Sex is 'sickening' for female fruit flies

Washington, Feb 20 (ANI): A new study has shown that mating affects female fruit flies' genes as well as immune systems.

Uppsala University researchers have observed that during mating, the females' genes are activated to roughly the same extent as when an immune reaction starts.

The researchers have revealed that they used a combination of behavioral studies and genomic technology, so-called microarrays, to determine how fruit fly females are affected by mating.

"We monitor how genetic expression is impacted by mating and show that the most common process that is affected is the immune defence system," says Ted Morrow at the Department of Ecology and Evolution, Uppsala University.

The researchers found that the cost of mating turns out to be rather high.

"Previous research findings show that if this cost were not a factor, females would produce 20 percent more offspring," Morrow said.

The researchers found that it is costly for females to mate because competition among males has led to behaviours and adaptations in males that are injurious to females, such as harassment during mating rituals and toxic proteins in their sperm fluid.

"Our results are the strongest evidence that the cost to females is probably tied to the cost of starting an immune reaction. In other words, the males are like a 'sickness' to females," said Morrow. (ANI)