Drosophila

When Drosophila melanogaster are shielded from bacteria during their first week of adulthood, their lives are shortened by a third, says a study published in PNAS this week. Eliminating the same bacteria late in adulthood, however, increases the flies' longevity. The authors also show that genetic mutations associated with longevity can modulate the effects of bacteria on lifespan.

"I wasn't surprised, but I was excited," Daniel Promislow of the University of Georgia said of the results. "I think this is just the beginning. A few years from now, we're going to look back and have a lot of really interesting data on the roles that parasites play" in organism lifespan, said Promislow, who was not involved in the study.

Ted Brummel of Sam Houston State University in Texas and his former colleagues at CalTech raised Drosophila in axenic conditions by treating eggs with bleach and ethanol and then keeping the ...