Some Factors Necessary to Produce Division Conditions in Tetrahymena Pyriformis

The discovery of diverse methods for the synchronization of cell division have provided many interesting problems and developments in the solution of the mechanism of cell division. These methods have been developed primarily with the aim of permitting the study of cell life cycle events on a larger cell mass than possible with the use of more conventional procedures. The results reported earlier indicate that the biochemical changes during the division cycle undoubtedly vary greatly with cell type, with environmental conditions and with synchronizing systems (Campbell, A., 1957; Mazia, D., 1961; Prescott, D. M., 1961; Watanabe, Y., 1960; Zeuthen, E., 1958)With the aim of demonstrating a generalized mechanism for multiplication of all cell types, two important facts must be recalled. First, artificially induced synchrony of cell division is initiated by a phase of recovery from specified imposed stress, therefore, induced division synchrony may not necessarily mean that the cells are synchronized with respect to all events of the cell life cycle in logarithmic growth phase. Second, most of the biochemical events during the cell life cycle may not be completely necessary for the succeeding cell division. The direct causal relations existing between biochemical changes and cell division must therefore be clarified.In the present experiments, a ciliate protozoan, Tetrahymena pyriformis possessing several advantages for the biochemical analysis of cell division was employed. The investigations were designed to demonstrate the vital connection between adenosinetriphosphatase activity and cell division in the synchronized system, and to prove that synthesis of a specific protein is necessary for division of logarithmically growing cells.