A HIGHLY SPECIFIC MICROTUBULE DEPOLYMERIZING AGENT (NOCODAZOLE) AFFECTING MEIOSIS ACTIVATION IN THE PROTOZOAN BLEPHARISMA-JAPONICUM (CILIATA, HETEROTRICHIDA)

The aim of the research presented here was to determine whether low co ncentrations (1 mu g/ml) of a highly specific microtubule depolymerizi ng agent, nocodazole (NOC), affects the meiosis activation process in conjugating pairs of the ciliated protozoan Blepharisma japonicum. In order to identify and quantify differences in meiosis, both NOC treate d and untreated coeval pairs were stained and examined for their meiot ic phases. A clear-cut delay in the progression of meiosis in treated pairs was found. The findings indicate that NOC reversibly inhibits me iosis induction and that treated pairs need both continuous cell union and a period of recovery in order to progress through meiosis after N OC is withdrawn. These results suggest that cytoplasmic microtubule dy namics may be involved in the meiotic activation processs of Blepharis ma conjugating pairs.