Insights into three whole-genome duplications gleaned from the Paramecium caudatum genome sequence.

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.

Direct observation of histone H2B-YFP fusion proteins and transport of their mRNA between conjugating Paramecia.

Cytoplasmic exchange between conjugating cells of Paramecium caudatum has been implicated by mating experiments using wild-type and behavioral mutant cells. To observe macromolecular transport between mating cells, we cloned and expressed the P. caudatum histone H2B gene as a fusion protein attached to an enhanced yellow fluorescent protein (YFP) named PcVenus.

Nd6p, a novel protein with RCC1-like domains involved in exocytosis in Paramecium tetraurelia.

In Paramecium tetraurelia, the regulated secretory pathway of dense core granules called trichocysts can be altered by mutation and genetically studied. Seventeen nondischarge (ND) genes controlling exocytosis have already been identified by a genetic approach. The site of action of the studied mutations is one of the three compartments, the cytosol, trichocyst, or plasma membrane.

Nuclear Differentiation in Paramecium caudatum: Analysis by the Monoclonal Antibody against a Micronuclear Antigen: (conjugation/micronuclear antigen/monoclonal antibody/nuclear differentiation/Paramecium caudatum).

I obtained the monoclonal antibody 93A against a micronuclear antigen of the ciliate Paramecium caudatum. Immunocytochemical observations showed that the antigen 93A appeared in some portion of the micronucleus in every stage of life cycle. In dividing micronuclei, the antigen appeared mainly in their both poles and in fibrous structures between the poles.

Role of Germ Nuclei in Conjugation of Paramecium caudatum: (Conjugation/conjugation-specific antigen/germ nuclei/monoclonal antibody/Paramecium caudatum).

Ciliated protozoa have two distinct nuclei, germinal micronuclei and somatic macronuclei. Macronuclei are transcriptionally active, but micronuclei are almost inert. To know whether micronuclei have any function in conjugation of Paramecium caudatum, expression of the conjugation-specific nuclear antigen, CSN-1, in amicronucleate cells during conjugation was examined.

Nuclear Differentiation in Paramecium caudatum: Analysis by the Monoclonal Antibody against a Macronuclear Antigen.

To know molecular mechanism controlling the differentiation of somatic nuclei (macronuclei) in Paramecium caudatum, I obtained the monoclonal antibody 36B against a macronuclear antigen. Immunocytochemical observations showed that the antigen 36B was dispersed in macronuclei. But in late stationary phase, large aggregation of the antigen was observed in some stocks, though this was not observed in another stock.