Microautoradiographic studies on host-parasite interactions II. The exchange of 3H-lysine between Uromyces phaseoli and Phaseolus vulgaris

A new species of anaerobic bacterium that degrades the even-numbered carbon fatty acids, butyrate, caproate and caprylate, to acetate and H₂ and the odd-numbered carbon fatty acids, valerate and heptanoate, to acetate, propionate and H₂ was obtained in coculture with either an H₂-utilizing methanogen or H₂-utilizing desulfovibrio. The organism could be grown only in syntrophic association with the H₂-utilizer and no other energy sources or combination of electron donor and acceptors were utilized. It was a Gram-negative helical rod with 2 to 8 flagella, about 20 nm in diameter, inserted in a linear fashion about 130 nm or more apart along the concave side of the cell. It grew with a generation time of 84 h in co-culture with Methanospirillum hungatii and was present in numbers of at least 4.5×10^-6 per g of anaerobic digestor sludge.     

Induction of synchronous differentiation (encystment) in Physarum polycephalum myxamoebae

Encystment of Physarum polycephalum myxamoebae, grown under nearly identical physiological conditions as plasmodia is induced by transfer to a salts medium containing 0.5 M mannitol or mannose. After 24 h induction approximately 50% of amoebae had differentiated to cells which were identified to be young cysts by light and electron microscopy. Several other polyols, sugars, biogenic amines, and a starvation period from 24 h to one week caused no reproducible cyst formation. In contrast to the formation of dormant forms in the plasmodial stage of the life cycle, the induction of cysts and their germination to amoebae are not inhibited neither by actinomycin C nor by cycloheximide. In addition, the isoenzyme spectra of aminopeptidases and acid proteases remain nearly identical in growing and differentiating amoebae.Abbreviations SD semi-defined BSS basal salts solution The investigation is a part of the Ph. D. thesis of A. Haars, Göttingen, 1976     

A simple and inexpensive alternative to shell freezing for rapid lyophilization of aqueous samples

Aqueous samples containing labile substances are rapidly lyophilized after the frozen solutions are crushed in Nalgene plastic bottles. Lyophilization time compares favorably with shell-frozen samples, and samples remain frozen at all times.     

Carbon-13 NMR chemical shifts of the common amino acid residues measured in aqueous solutions of the linear tetrapeptides H-Gly-Gly- X-L- Ala-OH

The ¹³C nmr chemical shifts of the common amino acid residues were measured in D₂O solutions of the linear tetrapeptides H-Gly-Gly-X-L -Ala-OH. For Asp, Glu, Lys, Tyr and His, the titration shifts arising from the ionization of te amino acid side chains were also obtained. These data are compared with the corresponding ¹³C chemical shifts in the protected tetrapeptides CF₃CO-Gly-Gly-X-L -Ala-OCH₃, the linear pentapeptides H-Gly-Gly-X-Gly-Gly-OH, and the free amino acids. On this basism the selection of suitable “random coil” ¹³C chemical shifts for conformational studies of polypeptides chain is discussed.     

European springtime temperature synchronises ibex horn growth across the eastern Swiss Alps

Direct effects of climate change on animal physiology, and indirect impacts from disruption of seasonal synchrony and breakdown of trophic interactions are particularly severe in Arctic and Alpine ecosystems. Unravelling biotic from abiotic drivers, however, remains challenging because high‐resolution animal population data are often limited in space and time. Here, we show that variation in annual horn growth (an indirect proxy for individual performance) of 8043 male Alpine ibex (Capra ibex) over the past four decades is well synchronised among eight disjunct colonies in the eastern Swiss Alps. Elevated March to May temperatures, causing premature melting of Alpine snowcover, earlier plant phenology and subsequent improvement of ibex food resources, fuelled annual horn growth. These results reveal dependency of local trophic interactions on large‐scale climate dynamics, and provide evidence that declining herbivore performance is not a universal response to global warming even for high‐altitude populations that are also harvested.     

Distinct Biology of Kaposi’s Sarcoma-Associated Herpesvirus from Primary Lesions and Body Cavity Lymphomas

The DNA sequence for Kaposi’s sarcoma-associated herpesvirus was originally detected in Kaposi’s sarcoma biopsy specimens. Since its discovery, it has been possible to detect virus in cell lines established from AIDS-associated body cavity-based B-cell lymphoma and to propagate virus from primary Kaposi’s sarcoma lesions in a human renal embryonic cell line, 293. In this study, we analyzed the infectivity of Kaposi’s sarcoma-associated herpesvirus produced from these two sources. Viral isolates from cultured cutaneous primary KS cells was transmitted to an Epstein-Barr virus-negative Burkitt’s B-lymphoma cell line, Louckes, and compared to virus induced from a body cavity-based B-cell lymphoma cell line. While propagation of body cavity-based B-cell lymphoma-derived virus was not observed in 293 cell cultures, infection with viral isolates obtained from primary Kaposi’s sarcoma lesions induced injury in 293 cells typical of herpesvirus infection and was associated with apoptotic cell death. Interestingly, transient overexpression of the Kaposi’s sarcoma-associated herpesvirus v-Bcl-2 homolog delayed the process of apoptosis and prolonged the survival of infected 293 cells. In contrast, the broad-spectrum caspase inhibitors Z-VAD-fmk and Z-DEVD-fmk failed to protect infected cell cultures, suggesting that Kaposi’s sarcoma-associated herpesvirus-induced apoptosis occurs through a Bcl-2-dependent pathway. Kaposi’s sarcoma-associated herpesvirus isolates from primary Kaposi’s sarcoma lesions and body cavity-based lymphomas therefore may differ and are likely to have distinct contributions to the pathophysiology of Kaposi’s sarcoma.