Fly study hints that sperm proteins change fast to block cheating chromosomes
In fruit flies, a protein that packs DNA tightly inside sperm keeps changing quickly. When scientists swapped in a related fly species' version, the daughter-making sperm packed badly, and the flies fathered mostly sons.
Why it matters
Inside every animal, each chromosome is supposed to have an equal chance of being passed on. Some chromosomes cheat, and harm their rivals so they end up in more sperm. This work suggests that sperm proteins keep changing over time mainly to keep those cheaters in check, which may be one hidden cause of male fertility problems. It was done in flies, and human sperm proteins may behave differently, so nothing here changes medical advice today.
Who's behind it: C.-H. Chang, H. S. Malik and colleagues, Fred Hutchinson Cancer Center and the University of Wisconsin-Madison.
Summary by the Lemma AI · how we grade