Mature Paramecium mitochondrial large subunit rRNA consists of two stable segments: a 20 S segment described previously and a unique 283-base segment similar to 5.8 S rRNAs typically found in eucaryotic cytoplasmic RNA. pBR325 clones of both gene regions from both Paramecium primaurelia and Paramecium tetraurelia were sequenced and aligned. The gene segments lie adjacent to each other very near...

Early in eukaryotic evolution, the cell has evolved a considerable inventory of proteins engaged in the regulation of intracellular Ca(2+) concentrations, not only to avoid toxic effects but beyond that to exploit the signaling capacity of Ca(2+) by small changes in local concentration. Among protozoa, the ciliate Paramecium may now be one of the best analyzed models. Ciliary activity and exo-/...

A Plasmodium falciparum cDNA expression clone, lambdaPf9, had been identified earlier as a protective epitope, using anti-lambdaPf9 antibodies and combinatorial phagotopes. A segment of the Pf9 gene showed homology with Paramecium immobilization surface antigens such as 51B, 51A and 156G. A synthetic Pf9-peptide was designed from this region, and specific antibodies were raised. Each of these a...

It has been known for many years that electric currents flowing through a suspension of Paramecium modify the beating characteristics of the cilia in such a way that the organisms turn and move towards the cathode (Ludloff, 1895; Jennings, 1906). Jahn (1961) has accounted for this behaviour by supposing that current flows through the cell membrane and either enhances or reverses the normal cili...

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...

In this study, we revealed that the lectin wheat germ agglutinin (WGA) and its specific binding sugars, N-acetylneuraminic acid (NeuAc) and Nacetylglucosamine (GlcNAc), inhibited mating pair formation in Paramecium caudatum. The concentrations that caused 50% inhibition (IC50) were 17 nM, 3 mM and 30 mM, respectively. Using FITCWGA, it was shown fluorescence-cytochemically that WGA bound to the...

Paramecium requires oleate for growth. The phospholipids of the ciliate contain high concentrations of palmitate and 18- and 20-carbon unsaturated fatty acids. We previously showed that radiolabeled oleate is desaturated and elongated to provide these 18- and 20-carbon unsaturated acids. We now report on saturated fatty acid (SFA) metabolism in Paramecium. Radiolabeled palmitate and stearate we...

The epigenetic influence of maternal cells on the development of their progeny has long been studied in various eukaryotes. Multicellular organisms usually provide their zygotes not only with nutrients but also with functional elements required for proper development, such as coding and non-coding RNAs. These maternally deposited RNAs exhibit a variety of functions, from regulating gene express...