Building Strong Mice and Worms
Via EurekAlert!: researchers "created super strong, marathon mice and nematodes by reducing the function of a natural inhibitor, suggesting treatments for age-related or genetically caused muscle degeneration are within reach. It turns out that a tiny inhibitor may be responsible for how strong and powerful our muscles can be. ... By acting on a receptor (NCoR1), [researchers] 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. ... By genetically manipulating the offspring of [mice and nematodes], the researchers were able to suppress the NCoR1 corepressor, which normally acts to inhibit the buildup of muscle tissues. ... In the absence of the inhibitor, the muscle tissue developed much more effectively. The mice with the mutation became true marathoners, capable of running faster and longer before showing any signs of fatigue. In fact, they were able to cover almost twice the distance run by mice that hadn't received the treatment. They also exhibited better cold tolerance. Unlike previous experiments with so-called super mice, this study addresses the way energy is burned in the muscle and the way the muscle is built. Examination under a microscope confirmed that the muscle fibers of the modified mice are denser, the muscles are more massive, and the cells in the tissue contain higher numbers of mitochondria - cellular organelles that deliver energy to the muscles. Similar results were also observed in nematode worms, allowing the scientists to conclude that their results could be applicable to a large range of living creatures."
Link: http://www.eurekalert.org/pub_releases/2011-11/epfd-tag110711.php