Paramecium bursaria, a species belonging to the genus Paramecium, is quite unique in that the species intracellularly maintains several hundreds of symbiotic algae. This species has been regarded as firstly branched-off species within this genus, and reported its higher genetic variation. We determined rDNA 5’ half regions of 13 strains of P. bursaria, and investigated their intraspecific genet...

The interaction between two swimming Paramecium caudatum was investigated experimentally. Cell motion was restricted between flat plates, and avoiding and escape reactions were observed, as well as hydrodynamic interactions. The results showed that changes in direction between two swimming cells were induced mainly by hydrodynamic forces and that the biological reaction was a minor factor. Nume...

Generation times were determined in vitro with a pure culture of Epidinium caudatum and a mixed culture of Epidinium caudatum and Entodinium caudatum. Measurement of logarithmic growth from a small inoculum for Epidinium caudatum alone, or in coculture, resulted in generation times of 30.8 and 19.5 h, respectively. Epidinium concentrations, either alone or in coculture, were maintained when cul...

Isolated oceanic islands are characterized by patterns of biological diversity different from that on nearby continental mainlands. Isolation can provide the opportunity for evolutionary divergence, but also set the stage for hybridization between related taxa arriving from different sources. Ferns disperse by haploid spores, which are produced in large numbers and can travel long distances in ...

Endosymbiotic associations between bacteria and eukaryotes are commonly reported (Taylor, 1983). The prokaryotic cell (the cytobiont (Taylor, 1979) or endocytobiont (Schwemmler, 1979)) may live non-specifically within the intracellular habitat provided by the host, but some endosymbiotic bacteria are specialized to invade specific cellular organelles. Three species of the bacterial genus Holosp...

Previous attempts to condition a 1-celled organism, paramecium, by either classical or instrumental procedures, have yielded equivocal results. The present experiments were designed to determine whether the use of positive reinforcement provided by DC electrical stimulation at the cathode, which had previously been shown to be attractive to paramecia, could be used to train these organisms in a...

positive transformant clones probed with the PcVenus sequence revealed that the injected DNA had become randomly inserted into the chromosome. Free linear monomers or multimers of injected DNA molecules as seen in P. primaurelia and P. tetraurelia were not evident even though the plasmid possessed extant telomeric repeats at its both extremities. We also cloned fragments containing the integrat...

Cells of Paramecium primaurelia in the immaturity period of the life cycle contain substances which repress the expression of mating ability when introduced into mature cells. When the immature cytoplasm of P. primaurelia was injected into mating-reactive cells of P. tetraurelia, P. caudatum and P. multimicronucleatum, immaturity was also induced in them. But the immature cytoplasm of P. primau...

Colletotrichum caudatum sensu lato is a widespread fungal pathogen of warm-season grasses. The fungus is easily differentiated from other Colletotrichum species through the presence of a unique filiform appendage at the apex of the conidium. Multi-locus phylogenetic analysis of four DNA sequence markers from 21 isolates of C. caudatum s.l. from six grass hosts recovered the morphospecies as a w...

Axenic cultures of free-living aerobic ciliates, such as Tetrahymena thermophila and Paramecium aurelia, have been established and routinely used in laboratory research, greatly facilitating, or enabling characterization of their metabolism, physiology, and ecology. Ruminal protozoa are anaerobic ciliates, and they play important roles in feed digestion and fermentation. Although, repeatedly at...