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!
Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH
Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences