The comparative influence of substituted phenols (especially chlorophenols) on yeast cells assayed by electro-rotation and other methods

The toxicity of 31 phenols was studied by electro-rotation of yeast cells. Control yeast cells show both anti-field and co-field rotation, depending upon the field frequency applied. After treatment with supra-threshold amounts of phenols the anti-field rotation is weakened or abolished and a stronger co-field rotation can be seen. The proportion of cells showing the co-field rotation was found to be a sensitive measure of toxicity. Doses of 2.2 mumol/l of pentachlorophenol, or of 0.3 mumol/l of pentabromophenol were detectable after 3 h incubation at pH 4.0. At a given pH, the toxicity of the chlorophenols correlated extremely well with their octanol:water partition coefficients (Pow). The complete set of phenols showed fair overall correlation with Pow, but less good correlation with their acidity constants (pKa). In particular the toxicity of a given phenol was less than predicted from its pKa if the incubation pH was higher than the pKa. Biochemical assays on 23 of the phenols showed that the rotational sensitivity runs closely parallel to the sensitivities of cell growth rate and of the plasmamembrane ATPase, but less closely to the inhibition of purine incorporation. It appears that the electro-rotation method provides a useful and rapid test for the presence of organic ecotoxins. The test enables us to distinguish differences between single cells, and is comparable in sensitivity to biochemical tests that use vesicles or homogenates derived from a cell population.     

Inactivation of C3a by a monocarboxypeptidase present in culture supernatants of stimulated guinea pig peritoneal macrophages

Hog C3a, as well as its derivative C3a-desArg were not found to act cytotoxically on starch gel-induced guinea pig peritoneal macrophages. Likewise, neither peptide significantly modified the secretion of N-acetyl-beta-D-glucosaminidase from these cells. However, C3a rapidly lost its spasmogenic activity during incubation in serum-free macrophage cultures and less rapidly in cellfree supernatants collected from cultured macrophages. The following results indicate that C3a is converted into its spasmogenically inactive derivative C3a-desArg by a macrophage-derived monocarboxypeptidase. The inactivated C3a product does not differ from native C3a in sodium dodecyl sulfate-polyacrylamide gel electrophoresis; it elutes from CM cellulose in the same position as purified C3a-desArg; and it is devoid of the carboxyl-terminal arginyl residue of C3a, but still contains the carboxyl-terminal sequence of C3a-desArg as determined by analysis after treatment with carboxypeptidases B or Y. Furthermore, inactivation of C3a in supernatants of macrophage cultures is completely blocked by the specific carboxypeptidase inhibitors guanidinopropylsuccinic acid and 2-mercaptomethyl-3-guanidinoethylthiopropanoic acid in final concentrations of 10 mM and 2.1 mM, respectively. The monocarboxypeptidase is apparently supplied by biosynthesis of new material but is not stored as a preformed enzyme because cycloheximide markedly inhibits its expression.     

Acetylcholine, ATP, and Proteoglycan Are Common to Synaptic Vesicles Isolated from the Electric Organs of Electric Eel and Electric Catfish as Well as from Rat Diaphragm

Cholinergic synaptic vesicles were isolated from the electric organs of the electric eel (Electrophorus electricus) and the electric catfish (Malapterurus electricus) as well as from the diaphragm of the rat by density gradient centrifugation followed by column chromatography on Sephacryl-1000. This was verified by both biochemical and electron microscopic criteria. Differences in size between synaptic vesicles from the various tissue sources were reflected by their elution pattern from the Sephacryl column. Specific activities of acetylcholine (ACh; in nmol/mg of protein) of chromatography-purified vesicle fractions were 36 (electric eel), 2 (electric catfish), and 1 (rat diaphragm). Synaptic vesicles from all three sources contained ATP in addition to ACh (molar ratios of ACh/ATP, 9-12) as well as binding activity for an antibody raised against Torpedo cholinergic synaptic vesicle proteoglycan. Synaptic vesicles from rat diaphragm contained binding activity for the monoclonal antibody asv 48 raised against a rat brain 65-kilodalton synaptic vesicle protein. Antibody asv 48 binding was absent from electric eel and electric catfish synaptic vesicles. These antibody binding results, which were obtained by a dot blot assay on isolated vesicles, directly correspond to the immunocytochemical results demonstrating fluorescein isothiocyanate staining in the respective nerve terminals. Our results imply that ACh, ATP, and proteoglycan are common molecular constituents of motor nerve terminal-derived synaptic vesicles from Torpedo to rat. In addition to ACh, both ATP and proteoglycan may play a specific role in the process of cholinergic signal transmission.     

