The toxicity of 14 commercial natural dyes which are widely used as food additives in Japan was studied on Paramecium caudatum. Laccaic acid and capsanthin were found to be very toxic to Paramecium caudatum. Some of the commercially available carminic acid and crocin were also toxic. The inhibitory effect of natural food dyes on leucine aminopeptidase, acid phosphatase and esterase in vitro was...

The environment is rarely constant and organisms are exposed to spatial and temporal variation that will impact life-histories. It is important to understand how such variation affects the adaptation of organisms to their local environment. We compare the adaptation of populations of the ciliate Paramecium caudatum exposed to constant (23 °C or 35 °C) and temporally variable temperature environ...

introduction: response to morphine and role of nitric oxide (no) on expression of morphine response has been studied in vertebrates. but, little evidence is provided in the matter in earlier invertebrates. this investigation for the first time evaluated the effect of no on expression of morphine potency in paramecium caudatum. methods: animal after isolation from natural media and specific iden...

In the present study experiments were conducted to evaluate the toxic effects of monocrotophos on ciliate models Paramecium caudatum and Oxytricha fallax, which can be considered as ideal organisms for investigating water quality fluctuations and risk assessment of pesticides. Cell viability, cell morphology, cell behaviour and macronucleus tests were performed using to different concentrations...

Previous experiments on physical non-contact communication within same species gave rise to test for this type of communication also across the species border, which was the aim of the present study. It was found that autotrophic unicellular organisms (Euglena viridis), separated by cuvettes, affected the proliferation rate of heterotrophic unicellular organisms (Paramecium caudatum). Further, ...

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...

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...

Paramecium has long been a model eukaryote. The sequence of the Paramecium tetraurelia genome reveals a history of three successive whole-genome duplications (WGDs), and the sequences of P. biaurelia and P. sexaurelia suggest that these WGDs are shared by all members of the aurelia species complex. Here, we present the genome sequence of P. caudatum, a species closely related to the P. aurelia ...

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...