Evaluation of the effect of BOLA-DRB3.2 locus polymorphism on blood serum biochemical characteristics and body weight of Sistani cattle

 The objective of the present study was to determine the extent of BOLA-DRB3 locus polymorphism in a herd of Sistani Cattle and their associations with body weight traits including birth weight, 3, 6, 9 and 12 months, and blood serum biochemical such as total protein, albumin and globulin. For this, blood samples collected randomly from 143 Sistani Cattle in a research herd at the Sistani Cattle Research Centre. DNA extraction from complete blood samples was performed with optimized saline method. The amplification of the 284-bp fragment of the BoLA-DRB3 gene was performed in two steps. In the first step, the HLO30 and HLO31 primers were used and in the second step the HLO30 and HLO32 primers were used. Then, the amplified fragment was digested by HaeIII enzyme. The digestion products were resolved on electrophoresis of 3% gel agarose. Population and genetic structure was calculated with POPGENE software and probable genotype patterns association with body weight traits and blood biochemistry traits were implemented by fixed linear model. The results of this study revealed two alleles and three genotypes as aa, bb and ab in locus of BOLA-DRB3.2 in Sistani cattle. Genotype frequencies of aa, bb and ab were 30, 41 and 28%, respectively, and alleles frequencies of a and b were calculated 44 and 56%, respectively. In this experiment, the Shannon index (I), Nei's index, heterozygosity was observed and the expected heterozygosity were calculated 69, 49, 28 and 50 respectively. The analysis of likelihood ratio test and X² in BOLA-DRB3.2 showed that the population of Sistani cattle studied in this study was beyond the Hardy-Weinberg equilibrium. Also, the correlation of different genotypes with body weight traits including birth, 3, 6, 9 and 12 months, and biochemical characteristics of serum were not significant.