Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Find Gene Critical to Sense of Smell in Fruit Fly

20.01.2012
Fruit flies don't have noses, but a huge part of their brains is dedicated to processing smells. Flies probably rely on the sense of smell more than any other sense for essential activities such as finding mates and avoiding danger.
UW-Madison researchers have discovered that a gene called distal-less is critical to the fly's ability to receive, process and respond to smells.

As reported in the current issue of the Proceedings of the National Academy of Sciences, the scientists also found evidence that distal-less is important for generating and maintaining self-renewing stem cells in the large brain structure that's responsible for processing odors and carrying out other important duties.

The corresponding gene in mammals and humans, called Dlx, is known to be important in the sense of smell. The Dlx gene has also been implicated in autism and epilepsy. By studying how distal-less works in fruit fly neurons, the scientists also hope to expand understanding of Dlx.

"We're really interested in knowing at a very fundamental level what distal-less is doing in the fly olfactory system and how it's doing it," says senior author Dr. Grace Boekhoff-Falk, associate professor of cell and regenerative biology at the University of Wisconsin School of Medicine and Public Health. "We're also hoping that what we learn in flies can give us a better understanding of how Dlx works in vertebrates, including humans."

Studying distal-less is much easier than studying Dlx, she adds, partly because mice and humans have six Dlx genes while flies have only one distal-less.

Odors enter fruit flies through nerve cells designed to receive smells - olfactory receptor neurons. From receptor neurons, projection neurons relay olfactory information to the large brain structure called the mushroom body (MB), which then triggers the animals to move in the right direction - toward the fragrance of food, for example, or away from the odor of a predator.

Boekhoff-Falk and her group have studied distal-less (dll) for years, previously investigating its role in the fruit fly hearing system and its limb development.

The current studies of the olfactory system were done in larvae rather than the more typically studied adult flies. Dissecting the younger, smaller flies demands the steadiest of hands, but the payoff is that larvae offer a substantially simpler view of brain development and wiring as well as insights into events occurring extremely early in development.

The researchers found dll was required for the development and growth of multiple cell types in the olfactory system, including those that receive, relay and process olfactory information. Dll must work for normal olfactory behavior to occur in larvae. And when dll is defective, the sense of smell is not present.

Zeroing in on the MB, the UW researchers also discovered an essential relationship between dll and the longest-living and most prolific neural stem cells found in fruit flies.

Boekhoff-Falk's team found that in flies with a mutated version of dll, these neural stem cells failed to proliferate. No other scientists have observed such strong defects in these cells at such an early stage.
The scientists identified markers that will allow them to learn how the stem cells decide which specialized cells they will become and how their growth may be regulated.

"We want to identify the niche, or the stem cell microenvironment, and the cells there that supply growth inputs needed to keep the stem-ness of the cells," she says.

Boekhoff-Falk believes the parallels to human stem cell biology may be strong.

"Our model may be useful for further analysis of how this gene regulates stem cells," she says.

The experiments also opened the door to a better understanding of the evolution of the sense of smell.

"The prevailing view is that fly and mammal olfactory systems evolved independently, multiple times over history," says Boekhoff-Falk, who has a long-standing interest in evolutionary biology. "But our work challenges that view. We think that when it comes to the olfactory system there may be a common ancestor shared by flies and mammals."

Earlier work by others had shown that the "wiring diagrams," or the arrangements of nerves, involved in olfaction in flies and mammals are similar. However, this was attributed to convergent evolution, the process by which unrelated organisms independently evolve similar traits as a result of having to adapt to similar environments, rather than shared ancestry.

The new work from Boekhoff-Falk's group suggests that the underlying genetic mechanisms used in the developing olfactory systems of flies and mammals are similar.

"This supports the idea that the last common ancestor already had some form of olfactory system," she says, "and that the overall architecture and key elements of the underlying genetics have been well conserved over time."

The long-shared similarity makes studies of fly genes in the olfactory system more relevant to human disease than previously thought, she says.

All told, the findings make the fruit fly a powerful model for investigating dll function.

"We think these studies have the potential to be highly relevant to human biology," says Boekhoff-Falk.

Dian Land | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>