Researchers discover fruit fly aphrodisiac

Sep 29, 2011 by Bob Yirka report
fruit fly

(PhysOrg.com) -- People, mostly of the male persuasion, have been searching the world for a true aphrodisiac for pretty much all of recorded history, unfortunately, the search has been mostly fruitless, which makes this latest discovery by a group of biologists all the more intriguing. As noted in their paper published in Nature, it appears the common fruit fly has found for itself, a substance that we humans can only dream about; a substance than when smelled, causes the smeller to engage in mating. Unfortunately, at least for the fruit fly, the stuff only works on males.

The substance in question is actually two: phenylacetic acid and phenylacetaldehyde; both of which are commonly found in ripe fruit. It seems that smelling either substance activates the sensory pathways that lead to courtship, which for seems to make sense. It’s commonly known that the female fruit fly lays its eggs in ripe fruit, thus, it seems pretty obvious why the male developed a certain sensitivity to the chemicals found in it. For the fruit fly, it’s the perfect environment. They can eat then mate and then after a while the females can lay their eggs, all in one convenient place. In some respects it’s rather reminiscent of the visual sensory activation that occurs in male humans when looking at certain images that are tied to their own mating rituals.

The sensory pathways in fruit flies that lead to courtship have been known for a while, but it wasn’t until this study was conducted that it became known that they could be activated by substances outside of the flies themselves. Previously, it had been assumed that such pathways would be activated by pheromones generated by flies of the opposite gender, as is the case with other animals. In fact, the team hadn’t really set out to make the connection; they were simply studying the sense of smell in Drosophila melanogaster. As their research continued, however, it became clear that something in the outside environment was activating the sensory pathways, and after further study they found it was the substances in the fruit. Of note is the fact that the chemicals are only present in ripe fruit, which we humans detect as a sweet odor. For fruit flies, it’s important because the female only lays eggs in fruit that has had time to ripen (or rot).

After more research, the team found that the sensory pathway activation only worked for males, which led to speculation that it was the males’ behavior that led to females laying their eggs in ripe fruit.

Because this is the first time a connection has been found between chemicals in the environment in which an organism lives, and sexual activation, the results of this research will almost certainly set off research in other animals to see if they respond in similar ways to chemicals in their surroundings.

Explore further: Vocal variety in African penguins: Four basic vocalizations used for adult communication, two more for the young

More information: An olfactory receptor for food-derived odours promotes male courtship in Drosophila, Nature (2011) doi:10.1038/nature10428

Abstract
Many animals attract mating partners through the release of volatile sex pheromones, which can convey information on the species, gender and receptivity of the sender to induce innate courtship and mating behaviours by the receiver. Male Drosophila melanogaster fruitflies display stereotyped reproductive behaviours towards females, and these behaviours are controlled by the neural circuitry expressing male-specific isoforms of the transcription factor Fruitless (FRUM). However, the volatile pheromone ligands, receptors and olfactory sensory neurons (OSNs) that promote male courtship have not been identified in this important model organism. Here we describe a novel courtship function of Ionotropic receptor 84a (IR84a), which is a member of the chemosensory ionotropic glutamate receptor family6, in a previously uncharacterized population of FRUM-positive OSNs. IR84a-expressing neurons are activated not by fly-derived chemicals but by the aromatic odours phenylacetic acid and phenylacetaldehyde, which are widely found in fruit and other plant tissues7 that serve as food sources and oviposition sites for drosophilid flies8. Mutation of Ir84a abolishes both odour-evoked and spontaneous electrophysiological activity in these neurons and markedly reduces male courtship behaviour. Conversely, male courtship is increased—in an IR84a-dependent manner—in the presence of phenylacetic acid but not in the presence of another fruit odour that does not activate IR84a. Interneurons downstream of IR84a-expressing OSNs innervate a pheromone-processing centre in the brain. Whereas IR84a orthologues and phenylacetic-acid-responsive neurons are present in diverse drosophilid species, IR84a is absent from insects that rely on long-range sex pheromones. Our results suggest a model in which IR84a couples food presence to the activation of the fruM courtship circuitry in fruitflies. These findings reveal an unusual but effective evolutionary solution to coordinate feeding and oviposition site selection with reproductive behaviours through a specific sensory pathway.

Related Stories

Fruit fly antennae are tuned in

Apr 01, 2011

(PhysOrg.com) -- The antennal ears of different fruit fly species are actively tuned to high-frequency components of their respective mating songs, according to new research led by University College London ...

New thinking on regulation of sex chromosomes in fruit flies

Sep 19, 2011

Fruit flies have been indispensible to our understanding of genetics and biological processes in all animals, including humans. Yet, despite being one of the most studied of animals, scientists are still finding the fruit ...

Recommended for you

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

that_guy
1 / 5 (1) Sep 29, 2011
Was this experiment done on Spanish fruit flies?

We have a similar stimulus that causes the mails of our species to engage in mating. It's called hot naked women.
Isaacsname
5 / 5 (1) Sep 29, 2011
" Scientists: Helping fruit flies get laid since 1909 "
gwrede
5 / 5 (1) Sep 30, 2011
Scents that make you think of spring (i.e., flower and blossom scents) laced with varying amounts of musk, and you're grabbed.

To my amazement, I've found an entirely artificial scent that works for me, but I don't know what it is. I suspect it is from a laundry detergent or fabric softener, and I've even sometimes tried to ask somebody about what they smell, but so far with no luck.

Of course, as a man, I'd much rather see a scent that affects women. :-)
that_guy
1 / 5 (1) Sep 30, 2011
To my amazement, I've found an entirely artificial scent that works for me, but I don't know what it is. I suspect it is from a laundry detergent or fabric softener, and I've even sometimes tried to ask somebody about what they smell, but so far with no luck.


So let me follow this line of logic from you gwrede...
- There is a scent that totally makes you want to do like these fruit flies in the study.
- Then you smell this 'scent', and you decide to ask the nearest person if they can help you identify it.

So if some obviously horny guy who is on the verge of ripping off his clothes walks up to you and asks you to help him identify a smell, would YOU help him? Or would you slowly back away...

As for your Laundry detergent/fabric softener theory - Have you ever accidently slammed the dryer door on yourself? I think that will answer that part of the question.