The genetics of a long life

Genetically diverse mice and cross-species comparison uncover links to longevity Elucidating the genetics of complex traits and diseases is a major undertaking, one that can lead to biological insights and, because genetics increasingly informs drug discovery ( 1 ), new treatments. Longevity reflects aging and other processes affecting health and disease, so unraveling its genetic basis would have far-reaching implications. However, it has been a challenge to identify the genetic determinants of longevity in humans or animals ( 2 ) in part because longevity as a phenotype encompasses multiple other traits and disease risks. Tackling the complexity of the genetic component of longevity requires an integrated approach that leverages multiple sources of evidence. On page 1508 of this issue, Bou Sleiman et al. ( 3 ) use genetically heterogeneous mice to find new life-span loci and further perform cross-species comparisons to better understand the genetic basis of mammalian longevity.