Formation and degradation of large extrusion bodies in Tetrahymena thermophila: The role of intramacronuclear microtubules in chromatin segregation.

Large extrusion bodies (EBs) in Tetrahymena thermophila were induced by treatment with aphidiocolin (APH), followed by transfer of the cells to a drug free medium. APH induces over-replication of DNA and reversible cell division arrest (Kaczanowski and Kiersnowska, 2011). After treatment the cells were transferred to a drug free medium, and a central granule of chromatin (a prospective EB) surrounded by microtubules developed inside the macronucleus.

Cohesion of Clonal Life History, Senescence and Rejuvenation Induced by Autogamy of the Histophagous Ciliate Tetrahymena rostrata.

The histophagous ciliate Tetrahymena rostrata was found as a parasite in the renal organs of the land snails Zonitoides nitidus and Cochlicopa lubrica. A starvation medium induced encystment, meiosis, autogamy, and development of new macronuclei. The cell division rate declined linearly with number of divisions from the last autogamy until senescence.

Inactivation of a macronuclear intra-S-phase checkpoint in Tetrahymena thermophila with caffeine affects the integrity of the micronuclear genome.

Aphidicolin (APH), an inhibitor of DNA polymerase α, arrested cell divisions in Tetrahymena thermophila. Surprisingly, low concentrations of APH induced an increase of macronuclear DNA content and cell size in non-dividing cells. In spite of the cell size increase, most proliferation of basal bodies, ciliogenesis and development of new oral primordia were prevented by the APH treatment.

[Dynamics of symmetric and asymmetric mitosis and cytokinesis].

During cell division the bipolar microtubular mitotic spindle ensures faithful segregation of daughter chromosomes and appearance of the cytokinetic membrane in an equatorial area separating genetically identical daughter cells. This process proceeds in consecutive morphological stages of prophase, metaphase, anaphase and cytokinesis. The progress in embryology and oncology concerns the new data about intervening mechanisms of rotation of a bipolar spindle in prophase and the change of the position of a mitotic spindle in anaphase that result in an asymmetric and differential mitoses.

Acquisition of cell polarity during cell cycle and oral replacement in Tetrahymena.

The aim of this study was to search for a mechanism responsible for the acquisition of cell polarity in a ciliate Tetrahymena. Homologs of the mammalian genes coding for CDC42-GSK3beta- MARK/PAR1-MAPs proteins were found in the Tetrahymena genome (Eisen et al., 2006, and this study).