Forget the battle between the sexes. There’s a tinier battle raging within the sexes — at the genetic level.
In some species’ sperm, X and Y chromosomes wrestle for dominance, each trying to improve its chances of reaching the next generation. New work from scientists at Fred Hutchinson Cancer Center show that certain genes in fruit flies used for DNA packaging have been conscripted into this tussle, shaping — and accelerating — their evolution. The study, published today in the journal eLife, reveals that these genes, which encode sperm-specific proteins called protamines, help maintain genetic balance by silencing “selfish” bits of DNA on sex chromosomes.
