INTERSPECIES TRANSPLACEMENT OF MITOCHONDRIA IN YEASTS

Protoplasts of a respiration-deficient rho(0) strain of Saccharomyces cerevisiae were incubated with mitochondria isolated from various resp iration-competent yeast species under conditions enabling transplaceme nt of mitochondria. Respiration-competent cybrids were selected by pla ting the protoplasts on agar media containing a non-fermentable energy source. The resulting cybrids contained nuclear DNA of the acceptor S . cerevisiae and mitochondrial DNA of the donor species, as detected b y pulsed-field gel electrophoresis of chromosomes and restriction anal ysis of mitochondrial DNA, respectively. Successful restoration of res piration in the S. cerevisiae mutant was achieved by transplacement of mitochondria isolated from the following Saccharomyces species: S. ba yanus, S. capensis, S. delbrueckii, S. exiguus, S. italicus and S. ovi formis.