Stumbling Fruit Flies Lead Scientists to Discover Gene Essential for Sensing Joint Position LA JOLLA, CA March 13, 2014 Scientists at The Scripps Research Institute (TSRI) have discovered an important mechanism underlying sensory feedback that guides balance and limb movements.
The finding, which the TSRI team uncovered in fruit flies, centers on a gene and a type of nerve cell required for detection of leg-joint angles. These cells resemble human nerve cells that innervate joints, said team leader Professor Boaz Cook, who is an assistant professor at TSRI, and they encode joint-angle information in the same way.
If the findings can be fully replicated in humans, they could lead to a better understanding of, as well as treatments for, disorders arising from faulty proprioception, the detection of body position.
A report of the findings appears in the March 14, 2014 issue of the journal Science.
A Mystery of Sensation
The proprioceptive sense of how the limbs are positioned is what enables a person, even with eyes closed, to touch the tip of the nose with the tip of a finger an ability easily impaired by alcohol, which is why traffic police often test suspected drunk drivers this way.
Scientists have known that proprioceptive signals originate from so-called mechanosensory neurons, whose nerve ends are embedded in muscles, skin and other tissues. The stretching or compression of these tissues opens ion channels in the nerve membrane, which results in a signal to the brain.
What hasn't been clear is how such a neuron can specialize in sensing just one type of membrane-distorting stimulus such as the angle of a limb joint yet exclude others, such as impact pressures.
In the new study, Cook and two members of his laboratory, first author Bela S. Desai, a postdoctoral fellow, and graduate student Abhishek Chadha, sought to shed some light on this mystery with a study of Drosophila fruit flies. Quickly maturing and easily studied, Drosophila often are analyzed for clues to the genetic underpinnings of basic animal behaviors.
Following the Trail
Cook and his colleagues began with a special collection of Drosophila containing a variety of uncatalogued mutations. The scientists sifted through the collection looking for mutant flies with walking impairments and soon zeroed in on several impaired walkers that turned out to have mutations in the same gene.
The scientists named the gene stumble (stum for short) for the abnormality caused by its absence.
Using a fluorescent tracer, they then localized the expression of stum in normal flies to neurons that lay close to the three main leg joints. Each neuron's input-sensing tendril (dendrite) grew right up to the joints a sign that its evolved function is to detect joint angle.
The researchers also found that the protein specified by the stum gene normally migrates to the tip of each dendrite. With high-resolution microscopy, they imaged each of these tips and observed an extra length branching more or less sideways at the joint.
At ordinary, at-rest joint angles, the relative positions of the main dendrite tip and its side branch stayed more or less the same; however, at extreme joint angles, the pair stretched out. As they did, the level of calcium ions in the neuron rose sharply, suggesting that ion channels had opened and the neuron was becoming active.
Cook noted the results show how a seemingly general mechanosensory, membrane-stretch-sensitive neuron can evolve a specificity for a particular type of proprioceptive signal. It's a nice example of how you can create that specificity from something that only stretches mechanically, he said.
The team is now trying to nail down the specific role of stum proteins in Drosophila and to determine whether the human version of stum which has never been characterized also works in joint angle sensing. Some sensory role for the human version of stum is likely, as the stum gene has been remarkably well conserved throughout animal evolution. Cook and his colleagues were even able to restore some normal walking ability to stum-mutant flies by adding the mouse version of the stum gene. Stum is probably doing the same thing in all animals, he said.
The title of the Science study is The stum Gene Is Essential for Mechanical Sensing in Proprioceptive Neurons.
About The Scripps Research Institute
The Scripps Research Institute (TSRI) is one of the worlds largest independent, not-for-profit organizations focusing on research in the biomedical sciences. TSRI is internationally recognized for its contributions to science and health, including its role in laying the foundation for new treatments for cancer, rheumatoid arthritis, hemophilia, and other diseases. An institution that evolved from the Scripps Metabolic Clinic founded by philanthropist Ellen Browning Scripps in 1924, the institute now employs about 3,000 people on its campuses in La Jolla, CA, and Jupiter, FL, where its renowned scientists including three Nobel laureates work toward their next discoveries. The institutes graduate program, which awards PhD degrees in biology and chemistry, ranks among the top ten of its kind in the nation. For more information, see www.scripps.edu.
# # #
For information:
Office of Communications
Tel: 858-784-2666
Fax: 858-784-8136
press@scripps.edu
Most recent headlines
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
04/08/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
04/07/2026
April 7 2026, 19:00 (PDT) Detective Conan: Fallen Angel of the Highway Opens in...
01/06/2026
January 6 2026, 05:30 (PST) Dolby Sets the New Standard for Premium Entertainment at CES 2026
Throughout the week, Dolby brings to life the latest innovatio...
08/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
08/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
08/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
08/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
08/05/2026
Liberty University on why broadcast technology isn't just a technical invest...
08/05/2026
COW Jobs: UGC, On-Camera Video Content
Brie Clayton May 7, 2026
0 Comments
UGC, On-Camera Video Content
April 17, 2026Documentary Editor - US,......
07/05/2026
Journalists reporting on Sudan are working in one of the most complex and fast-m...
07/05/2026
Multi-year partnership positions Victory+ as a free home for Dallas Cowboys orig...
