Transposable element expression with variation in sex chromosome number supports a toxic Y effect on human longevity

Why women live longer than men is still an open question in human biology. Sex chromosomes have been proposed to play a role in the observed sex gap in longevity, and the Y male chromosome has been suspected of having a potential toxic genomic impact on male longevity. It has been hypothesized that in aging individuals, where TE repression is diminished, an increase in somatic mutations and an acceleration of the aging process may occur. As the Y chromosome is typically enriched in transposable elements (TE), this could explain why the presence of a Y chromosome is associated with shorter longevity. Using transcriptomic data from humans with atypical karyotypes, we found an association between TE expression and the presence and number of Y chromosomes. These findings support the existence of a toxic Y effect on men’s longevity. ### Competing Interest Statement The authors have declared no competing interest.