Bernhard Jank

A multitude of suppressors of group II intron-splicing defects in yeast

Disruption of the nuclear MRS2 gene (mrs2-1 mutation) causes a strong pet- phenotype in strains with mitochondrial group II introns, and a leaky pet- phenotype in strains without group II introns. MRS3 and MRS4, the genes for two mitochondrial-solute carrier proteins, can suppress both phenotypes when present in high-copy-number plasmids. In order to search for further multicopy suppressors of the mrs2-1 mutant phenotype, an yeast genomic DNA library, MW90, was constructed in YEp351 from a strain deleted for the MRS2, MRS3 and MRS4 genes. Ten different Sau3A DNA fragments that act as multicopy suppressors of the mrs2-1 respiratory-deficient phenotype were isolated from this library. Some of the newly isolated genes suppress the pet- phenotypes of mrs2-1 cells in strains with and without mitochondrial group II introns. Other genes, however, are suppressors only for the mitochondrial intron-less strains. This supports the notion that the MRS2 gene product is bifunctional i.e., it is essential for the splicing of group II introns and is also involved in processes of mitochondrial biogenesis other than RNA splicing.

Biological Weapons Control

The current negotiations in Geneva to develop a legally binding instrument to strengthen the 1972 Biological and Toxin Weapons Convention (BTWC) are likely to result in an international declaration and inspection regime. This regime could have implications for both academic and industrial research, development, and production sites. In a recent Policy Forum ( Science s Compass, 20 Nov., p. [1423][1]), Thomas P. Monath and Lance K. Gordon express their concerns about on-site inspections in biological weapons control, concluding with support of the concept and leaning toward on-site inspections with sampling at the site triggered by national “intelligence-gathering activities.” At an international symposium held at the Institute for Applied Microbiology, Vienna, Austria, in May 1998, the value of on-site inspections and sampling in a possible future biological weapons control regime was also addressed. The participants came from varied backgrounds: regulatory affairs and biosafety managers from industry and academia, diplomats, weapons inspectors, and representatives of various international and national authorities. They concluded that triggering inspections through suspicion could very likely stigmatize any of the inspected institutions. In principal, a biological weapons control regime includes auditing, which presents the possibility of certifying that the site is compliant with the agreements on production, stockpiling, and use of biological weapons. If sites that possess dual use capabilities are inspected at random intervals, the inspection itself would leave no stigma; on the contrary, the outcome of the inspection could increase the level of confidence that the institution is complying with international agreements. This could reduce the need for restrictions in the international exchange of dual-use material, equipment, and know-how, a fear expressed at the symposium. The delegates suggested that, to minimize the extra workload, a future protocol should take into account existing control regimes. For biopharmaceutical industries, in particular, consideration should be given to how the new protocol could be implemented nationally through use of existing infrastructures, such as those established under health and safety legislation. # Response {#article-title-2} As Rath, Jank, and Doblhoff-Dier correctly point out, there is considerable debate about the pros and cons of an inspection regime as a means of enforcing the ban on biological weapons. We would like to correct one apparent misinterpretation of our position, with respect to triggers for visits. We do not suggest that the selection of facilities for inspection would be based principally on “intelligence-gathering activities.” Rather, it is anticipated that the content of declarations submitted by states or parties containing information about activities at research and production sites, specific biological agents, biological weapons defensive research, aerosol studies, containment level, and so forth will be the basis for visits. A system for right of entry to declared sites is needed to increase transparency and reduce suspicions. The declaration process has revealed, and will continue to reveal questions that can be clarified most effectively by on-site visits. Serious concerns about potential violations can be resolved only by challenge inspections, which would be conducted at very short notice and would be based on information sufficient to pass stringent criteria. Without challenge inspections and the possibility of on-site analysis, the treaty would remain a “dog without teeth.” It is likely that those states engaged in offensive biological research and development will continue to deceive the international community and that illegal activities will be carried out at undeclared facilities. Ultimately, intelligence gathering may be useful in revealing such facilities and bringing them under the scrutiny of the inspectorate. It is our expectation, however, that some states or parties may decide that it is not worth the political and economic risk to initiate (or continue) offensive programs. The threat of enforcement of the Chemical Weapons Treaty resulted in the declaration and abandonment of previously denied programs. We do not share the same apprehension expressed by participants at the Vienna conference with respect to the stigma attached to visits and inspections. Intrusive visits by various regulators are already frequent occurrences, and once biological weapons visits become regular events, they will hardly be “news.” We also do not share the view that the fox should guard the henhouse; self-enforcement through national legislation does not provide a reasonable safeguard against state-sponsored biological weapons programs [1]: /lookup/doi/10.1126/science.282.5393.1423

Yeast single copy gene URP1 is a homolog of rat ribosomal protein gene L21

SummaryThis communication reports on a single-copy gene of Saccharomyces cerevisiae which is homologous to the rat ribosomal protein gene L21. The yeast and the rat genes show 59% identity in DNA sequences and in the predicted protein sequences. This yeast gene is, therefore, assumed to code for an as yet unassigned ribosomal protein (URP1). The URP1 open reading frame is 480 nucleotides long and can encode a protein of about Mr 18 200. Like most of the other known ribosomal protein genes, URP1 is interrupted by an intron in its 5′ terminal part and it is preceeded by upstream sequence elements which usually regulate transcription of these genes. Northern blot analysis reveals that the URP1 gene is actually expressed in vivo.

The Risk of Pyrrolizidine Alkaloids in Human Food and Animal Feed

Toxicity from naturally occurring plant pyrrolizidine alkaloids bears substantial risk to humans and livestock. Risk management strategies must focus on minimizing the likelihood of such alkaloids entering into the food chain. To address this challenge, we describe the role of a tiered risk characterization approach and specific farm management practices.

Codex guideline and Food and Agriculture Organization database on low-level presence of genetically modified plants.

An increasing number of genetically modified (GM) plants are being approved for commercialization. However, different countries authorize use of certain GM plants at different times. As a consequence of these so-called ‘asymmetric authorizations’, low levels of GM plant material that have passed a food safety assessment in one country may on occasion be present in food in an importing country that has not yet determined the food safety of that GM plant.