Publication details
Meiosis and sporulation in fission yeast: the effect of cytoskeletal inhibitors
| Authors | |
|---|---|
| Year of publication | 1999 |
| Type | Article in Proceedings |
| Conference | 20 th International Specialized Symposium on Yeast 1999 |
| MU Faculty or unit | |
| Citation | |
| Field | Microbiology, virology |
| Description | Homothallic yeasts Schizosaccharomyces japonicus var. versatilis, undergo mass mating, meiosis and sporulation when they reach stationary phase after growth in malt extract broth glucose medium. Microtubular inhibitors benomyl (BEM), thiabendazole (TBZ) and methylbenzimidazole (MBC) were applied in concentrations 10 -150 mikro g/ml at different phases of culture growth and their cytological effects were followed microscopically. MBC inhibited the increase of cell number at 200 mikro g/ml and induced cytolysis. BEM disintegrated microtubules completely at 30 mikro g/ml. Lower concentrations of inhibitor (5 -20 mikro g/ml) disturbed sporulation -asci with 1 to 7 spore appeared instead of regular 8 spores per ascus. Frequently the sporulation process turned out abortive. TBZ affected the growth curve from concentration 30 mikro g/ml, where part of the cell population showed the microtubules partly disrupted. The microtubules disappeared completely at 50 mikro g/ml. Mating projections were formed at 30 or even at 50 mikro g/ml, but zygotes arose less frequently and sporulation was completely inhibited. TBZ at 20-30 mikro g/ml, like BEM, caused disturbances in spore size and number. Tear- like and horse-tail appearance of nuclei typical for shmoos and meiotic prophase respectively, persisted, suggesting that the microtubules do not take part in maintenance of nuclear morphology. Cytological observations showed that postmeiotic mitosis and meiosis II are much more sensitive to microtubule depolymerization than mating projection formation, fusion and sporulation. Cytochalasin D, the actin depolymerising agent, caused rapid disintegration of actin cables and dissipation of actin patches from the cell poles. If applied at a concentration of 25-50 mikro g/ml to the agglutinated cells, cell pairing, rebuilding of zygote walls and formation of spore wall were halted. The results suggest that these events require a fully functioning actin cytoskeleton. |
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