Effect of Alchol on Sexuality in Flies
In the flies, hypersexuality caused by chronic alcohol exposure has the effect of making the males chase anything with wings — other males included. Although sexual preference in humans is obviously a complex phenomenon not replicated by the fly work, the findings could be used to further establish a fly model system for the study of alcoholism.
As the concentration of ethanol in the body rises, flies begin to become uncoordinated and oblivious to their surroundings: they get tipsy. “They bump into each other. They bump into the walls.
Add more alcohol and the flies become sedated. Add still more and the soused flies die. Remarkably, even the concentrations of ethanol that induce these behaviours are nearly the same in flies and humans. Flies also develop a tolerance to alcohol, and can develop withdrawal-like symptoms.
Combine these features with the genetic information and tools available for flies, and you can begin to address questions that can’t be answered by studying humans, “In human genetic association studies, the only thing you can reliably detect is genes that have relatively large effects. “In flies you have far better resolution because you can grow many flies cheaply and quickly.”
A neurobiologist at Pennsylvania State University in University Park, and her colleagues tested the effects of chronic alcohol exposure on sexual behaviour in the fruitfly Drosophila melanogaster . The researchers noted that male flies repeatedly exposed to ethanol vapour became less discriminate in their mate selection. The buzzed flies often courted fellow males, pursuing them around the cage while serenading with a traditional fruitfly courtship song played on vibrating wing.
Eventually, the lusty flies devolve into a courting frenzy (craziness). “You get a chain of males chasing each other,” says Heberlein, who was not associated with the study but has observed similar behaviour in her own unpublished work. In contrast, alcohol had little effect on mating in female fruitflies, which normally do not court their mates.
The findings suggest that the flies do not fundamentally change their sexual orientation, but rather get over-sexed. “Multiple alcohol exposures makes them essentially hypersexual,” says Heberlein. The mind-dulling effects of alcohol might also make it more of a challenge for male fruitflies to distinguish the gender of other flies in the crowd.
Although the drunken dipterans were more amorous, their rates of successful copulation declined after getting tipsy (slightly intoxicated), the researchers found — a trend that has long been observed in humans. So alchohol provoke the desire but much reduce the performance.
At the end I would like to add that this is one of the reason that Alcohol is forbidden in many religions especially in Islam. Because when you drink, it provoke a strong sexual desire and also losses your power of discrimination, and result in many social problems.
Lee, H. G., Kim, Y. C., Dunning, J. S. & Han, K. A. PLoS ONE 3, e1391 (2008). [Only registered users see links. ]