Bewegungsstudien an Anatinen

Zusammenfassung Vorliegende Arbeit ist eine Weiterführung derLorenz'schen Bewegungsstudien an Anatinen aus dem Jahre 1941, fortgesetzt an Mischlingen zwischen den dort beschriebenen Arten. Die sich dabei ergebenden Befunde machten eine erneute Untersuchung der Elternarten notwendig. Außerdem wurden einige Arten beobachtet, deren Verhalten noch nicht untersucht worden war. Fragestellung und Begründung werden in der Einleitung gegeben.Im zweiten Abschnitt werden einige der vonLorenz gemachten Beobachtungen berichtigt. So zeigten einige der Kreuzungen mitbahamensis, daß die vonLorenz bei eben dieser Art als Kurzhoch-werden bezeichnete Bewegungsweise dem Ab-auf anderer Schwimmenten homolog ist. Ebenso ist die eine der beiden vonLorenz als Kurzhoch-werden bezeichneten Verhaltensweisen des Krickerpels als Ab-auf zu deuten. Der Gruß desflavirostre-Erpels wurde auch bei weiblichen Tieren gesehen. BeiAnas acuta wurde ein Kinnheben festgestellt, das sich in der Form stark vom Kinnheben beiplatyrhynchos unterscheidet. Als neue Verhaltensweisen wurden u. a. das Haltungannehmen und das Tendieren beimflavirostre-Erpel beschrieben.Im dritten Abschnitt werden einige Verhaltensweisen und ihre Funktion diskutiert und der Versuch gemacht, eine Motivationsanalyse zu geben.(Zeichnungen vonHermann Kacher)     

Isolation and characterization of β-glucosidases from Aspergillus nidulans mutant USDB 1183

Two extracellular -glucosidases (cellobiase, EC 3.2.1.21), I and II, from Aspergillus nidulans USDB 1183 were purified to homogeneity with molecular weights of 240,000 and 78,000, respectively. Both hydrolysed laminaribiose, -gentiobiose, cellobiose, p-nitrophenyl--L-glucoside, phenyl--L-glucoside, o-nitrophenyl--L-glucoside, salicin and methyl--L-glucoside but not -linked disaccharides. Both were competitively inhibited by glucose and non-competitively (mixed) inhibited by glucono-1,5-lactone. -Glucosidase I was more susceptible to inhibition by Ag⁺ and less inhibited by Fe²⁺ and Fe³⁺ than -glucosidase II.     

The effect of gyrase inhibitors and cyclic AMP on induction and glucose repression of the 6-hydroxy-nicotine oxidases in Arthrobacter oxidans

The induction by d,l-nicotine of the enantiozymes 6-hydroxy-L-nicotine oxidase and 6-hydroxy-D-nicotine oxidase in Archrobacter oxidans was differently affected by the inhibitors of Escherichia coli gyrase, novobiocin and nalidixic acid. These compounds inhibited 6-hydroxy-L-nicotine oxidase induction slightly, but led to an increase in the level of 6-hydroxy-D-nicotine oxidase activity. Furthermore, the specific repression by glucose of 6-hydroxy-D-nicotine oxidase synthesis was not abolished by the addition of cAMP but by that of novobiocin.Abbreviations 6-HDNO 6-hydroxy-D-nicotine oxidase - 6-HLNO 6-hydroxy-L-nicotine oxidase - cAMP cyclic 3,5-adenosine monophosphate - Enzymes Adenylate cyclase - ATP pyrophosphate-lyase (cyclizing) (EC 4.6.1.1) - cAMP-phosphodiesterase 3:5-cyclic-nucleotide 5-nucleotido-hydrolase (EC 3.1.4.17) - DNA gyrase DNA topoisomerase II (EC 5.99) - DNA polymerase deoxynucleosidetriphosphate: DNA desoxynucleotidyl-transferase (EC 2.7.7.7) - 6-hydroxy-L-nicotine oxidase 6-hydroxy-L-nicotine: oxygen oxidoreductase (EC 1.5.3.5) - 6-hydroxy-D-nicotine oxidase 6-hydroxy-D-nicotine: oxygen oxidoreductase (EC 1.5.3.6) - -lactamase penicillin amido--lactamhydrolase (EC 3.5.2.6) - nicotine dehydrogenase nicotine: (acceptor)6-oxidoreductase (hydroxylating) (EC 1.5.99.4)     

Purification and characterization of flavone-specific β-glucuronidase from callus cultures of Scutellaria baicalensis Georgi

-Glucuronidase from callus cultures of Scutellaria baicalensis Georgi was purified to apparent homogeneity by fractionated ammonium-sulfate precipitation and chromatography on diethylaminoethyl-cellulose, hydroxylapatite and baicalin-conjugated Sepharose 6B. A 650-fold purification was obtained by this purification system. When subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis the purified protein migrated as a single band with a molecular mass of 55 kDa. We determined that the native enzyme has a molecular mass of 230 kDa using gel-filtration chromatography. These results suggested that the enzyme exists as a homotetramer composed of four identical 55-kDa subunits. The enzyme showed a broad pH optimum between 7.0 and 8.0. The K _m values were 9 M, 10 M, 30 M and 40 M for luteolin 3 -O--d-glucuronide, baicalin, wogonin 7-O--d-glucoronide and oroxlin 7-O--d-glucuronide, respectively. The enzyme was most active with flavone 7-O--d-glucuronides.Abbreviations BA N⁶-benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - pI isoelectric point - R _t retention time     

Direct somatic embryogenesis through thin cell layer culture in Panax ginseng

Direct somatic embryos were differentiated on cotyledon transverse Thin Cell Layers (tTCLs) of Panax ginseng after 9 weeks in the Murashige and Skoog basal (MS) medium containing 2,4-d (5M). When MS medium containing 2,4-d (5M) was used for seedling pretreatment and for tTCLs culture, somatic embryos were observed 2 weeks earlier, i.e. after 7 weeks of culture. On the tTCLs from seedlings pretreated with 2,4-d (5M) combined with benzyladenine and zeatin at 0.1 M (BZ), somatic embryos were observed after 6 weeks of culture and the percentage of embryogenesis was higher (62%) than when 2,4-d was used alone for pretreatment (40%). Similar results were also obtained from pretreatment with combinations of 2,4-d (5M) and thidiazuron (TDZ) (0.01, 0.1M). When a combination of 2,4-d (5M) and BZ (0.1M) was used both for seedling pretreatment and for tTCLs culture, both somatic embryos and shoots were observed after only 3 weeks. As the concentration of BZ increased, the percentage of somatic embryogenesis decreased but the percentage of organogenesis increased. Similar responses were obtained with a combination of 2,4-d (5M) and TDZ (0.01M). On the medium containing both NAA (0.3M) and BZ (1M), globular- and heart- stage embryos developed after 4 weeks of culture into cotyledonary-staged embryos which remained dormant after a short elongation of the embryo axis. The importance of seedling pretreatment by growth substances in enhancing somatic embryogenesis is reported.Abbreviations BA 6-benzyladenine - BZ combination of BA and zeatin - 2,4-d 2,4-dichlorophenoxyacetic acid - MS medium Murashige and Skoog basal medium - NAA a-naphthaleneacetic acid - TDZ thidiazuron - tTCLs transverse thin cell layers - TCL longitudinal thin cell layer     

Transforming growth factor-beta isoform expression in mature human healthy and carious molar teeth

Transforming growth factor (TGF)- isoforms have been implicated in cellular signalling during tooth development and repair, but little is known of their cellular localisation or distribution within the dental tissues in the mature tooth. This study investigated the presence of TGF-1, 2 and 3 isoforms in tissues of sound and carious human molar teeth, to understand better the expression of TGF-s during health and disease. In healthy tissues, odontoblasts, cells of the cell rich layer, pulpal fibroblasts and endothelial cells were stained to varying degrees for all isoforms, with TGF-3 showing the greatest intensity and TGF-1 the weakest intensity. Similar patterns of staining were observed in carious teeth; however, TGF-1 showed significantly increased staining intensity within odontoblasts and pulpal cells of carious teeth (p<0.001). Biochemical analysis showed greater amounts of TGF-1 in tertiary dentine than in primary dentine samples. The expression of TGF-s in odontoblasts and the increased presence of TGF-1 in tertiary dentine suggest that these isoforms may be important in odontoblast behaviour and the modulation of the tissue response to injury.     

