Einschlußkörper in viruskrankenHesperis-Zellen

Zusammenfassung An einer Anzahl vonHesperis Candida undHesperis matronalis-Pflanzen zeigten sich im Botanischen Garten im Frühjahr 1959 Symptome einer Mosaikkrankheit. In den Trichomen der Blätter, in der Epidermis der Blattmittelrippe, in der Oberhaut des Stengels sowie in der Epidermis der Fruchtwand traten oft auffallend große protoplasmatische X-Körper auf. in denen sich Viruseiweißkristalle verschiedener Größe und Form bildeten.Herrn Professor Dr. Adolf Sperlich zum 80. Geburtstag.     

Spontane Mutationen bei Essigsäurebakterien

Zusammenfassung Mit einer modifizierten Penicillintechnik konnten aus Acetobacter-Populationen, die von einem prototrophen Klon stammten, spontane auxotrophe Mutanten isoliert werden. Bei sechs von acht untersuchten Stämmen wurden auxotrophe Mutanten gefunden. Die Häufigkeit dieser Mutanten betrug 10^-6.Die Auxotrophie, welche je nach Stamm auf Äthanol- oder Glucose-Medium auftrat, äußerte sich als Bedarf für Hefeextrakt. Hefeextrakt konnte durch Alanin, Prolin oder Glutaminsäure nicht ersetzt werden. Die Mutation von prototroph auf Äthanol-Medium zu auxotroph auf Äthanol-Medium hatte keine Änderung der spezifischen Aktivitäten der Schlüsselenzyme des Glyoxylsäurecyclus zur Folge.Es wurden auch spontane Mutanten gefunden, welche die partikelgebundene Äthanoldehydrogenase verloren hatten und dadurch unfähig waren, Äthanol zu oxydieren oder als C-Quelle zu verwerten.Bei den spontanen, auf Äthanol-Medium auxotrophen Mutanten handelt es sich um Mutationen von einer Art des Frateurschen Systems in eine andere. Mutanten, welche die partikelgebundene Äthanoldehydrogenase verloren haben, gehören definitionsgemäß nicht mehr in die Gattung Acetobacter. Die Bedeutung solcher interspezifischer und intergenerischer Mutationen für die Arteinteilung innerhalb der Essigsäurebakterien wird diskutiert.

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Spontaneous mutations in acetic acid bacteria

Summary 8 prototrophic Acetobacter-strains were examined for spontaneous auxotrophic mutants. Using a modification of the Penicillin technique, there were detected auxotrophic mutants in 6 strains. The mutant frequency was 10^-6.Auxotrophy manifested itself as a requirement for yeast extract. Alanine, proline and glutamic acid could not replace yeastextract. In addition to the auxotrophic mutants there were found spontaneous mutants, which had lost the particulate ethanol-dehydrogenase and therefore had become unable to oxidise ethanol.The mutation from prototrophic on minerals-ethanol medium to auxotropic on minerals-ethanol medium represents a mutation from one species of Frateur's system into an other species. Mutants which have lost the particulate ethanol-dehydrogenase belong no more to the genus Acetobacter. The importance of such interspecific and intergeneric mutations for the taxonomy of acetic acid bacteria is discussed.

     

Lipoide als zytochemisches Substrat der Bindungsorte basischer Vitalfarbstoffe in Blut-, Epithel- und Tumorzellen

Zusammenfassung Die zytochemische Natur der Anreicherungsorte basischer Vitalfarbstoffe (Akridinorange, Nilblausulfat und Neutralrot) im Zytoplasma von Blutplättchen, Leukozyten, Mäuseaszites-Tumorzellen und Epithelzellen wurde untersucht. Dabei stellte sich heraus, daß bei allen untersuchten Zelltypen Phospholipoide oder Phospholipoproteide als Substrat der umschriebenen Farbstoffbindung in lysosomalen Zellstrukturen dienen. Die Supravitalfärbung mit basischen Farbstoffen ist demnach als zytochemischer Lipoidnachweis geeignet, wenn unter bestimmten Bedingungen und unter Einhaltung eines definierten Färbestadiums (Stadium der granulären oder vakuolären Farbstoffverteilung) beobachtet wird. Auf die methodischen Vorteile der Supravitalfärbung wird hingewiesen.