Selective allele loss and interference between cauliflower mosaic virus DNAs

Summary Some cauliflower mosaic virus (CaMV) alleles are selectively lost during growth of the virus in mixedly infected turnip plants. Viral DNA from plants co-inoculated with DNA of the cabbage S isolate and infectious cabbage S DNA with an extra EcoRI restriciion site lacked the extra site. The EcoRI allele was also lost in most plants co-inoculated with a non-infectious mutant of cabbage S DNA while little selective allele loss was observed with two other non-infectious mutant DNAs. Plants co-inoculated with DNAs of closely-related isolates (CM4-184 and W) contained both parental viral DNAs and some DNAs with characteristics of both parents. Interference, scored as a reduced frequency of infection or a delay in symptom appearance relative to plants inoculated with wild-type DNA, occurred when plants were inoculated with wild-type and mutant DNAs covalently attached to one another in partial dimer plasmid DNAs. Similarities in the conditions leading to selective allele loss and those leading to interference suggest that both may have been due to active gene conversion between CaMV DNA molecules.     

Mitotic recombination between dispersed but related rRNA genes of Schizosaccharomyces pombe generates a reciprocal translocation

Summary Recombination between dispersed yet related serine tRNA genes of Schizosaccharomyces pombe does occur during mitosis but it is approximately three orders of magnitude less frequent than in meiosis. Two mitotic events have been studied in detail. In the first, a sequence of at least 18 nucleotides has been transferred from the donor sup3 gene on the right arm of chromosome I to the related acceptor gene sup12 on the left arm of the same chromosome, thereby leading to the simultaneous change of 8 bp in the acceptor gene. This event must be explained in terms of recombination rather than mutation. It is assumed that it represents mitotic gene conversion, although it was not possible to demonstrate that the donor gene had emerged unchanged from the event. The second case reflects an interaction between sup9 on chromosome III and sup3 on chromosome I. Genetic and physical analysis allows this event to be described as mitotic gene conversion associated with crossingover. The result of this event is a reciprocal translocation. No further chromosomal aberrations were found among an additional 700 potential intergenic convertants tested. Thus intergenic conversion is much less frequently associated with crossingover than allelic conversion. However, the rare intergenic conversion events associated with crossingover provide a molecular mechanism for chromosomal rearrangements.     

Die Bestandsentwicklung von Kleinv?geln in Mitteleuropa: Analyse von Fangzahlen

Zusammenfassung Im Mettnau-Reit-Illmitz-Programm (MRI-Programm) der Vogelwarte Radolfzell wurden von 1974–1983 auf drei Fangstationen in Süddeutschland, Norddeutschland und Ostösterreich (Abb. 1) 184 939 Vögel von 37 Kleinvogelarten gefangen. Die Fänge erfolgten jährlich während der gesamten Wegzugperiode von Ende Juni bis Anfang November an Durchzüglern in Japannetzen unter strikter und umfassender Standardisierung aller Fang- und Arbeitsmethoden. Die Fangzahlen (Tab. 1, Abb. 2–6) werden in fünf Regressionsanalysen (Tab. 2–9) auf systematische Änderungen untersucht.Von insgesamt 496 errechenbaren Koeffizienten waren 317 oder 63,9% negativ und nur 179 oder 38,1 % positiv. Bei 34 der 37 untersuchten Arten ließen sich signifikante Trends errechnen. Sie sind für 20 oder 54 % dieser Arten ausschließlich oder überwiegend negativ. 14 Arten zeigten mindestens auf zwei Stationen negative Trends. Nur für insgesamt 10 Arten ließen sich überwiegend positive Trends errechnen. Faßt man negative Trends und Tendenzen (Vorzeichen) zusammen, so ergibt sich für 26 oder 70 % der untersuchten Arten ein negatives Bild. Dieses stark negative Gewicht ist im statistischen Sinne keine zufällige Erscheinung. Da die Bestandszunahmen die Abnahmen nicht aufwiegen konnten, zeigten auch die jährlichen Gesamtfangzahlen aller drei Stationen negative Trends. Die mittlere jährliche Abnahme betrug auf den Stationen Mettnau, Reit und Illmitz etwa 1,6 %. Die Tendenzen und Trends der einzelnen Arten stimmen auf den drei Stationen weitgehend überein. Sie lassen für ihr Zustandekommen auf weitgehend gleichförmige Ursachen bei den durch Mitteleuropa wandernden Populationen schließen.Die Fangzahlen und Literaturdaten zeigen, daß beträchtliche Teile unserer Kleinvogelwelt von Rückgangserscheinungen betroffen sind, wie wir sie von vielen Großvogelarten seit langem kennen. Bei einer Reihe von Arten sind die Abnahmen gravierend und die jährlichen Fangzahlen inzwischen so niedrig, daß sich bei ihnen mit den in den 70er Jahren konzipierten Fanganlagen eine Reihe von Fragestellungen nicht mehr untersuchen lassen. Wir können der weiteren Entwicklung der Bestände unserer derzeit noch artenreichen Kleinvogelwelt — wie der vieler Großvögel — nur mit größter Sorge entgegensehen. Die Ursachen der Rückgänge sind weitgehend unbekannt, und demzufolge mangelt es fast vollständig an geeigneten Gegenmaßnahmen. Bisherige Schutzmaßnahmen haben die Rückgänge nicht aufhalten können. Künftiger Vogelschutz wird sich folglich weitergehender Maßnahmen bedienen müssen.

