Heat synchronization of cell division in Tetrahymena thermophila and a mutant, NP1, with a temperature sensitive defect for oral development

Abstract

Optimal conditions for induction of synchronous cell division in Tetrahymena thermophila have been investigated. Wild type cells and a mutant, NP1, with temperature sensitive oral development have been used. NPI forms no food vacuoles after long exposures to 37~ or higher temperatures. According to one temperature regime both clones were grown at 30~ and exposed to five 30 min heat shocks at 42.3~ spaced 30 min apart. This treatment resulted in 80% and in 50% increase in cell number over 15 min intervals placed at the time of the first and the second synchronized cell division, respectively. NP1 formed food vacuoles at the same rate as wild type cells. According to a second temperature regime the cells were grown at 30~ and heat shocks at 41.8~ were spaced one cell generation apart. This treatment resulted in division of about 95% of the cells within a one hour period between the sixth and seventh shock. Heat shocks were also applied to cells grown at 37~ Five shocks at 43.1~ spaced 30 min apart synchronized cell divisions of wild type cells but not of mutant cells.

The intrinsic fluorescence of Tetrahymena as a function of temperature

“…ZEtJTHEN (29) introduced the method of inducing synchrony in a population of Tetrahymena pyriformis GL by administration of a series of half hour heat shocks spaced at intervals corresponding to a generation time. This method of inducing synchrony has since been applied with partial success to other species of Tetrahymena, such as T. thermophila (28) and with more success, to a yeast (15).…”