Study of mutation in Second Intron of the bovine leptin gene in Guilan native and crossbreed cows using PCR-RFLP

The leptin gene has been known as a candidate gene and a key regulator of processes that is related to economic traits. In order to study the polymorphism of Leptin gene, total blood samples were collected randomly from 200 of native and crossbreed cows of Guilan province. DNA was extracted using salting out procedure and polymerase chain reactions (PCR) were carried out using a specific primer pairs for amplification a 522 bp fragment of leptin gene. Amplified fragment was digested by BsaAIrestriction enzyme and then samples were genotyped. For the studied locus Two patterns of A and B were identified with the frequency of 0.455 and 0.545 in native cows and 0.365 and 0.635 crossbreed cows, respectively. Three genotypes of AA, AB and BB with the frequency of 0.19, 0.53 and 0.28 in native cows and 0.14, 0.45 and 0.41 in crossbreed cows were detected, respectively. The chi-square test results showed that the studied populations was in Hardy-Weinberg equilibrium. Nei and Shanon indexes, observed and expected heterozygosities were calculated as 0.496 and 0.689, 0.53 and 0.498 in native cows and 0.464 and 0.656, 0.45 and 0.466 in crossbreed cows, respectively. The results revealed that the marker site of Leptin gene is polymorph in studied cows and the PCR-RFLP technique has a great potential for detection of such polymorphism.