Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Repeat act: Parallel selection tweaks many of the same genes to make big and heavy mice

09.05.2012
Max Planck scientists decode genes for a complex characteristic

Organisms are adapted to their environment through their individual characteristics, like body size and body weight. Such complex traits are usually controlled by many genes.


One giant mouse weighs more than six 'mini-mice' of the same age. The biggest mice in the world evolved through targeted breeding over many generations. Scientists can use these animals to identify the genes responsible for body growth. Credit: Lutz Bunger, University of Edinburgh

As a result, individuals show tremendous variations and can also show subtle gradations. Researchers from the Max Planck Institute for Evolutionary Biology in Plön have now investigated how evolution alters such traits through selection. To do this, they examined the genomes of mouse lines that were selected independently of each other for extreme body size. They discovered that a number of genomic regions, or loci, have undergone changes in genes that underlie this genetically complex characteristic. They also discovered many new genes that play a role in the regulation of body weight, which can lead to obesity.

The Plön-based researchers obtained mouse lines that have been specifically selected for extreme body weight for 25 years. The mice, which have been bred for over 150 generations, belong to seven different strains and now weigh two to four times more than mice of normal weight. The Max Planck scientists were able to identify a total of 67 loci on the genome that had changed in the heavy mice. The different strains have become so similar in these regions as a result of the extreme artificial selection pressure, that the genomes of the heavier but unrelated animals were more similar at these loci than with their closely related sibling mouse strains of those with normal weight. This clearly indicates that these loci are involved in the regulation of body weight.

The discovered loci regulate, among other things, energy balance, metabolic processes and growth. The Gpr133 gene, which is expressed in the adrenal gland, is a novel gene and presumably controls body weight through the release of hormones. The second identified gene, Gpr10, which is active in the hypothalamus in the brain, was found to influence appetite and metabolic rates. Accordingly, the team has also identified genes for the regulation of fat cells and for taste and olfactory perception that can affect body weight. Moreover, many of the regions discovered coincide with loci on the human genome that influence body weight. "These genes probably also determine body weight in humans, because size and body weight are such tightly linked processes. This evolutionary connection serves as a nice confirmation," says Frank Chan from the Max Planck Institute for Evolutionary Biology.

Interestingly, the genome of mouse populations living in the wild on remote islands, shaped by natural selection, have also changed in similar ways to the animals bred in the laboratory. For example, on the Faroe Islands and St Kilda off the coast of Scotland, mice populations have evolved to be among the largest mice in the world. The researchers have found that island mice retained little variation specifically at the same genomic loci that changed in the heavy laboratory-bred animal strains. These telltale signs suggest that artificial selection in the laboratory changes the same loci in the genome as natural selection.

Thus, when complex characteristics must adapt to altered environmental conditions, selection affects many responsible genes simultaneously. These then change in parallel and contribute to varying extents to the organism's capacity for adaptation. In this way, the genetic basis of complex traits can be decoded through parallel selection.

Original article: Chan, Y. F. et al. Parallel selection mapping using artificially selected mice reveals body weight control loci.

Current Biology: Volume 22, Issue 9, 8 May 2012, Pages 794 doi:10.1016/j.cub.2012.03.011

Dr. Y. Frank Chan | EurekAlert!
Further information:
http://www.mpg.de

More articles from Life Sciences:

nachricht Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo

nachricht Full of hot air and proud of it
18.04.2018 | University of Pittsburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>