Two new species of Heterokrohnia (Chaetognatha) from Antarctic waters

Summary Two new species of the genus Heterokrohnia, H. longidentata and H. fragilis, are described and compared with the other three known Heterokrohnia species, H. mirabilis Ritter-Záhony 1911; H. bathybia Marumo and Kitou 1966 and H. involucrum Dawson 1968. The species have been found at great depths (1,000 m–2,000 m) near Elephant Island, north of the Antarctic Peninsula.     

Analysis of the energy metabolism after incubation of Saccharomyces cerevisiae with sulfite or nitrite

After addition of 5 mM sulfite or nitrite to glucose-metabolizing cells of Saccharomyces cerevisiae a rapid decrease of the ATP content and an inversely proportional increase in the level of inorganic phosphate was observed. The concentration of ADP shows only small and transient changes. Cells of the yeast mutant pet 936, lacking mitochondrial F₁ATPase, after addition of 5 mM sulfite or nitrite exhibit changes in ATP, ADP and inorganic phosphate very similar to those observed in wild type cells. They key enzyme of glucose degradation, glyceraldehyde-3-phosphate dehydrogenase was previously shown to be the most sulfiteor nitrite-sensitive enzyme of the glycolytic pathway. This enzyme shows the same sensitivity to sulfite or nitrite in cells of the mutant pet 936 as in wild type cells. It is concluded that the effects of sulfite or nitrite on ATP, ADP and inorganic phosphate are the result of inhibition of glyceraldehyde-3-phosphate dehydrogenase and not of inhibition of phosphorylation processes in the mitochondria. Levels of GTP, UTP and CTP show parallel changes to ATP. This is explained by the presence of very active nucleoside monophosphate kinases which cause a rapid exchange between the nucleoside phosphates. The effects of the sudden inhibition of glucose degradation by sulfite or nitrite on levels of ATP, ADP and inorganic phosphate are discussed in terms of the theory of Lynen (1942) on compensating phosphorylation and dephosphorylation in steady state glucose metabolizing yeast.Abbreviations ATP adenosine triphosphate - ADP adenosine diphosphate - AMP adenosine monophosphate - P_i inorganic orthophosphate Dedicated to Prof. Dr. Hans Grisebach on the occasion of his sixtieth birthday     

Genetic control of murine hemagglutinin formation to H-2.5

When B10.D2 (H-2^d) mice are immunized with lymphoid cells from C57B1/10 (H-2 ^d ) and their antisera tested against B10.A (H-2 ^a ) target cells, only antibodies to H-2.5 are measured. The same is true for immunization of DBA/2 (H-2 ^d ) mice when their antisera are absorbed with B10.D2 cells prior to testing. Irrespective of the dose of immunogen administered, the primary hemagglutinin response of B10.D2 mice is significantly lower than that of DBA/2 mice and (B10.D2 × DBA/2)F₁ hybrids, but the secondary responses are similar. The low responsiveness of B10.D2 mice appears to be determined by a single dominant gene with incomplete penetrance; the gene is not linked to eitherH- 2, Hc, or the immunoglobulin allotype loci. In addition, the H-2.5 hemagglutinin response is susceptible to nongenetic influences. When antisera from B10.D2, devoid of H-2.5 hemagglutinins, were assayed in a complement-mediated cytotoxic test, they contained almost as much anti-H-2.5 activity as did the antisera from DBA/2 mice or (B10.D2 × DBA/2)F₁ hybrids. The possibility is discussed that the locus responsible for the deficient primary hemagglutinin response of B 10.D2 may not be determinant-specific but may affect hemagglutinin responses in general.     

