The Induction by Ultraviolet Radiation and the Photoreactivation of Heritable Respiratory Deficiency in Polyploid Saccharomyces

Abstract

The kinetics of the induction by ultraviolet radiation of extrachromosomally inherited respiratory deficiency in Saccharomyces is determined by the ploidy level of the cells. The fraction of the inducing radiation damage which is photoreactivatable is similarly ploidy dependent. These findings are taken to indicate that the primary radiation events which result in inactivation or loss of the extrachromosomal genetic determinants of cellular respiration are nuclear in nature.