07/05/2026
From sideline reporting to directing and producing, the talented sophomore is building a well-rounded foundation for a career in live sports production
In the ...
07/05/2026
Cobalt Digital has received two Future Best of Show awards at NAB Show 2026. The COBALT blueCORE platform was recognized by TV Tech, and the COBALT PACIFIC ULL-...
07/05/2026
ESPN analyst Mina Kimes will host the televised semifinals and finals of the 202...
07/05/2026
Bitmovin has announced that MUBI, the global film streaming platform, has selected Bitmovin as its cloud VOD encoding partner. Bitmovin's encoding infrastru...
07/05/2026
NBCUniversal Telemundo Enterprises and the U.S. Soccer Federation have announced...
07/05/2026
Angel City Football Club (ACFC) and Victory have announced a regional broadcast partnership bringing live match coverage to fans across the greater Los Angeles...
07/05/2026
Spiideo has announced the launch of AI Highlights inside Spiideo Play, its automated sports production platform. AI Highlights combines video, event data, audio...
07/05/2026
Leostream Corporation has announced a unified remote access ecosystem for high-p...
07/05/2026
The Atlanta Dream has partnered with Victory to stream all locally broadcast Dream games for free, expanding the team's digital distribution strategy and g...
07/05/2026
Riedel Communications has announced the appointment of Marc Engroff as Chief Fin...
07/05/2026
SES and ARD, Germany's largest public broadcasting network, have announced a long-term extension of their satellite distribution partnership through 2039. U...
07/05/2026
UpLight Technologies delivers a flexible video and lighting system for a new televised sportLaunching the Pro Cheer League required more than creating a compell...
07/05/2026
Full Day Productions and GSE Worldwide have announced Spikes Under the Lights, a...
07/05/2026
Seit dem Start im Jahr 2023 hat DJ (Beta) das personalisierte H rerlebnis von 94...
07/05/2026
Da quando stata presentata nel 2023, DJ (beta) ha aiutato a definire un'esperienza d'ascolto pi personalizzata per 94 milioni di utenti Spotify Premi...
07/05/2026
Since launching in 2023, DJ (beta) has helped shape a more personalized listenin...
07/05/2026
Desde o lan amento em 2023, o DJ (beta) j ajudou a deixar a experi ncia de ouvi...
07/05/2026
From our earliest days, Spotify has been built on a simple principle: Great audio should be easy to reach. It's what's driven us to expand from music to...
07/05/2026
Asian and Pacific Islander artists continue to shape the global soundscape, pushing creative boundaries and connecting with fans worldwide. This Asian & Pacific...
07/05/2026
Company announce long-requested choir instrument
In the latest expansion of their Symphonic Elements series, UJAM have introduced an all-new vocal instrumen...
07/05/2026
Modular-inspired sound generation with digital control
Buchla have introduced Ziggy, a new compact synthesizer built around the company's complex oscill...
07/05/2026
Combines analogue voices with digital synthesis and sequencing
Polyend have announced Drums, a new hybrid analogue and digital drum machine that combines sy...
07/05/2026
Control surface now officially supports four DAWs
When Nektar launched the Panorama CS12 control surface, it worked exclusively with Apple's Logic Pro, ...
07/05/2026
In the first quarter 2026, SGL Carbon generated consolidated sales of 184.5 million, which was 49.8 million, or 21.3%, lower than in the prior year (Q1 2025: ...
07/05/2026
Rohde & Schwarz and Greenerwave achieve precise and fast ESA antenna characteriz...
07/05/2026
Two multi-role L3Harris products - the Red Wolf launched effects vehicle and SK...
07/05/2026
L3Harris will be developing key features of a secure and resilient digital infra...
07/05/2026
Alysa Liu and Shohei Ohtani Help Drive Viewership as 91 of the Top 100 Broadcast...
07/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
07/05/2026
Cobalt Digital Wins Two Future Best of Show Awards at 2026 NAB Show
Manufacturer Recognized by TV Tech and TVBEurope for Innovation in signal processing
Cobal...
07/05/2026
Software and hardware platforms, AI power and user-friendliness on show...
07/05/2026
Intinor will demonstrate its latest technical enhancements for the Direkt series at BroadcastAsia 2026. With a continued focus on reliable contribution and remo...
07/05/2026
Bitmovin has announced that MUBI has chosen Bitmovin as its cloud VOD encoding partner, replacing MUBI's legacy on premises encoding setup to improve scalab...
07/05/2026
Meet Graduates from Berklees Class of 2026 Members of this years graduating class reflect on their proudest moments at Berklee and look ahead to whats next.
...
07/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
07/05/2026
At BroadcastAsia 2026, Interra Systems will demonstrate its latest innovations in automated quality control (QC), real-time monitoring, and captioning. The comp...
07/05/2026
At this year's Broadcast Asia, PlayBox Neo is set to unveil recent innovations across its PlayBox Neo Suite and integrated range of broadcast media solution...
Stumbling Fruit Flies Lead Scientists to Discover Gene Essential for Sensing Joint Position LA JOLLA, CA March 13, 2014 Scientists at The Scripps Research Institute (TSRI) have discovered an important mechanism underlying sensory feedback that guides balance and limb movements.
