MS+NAA0.2mg·mL-1+IAA0.5mg·mL-1。     

利用正交设计优化小苍兰ISSR-PCR反应体系

通过L₁₆(4⁵)正交试验,研究了镁离子浓度、dNTP浓度、模板DNA浓度、Taq DNA聚合酶浓度、引物浓度这5个因素在4个水平上对ISSR-PCR的影响,建立了适合于小苍兰ISSR-PCR的反应体系。优化体系为：25 μL PCR反应体系中含有1×Taq酶缓冲液(10 mmol·L^-1 KCl,8 mmol·L^-1(NH₄)₂SO₄,10 mmol·L^-1 Tris·HCl,pH 9.0,0.05% NP-40),2 mmol·L^-1 MgCl₂,0.06 U·μL^-1 Taq酶,0.4 μmol·L^-1引物,4.0 ng·μL^-1模板DNA,dATP、dCTP、dGTP、dTTP各0.6 mmol·L^-1。利用温度梯度PCR,确定了最适宜的退火温度为51.5℃。该优化体系的建立为下一步对小苍兰进行ISSR分子标记奠定了基础。