Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Single gene is genetic switch for fly sexual behavior

03.06.2005


A male fly’s sexual courtship of a female fly is a complicated business of tapping, singing, wing vibration, and licking, but a single gene is all that is needed to produce this complex behavior, according to new research published in this week’s issue of the journal Cell.




The gene encodes the Fruitless protein. Male and female flies carry different versions of the fruitless protein, as a result of sex-specific splicing of the mRNA. The male form of Fruitless is critical for the male courtship ritual and males’ preference for mating with females, as previous studies have shown.

Now, Barry J. Dickson and Ebru Demir of the Institute of Molecular Biotechnology of the Austrian Academy of Sciences show just how intimately fruitless is linked to these stereotypically male behaviors. They discovered that female flies with the male version of fruitless behave like males, directing at other females a sexual display nearly identical to their male counterparts.


Female flies with the male version of the protein also make amorous advances toward male flies that express female pheromones. In these cases, "we have been able to reverse the sex roles during Drosophila courtship," Dickson and Demir say.

Dickson and Demir created male-spliced versions of fruitless in female flies and female-spliced versions in male flies. Males with the female version of fruitless "barely court at all" when paired with virgin female flies in an observation chamber, according to the researchers.

Males with the female fruitless splice form were also more likely to court other males than flies with the male form, suggesting that male-specific fruitless splicing "not only promotes male-female courtship, it also inhibits male-male courtship," the researchers say.

Dickson and Demir refer to fruitless as a behavioral "switch gene" that is both necessary and sufficient to produce a particular behavior. Switch genes that trigger the development of a particular anatomical feature like wing structure have been studied extensively, but there are very few studies of switch genes that control a complex behavior, the researchers note.

In part, this is because finding behavioral switch genes can be a difficult task. The key, says Dickson, is demonstrating that a specific gene is sufficient to produce a particular behavior.

"This means showing that gene X is sufficient to create the potential for behavior Y in an otherwise normal animal. It is the ’otherwise normal’ part that is tricky," he says.

"Putting gene X into another species and expecting to see a behavior is unrealistic--a ’flight’ gene from Drosophila, if it existed, is not going to make a mouse fly," Dickson explains, noting that only members of the same species might be expected to share the same set of "normal" behaviors.

"So you need to put gene X in a normal animal of the same species that doesn’t normally do Y. This is really only possible with sex-specific behaviors" like courtship, he says.

Dickson also says there is "something of a debate going on between the view that single genes can have profound effects on behavior, versus the more holistic view that behavior is so complex that we can never learn anything meaningful about a behavior by studying the action of a single gene."

Still, studies show that a single gene can trigger the development of complex anatomical structures like eyes or limbs, by influencing sometimes hundreds of other genes, Dickson notes.

"I don’t see any good reason why innate behaviors, which are a consequence of how the nervous system is built, should be any different. Indeed, I think that is what our work shows," he says.

In a second Cell paper, Dickson and colleagues demonstrate that nerve cells expressing the fruitless gene are linked in a circuit in both males and females. The finding suggests that the "essential difference in sexual behavior between males and females lies in the functioning of this circuit and not its construction," according to the researchers.

Dickson and colleagues have already begun collaborations with other researchers to determine how the fruitless gene might be involved in other behavioral patterns like aggression. "I think it is going to be fascinating to try to figure out how a fly decides between ’love’ and ’war’, and what fruitless and the fruitless-expressing neurons have do to with this," he says.

Heidi Hardman | EurekAlert!
Further information:
http://www.cell.com

More articles from Life Sciences:

nachricht Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology

nachricht The secret sulfate code that lets the bad Tau in
16.07.2018 | American Society for Biochemistry and Molecular Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>