The present invention relates to a transcription regulatory region of a myostatin gene. In particular, the invention relates to a 2.5 kb polynucleotide immediately 5′ to the myostatin coding sequence, its nucleotide sequence and methods of using this regulatory region, and fragments thereof. The present invention relates to the use of the myostatin promoter of the present invention to direct expression of a target gene in a tissue specific manner, i.e. muscle tissue. The present invention relates to the use of the myostatin promoter of the present invention in high throughput screens to identify test compounds which inhibit myostatin promoter activity or myostatin expression. In accordance with the present invention, inhibitors of the myostatin promoter may be used to inhibit myostatin expression as a method of engineering animals with increased lean meat in order to decrease the time required to bring the animals to slaughter, and of promoting muscle growth for treating disorders related to expression of the myostatin gene, such as muscle wasting associated with aging or disease in humans and companion animals, particularly cats and dogs.