A derivative of an ataxia-telangiectasia (A-T) cell line with normal radiosensitivity but A-T-like inhibition of DNA synthesis

Ataxia-telangiectasia (A-T) cells are hypersensitive to the lethal effects of ionizing radiation and fail to inhibit DNA synthesis following radiation exposure. A cell line derived from an A-T line following DNA-mediated gene transfer has normal radiation sensitivity, but the kinetics of DNA synthesis after gamma-irradiation are similar to those of A-T cells.     

The acceptor for polar head groups of the lipid A component of Salmonella lipopolysaccharides.

We describe here experiments which determine at which stage in the lipid A biosynthesis the polar head groups 4-aminoarabinose, phosphorylethanolamine and 3-deoxy-D-manno-octulosonic acid are transferred to the diphosphorylated glucosamine backbone of the lipid A structure. Use was made of a conditional lethal mutant of Salmonella typhimurium (Ts1) which is defective in the synthesis of 3-deoxy-D-manno-octulosonic acid 8-phosphate and accumulates under nonpermissive conditions an underacylated lipid A intermediate [Lehmann, Rupprecht and Osborn (1977) Eur. J. Biochem. 76, 41-49]. Pulse-chase experiments, including a detailed analysis of radioactive pulse and chase products, demonstrated that this underacylated compound is a key intermediate in the lipid A synthesis. It can serve as direct acceptor for the incorporation of the polar head groups 4-aminoarabinose, phosphorylethanolamine and 3-deoxy-D-manno-octulosonic acid. On the basis of these findings some steps in the sequence of reactions involved in the lipid A biosynthesis are proposed.     

Introducing a product sustainability budget at an automotive company—one option to increase the use of LCSA results in decision-making processes

The International Journal of Life Cycle Assessment - Product sustainability assessment should evaluate the impacts on all three dimensions of sustainability (environment, economy, and society)....     

Witnessing extinction: Population genetics of the last European Rollers (Coracias garrulus) in Austria and a first phylogeographic analysis of the species across its distribution range

Due to broad‐scale habitat loss, European Rollers (Coracias garrulus) have been decreasing in numbers rapidly during the 20th century in parts of their European distribution range. In Austria, as of 2017, only a completely isolated relict population of two breeding pairs and a few non‐breeders remained in Styria compared to about 270 pairs in the 1950s. In 2018, no breeders have been recorded. Since 2002, all nestlings and adult birds in Austria have been ringed. Given the small census size, combined with lack of immigration from other populations, genetic depletion seems likely. In the present study, mitochondrial control region sequence and microsatellite data based on blood samples of nestlings from recent years were collected and compared with museum samples from historical times (when Rollers were more common and widespread in Austria) and with birds across the distribution range to arrive at a first preliminary phylogeographic dataset for the species. The mitochondrial DNA showed a decrease in variation over time in Austria, eventually reaching monomorphism, while genetic diversity of 10 microsatellite loci was higher than expected and a change in genetic structuring through time was observed. These results indicate drift effects in this relict European Roller population caused by the fast population breakdown and small population size. Our phylogeographic analysis indicates a division into a European and an Asian group, roughly (but not exactly) in accordance with the two subspecies C. garrulus garrulus (Europe) and Coracias garrulus semenowi (Asia). The lack of substructuring in the European group along with the results from nuclear DNA markers show the Austrian Rollers to be part of a formerly continuous population and opens the way to restocking the present relict population with birds from Eastern Europe (“genetic rescue”).