Cellular localization of glycoside hydrolases inBacteroides fragilis

The localizations of six glycosidases produced byBacteroides fragilis—-glucosidase, -glucosidase, -galactosidase, -galactosidase, -N-acetylglucosaminidase, and -l-fucosidase—were studied. Cell fractions and cell extracts were obtained by Triton X-100 release, by disruption by freeze-pressing and sonication, and by osmotic release. Isoelectric focusing of a cytoplasmic and of a Triton X-100 extract of the cell wall fraction was performed and revealed differences in the relative distribution of differently charged forms of -N-acetylglucosaminidase. -Galactosidase and alkaline phosphatase were used as cytoplasmic and periplasmic markers, respectively. It is concluded that inB. fragilis -glucosidase is periplasmic, -l-fucosidase and -galactosidase are cytoplasmic, and -n-acetylglucosaminidase is cell associated and bound to the cell envelope by hydrophobic interactions. -Glucosidase and -galactosidase are localized cytoplasmically and/or located in the cell envelope.     

Production of β-fructofuranosidase byAspergillus japonicus

A newly isolated strain, MU-2, which produces very high -fructofuranosidase activity, was identified asAspergillus japonicus. For enzyme production by the strain, sucrose at 20% (w/v) was the best carbon source and yeast extract at 1.5 to 3% (w/v) the best nitrogen source. Total enzymatic activity and cell growth were at maximum after 48 h, at 1.57×10⁴ U/flask and 0.81 g dry cells/flask, respectively. The optimum pH value of the enzymatic reaction was between 5.0 and 5.5 and the optimum temperature 60 to 65°C. The enzyme produced 1-kestose (O--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) and nystose (O--d-fructofuranosyl-(21)--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) from sucrose by fructosyl-transferring activity. The strain was found to be very useful for industrial production of -fructofuranosidase.     

Synthetic substrate analogues for UDP-GlcNAc: Manα1-6R β(1-2)-N-acetylglucosaminyltransferase II. Substrate specificity and inhibitors for the enzyme

UDP-GlcNAc: Man1-6R (1-2)-N-acetylglucosaminyltransferase II (GlcNAc-T II; EC 2.4.1.143) is a key enzyme in the synthesis of complexN-glycans. We have tested a series of synthetic analogues of the substrate Man1-6(GlcNAc1-2Man1-3)Man-O-octyl as substrates and inhibitors for rat liver GlcNAc-T II. The enzyme attachesN-acetylglucosamine in 1-2 linkage to the 2-OH of the Man1-6 residue. The 2-deoxy analogue is a competitive inhibitor (K _i=0.13mm). The 2-O-methyl compound does not bind to the enzyme presumably due to steric hindrance. The 3-, 4- and 6-OH groups are not essential for binding or catalysis since the 3-, 4- and 6-deoxy and -O-methyl derivatives are all good substrates. Increasing the size of the substituent at the 3-position to pentyl and substituted pentyl groups causes competitive inhibition (K _i=1.0–2.5mm). We have taken advantage of this effect to synthesize two potentially irreversible GlcNAc-T II inhibitors containing a photolabile 3-O-(4,4-azo)pentyl group and a 3-O-(5-iodoacetamido)pentyl group respectively. The data indicate that none of the hydroxyls of the Man1-6 residue are essential for binding although the 2- and 3-OH face the catalytic site of the enzyme. The 4-OH group of the Man-O-octyl residue is not essential for binding or catalysis since the 4-deoxy derivative is a good substrate; the 4-O-methyl derivative does not bind. This contrasts with GlcNAc-T I which cannot bind to the 4-deoxy-Man- substrate analogue. The data are compatible with our previous observations that a bisectingN-acetylglucosamine at the 4-OH position prevents both GlcNAc-T I and GlcNAc-T II catalysis. However, in the case of GlcNAc-T II, the bisectingN-acetylglucosamine prevents binding due to steric hindrance rather than to removal of an essential OH group. The 3-OH of the Man1-3 is an essential group for GlcNAc-T II since the 3-deoxy derivative does not bind to the enzyme. The trisaccharide GlcNAc1-2Man1-3Man-O-octyl is a good inhibitor (K _i=0.9mm). The above data together with previous studies indicate that binding of the GlcNAc1-2Man1-3Man- arm of the branched substrate to the enzyme is essential for catalysis. Abbreviations: GlcNAc-T I, UDP-GlcNAc:Man1-3R (1-2)-N-acetylglucosaminyltransferase I (EC 2.4.1.101); GlcNAc-T II, UDP-GlcNAc:Man1-6R (1-2)-N-acetylglucosaminyltransferase II (EC 2.4.1.143); MES, 2-(N-morpholino)ethane sulfonic acid monohydrate.     

