The knockout of genes ASH-2, WDR-5, and SET-2 promotes an inheritable longevity in the worm C. elegans
Recently is was shown that a histone methylation, namely the trimethylation of H3 at lysine 4, limits the lifespan of the worm C. elegans. This was found by a study (Greer, at al 2010) that deleted the genes that express three proteins that are responsible for the histone methylation: namely ASH-2, WDR-5, and SET-2. The result was a ~30% extension of the lifespan of the worm.
A follow-up study was also conducted by some of the same authors to study the heritability of the longevity effect. It was found that the effect is heritable up to the third generation.
This is a very interesting finding because it suggests that longevity can be promoted by manipulating chromatin, and that this longevity can be inherited to subsequent generations.