On the relation between recovery from potential lethal and sublethal radiation lesions of yeast cells

Summary Tetraploid yeast cells were used to study the time course of recovery from potential lethal lesions by delayed plating after a single dose of gamma-radiation and recovery from sublethal lesions by using two fraction dose technique. The mean lifetime of potential lethal and sublethal lesions in comparable conditions are the same. The elimination of lethals in the first steps of recovery process is accompanied by transition of lethally damaged cells into sublethally damaged ones.Sublethals are in principle completely reversible. As potential lethals consist of sublethals the number of which are critical the former immediately after irradiation also are complete reversible in principle. In a time course a definite fraction of potential lethals is fixed into true irreversible lethals. This pattern is in close agreement with the common model of formation of two-hit chromosome aberration.