The in vitro production of an anthocyanin from callus cultures of Oxalis linearis

Callus growth and the production of anthocyanins were sustained on the salts and vitamins of Murashige and Skoog. Callus growth was stimulated at a concentration of 8–32 M -naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-d). Benzyladenine (BA) and zeatin at 8 M inhibited callus growth whereas isopentenyladenine (iP) stimulated callus growth. NAA repressed anthocyanin production with an increase in NAA from 8–32 M. Anthocyanin synthesis was promoted by an increase in 2,4-d from 0.5 to 2 M and decreased thereafter up to a concentration 32 M 2,4-d. A concentration of 8 M BA, thidiazuron and zeatin, respectively stimulated pigment production. Sucrose stimulated callus growth at 60 mM and pigment production at 120–360 mM.Abbreviations BA 6-benzyladenine - 2,4-d 2,4-dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - iP isopentenyladenine - TZ thidiazuron-N-phenyl-N-1,2,3-thiadiazol-5-yl-urea - Bu-HCl Butanol-2N HCl - BAW Butanol-acetic acid-water     

Techniques for the quantitative study of mutation in plant viruses

Summary Hardly any other virus is chemically and ultramicroscopically as well known as TMV. It is not possible to perform genetic recombinations with this object. The phenomenon of mutation is, however, known and an analysis of the dosis-effect relationship was possible by using the characters chlorotic versus necrotic primary symptoms. Taking into account the phenomenon of interference (mutual exclusion), i.e., comparing the induced mutation frequency with that of a control virus sample diluted to the same level of infectivity, on can perform quantitative analyses. In this way the first chemical mutagensis in the test tube was demonstrated 10 years ago with nitrous acid as mutagenic agent. The criticism raised byBawden to the first publication ofMundry andGierer was already inappropriate at that time. In the meantime it has been demonstrated byWittmann-Liebold andWittmann through analysis of amino acid exchanges in spontaneous mutants and in those isolated after incubation with HNO₂ that the difference between spontaneous and induced mutants demanded byBawden, which cannot be postulated for symptoms in plants, lies, as expected, in amino acid exchanges of the protein coat.

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Zusammenfassung Kaum ein anderes Virus ist chemisch und ultramikroskopisch so gut bekannt wie das TMV. Rekombinations-Genetik ist nicht möglich. Das Phänomen der Mutation ist aber bekannt, und eine Analyse der Dosis-Effekt-Beziehung wurde möglich durch Benutzung der Symptomcharaktere chlorotische versus nekrotische Primärsymptome. Bei Berücksichtigung des Phänomens der Interferenz (mutual exclusion), d. h. wenn man die induzierte Mutationsrate mit der auf gleiche Infektiosität durch Verdünnen der Viruslösung gebrachten als Kontrolle vergleicht, kann eine quantitative Analyse durchgeführt werden. So wurde vor 10 Jahren die erste Chemomutagenese im Reagenzglas mit salpetriger Säure als mutagenes Agens nachgewiesen. Die an der ersten Veröffentlichung vonMundry undGierer vonBawden geäußerte Kritik war schon damals unzutreffend. Inzwischen ist durch die Analyse der Aminosäureaustausche von spontanen und nach Inkubation mit HNO₂ isolierten Mutanten vonWittmann-Liebold undWittmann gezeigt worden, daß die vonBawden geforderte Verschiedenheit spontaner und induzierter Mutanten, die für Symptome an den Pflanzen nicht postuliert werden kann, in den Aminosäureaustauschen des Hüllproteins wie zu erwarten vorhanden ist.

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This paper was a first written for Methods in Virology, Academic Press. The editors and the author did not come to an agreement in the question of citation ofBawden's criticism to the work ofMundry andGierer 1958. It is published here on the occasion of the 10th anniversary of the first chemomutagenesis in the test tube.     

