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Zusammenfassung Die Proteinsynthese der wachsenden Oocyten vonMusca domestica L. wurde autoradiographisch und elektrophoretisch auf einer mittleren Entwicklungsstufe (Stadium 3) und nach dem Abschlu\ des Wachstums (Stadium 6) in der Normalentwicklung und nach Applikation von Actinomycin untersucht. Die sehr hohe RNSSynthese der Nährzellen und des Follikelepithels von wachsenden Oocyten wurde durch Injektion von 16 g/g Körpergewicht Actinomycin völlig blockiert. Die Proteinsynthese im Euplasma der wachsenden Oocyte ist relativ hoch, auch das Stadium 6 zeigt trotz fehlender RNS-Synthese eine kräftige Proteinsynthese. Die Proteine des Ovars wurden elektrophoretisch auf Celluloseacetat-Streifen getrennt. Der Anteil neusynthetisierter Proteine wurde nach vorangegangener Inkorporation (30 min) von14C-Aminosäuren bestimmt. Nach 4–6 Std Inkubation mit Actinomycin wird die Proteinsynthese stimuliert. Nach längerer Einwirkung sinkt die Syntheseleistung im Einährverband allmählich unter den Ausgangswert. Die reife Oocyte zeigt, autoradiographisch gesehen, keine Reaktion auf das Antibiotikum. Die Synthese der euplasmatischen Proteine im Einährverband des Stadiums 3 sinkt nach Actinomycin-Behandlung nicht in toto ab, nur einige Fraktionen erweisen sich als empfindlich. Nach mittleren Inkubationszeiten mit Actinomycin treten dagegen neue Proteine im Ovar auf, deren Synthese in begrenztem Umfang auch noch nach 48 Std nachweisbar ist. Der reifen Oocyte steht keine neusynthetisierte RNS zur Verfügung. Sie reagiert aber ebenfalls auf Actinomycin mit partiellen Hemmungen und Neusynthesen von Proteinen. Der Wirkungsmechanismus des Antibiotikums bleibt in diesem Falle offen.
Inhibition and induction of protein syntheses by actinomycin in the growing oocytes ofMusca domestica
Summary The protein synthesis of growing oocytes ofMusca domestica L. is investigated by radioautographic and electrophoretic methods on an intermediate developmental stage (stage 3), and after the end of growth (stage 6) in the normal development and after treatment with Actinomycin. The very high RNA synthesis of the nurse cells and of the follicle epithelium of growing oocytes is completely blocked by injection of 16 g/g body weight Actinomycin. The protein synthesis in the euplasm of a growing oocyte is relatively high, the stage 6 shows a high protein synthesis in spite of the absence of RNA synthesis. The proteins of the ovary are separated electrophoretically on Cellogel-strips. The ratio of the newly-synthetized proteins is determined after incorporation (30 min) of14C-labelled amino acids. The protein synthesis is stimulated after 4–6 hours treatment with Actinomycin. After a longer influence of the antibiotic, synthesis of the egg-nurse cell unit decreases to below the control value. The ripe oocyte does not react autoradiographically to Actinomycin. Only some fractions of the newly-synthetized euplasmatic proteins are sensitive to treatment with Actinomycin. After intermediate incubation times with Actinomycin new proteins appear in the ovary and their synthesis is demonstrable in part even after treatment for 48 hours. There is no newly-synthetized RNA in the ripe oocyte, which, nevertheless, reacts with Actinomycin to inhibit some and to stimulate some new protein synthesis. In this case the action of the antibiotic is unknown.


Die Untersuchungen wurden mit Mitteln unterstützt, die von der Deutschen Forschungsgemeinschaft Herrn Prof. Dr. K. Bier zur Verfügung gestellt wurden.  相似文献   

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A method for the extrapolation of twodimensional patterns is suggested. A fixed and know part of the pattern is given and used to extrapolate it in a fixed intervall. Extrapolation is achieved by computing a correction for the coefficients of a series expansion of the pattern. The method is tested with handwritten numerals. The computed extrapolation and the extrapolation by a human gives approximately equal mean errors.

Die Arbeit wurde mit Mitteln des Bundesministeriums für Bildung und Wissenschaft im Rahmen des Technologieprogramms durchgeführt.

