By IANS,
Washington : Males and females, even among little flies, act as though they belong to different planets, but both come equipped with a unisex brain, says a study.
By triggering the neurons responsible for singing – normally a male activity – researchers made female flies play their first tune.
“You might expect that the brains of the two sexes would be built differently, but that does not seem to be the case,” said Gero Miesenböck, formerly of Yale University and now with University of Oxford.
“Instead, it appears there is a largely bisexual or ‘unisex brain’ with a few critical switches that make the difference between male and female behaviour.”
Male flies have to work hard to convince females to mate with them, he explained. They do it by showing their talents – sticking out one wing and vibrating it to produce sound.
“The mystery at the root of our study is the neuronal basis of differences in male and female behaviour,” said Miesenböck. “Anatomically, the differences are subtle. How is it that the neural equipment is so similar, but the sexes behave so differently?”
To answer that question in the flies, the researchers used a special technique they developed in which the singing circuit could be turned on in either males or females with a simple flash of light. First, they confirmed the connection between that circuit and the courting behaviour in males.
When they triggered the same circuit in members of the opposite sex, the otherwise quiet female flies immediately began acting like males. “They just stuck out their wing and started singing,” Miesenböck said. However, the rookie females did sing off key.
In another study, other researchers found that mice females took on masculine behaviours when a particular pheromonal cue was blocked, suggesting that male behaviour is actively repressed in the rodents.
Nevertheless, the findings suggest that the circuits for maleness are present but dormant in females. These findings have been published in Thursday issue of Cell.