Die Brutzeiten einiger Gänsearten und ihrer Bastarde in identischen Bedingungen

Zusammenfassung An Hand von 229 Brutbeginn-Daten von freilebenden Gänsen, die während der Jahre 1956–1966 in Seewiesen (Obb.) (48°N, 11°11E) brüteten, wurden die mittleren Brutbeginn-Daten von 5 Gänsearten und von Artbastarden bestimmt. Es zeigte sich, daß die untersuchten Arten unter diesen Bedingungen in derselben Reihenfolge brüteten, wie ihre Artgenossen in freier Wildbahn. Die mittleren Brutbeginn-Termine wurden allerdings um so mehr vorverlegt, je später die Art normalerweise brütet (Abb. 1). , die mit artfremden verpaart waren, brüteten zur selben Zeit wie ihre Artgenossen, die mit artgleichen verpaart waren (Abb. 1). GraugansxSchneegans-Bastard-, die mit Schneegantern verpaart waren, begannen meist nach den Graugänsen, aber stets vor den Schneegänsen zu brüten (Abb. 1, 2). Das intermediäre Brüten dieser wird als starkes Argument für die Richtigkeit der Hypothese gewertet, nach welcher die artspezifisch verschiedenen Brutzeiten wenigstens zum Teil genetisch bedingt sind. In der Diskussion wird die Frage kritisch erörtert, wie weit schon allein die Tatsache, daß die verschiedenen Arten über Generationen hinweg in derselben Reihenfolge wie ihre wildlebenden Artgenossen zu brüten beginnen, als Beweis für derartige genetische Unterschiede angesehen werden kann.

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Summary In 229 cases onset of breeding was recorded from free-living geese of 5 species and of some hybrids of these species, kept in Seewiesen/Obb. (48° N, 11° 11E) from 1956 to 1966. It was found that the species under these conditions bred in the same seasonal sequence as did wild birds. The mean breeding times, however, were found to be advanced in relation to the onset of breeding in the wild (Fig. 1). This was especially evident in the case of late-breeding species. paired with of another species came into breeding condition at the same time as paired with of the same species (Fig. 1). GraylegxSnowgoose hybrid paired with Snowgoose in most cases started to breed later than Greyleg geese but always earlier than the mean breeding time for Snowgeese (Fig. 1, 2). This intermediate breeding time is taken as a strong argument for the hypothesis that the species specific differences in breeding times are, at least in part, genetic in origin. The question as to the extent to which the differences in breeding times alone, persisting for generations in the same sequence as those of wild birds, can be attributed to genetic differences between the species, is critically discussed.

     

The Avena geo-curvature test

Summary The Avena geo-curvature test is a bioassay for auxin-type growth regulators. Etiolated oat coleoptiles are used and the test is conducted in special perspex trays under diffuse daylight. The coleoptiles, with the primary leaves intact, are arranged in grooves on the trays in 4 series of 6 coleoptiles each, and cut to a size of 10 mm. The test substance is applied on an agar strip covering only the lower halves of the apical cut surfaces of each series. After a 4-hour stay in the dark in moist Petri dishes the coleoptile cylinders are shadowgraphed on a 35-mm photographic film. The curvatures are measured from an enlarged projection (10 times natural size) of the shadowgraphs.The lowest IAA concentration which can be determined is around 30 to 60 g/l, i.e. about 1 to 2 ng IAA. The concentration response curves follow a logarithmic course up to 1,000 g/l. The standard error of the mean in a test series comprising 6 coleoptiles is on an average ± 7%. The simple and quick procedures make it possible for a worker to test 60 to 80 fractions a day.Dedicated to Professor Hans Söding on the occasion of his seventieth birthday. The senior author expresses his special gratitude for having been initiated by Professor Söding in the study of auxins.present address: Dpt. of Biology Princeton Univ. Princeton, N. J. 08540, U.S.A.     

Farbstoffgehalt und Grösse der Augen bei verschiedenen Mutanten von Drosophila melanogaster

