Exosomes Enter Vaccine Development: Strategies Meeting Global Challenges of Emerging Infections

New approaches for vaccination must be developed in order to meet the grand challenges for emerging infectious diseases. Exosomes now enter vaccine development and these are strategies are meeting these global challenges, as demonstrated by Anticoli et al., in this issue of Biotechnology Journal. Using exosome vaccines has been now been demonstrated in vivo for several viruses such as Ebola Virus VP24, VP40, and NP, Influenza Virus NP, Crimean‐Congo Hemorrhagic Fever NP, West Nile Virus NS3, and Hepatitis C Virus NS3. Now this technology must be tested in clinics.     

Eine einfache Mikromethode zur Bestimmung des spezifischen Gewichtes von FlÜssigkeiten

Ohne Zusammenfassung     

Geographic variation in seed dormancy among populations of Echinochloa crus-galli

In 1991–1993, we investigated the incidence of seed dormancy in 25 local populations of barnyard grass, Echinochloa crus-galli (L.) P.Beauv., in the western Czech Republic. The percentage of germination after 4 months afterripening of dry seeds at 25°C varied between 0.0 and 83.6%. Although there were significant annual differences in the percentage of germination at some localities, typical proportions of dormant seeds persisted over 3 years at field sites where the seed bank was not disturbed. One-way ANOVA (using data from 14 cultivated or abandoned fields) revealed that 73.0% of variance in seed dormancy incidence could be attributed to the effect of locality (P<0.001). Incidence of dormancy was not correlated with mother plant stature (dry above-ground biomass, number of tillers, maximal stem height) nor seed mass. There was a significant correlation (r ²=0.403, P<0.005) between dormancy incidence at natural localities in 1991 and in F₁ offspring sown at experimental grounds at Praha-Ruzyn in 1992. The results indicate that heredity is important in maintaining local variation in seed dormancy, probably favoured by the self-pollinating reproduction of barnyard grass.     

The steady-state mRNA levels for thylakoid proteins exhibit coordinate diurnal regulation

Steady-state mRNA levels for thylakoid proteins were analysed in spinach cotyledons under diurnally changing light conditions. Most fluctuate considerably throughout the day, while the levels of others show only low amplitude or no oscillation. Levels of mRNAs coding for proteins that belong to the same multiprotein complex generally oscillate in parallel and exhibit maxima that are specific for that complex: mRNAs for photosystem I proteins appear prior to those for photosystem II polypeptides and these again prior to mRNAs for the three polypeptides constituting the oxygen-evolving complex. For the mRNAs that change with high amplitudes (e.g. those for LHCP or the 20 kDa apoprotein of the CP24 complex) oscillations have also been found under constant conditions, indicating that a circadian oscillator is involved. Transgenic tobacco seedlings harbouring chimeric GUS gene fusions with 5-flanking sequences from the spinach genes Lhcb, PsaF and AtpD (encoding a light-harvesting chlorophyll a/b apoprotein of photosystem II, subunit 3 of photosystem I and subunit of the plastid ATP synthase, respectively) confirm that the differences in the amplitudes as well as the timepoints of maximum mRNA accumulation are perceived via cis-regulatory elements upstream of the respective ATG codons.     

Antimicrobial terpenoids of Gossypium: Hemigossypol, 6-methoxyhemigossypol and 6-deoxyhemigossypol

The sesquiterpenoid aldehydes, hemigossypol (1a), 6-methoxyhemigossypol (1b), and 6-deoxyhemigossypol (1c), were isolated and identified from Verticillium-infected stele tissue of Gossypium barbadense. Structures were established by spectral (UV, IR, NMR, MS) evidence and chemical transformations. This is the first report of (1b) and (1c) in nature, and of NMR and m.p. data for crystalline pure (1a). Compound (1a) occurred in diseased stele tissues of all 21 Gossypium species examined and in the genera, Cienfuegosia, Gossypioides, Hampea, and Thespesia; it was absent in three Hibiscus spp. Compound (1b) occurred in the same taxa as (1a), except that it was absent in species of two cytogenetic groups (A and B genome) of Gossypium. Compound (1c) occurred in trace quantities, or was not detected, in most species; however, its distribution appeared to besimilar to that     

