The mitochondrial transmission to the progeny of interspecific hybrids Saccharomyces cerevisiae x Saccharomyces uvarum was investigated. It was observed that la progenie degli hybrids ha un solo tipo di mitocondri parentali come è stato osservato attraverso l’analisi RFLP dell’intero mtDNA. The mitochondrial proteins, invece, sono il risultato della ricombinazione del genoma dei due parentali. We suppose an important role of mitochondrial proteins in the process of mitochondrial transmission in yeast and hypothesize that inheritance of mtDNA may depend upon nuclear DNA genes. It seems to be probable that uniparental inheritance is independent on position of mitochondria in the buds of zygotes when the haploid cells fuse.