Functional co-operation between the nuclei of Saccharomyces cerevisiae andmitochondria from other yeast species

We elaborated a simple method that allows the transfer of mitochondria from collection yeasts to Saccharomyces cerevisiae. Protoplasts prepared from d ifferent yeasts were fused to the protoplasts of the ade2-1, ura3-52, kar1- 1, rho (0) strain of S. cerevisiae and were selected for respiring cybrids on plates containing 5-fluoroorotic acid and a non-fermentable carbon sourc e. 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 specie s (S. italicus, S, oviformis, S. capensis and S. chevalieri) exhibited comp lete compatibility with S. cerevisiae nuclei. The closely related S. dougla sii mitochondrial genome could also partially restore respiration-deficienc y in rho (0) S. cerevisiae, whereas mitochondrial genomes from phylogenetic ally less related species could not.