Jj. Liou et al., SELECTIVE SYNCHRONIZATION OF TETRAHYMENA-PYRIFORMIS CELL-POPULATIONS AND CELL-GROWTH KINETICS DURING THE CELL-CYCLE, Biotechnology progress, 14(3), 1998, pp. 450-456
A selection synchronization technique based on ingestion of tantalum p
articles has been applied to obtain synchronized cultures of the filte
r feeding ciliate Tetrahymena pyriformis. Cell concentrations and cell
volume distributions of synchronized cell populations have been monit
ored for more than four average generation times. A simple curve-fitti
ng method has been used to decompose the cell volume distributions of
a synchronous population into two populations representing cells befor
e and after cell division. In this way, the time course of the growth
of an initially synchronous culture is decomposed into the growth of s
uccessive generations. The data indicate that at any given time only t
wo generations of cells are present in significant numbers. The measur
ed cell volume distributions show that T. pyriformis has a complicated
growth pattern during the cell cycle. Newborn T. pyriformis cells do
not grow significantly at the beginning of the cell cycle. After the n
ongrowing stage, cells start growing in a possibly exponential rate be
fore cells enter into a second nongrowing stage. The second nongrowing
stage lasts until cell division. The presented data demonstrate that
growing cell populations can be viewed as the composite of cells belon
ging to different generations. This concept has important implications
for solving corpuscular models of cell growth.