Fission yeast tmsl protein abrogates normal development in Xenopus laevis embryos

Recently we cloned tms1 (a putative dehydrogenase) by complementation of a human tumour-derived mutant p53 induced growth arrest in fission yeast. Microinjection of purified tmsl protein into Xenopus laevis embryos abrogated normal embryo development by causing cleavage retardation or cleavage arrest of injected blastomeres in a concentration dependant manner, whereas injection of specific affinity purified tms1 antiserum showed no significant morphological defects. Microinjection of tms1 protein together with affinity purified tms1 antibody resulted in a significantly reduced number of cleavage arrested embryos.     

Subcellular localization of ubiquitin in plant protoplasts and the function of ubiquitin in selective degradation of outer-wall plasmodesmata in regenerating protoplasts

Immunocytochemical localizations in Vicia faba L. protoplasts and cultures of regenerating Solanum nigrum L. protoplasts support former observations that in plant cells ubiquitin occurs within the cytoplasm, the nucleus, the chloroplasts and at the plasmalemma, but not within the vacuole or the cell wall. Immunoresponses were also observed within mitochondria and associated with the endoplasmic reticulum, which is in accordance with previous findings on animal cells. Moreover, the tonoplast membrane system was found to be labelled. For regenerating S. nigrum protoplasts, evidence is given that ubiquitin plays a role in selective degradation even of whole subcellular structures. Most of the discontinuous plasmodesmata formed in the newly deposited outer cell walls during the early stages of culture disappear later on, except for those near the periphery of division walls or of non-division walls, which are probably used for the formation of continuous cell connections during further culture. Outer-wall plasmodesmata which are destined to disappear show high immunoreactivity to ubiquitin antibody, but no conspicuous immunolabelling was observed with the remaining plasmodesmata. Thus, the selective disintegration of whole plasmodesmatal structures is obviously regulated by ubiquitination of plasmodesmatal proteins. A model for the mechanism of degradation of outer-wall plasmodesmata during extension growth of the cell wall is presented.Dedicated to Professor Dr. Andreas Sievers on the occasion of his retirementThis work was supported by grants to R. K. (Deutsche Forschungsgemeinschaft) and to M. S. (Bennigsen-Foerder Preis des Landes Nordrhein-Westfalen). We thank Dipl.— Biol. Kirsten Leineweber for help with the V. faba protoplast isolation and Dr. Olaf Parge, Institut für Psychologie und Sozialforschung, Kiel, Germany, for giving assistance with the statistical analysis.     

Inactivation of hepatitis A virus and indicator organisms in water by free chlorine residuals.

Hepatitis A virus (HAV) and selected indicator organisms were mixed together in chlorine-demand-free buffers at pH 6, 8, or 10 and exposed to free chlorine residuals, and the survival kinetics of individual organisms were compared. HAV was enumerated by a most-probable-number dilution assay, using PLC/PRF/5 liver cells for propagation of the virus and radioimmunoassay for its detection. At all pH levels, HAV was more sensitive than Mycobacterium fortuitum, coliphage V1 (representing a type of phage common in some sewage-polluted waters), and poliovirus type 2. Under certain conditions, HAV was more resistant than Escherichia coli, Streptococcus faecalis, coliphage MS2, and reovirus type 3. It was always more resistant than SA-11 rotavirus. Evidence is presented that conditions generally specified for the chlorine disinfection of drinking-water supplies will also successfully inactivate HAV and that HAV inactivation by free chlorine residuals can reliably be monitored by practical indicator systems consisting of appropriate combinations of suitable indicators such as coliform and acid-fast bacteria, coliphages, the standard plate count, and fecal streptococci.     

Species-specific antigens ofMycoplasma hyopneumoniae and cross-reactions with other porcine mycoplasmas

Cell proteins from the porcine mycoplasmasMycoplasma hyorhinis, M. hyopneumoniae, andM. flocculare have been analyzed by SDS-gel electrophoresis and immunoblotting. The protein profiles ofM. hyopneumoniae andM. flocculare were similar, but the protein profile ofM. hyorhinis was quite different from the others. Antisera prepared against whole cells of the above three mycoplasmas were used in immunoblotting of electrophoretically separated antigens and in enzyme-linked immunosorbent assay. One major antigen, which had a molecular weight of 73 k, was found to be common to all three mycoplasmas. Another major antigen, with a molecular weight of 41 k, was common toM. hyopneumoniae andM. flocculare and may also be present inM. hyorhinis. Several antigens of comparatively high molecular weights (108 k, 102 k, 93 k, 89 k, and 87 k) seemed to be specific forM. hyopneumoniae. Three antisera prepared by immunization of rabbits with immunoprecipitates obtained by crossed immunoelectrophoresis ofM. hyopneumoniae were also used in blotting experiments. One of these antisera was found to be directed against the 73 k antigen common to the three porcine mycoplasmas investigated. The other two antisera were directed againstM. hyopneumoniae-specific antigens with molecular weights of 74 k, 58 k, 45 k, 44 k, and 38 k.     

Web servicing the biological office

Biologists routinely use Microsoft Office applications for standard analysis tasks. Despite ubiquitous internet resources, information needed for everyday work is often not directly and seamlessly available. Here we describe a very simple and easily extendable mechanism using Web Services to enrich standard MS Office applications with internet resources. We demonstrate its capabilities by providing a Web-based thesaurus for biological objects, which maps names to database identifiers and vice versa via an appropriate synonym list. The client application ProTag makes these features available in MS Office applications using Smart Tags and Add-Ins. AVAILABILITY: http://services.bio.ifi.lmu.de/prothesaurus/