Scientists are now a step closer to knowing the role of female flies’ pleasure during the reproduction process after a new study has been published that shows that the sensation of copulating is actually responsible for female fruit flies to lose their interests in other partners.

Ulrike Heberlein and Lisha Shao, a senior fellow at the Howard Hughes Medical Institute in Virginia and at York University, respectively, investigated and studied about common fruit flies and the neurons that involve during their reproduction process.

Biologists have long known that proteins in a male fly’s ejaculate make females lose interest in other partners for up to a week — a trick used by males to ensure their own sperm is fertilized (AFP Photo/KERRY SHERIDAN)

They found a pair of sensory neurons in the abdomen that were “female-specific” and which will “likely transmit excitatory signals from abdominal sensory systems to the brain.”

For a long time, biologists already knew that the proteins in a male fly’s ejaculate make females lose interest in other partners for more or less than a week, which is known as a trick used by the males to make sure that their own sperm becomes fertilized.

With this, the researchers experimented on pairing female fruit flies with males that could not ejaculate.

They found that female flies lost interest in other males after mating, even though they haven’t received any sperm. It appears like the cells control the mechanisms by which the female flies determine if they have already had sex, which is known as the so-called “sperm effect.”

“The question of whether a successful mating has happened is very important in evolution,” Heberlein told AFP. “Females need to be able to tell whether they copulated successfully or not, else it makes a lot of sense to try to mate again.

Although they now have a “suspicion” about the neurons they found in the female flies’ abdomens were linked to sex, Heberlein believes more research and work are still needed to confirm whether the intercourse was pleasurable for them or not. 

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