Polyubiquitin genes from seven ciliate species were amplified, cloned and sequenced. It is estimated that Strombidium sulcatum, Euplotes vannus, E. rariseta and Anteholosticha manca have a polyubiquitin gene of 3 repeats, and A. parawarreni, Paramecium caudatum and Pseudokeronopsis flava 4 repeats. The newly obtained ubiquitins mostly differ from that of humans by 1-5 residues in amino acid seq...

1. The physiological actions of HCN and its salts appear to be due (a) to the ease with which HCN molecules penetrate living cells and then ionizing, exert their influence by means of H ions and CN ions; (b) to the weakness of HCN as an acid, which permits at neutrality or at even slight alkalinity the presence of a considerable amount of free HCN molecules in the presence of their salts; (c) t...

1. The quantitative relationship between chemoaccumulation and locomotor activity in specimens of Paramecium caudatum was examined by employing a novel chemoaccumulation assay system. 2. Distribution of the specimens in two adjoining solutions with different chemical compositions was dependent on both the rate of arrival of the specimens at the border between two solutions (the arrival rate) an...

The location and extent of local degeneration of cilia during sexual reproduction of Paramecium was studied using scanning electron microscopy to examine cells undergoing conjugation and autogamy. At some time during the mating reaction, but prior to conjugant pair formation, ciliary degeneration begins at the antero-ventral tip of cells and proceeds posteriorly along the suture. In the anterio...

The anticalmodulin drug, W-7 [N-(6 aminohexyl)-5-chloro-1-naphthalenesulphonamide] specifically inhibits the voltage-dependent Ca-current of Paramecium as well as the behavioural consequence of Ca2+ influx, backward swimming. The dechlorinated analogue, W-5, is four to five times less effective. Analysis of membrane currents under voltage clamp shows that W-7 not only reversibly inhibits the vo...

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim...

When cells of the behavioral mutant cnrC of Paramecium caudatum were mated with the wild type, phenotype change from CNR (no backward swinning) to wild type in the cnrC mate occurred immediately after the formation of tight pairs. No change of phenotype occurred when cells of cnrA or cnrB were mated with wild type. Phenotypic change from CNR to wild type in cells of cnrC was also induced by mic...

In order to realize the ecological specialty of man-made lake located in urban area in South China, species composition, dominant species dynamics and other parameters of ciliate community were investigated with the qualitative and quantitative observations from April of 2009 to March of 2010, in Dongshan Lake, a subtropical shallow urban lake in South China. The relationship between the parame...

Contrary to electrofocusing in sucrose gradients free [3H]oestradiol-17/l did not electrofocus and did not migrate significantly from the point of application. This could present difficulties in the interpretation and resolution of components if the sample is placed on the gel at a point close to the isoelectric points of the components of interest. By placing the sample 10-15mm from the cathod...