Benzyl-N-acetyl-α-d-galactosaminide inhibits the sialylation and the secretion of mucins by a mucin secreting HT-29 cell subpopulation

We have analysed the mucins synthesized by the HT-29 MTX cell subpopulation, derived from the HT-29 human colon carcinoma cells through a selective pressure with methotrexate (Lesuffleuret al., 1990,Cancer Res 50: 6334–43), in the presence of benzyl-N-acetyl--galactosaminide (GalNAc-O-benzyl), which is a potential competitive inhibitor of the 1,3-galactosyltransferase that synthesizes the T-antigen. The main observation was a 13-fold decrease in the sialic acid content of mucins after 24 h of exposure to 5mm GalNAc-O-benzyl. This effect was accompanied by an increased reactivity of these mucins to peanut lectin, testifying to the higher amount of T-antigen. The second observation was a decrease in the secretion of the mucins by GalNAc-O-benzyl treated cells. The decrease in mucin sialyation was achieved through thein situ -galactosylation of GalNAc-O-benzyl into Gal1–3GalNAc-O-benzyl, which acts as a competitive substrate of Gal1–3GalNAc 2,3-sialyltransferase, as shown by the intracellular accumulation of NeuAc2–3Gal1–3GalNAc-O-benzyl in treated cells.Abbreviations BSM bovine submaxillary mucin - MTX methotrexate - PBS sodium phosphate 10mm, NaCl 0.15m, pH 7.4 buffer - pNp p-nitrophenol - TBS Tris/HCl 10mm, NaCl 0.15m, pH 7.4 buffer Enzymes: CMP-NeuAc: Gal1–3/4GlcNAc 2,3-sialyltransferase, ST3(N), EC 2.4.99.6; CMP-NeuAc: Gal1–4GlcNAc 2,6-sialyltransferase, ST6(N), EC 2.4.99.1; CMP-NeuAc: Gal1–3GalNAc 2,3-sialyltransferase, ST3(O), EC 2.4.99.4; CMP-NeuAc: R-GalNAc1-O-Ser 2,6-sialyltransferase, ST6(O)-I, EC 2.4.99.3; CMP-NeuAc: NeuAc2–3Gal1–3GalNAc 2,6-sialyltransferase, ST6(O)-II, EC 2.4.99.7; UDP-GlcNAc: Gal1–3GalNAc-R·(GlcNAc to GalNAc) 1,6-N-acetylglucosaminyltransferase, EC 2.4.1.102; UDP-GlcNAc: GalNAc-R 1,3-N-acetylglucosaminyltransferase, EC 2.4.1.147; UDP-Gal: GalNAc-R 1,3-galactosyltransferase, EC 2.4.1.122.     

Comparative residual toxicities of pesticides to the predator Agistemus industani (Acari: Stigmaeidae) on citrus in Florida

Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions.     

Comparative structural analysis of snail galactans by a radioimmunoassay to elucidate species-specific determinants

Summary Galactans, the storage polysaccharides in the perivitelline fluid of many snails showed a high degree of species-specificity as revealed by quantitative precipitin formations with lectins, polyclonal antisera, myeloma proteins as well as by the reactivity with the enzyme galactose oxidase. However, their chemical compositions were remarkably similar since thed-Gal residues were all linked 13 and 16 glycosidically.The specificity seemed to be related to the different degrees of branching in the various galactans but could also be due to some other minor constituents in some galactans such asl-galactose or phosphate.In this study a Radioimmunoassay was developed using the galactan of the snailLymnaea stagnalis to elucidate those differences which were only related to a unique distribution of the 13 and 16 linkages, since this galactan was composed exclusively ofd-galactose residues. The galactan was labeled by sequential oxidation with galactose oxidase and reduction with tritiated sodium borohydride. Inhibition of the binding of the labeled galactan to insolubilized antibodies was investigated by galactans of different species, their chemically modified products, andd-galactose-composed oligosaccharides of unambiguously identified structures.Inhibition byLymnaea stagnalis galactan was about 45 000 times that ofHelix pomatia galactan. The most complementary oligosaccharide found was -d-Gal13[-d-Gal16]-d-Gal11l-Gro, being about 200 times more effective thand-Gal. However, a fraction with molecular weights between 700 and 1000 isolated from the partially hydrolized galactan was still seven times more effective. From the reactivity of the antiserum with the different oligosaccharides tested the following structure was inferred which most likely represented the complete determinant recognized by the antiserum: -d-Gal13[-d-Gal16]-d-Gal16[-d-Gal13]-d-Gal1. This determinant seemed to be most common inLymnaea stagnalis galactan and its frequency of occurrence appears to correspond to the inhibitory potency of other snail galactans.     

