Yeast QTL study revealed the importance of pan-genome on life span regulation in specific environmental condition

Genome-based prediction is one main goal of biology. Even for monogenic traits, prediction may deviate from reality notably due to the presence of genetic modifiers that are found in specific individuals. This is even harder for complex or polygenic phenotypes that need to integrate variations in many genes or pathways. Aging is a fundamental process of life and is regulated by nine known hallmarks. Each of them has the potential of being regulated by different pathways. We used the natural variation found in the budding yeast Saccharomyces cerevisiae to investigate the impact of genetic diversity on aging mechanisms in two different conditions. We found broad variation of chronological aging in both conditions that differs largely despite similar amount of glucose and raffinose were used. An enzyme encoded in the pan-genome of specific strains, described as a melibiase, is responsible to the liberation of all sugar molecules in the trisaccharide raffinose leading ultimately to a decrease of aging in this condition. Moreover, linkage mapping analysis using a biparental population allowed us to detect the WHI2 gene as major regulator of CLS in both glucose and raffinose conditions independently of the presence of the melibiase. Combination of both pan-genome information and Quantitative Trait Locus data are needed to accurate aging prediction in a condition-dependent manner.