Diversity, variability and fast adaptive evolution of the wine yeast (Saccharomyces cerevisiae) genome-a review

Due to the high propensity for genomic alteration of their genomes, wine yeast (Saccharomyces cerevisiae) strains are very diverse. Genetic/genomic differences often correlate with different enological and technological properties. Experimental data indicate that the plasticity of the genome makes wine yeast populations capable of adapting to the continuously changing and rather harsh fermentation environment. A model is proposed for this fast adaptive genome evolution (FAGE) that explains the roles of the changing clonal composition of the population during fermentation, genome purification by meiosis at the end of fermentation and subsequent autodiploidisation of the spore clones in the next vintage, and the generation of new genomes through conjugation of non-sister spore clones (heterodiploidisation). Possibilities for genome stabilisation are also considered.