Abstract

Leptin is a protein, which involved intricately in the growth and metabolism of animals and which plays an important role in the regulation of feed intake, energy metabolism, growth and reproduction of cattle. We used the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique to screen for DNA polymorphisms of the leptin gene in 112 Iranian Holstein cattle (Bos taurus) in Karaj Animal Breeding Center. PCR was carried out between exon 2 (intron 2). A strategy employing polymerase chain reaction was used to amplify a 422 bp from semen DNA. Digestion of polymerase chain reaction products with Sau3AI revealed two alleles: allele A was 390, 32 fragments and allele B was 303, 88 and 32 (only 303 fragment visible on the gel). Three patterns were observed and frequencies were 60.71, 37.5 and 1.79% for AA, AB and BB, respectively. This polymorphism could be further evaluated for marker-assisted selection and developed PCR methodology would expedite screening for large numbers of animals required for such studies.

Key words: Leptin, polymorphism, restriction fragment length polymorphism.