Eiweißkörper inNeomonospora furcellata

Zusammenfassung InNeomonospora furcellata wurden außer den bekannten hexagonalen und kubischen Eiweißkristallen auch Eiweißspindeln und -stäbe beobachtet. Da im Golf von Neapel auch pathologische Formen vorkommen, die ebenfalls (allerdings nicht immer) diese Eiweißbildungen zeigen, wird eine Viruskrankheit vermutet.Der Österreichischen Akademie der Wissenschaften danke ich für die gewährte Subvention, Herrn Prof. Dr. Höfler für die Überlassung des vom Pflanzenphysiologischen Institut Wien gemieteten Arbeitsplatzes. Herrn Direktor Dr. Peter Dohrn danke ich für die gastliche Aufnahme in dem von ihm geleiteten Institut.     

Die Leukoplasten vonHelleborus

Zusammenfassung Die großen Proteinoplasten, die für die Epidermis des Laubblattes vonHelleborus corsicus beschrieben wurden, konnten auch in der Fruchtwand-epidermis vonHelleborus foetidus, Helleborus niger und Helleborus olympicus beobachtet werden. Der Einschlußkörper, der häufig in den Leukoplasten in Einzahl zu sehen ist, kann nicht mit einem Granum identifiziert werden; bei Quellung in KOH treten in den Leukoplasten vonHelleborus ein oder zwei Partikel auf, die Ähulichkeit mit dem Granum vonAllium Cepa undVicia Faba haben. In der Fruchtwandepidermis vonHelleborus corsicus, Allium karataviense undAllium Ostroroskianum findet man in der Regel große Zellkerne mit Lappenbildung oder eine Anzahl von Teilkernen. In den Epidermiszellen der Frucht vonHelleborus corsicus liegen im Cytoplasma um den Zellkern kleine, sehr schwer lösliche Kristallnadeln unbekannter Natur.     

Is hypothermia necessary for the winter survival of the GoldcrestRegulus regulus?

Summary The Goldcrest is an interesting species for studies of physiological and behavioural adaptions to cold, since it is the smallest species present in Europe. Although many small birds have to lower their metabolic rate and enter hypothermia in order to make their energy reserves last throughout the night, our measurements of oxygen consumption of five Goldcrests suggest that these birds may be able to balance their nocturnal energy budget during the winter at normothermic body temperatures, provided that the available food supply is adequate. These results are in agreement with those of another small bird, the Common Bushtit, which, like the Goldcrest, reduce nocturnal heat loss by contact roosting. Since the energy saved by hypothermia decreases with decreasing ambient temperature and also decreasing body weight, this strategy might not be such an advantage for the smallest birds living at very low ambient temperatures.

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Zusammenfassung Am Wintergoldhähnchen als dem kleinsten europäischen Vogel interessieren besonders seine physiologischen und Verhaltens-Anpassungen an niedere Temperaturen. Viele Kleinvögel senken ihre Stoffwechselaktivität und verfallen in Hypothermie, um mit ihren Energie-Reserven während der langen Winternächte auszukommen. Unsere Untersuchungen über den O₂-Verbrauch von 5 Wintergoldhähnchen legen jedoch nahe, daß sich das nächtliche Energie-Budget auch im Tiefwinter auf Normalniveau bewegt und daß sie bei ausreichendem Nahrungsangebot ihre normale Körpertemperatur auch nachts beibehalten. Ähnliche Befunde liegen von den vergleichbaren kleinen amerikanischen Buschmeisen vor, die wie Goldhähnchen den nächtlichen Wärmeverlust durch Schlafen auf engem Gefiederkontakt reduzieren. Es ist anzunehmen, daß die Hypothermie als Überwinterungsstrategie für unsere kleinsten Vögel garnicht so vorteilhaft wäre: Die durch Hypothermie eingesparte Energie geht mit abnehmender Umgebungstemperatur und mit geringerer Körpergröße wieder verloren.

     

Soluble antigens of IgG receptor Fc gamma RIII in human seminal plasma

Human seminal plasma (SP) has been shown to affect several immunologic reactions in vitro. This might be due in part to the presence of proteins that specifically bind the Fc domain of IgG. By using mAb Leu 11a, Leu 11b, Leu 11c, and 3G8 we showed that the Fc binding of SP is associated with a molecule that antigenically resembles Fc gamma RIII. This molecule manifests specific affinity for solid phase-coupled IgG-Fc, and appears not be be cell membrane-associated. When compared with serum or blood plasma, its highest concentration was found in SP. Western blot analysis of SP performed with mAb Leu 11a, Leu 11b, Leu 11c, and 3G8 showed distinct bands at approximately 70 and 35 kDa, which contrasts with the broad area of electrophoretic mobility reported for membrane-bound Fc gamma RIII. These molecules in SP could influence maternal immune responses to paternal Ag during fertilization and pregnancy.     