Methodische Untersuchungen zur Ploidiebestimmung an Ruhekernen

Zusammenfassung BeiTrifolium pratense (2n=2x=14) undhybridum (2n=2x=16) ist in jedem haploiden Chromosomensatz ein bestimmtes Chromosom vorhanden, von dem ein bestimmter Abschnitt im ruhenden Zellkern als T-Chromozentrum gut sichtbar sein kann. Die Anzahl dieser T-Chromozentren schwankt innerhalb eines Organs und Gewebes einer Pflanze. Bei einer jeweils bestimmten Prozentzahl der Ruhekerne, die aus gewissen, nachfolgend aufgeführten Geweben und Organen stammen, ist die T-Chromozentrenanzahl gleich der Genomanzahl oder Ploidiestufe der betreffenden Einzelpflanze. Höher als die Genomanzahl wird sie bei jenen Organen und Geweben aber nicht. Man kann also durch Feststellung der Höchstzahl der T-Chromozentren die Ploidie einer Pflanze bestimmen. Dieses Verfahren, das im einzelnen eingehend beschrieben wird, ist leichter und schneller als das der Chromosomenauszählung. Geeignet sind folgende leicht zu präparierende Organe und Gewebe: Die Zellen der Kalyptra und die Epidermiszellen des Hypokotyls (beide für die Ploidiebestimmung beim Saatgut), ferner die Epidermiszellen des Stiels des Kotyledo und des Stielchens des Fiederblattes, weiter die subepidermalen Zellen der Innenseite des Kelchblattes, und schließlich — nur beiTr. hybridum — die Epidermiszellen des Stielchens der Einzelblüte.BeiTr. pratense kann man mittels der T-Chromozentrenmethode leicht Aneutetraploide auffinden, deren T-Chromozentrenhöchstzahl 3 oder 5 beträgt; ihr Vorkommen deutet darauf hin, daß die betreffende tetraploide Sorte noch nich frei von Meiosestörungen ist.Mit 7 TextabbindungenHerrn Professor Dr.Hans Bauer zur Vollendung seines 60. Lebensjahres gewidmet.     

Proliferation pattern and early differentiation of the optic lobes in Drosophila melanogaster

Summary The larval and early pupal development of the optic lobes in Drosophila is described qualitatively and quantitatively using [³H]thymidine autoradiography on 2-m plastic sections. The optic lobes develop from 30–40 precursor cells present in each hemisphere of the freshly hatched larva. During the first and second larval instars, these cells develop to neuroblasts arranged in two epithelial optic anlagen. In the third larval instar and in the early pupa these neuroblasts generate the cells of the imaginal optic lobes at discrete proliferation zones, which can be correlated with individual visual neuropils.The different neuropils as well as the repetitive elements of each neuropil are generated in a defined temporal sequence. Cells of the medulla are the first to become postmitotic with the onset of the third larval instar, followed by cells of the lobula complex and finally of the lamina at about the middle of the third instar. The elements of each neuropil connected to the most posterior part of the retina are generated first, elements corresponding to the most anterior retina are generated last.The proliferation pattern of neuroblasts into ganglion mother cells and ganglion cells is likely to include equal as well as unequal divisions of neuroblasts, followed by one or two generations of ganglion mother cells. For the lamina the proliferation pattern and its temporal coordination with the differentiation of the retina are shown.     

The development of Hexarthra spp. in a shallow alkaline lake

In Neusiedler See, a shallow alkaline lake with fluctuating water level and salinity, four species of Hexarthra occur: H. mira, H. fennica, H. jenkinae (occasional) and H. polyodonta. The analysis of longterm data reveals a general phenological pattern which does not change from year to year. They first occur in May, develop a maximum in June/July, sometimes a second one in August/September and disappear in October. But the species succession is different in the various years, occasionally only one species (H. mira or H. polyodonta) being present. There is a fairly consistent relation between the chemical conditions and the prevalent species; an increase in salinity favours the development of H. polyodonta. Low temperature and wind generated suspended particles have a negative influence on the development of the Hexarthra populations. Smaller populations of Hexarthra are in a relation to the occurrence of Leptodora indicating predation pressure of the latter species. In Neusiedler See the Hexarthra populations seem to be controlled to a great extent by abiotic factors, but predation by Leptodora and most probably by young fish seems to play an important role too.     

Chromozentrenuntersuchungen

Zusammenfassung Bei 4 Arten der Angiospermenfamilie der Kruziferen wurde die Zahl der Chromozentren (Prochromosomen) einer größeren Anzahl junger 1n–, 2n–, 3n–, 3n+ 2–, 4n–, 8n–, 16n– und 32n-Ruhekerne aus verschiedenartigen primären Meristemen zahlreicher, in verschiedener Entwicklungsstufe stehender Pflanzen festgestellt (Tabelle 1 und 2). Die Kerne stammten aus unbehandelten Gameto- und Sporophyten von Diund Tetraploiden sowie aus colchicinierten Keimwurzelspitzen von Diploiden. Die Chromozentrenzahl aller untersuchten Ruhekerne stimmte mit deren Chromosomenzahl überein.