Contrasting genome dynamics between domesticated and wild yeasts

Abstract

Structural rearrangements have long been recognized as an important source of genetic variation with implications in phenotypic diversity and disease, yet their evolutionary dynamics are difficult to characterize with short-read sequencing. Here, we report long-read sequencing for 12 strains representing major subpopulations of the partially domesticated yeast Saccharomyces cerevisiae and its wild relative Saccharomyces paradoxus. Complete genome assemblies and annotations generate population-level reference genomes and allow for the first explicit definition of chromosome partitioning into cores, subtelomeres and chromosome-ends. High-resolution view of structural dynamics uncovers that, in chromosomal cores, S. paradoxus exhibits higher accumulation rate of balanced structural rearrangements (inversions, translocations and transpositions) whereas S. cerevisiae accumulates unbalanced rearrangements (large insertions, deletions and duplications) more rapidly. In subtelomeres, recurrent interchromosomal reshuffling was found in both species, with higher rate in S. cerevisiae. Such striking contrasts between wild and domesticated yeasts reveal the influence of human activities on structural genome evolution.