Sporeless mutants of Bacillus thuringiensis. II. mutants derived from var. thuringiensis and var. sotto.

Three sporeless mutants of Bacillus thuringiensis, 2 derived from var. thuringiensis and 1 from var. sotto were selected after mutagenic treatment. They were completely lacking in ability to form spores, yet maintained intact insecticidal activity.     

Spontaneous mutants ofStaphylococcus aureus PS 80

Zusammenfassung Eine Reihe von Mutanten mit verschiedenen Phenotypen wurde nach einfähriger Lagerung desStaphylococcus aureus PS 80 isoliert. Sie untersucheiden sich in mehreren Merkmalen vom Wildtyp. Aus der Tetracyklin-empfindlichen population der PS-80-Zellen wurden Tetracyklin-resistente Mutanten selektiert, die gleichzeitig resistent gegen Streptomycin, Chloramfenikol, Erythromycin, Cephaloridin, Lincomycin und Spiramycin sind.     

Superactive mutants of thromboxane prostanoid receptor: functional and computational analysis of an active form alternative to constitutively active mutants

In class A GPCRs the E/DRY motif is critical for receptor activation and function. According to experimental and computational data, R3.50 forms a double salt bridge with the adjacent E/D3.49 and E/D6.30 in helix 6, constraining the receptor in an inactive state. The disruption of this network of interactions facilitates conformational transitions that generate a signal or constitutive activity. Here we demonstrate that non-conservative substitution of either E129^(3.49) or E240^(6.30) of thromboxane prostanoid receptor (TP) resulted in mutants characterized by agonist-induced more efficient signaling properties, regardless of the G protein coupling. Results of computational modeling suggested a more effective interaction between G_q and the agonist-bound forms of the TP mutants, compared to the wild type. Yet, none of the mutants examined revealed any increase in basal activity, precluding their classification as constitutively active mutants. Here, we propose that these alternative active conformations might be identified as superactive mutants or SAM.     

Esterase alterations in neurological mutants of the mouse

Zusammenfassung In Analysen von Gehirn-Zymogrammen verschiedener neurologischer Mäusemutanten wurden Abnormalitäten in Form von Esterasedefiziten gefunden. Da solche neulich auch für die multiple Sklerose des Menschen beschrieben wurden, wird vorgeschlagen, unspezifische Esterasen als signifikant für den normalen Myelinanabolismus zu bewerten.

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This investigation was supported by Public Health Service research Grant CA 04691-06 from the National Cancer Institute.     

Synergism between aggregation mutants of Dictyostelium discoideum]

The cells of an aggregateless mutant of Dictyostelium disco?deum, agip 235, can cooperate with other aggregateless or wild strains to form differentiated aggregates. A soluble mediator liberated by the coaggregating cells seems responsible for the development of agip 235. In most cases, the development of mutant agip 235 stops at the aggregation stage; however, its coaggregation with the mutant 518 results in cosporulation, with the production of viable spores of each genotype, effecting a phenotypic suppression of both mutations.     

Recombination among UV-induced adenine-1 mutants ofSchizosaccharomyces pombe

Zusammenfassung Zehn der vonLeupold isolierten UV-induzierten Mutanten beim Adenin-1-Gen vonSchizosaccharomyces pombe sind in zehn verschiedenen Stellen im Gen lokalisiert.

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I am extremely grateful to ProfessorU. Leupold for his help and hospitality in his laboratory, and to Dr.Charlotte Auerbach for her encouragement and interest.     

Osmotic remedial and osmotic sensitive mutants ofSchizosaccharomyces pombe

Zusammenfassung Das Wachstumsverhalten zweier Klassen von Mutanten der SpalthefeSchizosaccharomyces pombe in Medien hoher Osmolarität wird beschrieben. Das Wachstum der einen Mutantenklasse wird in solchen Medien gefördert und das der andern gehemmt.

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This investigation was supported by Grant No. 3467 from the Swiss National Science Foundation.