Chemical tags outside DNA are linked to extended life span in generations of roundworms
Although long life can be inherited, it doesn’t necessarily happen through the genes.
A new study shows that the grandchildren and great-grandchildren of long-lived roundworms live five to six days longer than usual even though they no longer carry the genetic mutations that caused their grandparents’ longevity. Instead, the descendants’ longevity may be because they inherited epigenetic marks — chemical tags on their DNA or DNA-associated proteins called histones — that change gene activity without changing the genes themselves, researchers at Stanford and Harvard universities report online October 19 in Nature.
The study is the first to demonstrate that longevity can be passed from generation to generation via these chemical tags known as histone modifications rather than by DNA variations. Only a few studies have suggested that any histone modifications can be inherited, “but this is a fairly definitive demonstration,” says Tony Kouzarides, a molecular biologist at the University of Cambridge in England.