Mechanism of reversibility of colcemid-induced colchicine mitosis

Abstract

Restoration of the normal course of mitosis after its blocking by colchicine takes place through additional protein synthesis—through the formation of new microtubules of the division spindle. A study of the reversibility of the stathmokinetic reaction to colcemid shows that blocking of protein synthesis by puromycin has little or no effect on the rate of restoration of the normal mitotic regime, whereas copper ions retard this process. It can be concluded from these facts that the restoration of the colcemid-induced C mitosis takes place chiefly through the repolymerization of tubulins. The predominance of the formation of new microtubules or repolymerization during the restoration of the microtubules is evidently determined both by the degree of their destruction and by the character of binding of the subunits of the tubular protein pool with the harmful agent.