Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Repairing Our Inner Clock with a Two-Inch Fish

21.07.2011
Humans and zebrafish share mechanisms that regulate our circadian system, says TAU researcher

Circadian rhythms — the natural cycle that dictates our biological processes over a 24-hour day — does more than tell us when to sleep or wake. Disruptions in the cycle are also associated with depression, problems with weight control, jet lag and more. Now Prof. Yoav Gothilf of Tel Aviv University's Department of Neurobiology at the George S. Wise Faculty of Life Sciences is looking to the common zebrafish to learn more about how the human circadian system functions.

Prof. Gothilf and his Ph.D. student Gad Vatine, in collaboration with Prof. Nicholas Foulkes of the Karlsruhe Institute for Technology in Germany and Dr. David Klein of the National Institute of Health in Maryland, has discovered that a mechanism that regulates the circadian system in zebrafish also has a hand in running its human counterpart.

The zebrafish discovery provides an excellent model for research that may help to develop new treatments for human ailments such as mental illness, metabolic diseases or sleep disorders. The research appears in the journals PLoS Biology and FEBS Letters.

A miniature model

Zebrafish may be small, but their circadian system is similar to those of human beings. And as test subjects, says Prof. Gothilf, zebrafish also have several distinct advantages: their embryos are transparent, allowing researchers to watch as they develop; their genetics can be easily manipulated; and their development is quick — eggs hatch in two days and the fish become sexually mature at three months old.

Previous research on zebrafish revealed that a gene called Period2, also present in humans, is associated with the fish's circadian system and is activated by light. "When we knocked down the gene in our zebrafish models," says Prof. Gothilf, "the circadian system was lost." This identified the importance of the gene to the system, but the researchers had yet to discover how light triggered gene activity.

The team subsequently identified a region called LRM (Light Responsive Model) within Period2 that explains the phenomenon. Within this region, there are short genetic sequences called Ebox, which mediate clock activity, and Dbox, which confer light-driven expression — the interplay between the two sequences is responsible for light activation. Based on this information, they identified the proteins which bind the Ebox and Dbox and trigger the light-induction of the Period2 gene, a process that is important for synchronization of the circadian system.

To determine whether a similar mechanism may exist in humans, Prof. Gothilf and his fellow researchers isolated and tested the human LRM and inserted it into zebrafish cells. In these fish cells, the human LRM behaved in exactly the same way, activating Period2 when exposed to light — and unveiling a fascinating connection between humans and the two-inch-long fish.

Shedding new light on circadian systems and the brain

Zebrafish and humans could have much more in common, Prof. Gothilf says, leading to breakthroughs in human medicine. Unlike rats and mice but like human beings, zebrafish are diurnal — awake during the day and asleep at night — and they have circadian systems that are active as early as two days after fertilization. This provides an opportunity to manipulate the circadian clock, testing different therapies and medications to advance our understanding of the circadian system and how disruptions, whether caused by biology or lifestyle, can best be treated.

Prof. Gothilf believes this model has further application to brain and biomedical research. Researchers can already manipulate the genetic makeup of zebrafish, for example, to make specific neurons and their synapses (the junctions between neurons in the brain) fluorescent — easy to see and track. "Synapses can be actually counted. This kind of accessible model can be used in research into degenerative brain disorders," he notes, adding that several additional research groups at TAU are now using zebrafish to advance their work.

George Hunka | EurekAlert!
Further information:
http://www.aftau.org

More articles from Life Sciences:

nachricht Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>