The study by McPherron and Lee investigates the myostatin gene in cattle, focusing on two breeds known for their increased muscle mass: Belgian Blue and Piedmontese. Myostatin, a member of the transforming growth factor β superfamily, is essential for regulating skeletal muscle mass in mice. The researchers identified mutations in the coding sequence of the bovine myostatin gene in these breeds. In Belgian Blue cattle, an 11-nucleotide deletion in exon 3 causes a frameshift, leading to a truncated protein. In Piedmontese cattle, a missense mutation in exon 3 substitutes tyrosine for an invariant cysteine in the mature protein. These mutations are highly conserved across vertebrate species, suggesting that myostatin functions similarly in different animals. The findings indicate that myostatin mutations are responsible for the double muscling phenotype in these cattle breeds and highlight its potential as a target for genetic manipulation in other farm animals.The study by McPherron and Lee investigates the myostatin gene in cattle, focusing on two breeds known for their increased muscle mass: Belgian Blue and Piedmontese. Myostatin, a member of the transforming growth factor β superfamily, is essential for regulating skeletal muscle mass in mice. The researchers identified mutations in the coding sequence of the bovine myostatin gene in these breeds. In Belgian Blue cattle, an 11-nucleotide deletion in exon 3 causes a frameshift, leading to a truncated protein. In Piedmontese cattle, a missense mutation in exon 3 substitutes tyrosine for an invariant cysteine in the mature protein. These mutations are highly conserved across vertebrate species, suggesting that myostatin functions similarly in different animals. The findings indicate that myostatin mutations are responsible for the double muscling phenotype in these cattle breeds and highlight its potential as a target for genetic manipulation in other farm animals.