Fragmenta mycologica

Summary Castellani's water culture method for microscopic fungi was re-examined and confirmed in its every detail. It is an ideal method for, at least, the smaller culture collection, in order to avoid continuous, short term subculturing. Benedek's suggestion for establishment of a mycotheca preserved in chlorallactophenol on the analogy of the herbarium of phanerogamists, may fill a long felt gap in mycological laboratories.

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Zusammenfassung Castellani's Wasserkultur-methode für mikroskopische Pilze wurde einer Kontrolluntersuchung unterzogen. Sie konnte in all ihren Einzelheiten bestätigt werden. Sie ist eine ideale Methode, wenigstens für kleine Kultursammlungen, um eine fortgesetzte, kurz-fristige Überimpfung zu vermeiden. Benedek's Vorschlag für die Einrichtung einer Mykotheka in Chlorallactophenol in Analogie mit dem Herbarium für Blütenpflanzen, mag eine lang gefühlte Lücke im mykologischen Laboratorium beseitigen.

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Résumé La méthode deCastellani, la culture en d'eau des champignons microscopiques, a été ré-examinée. Elle pouvait être confirmée en tous les détails. C'est une méthode idéale, au moins, pour la collection de cultures de petite dimension, pour éviter les transferts continus et d'intervalle courte.La suggestion deBenedek pour établir une mycothèque en chlorallactophénol, par analogie avec l' herbier pour les phanérogames peut remplir une lacune, existante pour long temps, aux laboratoires mycologiques.

     

Binding of the galactose-specificPseudomonas aeruginosa lectin,PA-I,to glycosphingolipids and other glycoconjugates

The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I Pseudomonas aeruginosa lectin I - Cer ceramide - lactosylceramide Gal4GlcCer - iso globotriaosylcerami Gal3Gal4GlcCer - globotriaosylceramide Gal4Gal4GlcCer - globoside or globotetraosylceramide GalNAc3Gal4Gal4GlcCer - Forssman glycolipid GalNAc3GalNAc3Gal4Gal4GlcCer - P1 glycolipid Gal4Gal4GlcNAc3Gal4GlcCer - lactoneotetraosylceramide Gal4GlcNAc3Gal4GlcCer - B5 glycolipid Gal3Gal4GlcNAc3Gal4GlcCer - gangliotetraosylceramide Gal3GalNAc4Gal4GlcCer - GM1 Gal3GalNAc4(NeuAc3)Gal4GlcCer - RBC red blood cells - BSA bovine serum albumin - PBS phosphate-buffered saline - SDS sodium dodecyl sulfate - TLC thin-layer chromatography - HPLC high pressure liquid chromatography - MS mass spectrometry - FAB fast-atom bombardment - EI electron impact     

High frequency somatic embryogenesis in Coffea canephora

Leaf explants of Coffea canephora (P. ex Fr.) produced a friable yellow callus when they were cultured on a conditioning basal medium with 2.2 M 2,4-D, 2.4 M IBA and 9.8 M 2iP for 4 weeks then on an induction basal medium with 4.4 M 2,4-D and 17.8 M BA for 10 weeks. This calus could be maintained by means of regular subcultures or it could give rise to somatic embryos depending on the culture medium. Cytological studies documented somatic embryogenesis and embryo development.Abbreviations BA 6-benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - IBA indole-3-butyric acid - 2iP 2-isopentenyladenine - MS Murashige & Skoog medium - NAA -naphthaleneacetic acid - NPR nucleoplasmic ratio - PGR plant growth regulator     

Sialidase of swine influenza A viruses: variation of the recognition specificities for sialyl linkages and for the molecular species of sialic acid with the year of isolation

The sialidase of swine influenza A viruses of N1 and N2 subtypes, isolated from 1930 to 1992, was studied for substrate specificity with ganglio-series, lacto-series type II and GM3 gangliosides containing Neu5Ac2-3Gal, Neu5Gc2-3Gal and Neu5Ac2-6Gal linkages. All viral sialidases tested showed that the activity for hydrolysing substrates with Neu5Ac2-3Gal was higher than the activities with Neu5Gc2-3Gal and Neu5Ac2-6Gal linkages. When GM1b, GM3 and sialylparagloboside were used as substrates, the earliest strain (A/Wisconsin/15/30 H1N1, isolated in 1930) showed the activity ratio of Neu5Ac2-6Gal to Neu5Ac2-3Gal to be 0.13:0.2, and the ratio Neu5Gc2-3Gal/Neu5Ac2-3Gal to be 0.19:0.37, while those strains isolated from 1978 to 1992 exhibited ratios of 0.29:0.58 for Neu5Ac2-6Gal/Neu5Ac2-3Gal and 0.51:0.76 for Neu5Gc2-3Gal/Neu5Ac2-3Gal. The above results indicate that the substrate specificities of sialidases from swine influenza A viruses towards sialyl linkages and the molecular species of sialic acid are related to the year of isolation, i.e. strains isolated after 1978 exhibited higher activity towards Neu5Ac2-6Gal and Neu5Gc2-3Gal linkages when compared with strains isolated in an earlier year, 1930.Abbreviation Neu5Ac 5-N-acetylneuraminic acid - Neu5Gc 5-N-glycolyneuraminic acid - Gal d-galactose - Glc d-glucose - Cer Ceramide - II³(Neu5Ac)Lac Neu5Ac2-3Gal1-4Glc - GM3(Neu5Ac2-3Gal) Neu5Ac2-3Gal1-4Glc1-Cer - GM3(Neu5Gc2-3Gal) Neu5Gc2-3Gal1-4Glc1-Cer - GM1b(Neu5Ac2-3Gal) Neu5Ac2-3Gal1-3GalNac1-4Gal1-4Glc1-Cer - GMlb(Neu5Gc2-3Gal) Neu5Gc2-3Gal1-3GalNAc1-4Gal1-4Glc1-Cer - IV³(Neu5Ac)nLc4Cer Neu5Ac2-3Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - IV³(Neu5Gc)nLc4Cer Neu5Gc2-3Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - IV⁶(Neu5Ac)nLc4Cer Neu5Ac2-6Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - TDC taurodeoxycholate.     

Bi-antennary oligo-(N-acetyllactosamino)glycans of I-type are galactosylated preferentially at the GlcNAcβ1-6Gal linked arms by α1,3-galactosyltransferase of bovine thymus

1,3-Galactosylation of radiolabelled bi-antennary acceptors Gal1-4GlcNAc1-3(Gal1-4GlcNAc1-6)Gal-R (R=1-OH, 1-4GlcNAc or 1-4Glc) with bovine thymus 1,3-galactosyltransferase was studied. At all stages of the reactions the three acceptors reacted faster at the 1 6 linked arm than at the 1 3 linked branch. Hence, in addition to the doubly 1,3-galactosylated products, practically pure Gal1-4GlcNAc1-3(Gal1-3Gal1-4GlcNAc1-6)Gal-R could be obtained from the three acceptors in reactions that had proceeded to near completion. The isomeric mono-1,3-galactosylated products were identified by using exoglycosidases to remove the branches unprotected by 1,3-galactoses and by subsequently identifying the resulting linear glycans chromatographically.Abbreviations Gal d-galactose - GlcNAc N-acetyl-d-glucosamine - Lac lactose - LacNAc Gal1-4GlcNAc - MH maltoheptaose - MP maltopentaose - MT maltotriose - MTet maltotetraose - WGA wheat germ agglutinin - 3 position 3 of the galactose unit of LacNAc or Lac - 6 position 6 of the galactose unit of LacNAc or Lac     

β-d-N-Acetylglucosaminidase,a new cytochemical marker of human lymphocyte subpopulations

Summary -d-N-acetylglucosaminidase staining characteristics of rosetted or non-rosetted normal and malignant lymphoid cells were compared with those observed after nonspecific esterase and acid phosphatase staining. With the three cytochemical techniques a similar staining pattern was observed in T cells (E-rosettes), their subpopulations T and T, B cells and the non-T, non-B cells, as well as in the T cell populations defined with the monoclonal antibodies OKT3,4 and 8. T cells mostly diplayed a dot-like reaction, T and the non-T, non-B cells a fine to heavy granular reaction, while most B cells were negative. OKT4 and OKT8 positive lymphocytes showed for the larger part a dot-like staining pattern, however, the frequency of cells with a granular pattern was distinctly higher in the OKT8, than in the OKT4 positive cells.E(+)mIg(–) and E(–)mIg(–) A.L.L. blasts stained either with a dot-like or granular pattern or failed to react when stained cytochemically for -d-N-acetylglucosaminidase, nonspecific esterase and acid phosphatase activity. Only in a few instances a discrepancy was observed between the types of staining for esterase and acid phosphatase on one hand and those for -d-N-acetylglucosaminidase on the other.