Domestication reprogrammed the budding yeast life cycle

Matteo De Chiara; Benjamin Barré; Karl Persson; Amadi Onyetuga Chioma; Agurtzane Irizar; Joseph Schacherer; Jonas Warringer; Gianni Liti

We next compared the quiescence survival of wild and domesticated yeasts (n=572, all euploid diploid), in carbon exhausted synthetic media in which not even wild yeast sporulates. We allowed cells to reach quiescence by exhausting sugars either using rich synthetic complete medium (SDC) or a calorie restricted such medium. After 7, 21, and 35 days we found nearly equal quiescence survival for wild and domesticated yeasts, with a small but significant advantage for domesticated yeasts in the richest environment (SDC, at days 21 and 35) that best resemble domestication niches (Fig. 4 panel B) . Rather than by domestication, survival variation under quiescence was explained by population stratification and therefore either by drift or local adaptation. Thus, wild Taiwanese and domesticated French Dairy yeasts died rapidly (<30% survivors after 7 days), while French Guiana, Mexican agave and West African Cocoa yeasts were the longest living (>60% survivors after 21 days) (Supplementary fig. 4 ). French Dairy carried loss-of-function mutations in SIC1, which is required for entry into quiescence 53 Given the high trait heritability (Fig. 4c , h 2 = from 0.77 to 0.90), we next probed alleles controlling survival under quiescence by GWAS. We identified 292 variants which were mostly (n=177) time and environment specific. Loss function mutations in the cell cycle regulator WHI2 was associated to shortened quiescence lifespan in all environments.