Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sex on the brain: 'Doublesex' gene key to determining fruit fly gender

22.03.2010
The brains of males and females, and how they use them, may be far more different then previously thought, at least in the fruit fly Drosophila melanogaster, according to research funded by the Wellcome Trust.

In a paper published today in the journal Nature Neuroscience, researchers from the University of Glasgow and the University of Oxford, have shown that the gene known as 'doublesex' (dsx), which determines the shape and structure of the male and female body in the fruit fly, also sculpts the architecture of their brain and nervous system, resulting in sex-specific behaviours.

The courtship behaviour of the fruit fly has long been used to study the relationship between genes and behaviour: it is innate, manifesting in a series of stereotypical behaviours largely performed by the male. The male chases an initially unreceptive female, and 'woos' her through tapping and licking and using wing vibration to generate a 'courtship' song. If successful, the female will slow and present a receptive posture, which allows copulation to occur.

For some time now, the gene 'fruitless' (fru), which is specific to the adult male fruit fly, was thought to be the key to male behaviour and the development of male specific neural circuitry of flies.

However, the researchers have shown that fru does not explain the complete repertoire of male behaviours in the fly: female flies in which the fru gene has been activated demonstrate some, but not all, of the characteristics usually associated with courtship behaviour in males. The researchers have also shown that dsx plays an important role in shaping the neural circuitry involved in this behaviour.

"The dogma was that dsx made fruit flies look the way they did and fru made them behave the way they did," explains Dr Stephen Goodwin from the University of Oxford, who led the research. "We now know that this is not true. dsx and fru act together to form the neuronal networks – the wiring – for sexual behaviour."

fru has so far been found only in insects; dsx, however, is found throughout the animal kingdom, where it plays a fundamental role in sex determination, and so is of particular interest to researchers.

Using a transgenic tool generated in his lab, Dr Goodwin and colleagues were able to map dsx throughout the fly's development using a fluorescent protein marker that illuminates areas where DSX is active. This highlighted profound differences in neural architecture between the sexes. In males, the researchers were able to show that dsx complements fru activity to create a 'shared' male-specific neural circuit; in females (where fru is inactive), dsx forms a female-specific circuit.

Importantly the researchers were able to manipulate these cells, impinging their ability to function, and show that these circuits are responsible for behaviours unique to the individual sexes.

"It has been suggested that there are only minor trivial differences between the neural circuits that underlie behaviour in males and females," explains Dr Goodwin. "We have shown that in fact there is quite a bit of difference in the number of neurons and how these neurons connect, or 'talk', to each other. These differences can have big consequences on the structure and function of the nervous system."

In addition, while dsx was known to establish the gender of the adult fly, the pattern of dsx activity in the adult was unknown. Dr Goodwin and colleagues have shown that this pattern is not ubiquitous, but rather is restricted in a specific and telling manner.

Some tissues, such as blood cells, may not require a defined gender in order to function. However, others such as the 'fat body', which in the adult fly functions in part to produce hormones, and the oenocytes, which produce sex-specific pheromones, require a specified sexual identity. It was unsurprising to Dr Goodwin and colleagues to find dsx expressed in these tissues in both males and females, as they would be key to establishing a normal sexual physiological state.

"Determining gender in a fruit fly seems to be about adding different splashes of ''colour' here or there," he says. "It's not like the canvas, meaning the nervous system, needs to be all blue or pink, just a little bit of blue over here or a little bit of pink over there. Not all cells need to know what sex they are, but those that do need to know will be ones that are important for sex-specific behaviours."

The research performed by Dr Goodwin and colleagues allows greater insight into how a male and female nervous systems may be established and how this may then coordinate the sex-specific physiology needed to create the complete, integrated adult sexual state.

Craig Brierley | EurekAlert!
Further information:
http://www.wellcome.ac.uk

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>