PHYSICAL STUDIES OF CELL DIVISION Statistical Fluctuations Effects Due to X-Radiation, Temperature, and Hydrostatic Pressure

摘要

A technique for determining the generation times of individual yeast cells is described. Mean generation times of haploid, diploid, triploid, and tetraploid yeast cells are tabulated, and distributions of the generation times of individual cells are presented. The effect of incubation temperature on generation time and on cells dividing in syn-chrony is determined.nThe effect of x-radiation on the generation times of individual cells and their progeny is studied. It is shown that ploidy does not have the same role in the division-delay effects of x-radiation as it has in the lethal effects of x-radiation. It is demonstrated that budding cells are resistant to the division-delay effects of x-radiation. Other workers have previously demonstrated that budding cells are resistant to the lethal action of x-rays. A theory of division delay is developed to fit the data.