Background: The present study was designed to investigate the association of GH and LEP genes’ single-nucleotide polymorphisms with fat-tail measurements (fat-tail dimensions) in Makooei sheep. Materials and Methods: DNA was extracted from whole blood samples collected from 100 sheep. Polymerase chain reaction (PCR) products were subjected to single-strand conformation polymorphism (SSCP) denaturation and polyacrylamide gel electrophoresis. Data were collected at the Makooei Sheep Breeding Station in Makoo (36°, 35′S and 48°, 22′E) of West Azerbaijan province. Climatically, this location has temperate summers and cold winters and receives a mean annual rainfall of about 400 mm. Ewes are raised in an annual breeding cycle starting in September. In general, the flock is managed under a semi-migratory system. Results: In the tested Makooei sheep population, significant statistical results were found in all traits of fat-tail measurements for GH and LEP genes. Individuals with the G4, L4 genotype of GH and LEP genes had lower tail length (rump length), fat thickness (the thick rump), and tail width (rump width) when compared to those of individuals with other genotypes (P < 0.05). In addition, the results demonstrated that individuals with the G5, L5 genotype of GH and LEP genes had superiority of tail length (rump length) and fat thickness (the thick rump) compared to those individuals with other genotypes (P < 0.05). Individuals with the G2, L2 genotype of GH and LEP genes had superiority of tail width (rump width) compared individuals with other genotypes (P < 0.05). Conclusion: These results confirmed potential usefulness of GH and LEP genes in marker-assisted selection programs of sheep breeding.
