Sequence homologies of glucose-dehydrogenases of Bacillus megaterium and Bacillus subtilis

The sequence homologies of the glucose dehydrogenase subunits of B. megaterium and B. subtilis are compared. From the known B. megaterium aminoacid sequence and the base sequence of the cloned B. subtilis structural gene we predict the B. megaterium structural glucose dehydrogenase gene. Assuming the minimal mutational changes to convert one gene into the other 23 transitions, 30 transversions, 1 inversion, 3 insertion-deletions, but no frameshifts are postulated necessary to interconvert the structural genes. The homology of both enzyme subunits of 85% reflects the close evolutionary distance between B. subtilis and B. megaterium.     

Increase of circulating beta-endorphin-like immunoreactivity correlates with the change in feeling of pleasantness after running

Twenty-one male regular long distance runners participated in two 10 km runs one week apart. Their beta-endorphin-like immunoreactivity (beta-EIR) was assayed in plasma before and immediately after running. Mood was monitored by an adjective check list (Eigenschaftsw?rterliste, EWL) pre- and post-run. beta-EIR was significantly elevated post-run. Self-reliance and good mood scored higher after running. Both mood elevation and plasma beta-EIR increase showed a considerable individual variability but there was a significant correlation in the mean values of the two runs between individual beta-EIR increases (delta beta-EIR) and the changes of ratings in feeling of pleasantness (delta FP). High delta beta-EIR corresponded to positive mood change post-run.     

Chromosomal damage induced in human lymphocytes by low doses of D-T neutrons

Unstable chromosome aberrations induced by in vitro irradiation with zero plus seven low doses of 14.8 MeV D-T neutrons in the range 3.55-244 mGy have been analysed in human peripheral blood lymphocytes. In order to obtain the required large numbers of scored cells for such low doses, fourteen laboratories participated in the experiment. The dose responses for dicentrics, excess acentrics and total aberrations, fitted well to the Y = alpha D model. The alpha coefficient of yield for dicentrics, 1.60 +/- 0.07 X 10(-2) Gy-1, compares well with the values obtained in previous studies with D-T neutrons at somewhat higher doses. Results from a previous collaborative study using 250 kVp X-rays over a comparable dose range indicated the possible existence of a threshold below 50 mGy. In the present study there is no clear evidence for neutrons for such a threshold. However, the data were insufficient to permit the rejection of a possible threshold below approximately 10 mGy.     

Molecular cloning of the c2 locus of Zea mays, the gene coding for chalcone synthase

Summary The c2 locus of Zea mays, identified as one of the genes affecting anthocyanin biosynthesis, was cloned using the transposable element En (Spm) as a gene tag. The Spm element present at the c2 locus in the autonomously mutating c2-m1 line was isolated using En1 element specific probes. Sequences flanking the element were identified as c2 locus specific and were used to clone the nonautonomous c2-m2 and wild-type alleles. The cloning and analysis of a cDNA complementary to the c2 locus provided evidence that this gene encodes the enzyme chalcone synthase.     

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.     

Recovery of adenine-nucleotide pools in terrestrial blue-green algae after prolonged drought periods

Summary The response of Nostoc commune and Nostoc flagelliforme (terrestrial blue-green algae), grown in their natural habitat, towards rewetting after prolonged drought periods (2 weeds up to five years) has been investigated. In Nostoc flagelliforme, the energy charge (EC) about 0.18 in dry condition increases rapidly (EC=0.7 after 1 h) and more slowly in a second phase (EC=0.8 after 6 h). The total content of AXP (=ATP+ADP+AMP) apparently increases due to de novo synthesis of adenine nucleotides. ATP-build-up after a drought period is probably provided by oxidative phosphorylation. It has been found to be about the same, regardless of whether the foregoing drought period had been extended over 6 months or 5 years.Dry samples of colony mats of N. commune exhibit very low ATP-, but high ADP-contents. Within 6 h after rewetting, the final level of extractable ATP (60–100 nmol/mg chlorophyll) is recovered.     

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     

Radiation protection of E. coli strains by cysteamine in the presence of oxygen

The survival of various E. coli K12 strains with defects in the rec system have been measured after gamma-irradiation in air in the presence (0.1 mol dm-3) or in the absence of cysteamine. The results confirm those of Bresler et al. (1978) indicating that the protection by cysteamine in the presence of oxygen is due to an influence on enzymatic repair. The low protection by cysteamine of wild-type cells pretreated with chloramphenicol which prevents protein synthesis, supports the above conclusion. The reason for the absence of a protective effect by OH radical scavenging and H-atom donation is discussed. It is proposed that DNA peroxyl radicals are formed during irradiation in the presence of oxygen and that they are transformed into hydroperoxides by H-atom donation from the intracellular glutathione and the added cysteamine. These hydroperoxides are still dangerous for the cell as indicated by the protective action of glutathione peroxidase observed by Marklund et al. (1984).     

Song types in the corn buntingEmberiza calandra: Matching and discrimination

Summary Corn Bunting populations in Central England have 2 song types, during spontaneous singing they are sung approximately equally frequently and in bouts. Playback of song does not elicit song matching. The tendency to approach the source of playback wanes with repeated presentation of song — the birds habituate. The approach response is restored by playback of the other song type (dishabituation) — evidence that Corn Buntings can discriminate between song types. The functional significance of song types and the reason for differences in song type use between British and European populations remain unclear.

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Strophentypen der GrauammerEmberiza calandra: Experimente zur Angleichung und zum Unterscheidungsvermögen

Zusammenfassung Die Populationen der Grauammer in Mittelengland besitzen 2 Strophentypen, die sie beim experimentell unbeeinflußten Singen jeweils in Serien und etwa gleich häufig vortragen. Tonbandvorspiel von Strophen löst keine Angleichung im Strophentyp aus. Die Tendenz, sich der Schallquelle anzunähern, läßt mit wiederholtem Vorspiel desselben Strophentyps nach, d. h. die Vögel gewöhnen sich an ihn (Habituation). Vorspiel des anderen Strophentyps führt dagegen wieder zur Annäherung (Antihabituation). Dies ist ein Beleg, daß Grauammern zwischen Strophentypen unterscheiden können. Die funktionelle Bedeutung der Strophentypen und die Ursache, warum sich britische und zentraleuropäische Populationen in der Verwendung von Strophentypen unterscheiden, bleibt weiterhin unklar.