Synchronized cultures of a cell wall-less mutant of Chylamydomonas reinhardii

Abstract

Synchronization and synchronous growth of a cell wall-less mutant of Chlamydomonas reinhardii have been described. The following growth conditions were used: A modified Sueokas' "high salt minimal medium", 14:10 h light-dark cycle, growth temperature 30 degrees C, light intensity 12-18 Klux and dilution of the culture at the end of the dark to a constant density of 1.0 . 10(6) cells/ml. The time course of increase and distribution of cell volume, cytopla-smic and nuclear division, release of motile cells after the division period and accumulation of DNA, RNA and protein are reported. These mutant cells did not make any sporangium in which the dividing cells were kept as a unit inside a mother cell wall. However, they usually adhered during the period of division, thus making clumps containing 2, 4 and 8 cells. Several of these cell clumps dissolved releasing either single or couples of 2 and 4 cells. After the end of division the cells became fl