Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lost the beat: Mice suffer from a decrease in biological fitness if their internal clock is mixed up

30.12.2015

Mice with deviant internal rhythms due to a genetic mutation have fewer offspring and shorter life spans than normal conspecifics whose rhythms follow the 24-hr cycle of a day more accurately. This discovery was made by a team of scientists led by researchers from the Max Planck Institute for Ornithology and Princeton University. Internal clocks that generate daily rhythms in living beings are among the most important achievements on earth. They are essential for coordinating processes of life with the environment. The study on mice shows that a deviation of internal rhythms from the 24-hr rotation of the earth has a direct influence on biological fitness.

Almost all living things possess internal clocks that govern periods of sleep and waking, and ensure that these processes are in synchrony with night and day. This circadian clock evolved to allow the anticipation of regular daily events.


Outdoor enclosure

Kamiel Spoelstra


For more than a year scientists investigated the development of six groups of mice in an outdoor enclosure

Kamiel Spoelstra

Sunlight aligns the internal clock with the 24-hour-rhythm of the rotation of the earth. A fundamental, unanswered question so far has been: is the functioning of the internal clock important for how long an organism lives and how well it is able to reproduce in its natural environment?

Mutations in certain genes can disrupt the internal clock so that it runs out of sync with the day-night cycle. In mice, a mutation called tau is known to alter daily rhythms: mice carrying this mutation run through their day about two hours faster than normal mice.

Scientists from the Max Planck Institute for Ornithology in Seewiesen and Radolfzell together with colleagues from the University of Groningen, the University of Manchester and Princeton University studied the biological fitness of such mice with deviant circadian rhythms in a large outdoor enclosure for over a year, where they were exposed to natural predators.

At the beginning of the study the researchers divided 238 mice into six groups. For each group they housed an identical mix of mice without the mutation together with mice carrying either one or two copies of the mutation in their genes. Each mouse was equipped with a transponder, so that the scientists could monitor their activity rhythms at feeders. Mice with one or two copies of the mutation showed aberrant daily rhythms.

Mice without the mutation were observed to live longer and to produce more offspring than mice with the mutation that showed abnormal rhythms. As a consequence, after more than one year the prevalence of the mutation in the population dropped from an initial 50 percent in the starting population to only about 20 percent in the last cohort that was studied.

This finding led the researchers to conclude that strong selection pressures must exist against the tau mutation in a natural environment. “Our findings highlight the fundamental importance of circadian clocks for the biological fitness of living beings. This has never been shown that clearly”, summarizes senior author Michaela Hau. (SL/HR)

Contacts:
Prof. Dr. Michaela Hau
Max-Planck-Institut für Ornithologie
Abteilung Evolutionäre Physiologie
Tel. +49 (0) 8157 932-273
E-Mail: mhau@orn.mpg.de

Dr. Kamiel Spoelstra
Netherlands Institute for Ecology, Wageningen
Department of Animal Ecology
Phone +31 (0)317 473 453
E-Mail: K.Spoelstra@nioo.knaw.nl

Weitere Informationen:

http://www.pnas.org/content/early/2015/12/28/1516442113.full.pdf
http://www.mpg.de/9814892/internal-clock-fitness?filter_order=L&research_top...=

Dr. Sabine Spehn | Max-Planck-Institut für Ornithologie
Further information:
http://www.mpg.de/9814892/internal-clock-fitness?filter_order=L&research_topic

More articles from Life Sciences:

nachricht A room with a view - or how cultural differences matter in room size perception
25.04.2017 | Max-Planck-Institut für biologische Kybernetik

nachricht Studying a catalyst for blood cancers
25.04.2017 | University of Miami Miller School of Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Early organic carbon got deep burial in mantle

25.04.2017 | Earth Sciences

A room with a view - or how cultural differences matter in room size perception

25.04.2017 | Life Sciences

Warm winds: New insight into what weakens Antarctic ice shelves

25.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>