Scientists have for the first time identified a gene that influences an economically important trait in beef cattle. When mutated, the gene, which codes for a protein called myostatin, leads to a phenomenon called "doubling muscling" in which the muscles grow much larger than normal, while still retaining their tenderness. Because the gene has also been found in nine additional animals, including the pig, turkey, and chicken, the discovery may lead to development not only of meatier strains of cattle but of other domestic animals as well.