Functional co-operation between the nuclei of Saccharomyces cerevisiae and mitochondria from other yeast species.

We elaborated a simple method that allows the transfer of mitochondria from collection yeasts to Saccharomyces cerevisiae. Protoplasts prepared from different yeasts were fused to the protoplasts of the ade2-1, ura3-52, kar1-1, rho0 strain of S. cerevisiae and were selected for respiring cybrids on plates containing 5-fluoroorotic acid and a non-fermentable carbon source. The identity of putative cybrids was assessed by restriction analysis of mitochondrial DNA, pulse field electrophoresis and tetrad analysis. In the comprehensive screening, only mitochondrial genomes from synonymous species (S. italicus, S. oviformis, S. capensis and S. chevalieri) exhibited complete compatibility with S. cerevisiae nuclei. The closely related S. douglasii mitochondrial genome could also partially restore respiration-deficiency in rho0 S. cerevisiae, whereas mitochondrial genomes from phylogenetically less related species could not.