Effect of cold on metaphase cells: Extended generation times and aberrant cytokineses

Abstract

When mitotic populations of CHO cells were stored at 0 °C, the generation times of the subsequent cell cycle were extended in the amount of 0.2 h for each hour in the cold. The major part of this extension in generation time reflects a lengthening of the G1 phase of the cycle. Increasing length of cold storage also resulted in an increasing proportion of the cells showing cytological abnormalities. These were usually expressed by fusion of the daughters at the zero-th division to give giant cells and extension of such difficulties to subsequent divisions e.g., division into 3 or 4 cells. There is a high probability that the cells exhibiting such abnormal symptoms did not give rise to viable colonies. Caution must be observed when using accumulated mitotic shake populations in experiments to measure the temporal sequence of metabolic events in the cell cycle.