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The development of songbird populations in central Europe: Analysis of trapping data

Summary In the Mettnau-Reit-Illmitz-Program (MRI-Program) of the Vogelwarte Radolfzell 184 939 birds of 37 songbird species were caught in the period 1974–1983 on three trapping stations in S. and N. Germany and E. Austria (Fig. 1). Trapping of passage migrants in mist nets occurred annually from the end of June to the beginning of November, the entire autumn migratory period. All trapping and working methods were strictly and comprehensively standardized. The trapping figures (Tab. 1, Fig. 2–6) were analyzed with respect to systematic alterations to gain information about changes in the population levels of species migrating through central Europe. The investigation is based above all on five regression analyses (Tab. 2–9).The most important individual results are: out of a total of 496 coefficients which could be calculated 317 or 63.9 % were negative and only 179 or 38.1 % positive. For 34 of the 37 investigated species significant trends could be calculated. In 20 or 54 % of these species they were (exclusively or predominately) negative. 14 species showed negative trends at least at two stations. Mainly positive trends could be found in only 10 species. Taking negative trends and tendencies (negative signs) together, 26 or 70 % of the species were included. This strongly negative bias is not accidental in a statistical sense. Since the increases could not balance the declines, the annual trapping totals of all three stations also showed negative trends. The mean annual decline in the stations Mettnau, Reit and Illmitz was about 1.6 %. Trends and tendencies of the species show a high degree of agreement for the three stations. This suggests that in the species migrating through central Europe rather uniform factors control the population levels. From the most recent literature results, it appears that most of the species with declining trapping figures in the MRI-Program demonstrate decreases elsewhere.The trapping figures of the MRI-Program and data from the literature together clearly indicate that considerable parts of our small birds are affected by declines as have been known in many large bird species for long time. In a number of species the decreases have been quite dramatic and their annual trapping totals are now so low that a number of problems can no longer be studied. We should be alarmed when considering this negative development among our small birds as we must be with respect to many large bird species. The reasons for the declines are almost unkown and thus there is lack of appropriate counter-measures. Hitherto existing efforts for conservation which are briefly discussed have not been able to prevent the decline. Consequently, bird conservation in the future has to be based on more effective methods. Proposals, briefly raised, will be discussed in a forthcoming paper.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft und gefördert mit Hilfe von Forschungsmitteln des Landes Niedersachsen. 15. Mitteilung aus dem MRI-Programm     

Monoclonal antibodies to bovine UDP-galactosyltransferase. Characterization, cross-reactivity, and utilization as structural probes

A series of mouse monoclonal antibodies has been developed against a soluble form of bovine UDP-galactose:N-acetylglucosamine galactosyltransferase purified to apparent chemical homogeneity by a combination of affinity and immunoadsorption chromatography. The purified enzyme consists of two molecular mass variants of 42 and 48 kDa. Individual monoclonal antibodies were selected for by their ability to recognize immobilized affinity-purified galactosyltransferase and were not reactive against bovine alpha-lactalbumin and bovine immunoglobulins. Based on competitive binding assays and Western blot analysis with either galactosyltransferase or lactose synthetase (covalently cross-linked alpha-lactalbumin galactosyltransferase), these monoclonal antibodies can be subdivided into four groups. Group A (3 clones) recognize an epitope at or near the alpha-lactalbumin binding site. In addition, this group is cross-reactive with soluble galactosyltransferase from human milk and pleural effusion. Group B (6 clones) and D (1 clone) appear to recognize two different epitopes on the 6-kDa fragment which is released when the 48-kDa galactosyltransferase polypeptide is converted to the 42-kDa form, apparently by proteolysis. Groups A and C (1 clone) recognize epitopes found on both the 48- and 42-kDa polypeptide. Interestingly, immunofluorescence studies indicate that only two monoclonal antibody groups (C and D) are able to decorate membrane-bound galactosyltransferase (Golgi-associated) in formalin-fixed, methanol-, or detergent-permeabilized cells. Thus, these groups of monoclonal antibodies appear to identify four separate structural/functional domains on soluble galactosyltransferase, two of which are not readily accessible for binding in situ.     

Osmotic responses of preimplantation mouse and bovine embryos and their cryobiological implications

Cells subjected to the events occurring before, during, and after freezing and thawing are exposed to major changes in the osmotic pressure of the surrounding medium; i.e., the osmolalities can exceed 30. An important question in understanding the mechanisms of injury is whether cells respond as ideal osmometers to these strongly anisotonic solutions. Mouse and bovine embryos from eight-cell to blastocyst stage were used to investigate the question. They were found to behave as ideal osmometers at room temperature over a wide range of tonicities; i.e., from four times isotonic to almost 1/3 times isotonic, ideality being defined by a Boyle-van't Hoff equation. Embryo volumes increased from 40 to 200% of isotonic over this range and survivals of mouse embryos were unaffected. However, outside this range the membrane apparently becomes leaky and the survival of mouse embryos drops sharply. Osmolalities rise to high values during freezing and the paper develops the thermodynamic equations to show how computed cell volumes as a function of subzero temperature can be translated into the Boyle-van't Hoff format of cell volume as a function of the reciprocal of osmolality.