Predator pheromone elicits a temporally dependent non-consumptive effect in prey

1. The influence of predator cues on the behaviour of prey is well supported in the literature; however, a clear understanding of how predator cues affect prey in variable environmental conditions and over longer time scales is needed to better understand the underlying mechanisms. Here, we measure how predator odors affect herbivore colonization, abundance, oviposition, and plant damage across two growing seasons.
2. The study system consisted of Leptinotarsa decemlineata (Colorado potato beetle) as prey, and the aggregation pheromone of live Podisus maculiventris (spined soldier bug) as the predator cue in a potato field.
3. In 2016, the amount of feeding damage by early beetle colonists was lower in predator odor-treated plots, reducing plant damage by 22%. Larval abundance was also reduced in treated plots in 2016. Beetle abundance and damage in 2017 was similar in the treatment and control plots. Two mechanisms were investigated to better understand why prey response to the predator odor treatment weakened over the first season, including changes in predator odor cue strength and prey habituation. Predator odor cue strength emerged as a likely explanation, as dispensers, which released a synthetic predator pheromone over the entire season, reduced the probability of finding damage more consistently than the live predator treatment.
4. These results suggest that temporal patterns of predator cue release and strength may drive prey response across the season, underscoring the importance of cue release-rate and consistency in both species interactions and for the future application of modifying insect behaviour using non-consumptive effects in agricultural systems.

     

Sphärit-Bildung ausCirsium-Zellsaft

Zusammenfassung In den Epidermiszellen des Laubblattes vonCirsium arvense können in der Vakuole Sphärite entstehen. Sie bilden sich, nachdem vorher im Zellsaft durch Entmischung Koazervattropfen auftreten. Die Entmischung des Zellsaftes erfolgt in den Epidermiszellen kranker Blätter von selbst, in denen gesunder Blätter erst bei Alteration verschiedener Art.DieCirsium-Sphärite sind doppelbrechend und zeigen eine intensive rote Eigenfluoreszenz. Mit Akridinorange vital fluorochromiert, fluoresziert der Zellsaft im sauren Bereich intensiv grün, die Koazervattropfen sowie die Sphärite dagegen fluoreszieren leuchtend rot.Die chemische Natur der Sphärite steht noch nicht fest, möglicherweise sind es hesperidinähnliche Stoffe.In plasmolysierten Parenchymzellen derDahlia-Knolle wandelt sich der ganze inulinreiche Tonoplast in situ in eine Sphäritkugel um, und zwar erst post mortem des Protoplasten.     

Serum protein synthesis in mutant mice with abnormal hepatic endoplasmic reticulum.

Severe ultrastructural abnormalities of liver endoplasmic reticulum have been described in newborn mice homozygous for radiation-induced deletion alleles at the colour locus. The ultrastructural defects were accompanied by deficiencies of several enzymes and lowered serum protein levels. Studies on serum protein synthesis were undertaken to see if decreased rates of synthesis, especially of constituents thought to be synthesized on membrane-bound ribosomes, were the cause of the deficiencies. Although decreases or absence of several serum proteins were shown, radiopulse-immunoprecipitation studies of albumin and fibrinogen synthesis suggested that the decreased synthesis rates were a secondary defect. Serum glycoproteins were not altered more than other constituents in the mutant material.     

Evidence for the presence of two sympatric species of mice (genus Mus L.) in southern France based on biochemical genetics

Populations of mice established outdoors as well as indoors have been investigated at 24 loci using starch gel electrophoresis. Two reproductively isolated groups are recognized, one of which is referable to a house mouse subspecies, Mus musculus brevirostris, and the other to a different species, Mus spretus, contrary to the view of Schwarz and Schwarz that only one species of Mus is present in the Mediterranean Basin. The genetic distance between these two groups is larger than between any pair of investigated subspecies of M. musculus. M. m. brevirostris is biochemically almost indistinguishable from M. m. domesticus. On the other hand, M. spretus exhibits several allelic variants unknown or at most very infrequent in M. musculus, as for instance at the lactate dehydrogenase B-chain locus.This work was supported by research grants from the Centre National de la Recherche Scientifique (E.R.A. No. 261) and the Ecole Pratique des Hautes Etudes.     

Alteration in biological properties of human albumin during storage

The effects of human albumin preparations on oxidative energy metabolism and lipid svnthesis were investigated in rat liver slices incubated with sodium [1-¹⁴C]acetate as precursor. Labeled CO₂ production and incorporation of precursor into the major lipid classes was increased 2 to 3-fold by fresh preparations of albumin (fraction V), and by defatted fraction V, whereas highly purified cystalline albumin was less active. Albumin preparations from various commercial suppliers varied widely in activity. Activity of fraction V was preserved during storage at ?20°C, and gradually lost at +3°C in the course of 1 year. In contrast, defatted fractions rapidly lost activity in storage at both temperatures. After 1 year in storage at +3°C, albumin preparations became inhibitory to CO₂ production and lipid synthesis. The results suggest that commercial albumin used in metabolic studies, and in clinical situations may have unpredictable or undesirable effects related to state of purity and storage conditions of the protein.