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, ...

Here, we report a comprehensive description of the stable associations between two Paramecium species (P. nephridiatum and P. caudatum) their cytoplasmic bacterial endosymbiont Pseudolyticum multiflagellatum. These spindle-like, rod-shaped, non-motile peritrichous bacteria demonstrate significant phenotypic polymorphism. Considering differences in morphology host species, several scientific gro...

Experiments were conducted to evaluate the toxic effects ofmonocrotophos in ciliate models Paramecium caudatum and Oxytricha fallax. In acute toxicity studies higherconcentrations of monocrotophos caused marked increase in mobility of cells exhibiting rocking movements within two mins of exposure but were decreased after 30 mins. LC50 value by mortality curve for 3 hr acute toxicity test of Oxy...

Fertilization process of Paramecium caudatum includes a reciprocal exchange of migratory pronuclei across a temporary junction between conjugating cells. To know the role of microtubules on the behavior of pronuclei during conjugation in P. caudatum, the localization of microtubules was investigated by indirect immunofluorescence with a monoclonal anti-a-tubulin antibody. The immunofluorescence...

The environment is rarely constant and organisms are exposed to temporal and spatial variations that impact their life histories and inter-species interactions. It is important to understand how such variations affect epidemiological dynamics in host-parasite systems. We explored effects of temporal variation in temperature on experimental microcosm populations of the ciliate Paramecium caudatu...

Firmly united conjugant pairs of P. caudatum were easily separated by treatment with trypsin, 0.025--1.0 mg/ml in 2 mM phosphate buffer at pH 7.2. Cytological observations showed that pairs separated by this means undergo normal meiosis and subsequent prezygotic divisions. Microspectrophotometric comparisons of G1 micronuclei in the parent with those in clones derived from prematurely separated...

Mating-reactive cells of Paramecium multimicronucleatum attach to a polystyrene surface (Falcon 10070 culture dishes) irrespective of extracellular ion concentration and swimming velocity. This attachment is induced in cells that are not mating-reactive by treatment with purified immunoglobulin G from antiserum, which blocks cells from mating or from antiserum prepared against the surface-local...

Timing and duration of pre-meiotic G1, S and G2 phases in Paramecium caudatum have been clarified by microspectrophotometry of DNA content and autoradiography with [3H]thymidine ([3H]dThd) and [3H]deoxyuridinemonophosphate ([3H]dUMP). Microspectrophotometric measurement of DNA content showed that cells in stationary phase have a G1 micronucleus, and that pre-meiotic DNA synthesis begins with th...