Abstract: | Propidium iodide treatment of yeast under resting conditions resulted in cells which grew as sectored colonies comprised of both respiratory-deficient and -proficient progeny. Such treated cells also did not grow when plated initially on glycerol medium. These results suggested that propidium iodide produced reversible or transient lesions of the mitochondria within a single cell which interfered with function, but that recovery of mitochondrial competence could occur during growth of early progeny. Ethidium bromide, in contrast, provoked irreversible loss of respiratory function. Propidium may prove to be a useful agent to investigate the initial molecular events in petite mutation induction in yeast. |