We investigated nitric oxide (NO) production in Paramecium caudatum, and the role of NO production in population growth in culture and thermoregulation. Nitrite (NO2 -) concentration in media containing P. caudatum [6350 ± 390 (SD) paramecia/ml] was 2.37 ± 0.53 μM after 6 h, compared to 0.16 ± 0.06 μM in media alone (p<0.005), and the NO synthase (NOS) inhibitor, Nω-nitro-L-arginine methylester...

Legionella pneumophila, the causative agent of Legionnaires' disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating facto...

Telomeric DNA at the ends of chromosomes consist of short, tandem repeat sequences. The telomeres of Paramecium tetraurelia are made up of variable repeats, whereas Paramecium caudatum telomeric repeats are largely invariant. To investigate variable repeat synthesis in P. tetraurelia, mutated telomerase RNA genes were expressed in vivo. We demonstrate that the P. caudatum telomerase RNA can par...

1. The N-(2-hydroxyethyl)alanine esterified to phosphatidic acid in anaerobic ciliate rumen protozoa has the l configuration. 2. Labelling experiments with Entodinium caudatum cultures using [(32)P]P(i) [2-(14)C]ethanolamine and (32)P- and (14)C-labelled phosphatidylethanolamine show that phosphatidylethanolamine is the direct lipid precursor of the N-(2-hydroxyethyl)alanine-containing phosphol...

The nanotechnology revolution has allowed us to speculate on the possibility of hybridising nanoscale materials with live substrates, yet significant doubt still remains pertaining to the effects of nanomaterials on biological matter. In this investigation, we cultivate the ciliated protistic pond-dwelling microorganism Paramecium caudatum in the presence of excessive quantities of magnetite na...

The gram-negative bacterium Holospora obtusa is a macronucleus-specific symbiont of the ciliate Paramecium caudatum, which invades the host cell via a food vacuole, infects its macronucleus and grows exclusively in the nucleus. From infection experiments, we showed that a property of the macronucleus that is necessary for it to be recognized and infected by H. obtusa is commonly provided by P. ...

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 ...

Holospora undulata is a micronucleus-specific symbiont of the ciliate Paramecium caudatum. We report here the draft genome sequence of H. undulata strain HU1. This genome information will contribute to the study of symbiosis between H. undulata and the host P. caudatum.