RESUMEN
The use of polymorphic markers in breeding programmes could make selection more accurate and efficient. A total of 324 individuals from six Iranian cattle populations [Sarabi, Golpayegani, Sistani, Taleshi, Mazandarani, Dashtiyari], F1 Golpayegani Brown Swiss and Iranian buffalo populations were genotyped for the Pit-1 HinfI and leptin Sau3AI polymorphisms by the polymerase chain reaction and restriction fragment length polymorphism [PCR-RFLP]. The genotype and gene frequencies for each breed were determined and shown to be quite variable among the breeds. The highest frequencies of allele B for the leptin gene and allele A for the Pit-1 gene were found in Dashtiyari and Sistani cattle, respectively. According to our results, the highest AB genotype frequencies were found in the Taleshi and F1 Golpayegani x Brown Swiss cross for the leptin and Pit-1 genes, respectively. These allele frequencies were comparable to previously published data on exotic breeds. The highest and lowest heterozygosities were found in Taleshi and Dashtiyari cattle for the leptin gene and in F1 Golpayegani x Brown Swiss cross and Sistani cattle for the Pit-1 gene, respectively. These values indicated the presence of low variation for these genes in the studied populations. The possible association between molecular polymorphisms within these candidate genes and economic traits for the studied populations should be further investigated