Mitochondrial Genomes of Flor Yeast Strains Are Characterized by Low Genetic Variability

Resumo

High concentrations of ethanol and oxidative stress can cause a mutagenic effect on mitochondrial genomes (mtDNAs) of flor yeasts. We performed a comparative analysis of mtDNAs of wine yeast strains and three sequenced flor yeast strains. mtDNAs of flor strains are characterized by high conservation of nucleotide sequences and the structure. The numbers of destabilizing elements of mtDNA (GC clusters, short repeats, active ori sequences) in flor strains are generally lower than that in wine yeasts. The mtDNA conservation of flor strains can be determined by both bottleneck effects in the course of evolution and mechanisms aimed at maintaining the genetic stability. In general, the data obtained do not confirm the hypothesis of increased genetic variability of the mitochondrial genomes of flor yeast strains.