Gene Implicated in Fighting Styles

In the battle of the sexes, one gene may explain differences in male and female fighting styles, a Harvard Medical School study reported last weekend. Fighting styles in fruit flies, that is.

The study, published in the journal Nature Neuroscience, found that swapping a gene linked to aggression—known as “fruitless”—could make male fruit flies fight like females and could make females fight like males.

In their natural environment, fighting males lunge and stand up on their hind legs in battle, while fighting females shove and head-butt, according to the study.

Unless their genes were switched, males would not normally head-butt in battle, and females would not lunge, said Berry Professor of Neurobiology Edward A. Kravitz, a co-author of the study.

“We’re trying to learn how a gene specifies all that complicated stuff that animals know how to do,” Kravitz said. “There’s so little known about how complex behaviors”—like aggression—“get wired into the nervous system.”

But human beings will probably not benefit directly from the fruits of Kravitz’s research any time soon.

Humans do not have a gene analogous to “fruitless,” Kravitz said, and the genetic behavioral patterns seen in the fruit flies cannot be extrapolated to humans.

“Experience is probably much more important in human behavior, but there are some genetic components involved,” he said.

Kravitz published another study on fruit fly behavior earlier this month, which pitted male flies against each other in fights. The study, which appeared in the Proceedings of the National Academy of Sciences, found that fruit flies can remember the outcomes of previous battles and that those memories influence their fighting mentality.

Flies that won fights tended to go on the offensive, while flies that lost previous fights usually retreated more, according to the study. Winning flies would keep winning, while a fly that had lost before did not win another battle unless it was pitted against another fly that had also previously lost.

Unlike the study on male and female fruit fly aggression, this study may hold relevance for humans. The research, Kravitz said, could help improve psychiatric models on depression and feelings of resignation.