Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Causative gene for human "lobster claw" syndrome identified

21.05.2002


A new study using mouse "knockouts" shows that genes that control limb formation in insects have similar functions in mammals.



Split hand/foot malformation (SHFM) or ectrodactyly (the "lobster claw" anomaly), is a severe congenital malformation syndrome characterised by a profound median cleft of the hands and/or feet, typically associated with absence or fusion of the remaining fingers. This condition is quite frequent as about 6 cases of SHFM are observed for every 10,000 human births.

Several forms of SHFM are each associated with a different genetic mutation. One of the most frequent forms called Type I is associated with a specific region of human chromosome 7 that contains two homeobox genes, DLX5 and DLX6. These genes are similar to a gene in insects called distal-less that controls limb development. When this gene is defective in the fruit fly the distal part of the insect limb is missing. It was therefore assumed that DLX5 and DLX6 might have conserved this function through evolution and could have a role in vertebrate limb development. However, in spite of intensive searches for mutations of these genes in SHFM patients, no direct evidence was found to date on their involvement in mammalian limb development.


A research team led by Dr. Giovanni Levi from the Centre National de la Recherche Scientifique (CNRS) working in the Museum of Natural History in Paris and co-workers from the Italian Institute for Cancer Research (IST) supported by Telethon (Italy), has now generated knockout mice in which both the Dlx5 and Dlx6 genes have been inactivated through gene targeting and embryonic stem cells. These Dlx5/Dlx6 mutant mice have a limb defect that is very similar to that observed in SHFM1 patients. This finding, to be published in the June 2002 issue of genesis, is critical for an understanding of the molecular origin of the disease as it demonstrates that these are the genes responsible for the SFHM syndrome.

These studies should also warrant renewed efforts to find specific human mutations associated with DLX5 and DLX6 genes through genomic and mutational analyses. It is possible that knowledge of these genetic defects might permit early prenatal diagnosis of the disease. Furthermore, the availability of an animal model of the human disease will permit a molecular understanding of the etiology of SHFM1. Detailed studies of these mice will make it possible to understand how the genetic lesion is associated with a limb malformation in humans.

The data reported in Dr. Levi`s article show that in spite of the very different structure of insect and vertebrate limbs, the same genes control their development. This is further proof that the limb of a fly is homologous to a human limb.

Joanna Gibson | alphagalileo

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>