Effects of griseofulvin on fertilization and early development of sea urchins. Independence of DNA synthesis, chromosome condensation, and cytokinesis cycles from microtubule-mediated events
Schatten, H.; Schatten, G.; Petzelt, C.; Mazia, D.
European Journal of Cell Biology 27(1): 74-87
1982
ISSN/ISBN: 0171-9335 PMID: 7084254 Document Number: 189103
Griseofulvin (4-6 .times. 10-5 M and 1 .times. 10-4 M) prevents the formation of any microtubule-based structures in sea urchin (Strongylocentrotus purpuratus, Lytechinus variegatus, Arbacia punctulata) eggs at fertilization. Sperm incorporation occurs, though the migrations of the pronuclei, dependent on the formation of the sperm aster, are arrested. Similarly the streak and the mitotic apparatus fail to assemble. Cycles of DNA synthesis, chromosome activity, nuclear breakdown and reconstitution, and even cleavage attempts occur on schedule in the absence of any mitotic movements. The action of griseofulvin, unlike that of colchicine, is readily reversible by the removal of the drug. Microtubules are formed, and the chromosomes are separated. At 1 .times. 10-6 M, diminutive microtubule-based structures (e.g., sperm aster, mitotic apparatus) are observed though syngamy and division are arrested. These results demonstrate an independence of the cycle of microtubule-mediated events from other cyclical processes during the 1st cell cycles.