Experimental evolution on yeast cybrids

In eukaryotes, genetic interactions between the mitochondrial and nuclear genomes exert a critical influence on organism fitness. A selective pressure thus exists to maintain close cooperation between the products of both genomes. We have tested the impact of mitonuclear interactions on evolutionary divergence by performing experimental evolution on cybrids of the yeast Saccharomyces cerevisiae, displaying various combinations of nuclear and mitochondrial genotypes. Seven mitonuclear backgrounds were evolved for approximately 300 generation as 96 replicates in presence and absence of explicit selection for respiratory function. At the end of the experiment, one individual was isolated from each surviving population, and submitted to whole-genome sequencing, enabling the identification of mutational patterns specific to individual mitonuclear backgrounds. The results of this study thus demonstrate the influence of mitonuclear interactions on evolutionary divergence.