ABOVE: Male Drosophila live shorter lives than females, possibly because the Y chromosome loses heterochromatin that normally suppresses selfish genetic elements.
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The paper
E.J. Brown et al., “The Y chromosome may contribute to sex-specific ageing in Drosophila,” Nat Ecol Evol, 4:853–62, 2020.
The Y chromosome is chock-full of “selfish” genetic elements, which can jump around causing mutations. But the Y chromosome’s densely packed DNA, called heterochromatin, keeps these elements in check. Because heterochromatin deteriorates as organisms age, University of California, Berkeley, evolutionary biologist Doris Bachtrog wondered what role that change played in how long individuals live.
She and colleagues turned to Drosophila. As in mammals, males are XY and tend to live shorter lives than XX females. Quantifying the amount of heterochromatin in the genomes of young and old flies, Bachtrog’s team found that levels were well maintained in females as they aged. In old males, the amount ...
