Scientists from the EPFL and the University of Geneva have discovered a genetic mechanism that defines the shape of our members in which, surprisingly, genes play only a secondary role. The research published in Cell, online the 23rd of November, shows the mechanism is found in a DNA sequence that was thought, incorrectly, to play no role.
Turbos on the genome
DNA is composed of only about 2% genes. But it has other types of sequences, such as enhancers that increase the activity of certain genes at key moments. "The discovery we have made is that the group of genes involved in finger growth is modulated by seven enhancers, not just one, and they combine through contact," says Thomas Montavon, lead author of the article and researcher at the EPFL.
When the fingers in the embryo begin to take shape, the string of DNA folds and the enhancers, located on different parts of the string, come into contact. They then bring together various proteins that stimulate the activity of the genes, and the fingers start to grow. If one of these seven enhancers is missing, the fingers will be shorter, or abnormally shaped. When two are missing, the defects are even more pronounced. Without enhancers, the genes work slowly, and generate only the beginnings of fingers.How does the DNA fold in exactly the right way so that the enhancers will correctly do their job? The recently discovered process remains largely unexplained. "In other tissues, such as the brain, the string of DNA folds differently," says Denis Duboule, director of the study and researcher at both the EPFL and the University of Geneva. "To our knowledge, it is only in the fingers that it adopts this shape."
An explanation for evolutionary diversity
Statistically, the seven enhancers involved in finger growth create seven opportunities for a mutation to occur. The flexibility of this mechanism, with no known equivalent to date, causes not only hereditary malformations, but also the many variations in the hands, legs and other appendages in nature. "Just think of some ungulates, which walk on a single finger, or the ostrich, which has only two, and the human hand, of course" explains Denis Duboule.
Other genetic processes may also function on the basis of a similar principle. This could explain the diversity of the products of evolution, in areas other than the fingers, according to Denis Duboule. "When a mutation occurs on a gene, for instance in cystic fibrosis, it is often binary. This amounts to an 'all or nothing' situation. With the mechanism we have discovered, it is a 'more or less' situation. It is combined, it is modulated."
This research is carried out within the National Center of Competence in Research (NCCR) Frontiers in Genetics. The NCCRs are an initiative of the Swiss government to stimulate research and education in key areas. http://www.frontiers-in-genetics.org
Vidéo (interview with Denis Duboule) : http://www.youtube.com/watch?v=jrFG34HPqN8
Denis Duboule firstname.lastname@example.org or 41-21-693-83-38
Thomas Montavon email@example.com or 41-21-693-06-05Lionel Pousaz, EPFL Media & Communications, firstname.lastname@example.org
Lionel Pousaz | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences