US scientists have made a “mighty mouse” whose big muscles could help find a way to prevent bones weakening. It has 70% more muscle mass than normal mice as it lacks the myostatin gene that ensures muscles do not overgrow. Six years ago, a German boy was born with a myostatin mutation and had muscles twice the normal size. A Medical College of Georgia team says bones may respond to the stress placed on them by extra muscle by forming more bone - helping to fight osteoporosis.