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Summary The cytochemical character of the substrat for basic vital dyes (acridine orange, nil blue sulfate, neutral red) has been studied in the cytoplasma of blood platelets, leucocytes, Ehrlich Ascites tumor cells and epithelial cells. It could be demonstrated that the vital dyes are bound to lysosomal phospholipids or phospholipoproteins in the different cell types. Supravital staining with basic dyes is therefore considered to be a useful method for identifying lipid material in cytology, provided defined conditions and stades of staining are observed. The advantages of the proposed method are discussed.

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Stipendiat der Deutschen Forschungsgemeinschaft     

Anatomical Studies of Haustorium Ontogeny and the Remarkable Mode of Penetration of the Haustorium in Nuytsiafloribunda (Labill.) R. Br.

The development and structure of secondary haustoria of Nuytsia floribunda are described and compared with other Santalalean haustoria. After establishing contact with the host root, cortical folds of the haustorium grow around the root in separate directions and fuse forming a ring around it. At an early stage of development, meristematic tissue differentiates in the interior proximal part of the haustorium. Zones of collapsed layers are present in the outer cortical region. Subsequently, in the proximal part, two vascular cores, two lysigenous cavities and extensive masses of sclerenchyma develop prior to penetration of the host root. The sclerenchymatous cells form a characteristic structure, described as the sclerenchyma prong. During penetration the intrusive part of the haustorium reaches not only the host xylem but continues growing downwards until it entirely splits the host root. Comparable to a guillotine, the sclerenchyma prong is directly involved in this remarkable process. The sclerenchyma prong finally lies in the distal part of the haustorium. Following this mechanical slicing of the host root, tube-like cells of the intrusive part actively penetrate the host xylem in an axial direction.     

A comparison of two plating techniques to estimate plasmid stability of a prolonged chemostat culture

Summary A comparison of two plating techniques to estimate the segregational stability ofEscherichia coli RR1 harboring plasmid pBR322 in a chemostat was studied. No significant differences were observed between the spread and replica plating techniques in the beginning of the experiments. However, a noticeable discrepancy between these two methods appeared after approximately 100 hours. This inconsistency can be shown to be statistically significant.     

A novel photoaffinity ligand for the phencyclidine site of the N-methyl-D-aspartate receptor labels a Mr 120,000 polypeptide

A radiolabeled photoaffinity ligand has been developed for the N-methyl-D-aspartate (NMDA)-preferring excitatory amino acid receptor complex. [3H]3-Azido-(5S, 10R)(+)-5-methyl-10,11-dihydro-5H- dibenzo[a,d]cyclohepten-5,10-imine [3H]3-azido-MK-801 demonstrated nearly identical affinity, density of binding sites, selectivity, pH sensitivity, and pharmacological profile in reversible binding assays with guinea pig brain homogenates to those displayed by its parent compound, MK-801. When employed in a photo-labeling protocol designed to optimize specific incorporation, [3H]3-azido-MK-801 labeled a single protein band which migrated in sodium dodecyl sulfate-polyacrylamide gels with Mr = 120,000. Incorporation of tritium into this band was completely inhibited when homogenates and [3H]3-azido-MK-801 were coincubated with 10 microM phencyclidine. These data suggest that the phencyclidine site of the NMDA receptor complex is at least in part comprised of a Mr = 120,000 polypeptide.     

Recombinogenic properties of herpes simplex virus type 1 DNA sequences resident in simian virus 40 minichromosomes.

In a previous work, it was demonstrated that the bacterial transposon Tn5 is capable of undergoing sequence inversion via recombination between its duplicated IS50 elements when replicated by the herpes simplex virus type 1 (HSV-1) origin oris but not by the simian virus 40 (SV40) origin orisv. Further analysis of the latter phenomenon indicated that this lack of recombination was the result of topological constraints imposed by the SV40 minichromosome, such that recombination events could be readily detected in Tn5 derivatives in which the IS50 elements were arranged in a direct rather than inverted orientation. With this information, a second set of experiments were carried out to examine how the highly recombinogenic sequences which mediate the inversion of the long (L) and short (S) components of the HSV-1 genome behave in an SV40 minichromosome. Tandem copies of the L-S junction of the HSV-1 genome were observed to promote deletions in an SV40 shuttle plasmid at a frequency that was considerably greater than that of duplicated bacterial plasmid vector DNA. However, the presence of superinfecting HSV-1 did not enhance the frequency of these recombination events. These results support our previous findings that HSV-1 genome isomerization is mediated by a homologous recombination mechanism which is intimately associated with the act of viral DNA synthesis. Moreover, they demonstrate that the sequences which comprise the L-S junction appear to be inherently recombinogenic and, therefore, do not contain specific signals required for HSV-1 genome isomerization.