Zusammenfassung Quantitative Untersuchungen über den Farbstoffgehalt der Drosophilaaugen haben schon wiederholt gezeigt, daß die Werte bei bestimmten Mutanten von der Erwartung abweichen. So fand man regelmäßig bei den rotäugigen Mutanten v bzw. cn weniger Pterin und bei der braunäugigen Mutante bw weniger Ommochrom als bei Wildfliegen.Wir haben diese Befunde zunächst mit Hilfe einer vereinfachten Extraktions- und Meßtechnik nachgeprüft und bestätigt. Die genauere Analyse ergab dann aber, daß das Farbstoffdefizit der Mutanten v, cn und bw lediglich darauf beruht, daß diese Tiere kleinere Augen haben als die Wildfliegen. Die Augenverkleinerung ist jedoch nicht, wie gelegentlich vermutet wurde, die Folge einer polyphänen Wirkung der Gene v, cn und bw, sondern nur eine besondere Eigenschaft bestimmter Fliegenstämme, die heute in fast allen Laboratorien gehalten werden.Die Erscheinung selbst beruht auf der Wirkung augenverkleinernder Modifikationsgene, die bei diesen Stämmen zufällig mit den Farbgenen gekoppelt sind, durch geeignete Kreuzungen aber eliminiert werden können. Unsere so erhaltenen neuen v-, cn- und bw-Stämme besitzen nicht nur ebenso große Augen wie die Wildfliegen, sondern enthalten auch die theoretisch erwarteten Mengen an Augenfarbstoffen. Der Zusammenhang zwischen der Größe der Augen und ihrem Farbstoffgehalt hat u. a. zur Folge, daß die Männchen, die ja stets kleinere Augen haben als die Weibchen, bei allen Mutanten weniger Augenpigment besitzen als jene.Der Farbstoffgehalt der Augen hängt außerdem von der Zucht-temperatur ab. Fliegen, die sich bei 18° C entwickeln, besitzen weniger Pterin aber mehr Ommochrom als solche, die bei 26° C aufgezogen werden. Auch die Melaninsynthese im Integument der Tiere wird durch Temperaturerniedrigung begünstigt; aus 18°-Zuchten stammende Fliegen sind deutlich dunkler als die entsprechenden 26°-Tiere.     

Crown gall an viruskranken Pflanzen

Zusammenfassung Es wurden viruskranke Pflanzen vonSchlumbergera truncata und vonHesperis Candida mitAgrobacierium tumefaciens infiziert. In den daraufhin entstandenen Tumoren ließ sich das Vorkommen des Virus dadurch nachweisen, daß in den Tumorzellen Viruseinschlußkörper vorkommen und daß sich durch Infektion mit Tumorpreßsaft dieselben Virosen hervorrufen lassen. In Tumorzellen entwickelt sich demnach das Virus in gleicher Weise wie in den nicht tumorisierten Zellen.Dem Vorstand des Instituts für Anatomie und Physiologie der Pflanzen, Herrn Professor Dr. Otto H ä r t e 1, danke ich für die Überlassung des Themas, Frau Dozent Dr. Irmtraud Thaler bin ich für die ständige wertvolle Förderung meiner Arbeit zu besonderem Dank verpflichtet.     

The Effect of Light and Exogenously Supplied Ammonium Ions on Glutamate Dehydrogenase Activity and Isoforms in Young Mustard (Sinapis alba L.) Seedlings

Glutamate dehydrogenase (GDH, E.C. 1.4.1.3) of mustard cotyledons was investigated during the first 4 days of seedling development. The enzyme was found to be composed of seven catalytically active isoforms (each with a molecular mass of 270 kDa) which exhibited a charge heterogeneity when investigated by isoelectric focusing. Antibodies against the purified isoform 7, raised in rabbits, cross-reacted with each of the isoforms in Western blotting experiments. In addition, each of the isoforms was composed of four immunopositive reacting polypeptides with 19, 21, 23 and 25 kDa. During development of the seedlings, a shift in the isoform pattern towards the more acidic forms was found which was more pronounced when the seedlings were supplied with 15 mM NH₄Cl. The time course of changes in total GDH level can be correlated with the time course of disappearance of storage proteins. Both parameters are negatively regulated by light possibly via the photoreceptor, phytochrome. There are some indications that GDH in young mustard cotyledons mainly acts in the deaminating direction.     

Clinical and biochemical studies in three patients with severe early infantile Cockayne syndrome

Summary We present clinical and biochemical data from three patients with severe Cockayne syndrome (CS) of very early onset. Unlike in classic CS, signs became evident in the first weeks of life and led to unusually early death. Fibroblasts from two of the patients showed a complete defect of the repair of UV-induced thymine dimer lesions. They were unable to remove thymine dimer lesions from their DNA, had a severe reduction of the RNA synthesis rates after UV irradiation, and showed no reactivation of an UV-inactivated indicator gene and no DNA recondensation after UV irradiation. DNA repair investigated in these two fibroblast cell strains resembled that of xeroderma pigmentosum cells of complementation group A. In contrast, fibroblasts from the third patient showed the same in vitro repair characteristics as classic CS cells.