Ain't No Party Like A Fruit Fly Party

Photo by: Dan Foy

               It’s party time, fruit fly style. Kyung-An Han and a group of researchers at Pennsylvania State University studied the mating patterns of intoxicated fruit flies and learned that like humans, fruit flies also show poor judgment under the influence.  The purpose of the study was to discover whether or not, alcohol, or ethanol in the case study, would sexually disinhibit drosphilic fruit flies. While the fruit flies did partake in blatant sexual disinhibition, they did so a little differently than way humans typically do.  The researchers learned that when intoxicated, fruit flies stop distinguishing between male and females and try to mate with whatever fly is closest. Males were the primary subject of the study, but the researchers also learned that females also lost their guard when in the aptly named “fly pub.”
        The study begins with an explanation of the various strands of drosophilic fruit flies that were used in the experiment. The researchers used three different male strands of flies, one more sexually disinhibited naturally, one unaffected, and one less sexually active. Each strand of fly acted as a control against the others to compare and monitor the levels of sexual disinhibition in relation to one another. Each of these flies, in natural circumstances does not typically try to mate with flies of their own sex.  Only in rare occurrences do male fruit flies try to copulate with other male fruit flies and it is even rarer for females to engage in such behavior. All of this changed though when the flies entered “fly pub.”
        After injecting a fruit fly sized dose of ethanol into the container of fruit flies, the scientists began monitoring the fruit flies behavior. At first, there was little difference as the flies merely flew around and occasionally attempted to mate with a member with the opposite sex. However, as the ethanol sank in and the fruit flies became subject to its effects, their sexual interactions increased and so did their disinhibition. DA, a neurochemical that influences fruit fly sexual behavior played a major role.  The scientists learned that after ingesting high levels of ethanol, DA production increased exponentially within the fruit flies’ brains. This increase they discovered, led the flies to seek sexual intercourse at higher rates.  Scientists also learned that with the increase of DA production, the ability of the flies to distinguish between male and female counterparts also decreased.  The fruit flies didn’t just try to mate more frequently, they tried to mate with anything around them. The study concluded that the male-male interactions were caused mainly by a decrease in sensory perception.  The flies literally couldn’t tell if their mates were male or female.
        While the fruit flies’ sexual disinhibition may have been a little more intense than what normally happens in human bars and night clubs, it definitely shows that humans aren’t the only subjects of alcohol’s wrath.  Fruit flies and humans alike lose the ability to accurately perceive their potential mates after drinking.