Electron Microscopy on Mitotic and Chromosomal Aberrations Induced by Colchicine, Mercaptoethanol and Nitrogen Mustard

抄録

The effect of colchicine, mercaptoethanol, and nitrogen mustards on the pollen mother cells of Lilium have been studied at the electron microscopic and the light microscopic levels. The treatment of PMCs with colchicine induced the inhibition of the spindle activity, which was caused by the dissociation of chromosomal fibers. The colchicine-treated chromosomal fibers showed a number of granules corresponding to the precursors of elemental fine fibrils of the fiber. Therefore, no chromosomal fibers remain to induce the chromosome movement at anaphase.
The inhibition of spindle activity induced by mercaptoethanol was similar to that by colchicine, but the ultrastructural changes of chromosomal fibers caused by the former were different from those by the latter. The chromosomal fibers treated with mercaptoethanol became sticky and could not act normally.
Cytological effects of alkylating agent, nitrogen mustard, were lethal inducing chromosome breakage, stickiness in nuclei, and extreme alveolation of the cytoplasm.
The authors would like to thank Professor Emeritus B. Wada and Professor N. Tanaka, University of Tokyo, for their helpful criticism of the manuscript. This work was supported by the grant from the Ministry of Education of Japan.