Better muscles thanks to a genetic knock-out

A team of researchers has improved the muscle structure and stamina of mice and nematodes by reducing the function of a natural inhibitor, suggesting treatments for age-related or genetically caused muscle degeneration are within reach. If they weren't held back by the effect of a natural inhibitor, our muscles would be stronger, more powerful and better formed than they are in reality. This is the surprising conclusion reached by scientists in EPFL's Laboratory of Integrative Systems Physiology (LISP), in collaboration with a group in the Center for Integrative Genomics at the University of Lausanne and the Salk Institute in California. By acting on a receptor (NCoR1), they were able to modulate the transcription of certain genes, creating a strain of "mighty mice" whose muscles were twice a strong as those of normal mice. Two protein-building "regulators" The process of transcription, in which proteins are manufactured by an organism in response to instructions contained in its DNA, is modulated by so-called "co-factors." These either favor (coactivators) or inhibit (corepressors) transcription, for example during the buildup of fat or muscle tissues. They respond in principle to the concentration of certain hormones in the body, which are in turn associated with the organism's environment. In an article appearing today in the journal Cell , a team led by EPFL professor Johan Auwerx reports on the results of experiments done in parallel on mice and nematodes. The researchers were able to suppress the NCoR1 corepressor, which normally acts to inhibit the buildup of muscle tissues. Better muscles