Der Autor ist seit 1. 1. 1973 bei der Fachhochschule Gießen.  相似文献   

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Peroxidases have been shown to catalyse the degradation of flavonols via 2,3-dihydroxyflavanones to benzoic acids. Incubation of (U-14C)-kaempferol with pure horseradish peroxidase leads to the same reaction products (2,3,4,5,7,4′-pentahydroxyflavanone, p-hydroxybenzoic acid, 14CO2, several polar, water soluble catabolites as given by enzyme preparations from various plant species. Further reactions of flavonols and their glycosides with peroxidases are discussed. All peroxidase isoenzymes of Sinapis alba and Cicer arietinum, obtained by isoelectric focusing, have been shown to degrade flavonols at the same rate. The peroxidase catalysed degradation of polyphenols is discussed in relation to IAA oxidase.  相似文献   

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Short-term experiments with hypo-osmotic, radioactive sodium chloride solutions revealed that larval Dytiscus marginalis L. and Acilius sulcatus L. (Coleoptera, Dytiscidae) take up these ions into the hemolymph almost exclusively through the intestine by drinking. Out of 20 Acilius larvae whose mouth had been occluded, 7 were also able to ingest the external solution through the anus. The results of fine-structural investigations lead to the conclusion that the ileum, which is lined by a highly differentiated transporting epithelium throughout its entire length, is the main site of ion absorption. Both the rectum, which lacks the rectal papillae, and the rectal caecum possess a thin epithelium showing no structural indications of any substantial active transport function.  相似文献   

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Ohne ZusammenfassungMit Unterstützung der Deutschen Forschungsgemeinschaft, des Kultusministeriums und des Wirtschaftsministeriums des Landes Nordrhein-Westfalen.Herrn Prof. Dr. W. v.Buddenbrock zur Erreichung des 70. Lebensjahres gewidmet.  相似文献   

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Summary Seedlings of Sinapis alba which were grown in light for 24, 48 and 72 h after 36 h of dark treatment renew elongation when transferred to dark again. The rate of elongation decreases with increased light treatment. The per cent as well as absolute inhibition of elongation by FUDR decreases with the duration of light treatment. The shortening of the hypocotyl is due mainly to the inhibition of cell elongation. The inhibition is not directly proportional to DNA synthesis at any particular time.Plants without cotyledons are less inhibited than those with cotyledons. Cytosine arabinoside is inhibitory only at high concentrations. According to these results elongation inhibition by FUDR does not involve the entire DNA-synthesis.  相似文献   

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The ability of 16 Fusarium species to degrade polyphenols was investigated. Phenols, benzoic acids, cinnamic acids, flavonoids and isoflavones are efficiently catabolized by all strains investigated. o-coumaric acid is transformed into 4-hydroxycoumarin by 7 species. A pronounced capability for methyl ether cleavage is demonstrated by stepwise o-demethylation of veratric acid and 5,7,4′-trimethoxyisoflavone. The latter compound is degraded via the sequence: 5,7,4′-trimethoxyisoflavone → 5,4′-dimethoxy-7-hydroxyisoflavone → biochanin A → genistein → orobol → ring fission products.  相似文献   

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Ohne ZusammenfassungMit UnterstÜtzung der Deutschen Forschungsgemeinschaft und des Kultusministeriums des Landes Nordrhein-Westfalen.  相似文献   

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Zusammenfassung Der Abbau von n-Alkanen durch cunninghamella echinulata, Absidia glauca und Mucor sp. erfolgt durch monoterminale Oxidation ohne Freisetzung von primären oder sekundären Alkoholen, Ketonen und Aldehyden. Das Fettsäuremuster der cellulären Lipide zeigt eine deutliche Abhängigkeit vom gegebenen n-Alkan. Aspergillus-, Penicillium- und Verticillium-Arten oxidieren n-Alkane subterminal unter Bildung verschiedener isomerer sekundärer Alkohole und Ketone. Das Fettsäuremuster zeigt keine deutliche Abhängigkeit vom gegebenen n-Alkan. —Die Abbauwege werden diskutiert.
Terminal and subterminal oxidation of n-alkanes by molds
Summary Degradation of n-alkanes by Cunninghamella echinulata, Absidia glauca and Mucor sp. is effected by monoterminal oxidation of the alkane chain and production of a cellular fatty-acid pattern that depends on the given n-alkane. Primary and secondary alcohols, ketones and aldehydes were not excreted in course of the oxidation. Subterminal attack on the alkane chain is found in members of the genus Aspergillus, Penicillium and Verticillium with the concomitant release of various isomeric secondary alcohols and ketones, and production of a cellular fatty-acid pattern which does not clearly depend on the given n-alkane. — The degradation pathways are discussed.
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