[Effect of suboptimal temperature on the mitotic regime].

A two-hour treatment of Chinese hamster cells with a suboptimal temperature of 21 degrees C leads to a decrease of the mitotic index and to a delay in division at the metaphase. Cooling causes a sharp rise of the pathological mitosis, represented mainly by the forms of pathology connected with the disorganization of the mitotic apparatus, such as C-mitosis and dispersion of chromosomes in the metaphase. After being transferred to the optimal temperature conditions the cells completely restored their mitotic regimen in one hour, the amount of the pathological mitosis during that time still being much higher than the control level.