Specific Loss of Newly Replicated Deoxyribonucleic Acid in Nalidixic Acid-Treated Bacillus subtilis 168

Bacillus subtilis 168 thyA, thyB cells degrade and lose from 20 to 30% of their deoxyribonucleic acid (DNA) in 3.5 hr of exposure to 20 mug of nalidixic acid per ml. Degradation appears to be initiated at the replication point and to proceed sequentially along the chromosome from the most recently synthesized DNA to "older" DNA. Both DNA strands appear to be degraded equally, and essentially all of the products of degradation are soluble in cold acid.     

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.     

Identification and characterization of a defective SSV1 genome integrated into a tRNA gene in the archaebacterium Sulfolobus sp. B12

Summary Within the chromosome of the archaebacterium Sulfolobus sp. B12, a 7.4 kb region was identified which displayed extensive sequence similarities to the 15.5 kb genetic element SSV1 carried by the same strain both as a circular form and as a site-specifically integrated copy. DNA sequence analysis indicated that this 7.4 kb region (designated SSV1^intB) represented an SSV1-like element distinguishable from the full-length integrated copy (designated SSV1^intA) by extensive deletions and point mutations. The physical organization of DNA sequences of SSV1^intB indicated that this element was integrated at the same attP site as previously identified for SSV1^intA. A comparison of the DNA sequences at the left attachment sites of SSV1^intA and SSV1^intB revealed that they both represented very similar putative arginine tRNA genes followed by a 10 by inverted repeat sequence. S1 nuclease mapping experiments indicated that these tRNA genes are transcribed. Offprint requests to: W. Zillig     

Human appropriation of net primary production as driver of change in landscape-scale vertebrate richness

Aim

Land use is the most pervasive driver of biodiversity loss. Predicting its impact on species richness (SR) is often based on indicators of habitat loss. However, the degradation of habitats, especially through land-use intensification, also affects species. Here, we evaluate whether an integrative metric of land-use intensity, the human appropriation of net primary production, is correlated with the decline of SR in used landscapes across the globe.

Location

Global.

Time period

Present.

Major taxa studied

Birds, mammals and amphibians.

Methods

Based on species range maps (spatial resolution: 20 km × 20 km) and an area-of-habitat approach, we calibrated a “species–energy model” by correlating the SR of three groups of vertebrates with net primary production and biogeographical covariables in “wilderness” areas (i.e., those where available energy is assumed to be still at pristine levels). We used this model to project the difference between pristine SR and the SR corresponding to the energy remaining in used landscapes (i.e., SR loss expected owing to human energy extraction outside wilderness areas). We validated the projected species loss by comparison with the realized and impending loss reconstructed from habitat conversion and documented by national Red Lists.

Results

Species–energy models largely explained landscape-scale variation of mapped SR in wilderness areas (adjusted R²-values: 0.79–0.93). Model-based projections of SR loss were lower, on average, than reconstructed and documented ones, but the spatial patterns were correlated significantly, with stronger correlation in mammals (Pearson's r = 0.68) than in amphibians (r = 0.60) and birds (r = 0.57).

Main conclusions

Our results suggest that the human appropriation of net primary production is a useful indicator of heterotrophic species loss in used landscapes, hence we recommend its inclusion in models based on species–area relationships to improve predictions of land-use-driven biodiversity loss.     

Characterization of a quail suspension cell line for production of a fusogenic oncolytic virus

The development of efficient processes for the production of oncolytic viruses (OV) plays a crucial role regarding the clinical success of virotherapy. Although many different OV platforms are currently under investigation, manufacturing of such viruses still mainly relies on static adherent cell cultures, which bear many challenges, particularly for fusogenic OVs. Availability of GMP-compliant continuous cell lines is limited, further complicating the development of commercially viable products. BHK21, AGE1. CR and HEK293 cells were previously identified as possible cell substrates for the recombinant vesicular stomatitis virus (rVSV)-based fusogenic OV, rVSV-NDV. Now, another promising cell substrate was identified, the CCX.E10 cell line, developed by Nuvonis Technologies. This suspension cell line is considered non-GMO as no foreign genes or viral sequences were used for its development. The CCX.E10 cells were thus thoroughly investigated as a potential candidate for OV production. Cell growth in the chemically defined medium in suspension resulted in concentrations up to 8.9 × 10⁶ cells/mL with a doubling time of 26.6 h in batch mode. Cultivation and production of rVSV-NDV, was demonstrated successfully for various cultivation systems (ambr15, shake flask, stirred tank reactor, and orbitally shaken bioreactor) at vessel scales ranging from 15 mL to 10 L. High infectious virus titers of up to 4.2 × 10⁸ TCID₅₀/mL were reached in orbitally shaken bioreactors and stirred tank reactors in batch mode, respectively. Our results suggest that CCX.E10 cells are a very promising option for industrial production of OVs, particularly for fusogenic VSV-based constructs.     

Kinetics of cooperative ligand–lattice binding: Fast Monte Carlo integration

A fast Monte Carlo integration algorithm with varying time step is described for cooperative binding of ligands of arbitrary length to a one-dimensional lattice. This algorithm is particularly suitable for strongly cooperative or anticooperative systems, i.e., when the time scales for different kinetic events are very different. As an application, the kinetics of a bimodal two-ligand system are briefly discussed.     

The role of the neurohormone melatonin as a buffer against macromolecular oxidative damage

This paper summarizes the recent findings which show that the neural hormone melatonin is a free radical scavenger and general antioxidant. When compared with other antioxidants melatonin seems to have greater efficacy in protecting against cellular oxidative stress. These findings illustrate that melatonin preserves macromolecules including DNA, protein and lipid from oxidative damage following the administration of the chemical carcinogen, safrole, after exposure to ionizing radiation, following glutathione depletion, and after administration of the free radical generating herbicide, paraquat. In vitro evidence shows that melatonin is a potent scavenger of the highly toxic hydroxyl radical and in vitro evidence suggests that melatonin is an important and powerful antioxidant. Considering its high lipophilicity and its non-toxic nature as well as its ability to readily cross the blood-brain barrier, the neurohormone melatonin may prove to be an effective and important molecule in the antioxidative defense system, especially in the central nervous system. Besides the ease with which melatonin enters the brain, neurons seem to accumulate readily this hormone.