The ciliate Tetrahymena pyriformis GL was tested for its applicability to the detection of botulinum neurotoxins. Botulinum neurotoxins attack different proteins of the SNARE-complex, which is involved in fusion processes of the cellular membrane traffic. The exocytosis of enzymes and the phagocytosis of germs include several presumptive SNARE-dependent pathways within T. pyriformis. Acid phosp...

We have used the abnormal form of conjugation known as "genomic exclusion" to isolate a collection of heat-sensitive mutants of Tetrahymena pyriformis, syngen 1. Growth at room temperature in bacterized medium and no growth at 40 degrees C in the same medium was the criterion used for the isolation. The mutant strains were tested for growth in pure (axenic) culture in proteose peptone medium; o...

This paper presents the toxicity data of 10 nonpolar narcotic chemicals on Pseudokirchneriella subcapitata (green algae) assessed by a new algal toxicity testing technique conducted under air-tight environment. Based on DO production, median effective concentration (EC50) varies from 1.73 mg/L (1-octanol) to 8,040 mg/L (2-propanol). The endpoint of algal growth rate reveals similar sensitivity ...

Spores of Bacillus thuringiensis subsp. israelensis and their toxic crystals are bioencapsulated in the protozoan Tetrahymena pyriformis, in which the toxin remains stable. Each T. pyriformis cell concentrates the spores and crystals in its food vacuoles, thus delivering them to mosquito larvae, which rapidly die. Vacuoles containing undigested material are later excreted from the cells. The fa...

The ease with which Tetrahymena can be grown in relatively large quantity makes it an exceptionally useful source of cilia for biochemical study. Several methods of isolating the cilia have been described (3, 11). Although excellent for many purposes, these procedures all suffer from the limitation that the isolated cilia seem incapable of being reactivated by ATP. This paper describes a method...

The use of the termination codon UGA as a tryptophan codon in mitochondria appears to be one of the most common deviations from the standard genetic code. This change in the mitochondrial genome is accomodated by the presence of an anticodon U*CA in mitochondrial (mt) tRNAP (1). Recently a tRNA gene with a TCA anticodon has been identified in the mt genome of the ciliates Poramecium tetraurelia...

A truncated cDNA clone encoding Tetrahymena thermophila histone H2A2 was isolated using synthetic degenerate oligonucleotide probes derived from H2A protein sequences of Tetrahymena pyriformis. The cDNA clone was used as a homologous probe to isolate a truncated genomic clone encoding H2A1. The remaining regions of the genes for H2A1 (HTA1) and H2A2 (HTA2) were then isolated using inverse PCR o...

A pilot study was performed to examine the potential of stable isotope techniques for monitoring the impact of a harmful substance on the cellular nitrogen metabolism in the ciliate species Tetrahymena pyriformis. After identical cultivation periods of control cells and toluene-exposed cells in a defined culture medium enriched with [guanidino-15N2]l-arginine, a number of nitrogen-containing po...

Wragg, June B. (Agricultural Research Service, Beltsville, Md.), Howard Reynolds, and Michael J. Pelczar, Jr. Free amino acids in serine-antagonized cells of Tetrahymena pyriformis. J. Bacteriol. 90:748-754. 1965.-Growth inhibition of Tetrahymena pyriformis by l-serine in a chemically defined medium was reversed by l-arginine in a manner which resembled competitive antagonism. Composition of th...

The relative in vitro susceptibility of HeLa cells and three protozoan species to a number of fermentation-derived materials was determined. Of the 61 purified agents tested in tube dilution and plate diffusion tests, 35 had displayed antitumor activity in rodents. The test system found to be most sensitive to the antitumor agents was that employing HeLa cells. Among the protozoan species, the ...